I I - Defense Technical Information Center I DAVID W. TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT...

I" DAVID W. TAYLOR NAVAL SHIP

I RESEARCH AND DEVELOPMENT CENTERfthtda. Mwy-and 2oOM

AERODYNAMIC CHARACTERISTICS OF THE CLOSE-COUPLED CANARD

SAS APPLIED TC LOW-TO-MODERATE SWEPT WINOS

VOLUME 3: TRANSONIC-SUPERSONIC

SPEED REGIME

w by

Dvid W. Laosy

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AV/.IATION AND SURFACE EFFECTS DEPARTMENT3 RESEARCH AND DEVELOPMENT REPORT

Duuinbgrý 1079 DTNSRDC-7/00O

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OFFICER-IN-CHARGE OFFICER-IN-CHARGE

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COMPUTATION,

1 TRTMEN MATHEMAT1CS AND J

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(Block 20 continued)

4 ,• analysis is based on four canard geometries varying in planform from a 60-.. 5degree delta to a 25-degree swept wing, high aspect ratio canard. The

canards were tested at several positions and deflected from -10 to +10degrees. In addition, configurations consisting of a horizontal tail and acanard with horizontal tails are analyzed.

-•.Ph•sults of the analysis indicate that the canard is effective inincreasing lift and decreasing drag at Mach numbers from subsonic to hightransonic speeds by delaying wing separation. The effectiveness of thecanard is, however, decreased with Increasing Mach number. At supersonicspeeds the canard has little or no favorable effects on lift or drag.

It is further shown that the horizontal tail is a superior trimmingdevice than the close-coupled canard at low-to-moderate angles of attack andthat a configuration consisting of canard, wing, and horizontal tail issuperior in performance, to either canard or horizontal tail at high anglesof attack.

?8

UNCLASSIFIEDSECURITY CLASSIOPICATION OF THIS PAGE('WYew Data Entered)

FOREWORD

This report summarizes the findings of close-

coupled canard research performed by the Aviation

and Surface Effects Department of the David W.

Taylor Naval Ship Research and Development Center.

The work was performed between 1970 and 1974 and was

funded by the Naval Air Systems Command (AIR 320).The purpose of the report is to provide a summary of

the aerodynamic findings obtained from a series of

wind tunnel evaluations involving three generalresearch models and the F-4 aircraft. The report

is presented in four volumes--Volume 1: General

Trends; Volume 2: Subsonic Speed Regime; Volume 3:

Transonic-Supersonic Speed Regime; and Volume 4:

F-4 Phantom II Aircraft.

N

., ,..• .. c-",

i. iii

Im

TABLE OF CONTENTS

4. Page

LIST OF FIGURES . . . . . . .. . . . . . . . . . . . . . . . .

LIST OF TABLES. . . ............. . . . . . . . . . . . . .

NOTATIONR . . . . . . . . . . . ........ .. ................... .. . . . . xi

ABSTRACT. . . . . . . . . . . . . . . .* . . . . . .

ADMINISTRATIVE INFORMATION. . . . . . . . . ................. . . 1

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

CF .N.R.D S o . . . . . . . . . . . . . . . . . . . . . . . . . 5

POSITION o. . . . . .I . . . . . . . . . . . . . . . . . . . .. . 8

CANARD SO AE . . . . . . . . . . . . . . . . . . . . . . 15

DEFLECTION . . . . . . . . . . . . . . . . . . . . . . 15

TRISURFACE CONFIGURATIONS ..................... 25

PITCHING MOMENT .. . . .. .. .. . . .. .. .. . . . . .. . . . 30

POSITION . . . . . . . . .......... . . . . ... ................... . 30

CANARD SHAPE . ....... ................. . . . . . . . . . . . 42

DEFLECTION . . ... . . ..... . ................. . ... . ..... ...... . 42

TRISURFACE CONFIGURATIONS. . . ....... ................ . . . 157

BU E . IT NT .E.NS . . . . . . . . . . . . . ....................... 61

CANARD SHAPE ................................. . . . . . . . . 85DEFLECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90TRISURFACE CONFIGURATIONS .. .. .. .. .. .. .. .. .. . .. 110

BUFFET . . . . . . . . . . . . . . . . . . . . . . . . .. . . 117BUFFET INTENSITY . . . . .. . . . . . . . . .. . . . . .. . . . 124

SUPERSONIC SPEEDS . . . . . . . . . . . . . . . . . . . . . . . . . . 131

SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 150

LIFT . . . . . . . . . . . . . . . . . . s. . . . . . . . . . .. . 151

PITCHING MOMENT. . . . . . . . . . ..... ........................ . 151

iv

• • - . . . . . .. . .. .. . .. ... .. . . . ..-..

Page

DRAG . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 152

BUFFET . . . . . . . . . .. ............................ 153

ACKNOWLEDGMENTS .. .. .. .. .. .. .. .. .. .. .. .. . .. !.t3

APPENDIX A - MODEL GEOMETRY ..................... 155

APPENDIX B - BUFFET INTENSITY o . . . . . . . . . . . 163

REFERENCES. . . . . . . . . . . . . . . . . . . .oo . . . . . 169

LIST OF FIGURES

1 - Sketch of Models . . . . . . . . . . . . . 32 -Canards.. . . . . . . . . .

* 3 - Supersonic Half-Model . . . . . . . . . . . . . . .. 4

4 - Lift Variation at 25-Degrees Angle of Attackwith Mach Number . . . . . . . . . . . . . . . . . . . . . .. . 6

5 - Lift Coefficient versus Mach Number at ConstantAngle of Attack . . . . . . . . . . . . .............. . . . . . . 6

6 - Required Angle of Attack . . . . .. . . . . . . . . .. . . . 7

7 - Effect of Canard Longitudinal Position on RequiredAngle of Attack . . . . . . . . . . . . . . . . ..... 9

8 - Effect of Canard Position on Incremental Lift. . . . . . . . . . 10

9 - Effect of Canard Position on Incremental Lift forthe 25-Degree Wing ...................................... ...... 12

10 - Effect of Canard C,, Position on Incremental Lift.. . . ....... 12

11 - Effect of Canard Vertical Position on Incremental Lift . . .. . 13

12 - Effect of Canard Shape on Incremental Lift...... . . . . . 16

13 - Effect of Deflection on Incremental Lift at Position P .3 . . . 17

14 - Effect of Deflection on Incremental Lift at Position P .. .. 20

15 - Comparison of Control Surface Effectiveness for25- and 50-Degree Wings ......... .... .......... 21

g.;

', . ... ... -- • •• /' • ,.., , ,

Effect of Deflection on Canard C1 Incremental Lift . . . . . . . 22

17 - Control Surface Effectiveness for Canard C1 . . . . . . . . . . 24

18 - Effect of Deflection on Canard C2 Incremental Lift . . . . . . . 26

W 19 - Effect of Deflection on Canard C Incremental Lift . . . . . . . 27

20 - Trisurface Configuration........... . . ........ . 28

21 - Incremental Lift Characteristics of Tail, Canard,and Trisurface Configurations. . . . . . . . . . . . . . . 29

22 - Comparison of Measured and Summed TrisurfaceIncremental Lift . . . . . . . . . . . . . . . . . . . . . . . . 31

23 - Pitching Moment at 25-Degrees Angle of Attack .. . . . . . .. 32

24 - Comparison of Pitching Moment for Tail, Canard, andBasic Wing-Body at Lift Coefficients of 0.5 and1.0 for the 50-Dzgree Sweep Model . . . . . . . . . . . . ... 32

t25 - Effect of Position on Incremental Pitching Moment. . . . . . . . 33

26 - Effect of Position on Incremental Moment for Canard C1 ..... 35

27 - Effect of Canard Position for the 25-Degree Wing Model . ... 35

28 - Pitching Moment Variation with Mach Number atConstant Lift Coefficient . . . ................ 37

29 - Neutral Point Variation with Mach Number . . . . . ...... 38

30 - Incremental Neutral Point Behavior with Mach Number ........... 38

31 - Effect of Canard Vertical Position on Incremental Moment . . . . 39

32 - Effect of Canard Shape on Incremental Momentfor the 50-Degree Wing .... ..................... 43

33 - Effect of Canard Deflection on Incremental Moment ........... 45

34 - Effect of Canard Deflection on Center of Pressure ....... 49

35 - Incremental Pitching Moment Due to Canard Deflection ......... 51

36 - Canard Control ?ower versus Angle of Attack atMach Numbers of 0.6 and 0.8. . .. ............... 55

vi

, , ... .. ., .... . .... .......

Pitching Moment Characteristics of Tail, Canard,V and Trisurface Configurations. . . . . . . . . . . . . 58

38 - Incremental Moment Characteristics of Tail, Canard,and Trisurface Configurations .................. 59

39 - Comparison of Measured and Summed Incremental Moments

of the Trisurface Configuration ............... . .. ... 62

40 - Normalized Conrol Power ................. . 64

41 - Control Surface Efficiency . . . . . . . . . . . 65

42 - Effect of Canard on Horizontal Tail Control Powerat Constant Angle of Attack. . . . . . . . . . . . . . . . . . . 67

43 - Effect of Canard on Horizontal Tail Control Powerat Constant Mach Number. . . . . . 68

44 - Lift-to-Drag Ratio at Constant Lift Coefficient . . . . . . .. 68

45 - Required Angle of Attack.. .......... .......... 70

46 - Effect of Canard Position on Minimum Drag. . . . . . . . . . .. 71

47 - Effect of Canard Position on Wave Drag .......... ... 71

48 - Effect of Longitudinal Canard Position on MinimumDrag for the 25-Degree Wing .. . . . . . . . . . . . . . . 73

49 - Minimum Drag of the 25-Degree Wing with

and without Canard ...................... . . . . 73

50 - Effect of Canard Longitudinal Position on MinimumDrag at Constant Mach Number . . . . . . . . . . ... 74

51 - Effect of Canard Vertical Position on Minimum Drag . . . . . . . 75

52 - Effect of Canard Pnaition on Induced Drag. . . . . . . . . . . . 77

53 - Effect of Canard Position on Induced Drag atConstant Angle of Attack......... .... .......... 79

54 - Effect of Vertical Position on Induced Drag Factor . ...... 81

55 - Effect of Longitudinal Position on Lift-to-Drag Ratio. . . . . . 83

56 - Effect of Vertical Position on Lift-to-Drag Ratio* ... ........ 86

vii

Effect of Canard Shape on Minimum Drag . . . .. ... . . 88

58 - Effect of Canard Shape on Induced Drag Factor ......... .. .... 89

59 - Effect of Canard Shape on Lift-to-Drag Ratio .... ..... . . 91

60 - Minimum Drag as a Function of Canard Deflection .... ...... ... 92

61 - Incremental Drag Due to Canard Deflection. . . . . . . . . . . . 94

62 - Effect of Deflection on Induced Drag Factor ..... ...... . . 96

63 - Effect of Canard Deflection on Induced Drag Factor ... ..... ... 98

64 - Effect of Canard Deflection on Lift-to-Drag Ratiofor the 50-Degree Wing ......................... 105

65 - Effect of Canard Deflection on Lift-tn-DragRatio for the 25-Degree Wing. . . . . ............. 106

66 - Effect of Canard Deflection on Lift-to-Drag Ratio. . . . . ... 107

67 - Comparison of Minimum Drag of Canard, HorizontalTail, and Trisurface Configurations ..... .................. 111

68 - Induced Drag Factor for Canard, Horizontal Tail, andTrisurface Configurations. ................. .. 113

69 - Lift-to-Drag Ratios for Canard, Horizontal Tail,and Trisurface Configurations. . . . .. ........... 115

70 - Lift-to-Drag Ratios at C = 1.0 and 0.9 for 50- and

25-Degree Wings, Horizontal Tail, and Trisurfice

Configurations with Horizontal TailDeflected -10 Degrees ......... .... .............. .. 116

71 - Comparison of Lift Curve Deviation and Axial ForceTechniques for Buffet Onset Determination. ................. ... 118

72 - Effect of Canard Position on Buffet Onset Lift

Coefficient and Angle of Attack ....... ................ ... 120

73 - Variations of Axial Force Slope with Lift Coefficient .... ...... 122

74 - Comparison of Buffet Onset Lift Coufficient Based onAxial Force Criteria for Canard and Wing-Body .............. ... 123

75 - Effect of Canard Shape on Buffet Onset LiftCoefficicnt and Angle of Attack ...... ................. .... 123

viii

Effect of Canard Deflection on Buffet OnsetLift Coefficient and Angle of Attack .......... ............. 125

77 - Comparison of Buffet Onset Lift Coefficient and AngleF of Attack for Horizontal Tail, Canard, and

Basic Wing-Body. .. .. ............. . . . . . . . . . . . . . . 1.25Ba nd Wing-Body Ca ar..

...... .. .... . . . . . . . . . . . . 12 7

78 - Incremental Buffet Intensity for Basic Wing-Bodyand Wing-Body Canard . .. .. .. .. .. .... . .. 127

79 - Comparison of Incremental Buffet Intensity for Hori-zontal Tail, Canard, and Wing..Body as Functions ofLift Coefficient and Angle of Attack . . . . .......... 128

80 - Effect of Canard Position on Incremental Buffet Intensity. . . . 129

81 - Effect of Canard Shape on Incremental Buffet Intensity . . . . . 130

82 - Effect of Canard Deflection on IncrementalBuffet Intensity ..... . . . .. . . . .......... 130

83 - Longitudinal Characteristics of the Canard, HorizontalTail, and Wing-Body at M - 1.88 and 2.48 .... ...... 132

84 - Incremental Pitchin$ Moment of Canard andHorizontal Tail. .. . . . . . . . . . . . . . . . . . . . . . . 134

85 - Stability Characteristics of Canard, Horizontal Tail,and Wing-Body at Mach Numbers of 1.88 and 2.48 ..... ......... 135

86 - Incremental Neutral Point Change Due to Canard

and Horizontal Tail ...................... .... 137

87 - Normalized Absolute Incremental Neutral Point Change ........ .. 137

88 - Longitudinal Characteristics of Horizontal Tailand Trisurface Configurations. . . . .......... . . . 138

89 - Incremental Lift and Pitching Moment Due to Canard ........... 141

90 - Lateral Center of Pressure for Horizontal Tail andTrisurface Configurations ............. ......... 142

91 - Stability Characteristics of Horizontal Tail andTrisurface Configurations. . . ................ 144

92 - Effect of Canard Deflection on the LongitudinalCharacteristics ............. ......................... ... 146

ix

S.. ..... !

Effect of Canard Deflection on Stability Characteristics .... 148

94 - Trim Efficiency .. . . .. .. .. .. ... o. ..... 14995 -. omlzTrim Efficiency......................... 149

95 --Normalized Trim Efficiency . . . . . . . . . . . . . . . . *..149

96 - Neutral Point Variation for Canard, Horizontal Tail, andWing-Body at Mach Numbers from 0.6 to 1.88 ..... .... 149

97 - Research Aircraft Fuselage. . . . . . . . ........ 158

98 - Planform View of the Wings. . . . ............ . 159

99 - Planform View of the Canards. . . . . . . . . ...... 160

100 - Canard Pivot Locations. . . . . . . ........ . . 161

10i - Wind-Tunnel Model Components . .. .. .. .. .. .. .. ... 162

102 - incremental Root Mean Square Data for the101 -DWind-Tunnel Bodel .. Co nns. . s. . . * . . . . . ..... .... 162i50-Degree Win g-Body y.......................... 164

103 - Incremental Root Mean Square Data for theHorizontal Tail .M.e.a . .S ... a 0 . . . . . . . .. . . . . . . . 164

104 - Incremental Root Mean Square Data for Canard CO ........ 165

105 - Incremental Root Mean Square Data for Canard C1

at -5-Degree Deflection. . . . . . . . . . . ........ . 166

106 - Incremental Root Mean Square Data for Canard C2at -5-Degree Deflection . . . . . . . . . . . ......... 167

107 - Incremental Root Mean Square Data for Canard C3at Position P3 and -5-Degree Deflection .. .......... 167

LIST OF TABLES

1 - Geometric Characteristics of the Wings. . . ........... 156

2 - Geometric Characteristics of the Canards. . . .......... 157

x

NOTATION

A Axial force, pounds

AR Aspect ratio

CA Axial force coefficient A/q

CD Drag coefficient, D/qSw

CD Minimum drag coefficientmin

CD aCD/1 6

Ci Canard

CL Lift coefficient, L/qSw

CLo Buffet onset lift coefficient

CL Lift coefficient evaluated at a - 25 degreesL25

CL aCL//am

*C L C/L 16CL6 L

CM Pitching moment coefficient, pitching moment/qSw

C Pitching moment coefficient of body and wingMWB

o Zero lift pitching moment

CM25 Pitching moment coefficient evaluated at a - 25 degrees

CM a cM/3

CM6 CM

xi

t ,

CN Normal force coefficient N/qSw

Sc Mean aerodynamic chord, inches

D Drag, pounds

HT: Horizontal tail

i Canard shape

j Canard position

Sk Induced drag factor

L Lift, pounds

L/D Lift-to-drag ratio

(L/D)max Maximum lift-to-drag ratio

i Distance between center of gravity of wing and/or canard/c tail pivot location, inches

M Mach number

N Normal force, pounds

P Canard position

Sq

Dynamic pressure, pounds per square foot

-. W Wing reference area, square feet

WB Wing-body

x Longitudinal distance, inches

z Vertical distance, inches

Q Angle of attack, degrees

AC A/CL Axial force slope

AC C -CD D DWB

xii

* ACL CL CJV

CMM CMIW

6 Canard deflection angle, degrees

a RNS, root Mean square bending moment, inch-pounds

xiii

ABSTRACT I

An analysis of the effects of canard shape,positioa, and deflection on the aerodynamic charac-teristics of two general research models having leadingedge sweep angles of 25 and 50 degrees is presented.The analysis is a summary of the findings of threeexperimental transonic wind-tunnel programs and onesupersonic wind-tunnel program conducted at the DavidW. Taylor Naval Ship Research and Development Centarbetween 1970 and 1974. The analysis is based on fourcanard geometries varying in planform from a 60-degreedelta to a 25-degree swept wing, high aspect ratiocanard. The canards were tested at several positionsand deflected from -10 to +10 degrees. In addition,configurations consisting of a horizontal tail and acanard with horizontal tails are analyzed.

The results of the analysis inidcate that thecanard is effective in increasing lift and decreasingdrag at Mach numbers from subsonic to high transonicspeeds by delaying wing separation. The effectivenessof the canard is, however, decreased with increasingMach number. At supersonic speeds the canard haslittle or no favorable effects on lift or drag.

It is further shown that the horizontal tail is amore superior trimming device than the close-coupledcanard at low-to-moderate angles of attack and that aconfiguration consisting of canard, wing, and horizontaltail is superior, in performance, to either canard orhorizontal tail at high angles of attack.

ADMINISTRATIVE INFORMATION

This work was undertaken by the Aircraft Division of the Aviation and

Surface Effects Department of the David W. Taylor Naval Ship Research and

Development Center (DTNSRDC). The program was sponsored by the Naval Air

Systems Comnand (AIR 320) and was funded under WF 41432-09, Work Unit

1600-078.

INTRODUCTIONThe previous volumes of this report have dealt almost exclusively with

the close-coupled canard at subsonic speeds. This volume includes the

work on canards to transonic and supersonic speed regimes. The trends

noted in Volumes 1 and 2 are also evident at transonic speeds albeit

1 . ,. . .. . ... . . . •. • •

modified to some extent. The primary features to be discussed will be the

effect of canard position, shape, and deflection at transonic speeds from

Mach numbers (M) of 0.6 to 1.1. The two basic models used in Volumes 1 and

2 were also used in the transonic study and are shown in Figure 1. Similar-

ly, the four canard geometries used in the previous volumes are used in the

present volume. The canards are shown in Figure 2. Pertinent dimensions

of the models and canards are given in Appendix A.

The data 1-3 on which this volume is based were obtained in theDTNSRDC 7-foot x 10-foot transonic wind tunnel.

Supersonic data were obtained in the DTNSRDC 18-inch supersonic blow-down tunnel. The model used in obtaining this data is a geometrically

similar half model of the 50-degree sweep model and is shown in Figure 3.

Data at supersonic speeds were obtained at M - 1.88 and 2.48. In the

supersonic wind-tunnel program only the truncated 45-degree delta canard,

cot was used.

The organization of this volume is similar to the organization of

Volume 2; the major sections are lift, drag, and pitching moment at tran-

sonic speeds, and an additional section on the effect of the canard on

buffet onset and buffet intensity.

The supersonic data are presented as a separate section. Subtopicsunder each major section include the effects of canard position, deflection,and shape. Comparisons are made between canard and horizontal tail and

data are presented on configurations consisting of canard, wing, and hori-

zontal tail. This configuration will be referred to as the trisurfaceconfiguration. As with Volume 2, data end analysis are presented for both

25- and 50-degree sweep models.

The majority of the data are presented as incremental changes in lift

and pitching moment at constant angle of attack as a function of Mach

number. Drag is presented as lift-to-drag ratio L/D, induced drag factor,and minimum drag CDmin as a function of Mach number at constant lift

ccpfficient. Buffet data are presented in the form of buffet onset lift

coefficient and angle of attack, and buffet intensity.

*A complete listing of references is given on page 169.

2

I-

50. DEGREE SWEPT WING

25-DEGREE SWEPT WING

Figure 1 -Sketch of Models

Figure 2 -CanardsI3-.

Ki| i ,.. ••Tw,

rc

h

h

Figure 3 - Supersonic Half-Model

S- •," • u ihm ,,,.. -• __" ,.•• •__--"- .... • • .....4

The following analysis will indicate that the favorable results due to

the canard at subsonic speeds also occur at transonic speeds and that the

canard has only little influence on the lift and drag at supersonic speeds.

LIFTThe variation of lift coefficient with Mach number for both the 25-

and 50-degree wing models is shown in Figure 4. The data are for an angle

of attack of 25 degrees for both canard on and off. Also included in the

figure are the appropriate data points from Volume 2. As shown in three of

the four configurations, lift dropped off slightly with increasing Mach

number and then increased as true transonic speed is obtained. ýWhere this

increase occurs is a function of the wing sweep angle. The point where

the increase in lift coefficient with Mach number occurs is at M - 0.6 for

the 25-degree wing model and approximately M - 0.7 for the 50-degree sweep

model. What is of primary interest in this figure is the fact that the

incremental change between canard on and off is relatively constant with

Mach number for both models.

A similar plot for the 50-degree wing at various angles of attack ispresented in Figure 5. Mach number range is from 0.6 to 1.1 and shows

that the incremental lift is approximately constant with Mach number at

constant angle of attack. It should be noted, however, that the influence

of Mach number on the lift variation is more pronounced for the basic wing-

body than the wing-body canard. This is particularly true at the higher

angles of attack. An example of thir influence is shown in Figure 6 where

the angles of attack required for lift coefficient of 1.0 for the 50-degree

wing and 0.9 for the 25-degree wing model are presented. For both models,

the angle of attack is relacively constant throughout the Mach number range

when the canard is installed. The basic wing-bodies, however, exhibit a

pronounced reduction in required angle of attack with increasing Mach

number. This behavior is probably due, in part. to the expected increase

in lift curve slope CL with Mach number, but also is due to a reduction

in flow separation over the basic wing with increasing Mach number. This

reduction in separation is also expected since a large portion of the wing

5

1.6

VOLUMI 2

1A O'....~CSPa6.s ISO-C01i45 WINGI

CP,6, 12&1-bER1 WIND)

f,, 1.4

iPIAIII WING

.... 110111 WINO

0.6 I I I

0 0.2 0o4 a.I 0.a 1.0MAOH NUMBIR

Figure 4 - Lift Variation at 25-Degrees Angle of Attack

with Mach Number

1.4 -OIORhe WING, C0P60

a-isI,, .., 20. .B 1.0 *-•• . _

1jd 0,.6I

0.4 --.. CANARD OPP

CANARD ON0.2

02I I I0.4 0.6 0., 1.0 1.2

MACH NUMBN

Figure 5 - Lift Coefficient versus Mach Number at ConstantAngle of Attack

6

-. :1-.

42

CL *1. 0e

Is 23

24 - H

12 -20

4:4

CO

0.4 0.6 0.6 1.0 1.2 0.4 0.6 0.3 1.0MACH NUMBER MACH NUMBER

Figure 6m Wing at 50 Degrees Figure 6b - Wing at 25 Degrees

Figure 6 -Required Angle of Attack

7

would be in the mixed supersonic-subsonic flow regime. The canard tends to

suppress leading edge separation, and with increasing Mach number, less of

this separation is in evidence and as expected the canard would have a

smaller effect on the total characteristics of tha vehicle. This trend

will also be noted at supersonic speeds, where the effect of the canard was

small. The supersonic effects will be discussed in detail in a later

section.

POSITION

It wae noted in the previous volumes of this report, that lift was

maximum at subsonic speeds at a position where the canard exposed trailing

edge was slightly in front of the exposed wing leading edge. Similar

results are noted at M - 0.6 as shown in Figure 7. Figuro 7 presents data

similar to Figure 6, where angle of attack required for CL - 1.0 and 0.9

is presented. The data indicate that as the canard is moved aft, the re-

quired angle of attack is smaller. It is seen that the optimum position

P3 has a relatively flat angle of attack variation with Mach number. The

influence of Mach number on the off optimum positions is similar in behavior

to the basic wing-body data presented in Figure 6. With increasing Mach

number the required angle of attack is rapidly reduced. It can thus be

said that at transonic speeds as well as at subsonic speeds, as the flow

characteristics of the basic wing are improved the influence of the canard

is reduced and the parameters which determine optimum performance of the

canard are of lesser importance.

The majority of the data presented in this section is in the form of

incremental lift coefficient ACL at constant angle of attack. The first/L

such data are presented in Figure 8, where ACL, for the basic Co canard is

presented at positions PIV P3, and P7 for the 50-degree wing model. These

three positions were the only positions evaluated at Mach numbers greater

than 0.9. Data are presented for nominal angles of attack of 12, 16, 20,

and 24 degrees. As in the case of subsonic speeds, incremental lift is

maximum at position P3 Position P 3 corresponds to the highest, most aft

position. Moving the canard forward or down reduces the incremental lift

8

Kn

24

20

s - -- PI

a sCL . 24-

12 - 20- P

12 - P3

4

4 L 0.S

0 I I I0.4 0.6 0.3 1.0 1.2 0.4 0.6 0. 1.0

MACH NUMBER MACH NUMBER

Figure 7a - Longitudinal Position Figure 7b - Longitudinal Positionon 50-Degree Wing on 25-Degree Wing

Figure 7 - Effect of Canard Longitudinal Position on

Required Angle of Attack

9

0.6

0.4 -. , COP,

4-DEGREE WING

0.2 -•

a.--24

o I I I

0 -20

0'I 1

e~i

IIs

0 I1I0.4 0.8 0.9 1.0 1,2

MACH NUMBER

Figure 8 - Effect of Canard Position on Incremental Lift

10

ZVI.

*i

at. Mach numbers below 0.9. As Mach number is increased beyond 0.9, theforward canard had the largest increment at a - 12 degrees. In general atMach numbers greater than 0.9, little difference is evident in incremental

lift due to position.The effect uf longitudinal position for the 25-degree wing is presented

in Figure 9. The C0 canard was evaluated at positions PV, P2, and P3.

Similar trends are noted for the 25-degree wing configurations as for the

50-degree wing, i.e., moving the canard aft increased ACL. The data for

the 25-degree wing model were limited to a Mach number of 0.85 so the

effect of positions at higher Mach numbers are unknown. However, the curves

appear to be converging at the higher angles of attack and thus the same

behavior of canard position as the 50-degree model is expected.

The effect of longitudinal canard position on the aerodynamic char-

acteristics of the 50-degree model had been well established by the time

the transonic wind-tunnel program was run. The majority of the programwas concerned with vertical position and only one systematic variation was

attempted. These data are shown in Figure 10. The data are for the 60-

degree delta C1 , evaluated at positions P2 and P3. The subsonic data indi-cated that the optimum position for this canard was position P2 and the data

at transonic speeds also indicate this to be the case.The effect of vertical position on incremental lift is presented in

Figure 11. The configur tions shown are canards CO, C1 , and C2 for the

50-degree wing located at positions P3 and P6' and canard Co located at

positions P2 and P 7 P3, and P6 for the 25-degree wing model. In general,lowering the canard reduced the incremental lift. As both Mach number and

angle of attack are increased, the differences in incremental lift becomesmaller and, for canards C and C on the 50-degree wing, crossovers occur

0 1and the lower positions become the most effective lift generator. An angleof attack of 25 degrees corresponds closely to the angle of attack for

ACL presented in Volume 2. At subsonic speeds ACL was higher for themax max

C canard at the low position and was only slightly lower for the C101canard. It appears that with increasing Mach number th trends become

11 --

I-. PS

0.4 INCREASING 9/1 AND 0

CoP2

n . -m COP20.2-

0.4

0.2 0

m0.2

~.-a -,

0. - ~ o.0o22INCREABING ONalc

a-r-2d

o I .- 10

o -12

o IoI

0.4 0.6 0.8 1.0 0.4 0.6 0. 1.0MACH NUMBER MACH NUMBER

Figure 9 - Effect of Canard Position Figure 10 - Effect of Caaard CI,

on Incremental Lift for the 25- Position on Incremental LiftDegrec Wing

12

rJ

Figure 11 - Effect of Canard Vertical Position on Incremental Lift

0* ---- CoP.8o

WE-DOGREE WING

0.6

0,--

A.,0 e25

0.40.2

("J 50-DEGREE W.NG, C1 8oM P3

0.1%

a -220,22

00.2.

o I

00

Uo 2

0 0

o 1- I __ _ __ _ _

,.-12

OA 0.6 0.8 1.0 OA 0.6 0.8 1.0MACH NUMBER MACH NUMBER

Figure lla - Canard CO Figure lib - Canard C1

13

-- -_-

Figure 11 (Continued)

bO0DEGREE WING C2 60 p3

25-DEGREE WING

-. 0 .4 - - A ' " C O P

--- Cos2"•"• %,,- ... , €P2

INCREABING al l •un' CoP70.4

0.2-

0 a+ . 22 01. -_ .. ,0825 0.2___

0 0

0 I

S .0.2

0.2 -0.2

Cole a -16

a -12-2-II ,00.4 0.6 0.6 1.0 0.4 0.6 0.8 1.0


Figure 11c - Canard C Figure lid - Canard C2 0

14

more dominant and thus the low position may be advantageous at high tran-

sonic Mach numbers. Similar trends are noted for the 25-degree wing model

in that crossovers occur at the high angles of attack.

CANARD SHAPE

The effect of canard shape on the 50-degree wing model is presented in

Figure 12 for canard shapes C0, Co, C2, and C3 at position P3 and shapes

C0 , Cl, and C2 at position P6. The trends noted are the same as at sub-

sonic speeds. High sweep and low aspect ratio canards generate larger

values of incremental lift at high angles of attack. At low angles of

attack the reverse is true. The extent of these changes of incremental

lift with canard shape is clearly a function of position. At the lower

position the differences in incremental lift are clearly larger than those

differences at the high position. The trends with increasing Mach number

are similar for each position. At low angles of attack (a - 12 and 16)

incremental lift increases with increasing Mach number; at the higher angles

of attack incremental lift increases and then tends to drop off.

DEFLECTIONIt was mentioned in Volume 2 that small negative deflections had a

beneficial effect on performance at low angles of attack and only minor un-

"* favorable effects at high angles of attack. For this reason, the majority

of the transonic wind-tunnel program was concerned with negative deflec-

tions. The effect of such deflections will be discussed in the following

section.

As mentioned, the majority of the data were concerned with negative

canard deflections, however, certain configurations were evaluated withpositive deflections. Those configurations were the C0 canard at position

P for the 50-degree wing and positions P and P for the 25-degree wing.3 1 3

These data are shown in Figure 13. In general, the incremental change in

lift due to either positive or negative deflection is relatively constant

with Mach number at each angle of attack for all configurations. There

are some differences associated with position on the 25-degree wing model.

15

- CO - Co

- -- C1 Cc3 a

qm--g 260.4 - Co

INCREASING .

CANARD LEADINGEDGE SWEEP INCREADING

|: LEADING

0.2 .20- EDGE SWEEP

am25

0 0

4. .U .0.2

a-222•. •0..,- ff0.2

0 0

O I 0 ,III

-16' '

S0.2 - 0. -

0

-- Ai 0.4 O 'S0, 1.0 0.4 O.6 0.E 1.0•i•MACH NUMBER MACH NUMBER

iFigure 12a - Position P 3 Figure 12b - Position P 6

Figure 12 -Effect of Canard Shape on Incremental Lift:

e 16

r,•_ ' ,Ok• -• • ..... "=m- • • -r• :i......ENSE•

Figure 13 - Effect of Deflection on IncrementalLift at Position P3

0.0.

SoA

8 0.2 25

0 DECREASING 8DEFLECTION 0

-- - .. 10-10 - 1.- +10

a-ZR_ *..I a21

0.2 - 0 --

JI0 I

0.2 -- 0a.I. ~0,0.2 -

0,2

a. 12 so-

0II 0

0i

0 Ono 0 -- -0'

, I , I . . . I I

0.4 0.6 0.6 1.0 0.4 0.6 0. 1.0


Figure 13a - Position P3 on Figure 13b - Position P 3 on

50-Degree Wing 25-Degree Wing

"17


0.4

a, 20

0----- .0'U- -1

0.2 a-24

"0" n

0.2

0 "0

I I

0 0.2

0.4 0.6 0ll 1.0

i MACH NUMBER

Figure 13c -Position PI on 25-Degree Wing

a 18

goal,

Positive deflection on the moat forward position P1 increased ACL at all1L

angles of attack, however, at the aft position P3, the effect of positive

* deflection was small at the highest angle of attack presented.

A comparison between the incremental change due to negative deflection

CL for the 25- and 50-degree wings indicates that at low angles of attack

C L was greater for the 25-degree wing, however, at high angles of attack

C L was greater for the 50-degree wing model. The exact reason for this

behavior is unknown, however, it may be due, in part, to the fact that the

vertical distance ratio, Z t r, is greater for the 25-degree wing model than

"for the 50-degree model. The canard, when given a negative deflection,

increases this gap ratio and thus becomes somewhat less effective in in-

fluencing the flow of the wing.

Lowering the canard to position P6 for both 50- and 25-degree wings

indicates similar trends. These data are presented in Figure 14. The

incremental lift due to deflection is approximately the same as that of

position P3 for the 50-degiee wing at high angles of attack. However, CL

is increased for the 25-degree wing indicating that there is a strong effect

of vertical trailing edge gap height on incremental lift at high angles of

attack when the canard is deflected. A plot of CL at a Mach number of

0.6 is shown in Figure 15. Data are evaluated between canard deflection

angles of 0 and -10 degrees, As shown for both wing sweeps, lowering the

canard reduced C at low angles of attack.L6

The remainder of the deflection data are based on the three other

canard shapes C1 , C2 , and C3. Canard C1 was evaluated at three positions,

P2' P3, and P6 and canards C2 and C3 were evaluated at P3 and P6. Deflec-

tion angle was limited to -5 degrees.

Canard C1 exhibited maximum incremental lift at position P2 at 0-

degree canard deflection. This is not the case when the canard is

deflected. When the canard was deflected to -5 degrees, maximum liftoccurred at position P6' Incremental lift is presented in Figure 16 for

the three positions; CL is presented in Figure 17. As shown in Figure 16,

6

19

0..6

0.0.4_ _ _b

20.

0.2- 8aERASN

r. - 0 DEFLECTION0

- I SOW -

a*22 0 1 a*2

0.2 ~0.2 - -

0 0

~0.2 at*1

0

0.0.2___

0. n 12______o1

00

0 a - - 0 0

0,4 0.6 08 1.0 OA 04 0.0 1.0MACCH NUMBER

Figure 14a - Deflection on 50- Figure 14b - Deflection onl 25-

Degree Wing Degree Wing

Figure 14 -Effect of Defle'.tion on IncrementalLift at Position P6

20

I~i.

.0.04

0.04 23 50-DEGREES

- 3 2,• 25-R•G"ES M-" DaP

, 0.02

00 0 l6 24 32

Figure 15 - Comparison of Control Surface Effectivenessfor 25- and 50-Degree Wings

21

Figure 16 - Effect of Deflection on Canard C1 Incremental Lift

0.6

0

0.4- -a

- --- n---0

0.6

0 0.9

a,,20

0. *•"--2I0,

~0.4 0.2

0.

02 ~0.

0.2200.2

0 *2

20.

a II

o0do

•- 0 0

Ii ffo.,- - 12o

00.6__ 0. 61+. 0 oI I

0.4 0.e 0.8 1.0 0.4 0.6 0.6 1.0MACH NUMBER MACH NUMBER

Figure 1.6a - Position P 2 Figure 16b - Pcbition P3

22


0.3

0.6

hN0o.4

0.2

0*a 22

o0.2 .

p0,2

a I

.... 010l 12

0 I

0.4 0.6 0.8 1.0

MACH NUMBER

Figure 16c - Position P6

23

0.04

P3

p, 1 e

0.03 -

0.02 -

M "0.8 w O NO"0.01 3C

I

IIBASED ON be-0,-

0 16 24

a, (dog)

Figure 17 - Control Surface Effectiveness for Canard C1

24

I-Ali.. .

large lift losses occurred at position P2 whereas little lift was lost at

position P 6' The large loss in lift (ACL m 0.20) at a - 25 degrees for

position P2 is not due to the canard deflection primarily but is due to thegap between wing and canard opening beyond a critical length. The vertical

gap at position P3 is the same as that at position P20 however, the total

gap distance is greater for position P2 than for position Py3 Insufficient

• data are available to analyze this trend further but it appears that there

is not only a lower gap boundary as discussed in Volume 2 but an upper Sap

boundary as well.

Similar trends are noted for canard C2 as shown in Figure 18. Incre-

mental CL due to deflection was greater at the high position than at the

low position. Data were available only at position P3 for the high aspect

ratio canard C3 and are presented in Figure 19. As shown, CL is approxi-

mately constant over most of the Mach number angle of attack range.

TRISURFACE CONFIGURATIONS

The canard, if in proper position foi favorable interference, is not

as efficient a trimming device for a stable configuration. This is due in

part to the short moment arm as well aa to the large drag increase caused

by positive canard drflectiona. This increase in drag is particularly

severe at low angles of attack. Due to the above reasons, configurations

consisting of canards, wing, and horizontal tail were evaluated. A sketch

of this configuration is shown in Figure 20. The rationale behind the

configuration is to use the horizontal tail for trim at low-to-moderate

angles of attack and to supplement the tail trim power with the canard at

higher angles of attack when the negative deflection of the tail causes

large lift losses.

The incremental lift characteristics for such configurations are

shown in Figure 21. Data are shown for both 50- and 25-degree wing con-

= , figurations. The canard is the basic truncated delta C located at

position P3 for both wing sweeps. As shown in the figures, the trend of

the complete configuration with Mach number is very similar to the canard

25

FJ0.6 0.6

0 0

0.4 0.4

0.2 0.2

~-250 I0

-.j J

0.2 -0.2

w 22

0.2 - 0.2

0 I I 0 I -"

s -120 0 I

a 12

I -0 100,A 0.6 0.8 1.0 0.4 0.6 0.6 1.0


Figure 18a - Position P 3 Figure 18b - Position P6

Figure 18 - Effect of Deflection on Canard C2 Inccemental Lift

26

r • -'---

0.4

SQk26p ~-m,-- -5

,0.2

0 I

~m22

0.

-i

S-0.2a--

0

S 12

-,ag

. Q : - , , I , . I

0 -

- -- t

0 I0.4 0.8 0.8 1.0

MACH NUMBER

Figure 19 - Effect of Deflection on Canard C3Incremental Lift

27

L 1 _ _I__I_ __ _ _

I

U I



Id

Figure 20 - Trisurface Configuration

28

. ... ..........

--- HTP 0.. Oa8 C, 3 048.

0,4 TPO

ff -- -- C0P5o

0.. %P3 +,TP- O

0.4- own-as0 0.2

0.2

Fiue2a-nrmnalLf* n Fsr 1 22Icrmeta L- f o

50Der2 Wng25Der21Wn

0

Fig iguee22a - Incremental Lift o haFaguerisb Ics Lf on

Canard, and Trisurface Configurations

0.2 29

-- -w o

alone configuration. Figure 22 presents a comparison between the measured

incremental lift and the sum of the individual increments of the canard and

horizontal tail. In general, the measured data are less than the summed

data. This is due to a changing of the downwash of the wing due to thecanard, thus reducing the loading of the horizontal tail. The trends with

Mach number are very similar, thus indicating that superposition of the

increments is reasonable for a first pproximation for preliminary design

purposes.

PITCHING MOMENT

The variation of pitching moment coefficient with Mach number at an

angle of attack of 25 degrees is shown in Figure 23. The configurations

are the same as those shown in Figure 4. The canard is the truncated 45-degree delta C0 located at position P3. As expected, the pitching moment

for both canard off and canard on configurations decreases with increasing

Mach number. The canard causes a noseup moment, however, the incremental

change between canard off and on is approximately constant with Machnumber.

Figure 24 presents pitching moment for the 50-degree wing model at

lift coefficients of 0.5 and 1.0. Data are presented for both canard on

and off, The Mach number range is from 0.6 to 1.10.

The incremental change between the two configurations is constant at

both lift coefficients throughout the Mach number range and the rate of

decrease is also constant thereby indicating that the rate of change of

neutral point with Mach number is the same for both canard on and off

configurations.

POSITION

The effect of canard longitudinal position on the incremental pitching

moment is shown in Figure 25. Data are for Mach numbers from 0.6 to 1.10

and the canard positions are P 1 and P As expected, moving the canard

forward increases the incremental pitching moment. The aft' location had

relatively constant vilues of ACM with Mach number at constant angle of

30

r . .

V - MEASURED0.AC6 + ACLm.0.6 •

OAj Sa "24eZ4 0.6

MEASURED0.2Geon 4

CL, + 4 0CLig0.2.

.4a I 0.2

•, ffo., •- __

00 1

i•: ff o,2

0. 0.Za2

!"0.. I I00

~~jJ0. - -Ca 1

lr-1a-1'. 0 I I

a. -. 120

GA0.6 0.6 1.0 0.4 MACH NUM1.0MACH NUMBER MACH NUMBER

Figure 22a - Incremental Lift on Figure 22b - Incremental Lift on50-Degree Wing 25-Degree Wing

Figure 22 - Comparison of Measured and SummedTrisurface Incremental Lift

31

IWS

4; OA

VOLUMN 2

I&S.IECIN W1NG

0.3IN

CANARD ONd

10.3

CANARD OFF

00 .3 CA 0.6 0.4 1.0

MACH NUMBER

Figure 23 -Pitching Moment at 25-Degrees Angle of Attack

CIL

000

10.

.0.1

-0.30.

0.4 0.6 0.0 1.0 1.1MACN NUMBER

Figure 24 - Comparison of Pitching Moment for Tail,Canard, and Basic Wing-Bo~dy at Lift Coefficients

of 0.5 and 1.0 for the 50-Degree Sweep Model '

32

0.3-

a i

I,,j

'C'

DO, DEG"aE WING

0.1 - 0. -

C I I - *, L

"' 0MAC4 NLORII MACH NUMISA

Figure 25 - Effect of Position on Incremental Pitching Moment

33,

attack. This is not the case for the forward position P1 particularly at a

.2 and 16 degrees. At these angles, the incremental moment increases

with increaoing Mach number. This behavior in pitching moment is somewhatat odds with the incremental lift data presented in Figure 8. The incre-

mental lift tended to increase at the same rate for both positions. At

the higher angles of attack the incremental moment dropped off with in-

creasing Mach number which is keeping with the trends on incremental lift.At low Mach numbers the incremental moment continually increased with in-

creasing angle of attack up to the highest angle of attack presented (a

24 degrees). As Mach number is increased, there is evidence of a distinct

stall if the canard for the forward position in that ACM is lower at 24

degrees than at 20 degrees. Similarly, it appears that this stall may also

occur for the aft canard P3 albeit at a higher Mach number. This behavior

is at variance with the results observed at subsonic speeds, where no loss

in incremental moment was observed for the P3 position up to angle of

attack of 32 degrees and no reduction occurred for the P1 position up to

28 degrees angle of attack, Thus, it appears that this reduction in momentis purely a Mach number effect.

Siminlar trends are noted in Figure 26 where the 60-degree delta canardis shown at: positions P2' P3, and P6. The change of incremental pitching

moment wlrnh Mach number is far more severe for the forward position P2 thanfor either aft positions.

These trends did not occur for the 25-degree wing model, however.

Figure 27 presents data for the CO canard at positions P1 1 P20 and P. The

effectiveness of the forward canard is dropping off with increasing angle

of attack. This reduction in effectiveness with forward canard locationhas been observed, however, from the subsonic data.

The difference in incremental moment behavior between the two wing

sweeps may be due, in part, to the canard delaying separation on the swept

back wing tips of the 50-degree wing. This shifts the center of pressure

of the wing aft thereby reducing the noseup moment of the canard. The 25-

degree wing, having little sweep, would not experience this effect on

moment.

34

.............................. •................................

0,4

4 p2•--.--- p2

""" P0.5.DEGRKE WING C0 600.3 - 0.3

aoat

Sa"-20

0.1o.2 I • '-22

0.20.

0.1

11 •--•"' • '•w' t-11 w'• '

wwo a-*12

011 INCRAEINO Q13 & 0 0,1

0.2a-is

0.1---. .

0 0

o ,.. I! 1.o .011

OA o.0. 1.0 04 0.6 0. 1.0MACH NUMBER MACH NUMBIR

Figure "6 - Effect of Position on Figure 27 - Effect of Canard PositionIncremknLal Moment for Canara C for 25-Degree Wing Model

-J-

When the angle of attack is allowed to vary and pitching moment isplotted against Mach number at constant CL as in Figure 28, we see the rate

of change of moment with Mach number is approximately the same for both

canard on and off. Figure 28 presents data for the C0 canard at positions

P ' P3Y and P . Positions P1 and P3 exhibit the same trend as the basic

wing-body. Position P,7 which is the canard nearly in the wing chord

Splane, exhibits a dropoff in moment at CL - 1.0 and is approximately the

same as position P 3 at CL 05. This dropoff and having the same value

as position P 3 indicate that this is a poor canard location. Because posi-

"tion P7 is located forward of position P3, the moment should be increased

at C L -0.5 merely based on canard volume coefficient considorations.

The effect of canard position on neutral point shift with Mach number

is indicated in Figure 29. Figure 30 presents the identical data, however,

the appropriate neutral point variation at M - 0.6 has been subtracted fromthe data for each configuration. As can be seen in the figureu, the

neutral point shift with Mach number is approximately the Pame for the

most aft position P3 as for the basic wing-body. For the other two posi-

tions, the stability is increasing at a faster rate than the basic

wing-body. This is uspecially the case for the canard located in the for-

ward position P1.

The eaffect of canard vertical position on the incremental pitching

moment is presented in Figure 31. In general, the trends with incremental

pitching moment with vertical position follow those trends exhibited by

the incremental lift characteristics presented in Figure 11. Therefore,

the position had the greater lift value also had the largest moment value.

The magnitude of the pitching moment change was usually less than the

corresponding lift change indicating that the majority of the lift change

is on the wing rather than on the canard. The largest change in pit':hing

moment due to canard vertical position was at positions P2 and P7 on the

25.degree wings Position P7 is very close to the wing and AC was reduced

approximately 0.1 by lowering the canard.

In general, lowering the canard reduced the incremental pitching

moment at low angles of attack and low Mach numbers fur the 50-degree wing

36

MAGNA........ .......

SODEGREE WING 0 ~ - -p

0.3 -INCREASINORM/

0.2 k -

0

0.2

0.10.

0

0. - 0.6 Ol6 1.0 1.2

MACH NUMBER

I'Figure 28 -Pitching Moment Variation with Mach N~umber

at Constant Lift Coefficient

37

0.3S0-DEGREE WING C080 ,

INCREASING W/E

0.2 P'

-P 2 ........

-0.1

0.4 0.6 0.0 110 1.2

MACH NUMBER

Figure 29 -Neutral Point Variation with Mach Number

0

SX we

..0. 1 tj.

!.0.4 0.6 0.8 1.0 1.2.!' MACH NUMBER

•,Figure 30 -Incremental Neutral Point Behavior with Mach Number

,. 38

k!

Figure 31 - Effect of Canard Vertical Positionon Incremental Moment

SP2

0.3 N0.3

a25 o25

00.2 2 0.2

0O.3 - 0.3

22a 22

0.2 0.2o, o I

0.2 0.2

woo

0.1 0.1

-16 aiC I C.

0 0

a-12 o=12o 0I i I

0.4 0.8 0.8 1.0 0.4 0.6 0.9 1.0MACH NUMBER MACH NUMBER

Figure 31a - Canard C on Figure 31b - Canard C1 on50-Degree Wing 0 50-Degree Wing

39


CA0.4 -- 0.2 .,.

P3 a16

-, .-- PS

0.$3 0.1

SC.2

~ a* 12

0.3 -0.1

"• 222

I o., - I02 0.6 Ole 1.0 0.C 0.6 O., 1.0

MACH NUMBER MACHLM

Figure 31c - Canard C2 on 50-Degzee Wing

/40

rlFigure 31 (Continued)

- P 2 "- Pu2

0.3 0-- P -03- Ps

0.2 - INCREASING A/8 0,2 - INC.ARAPO 2R

0.- . 0.13

0.2 - 0.2-

0,2 - _ ,- el

0.1 .I 01

0.2 00.2

1 a-12

0o.1-- - . 0r.1- -----..u::%-g''

- 4 - - --- - 4

or-wo

OA 0.6 0.e 1.0 0.4 0.1 0. 1..MACH NUMBER MACH NUMBER

Figure 31d - Canard C0 on Figure 31e - Canard CO on

25-Degree Wing 25-Degree Wing

41. . .

model. At high Mach numbers the difference in AC between positions wasM

small. in the case of the 45-degree truncated delta canard CO, the lower

position had a larger incremental moment than the upper position at angles

of attack greater than 20 degrees. This behavior was the same for the 60-

degree delta canard C1 .

The effect of canard vertical position on the 25-degree wing was some-

what different than that of the 50-degree wing model. Lowering the canard

on the 25-degree wing model caused a reduction in incremental pitching

moment at both longitudinal stations evaluated.

CANARD SHAPE

The effect of canard shape on the incremental moment characteristics

is shown in Figure 32. In Figure 12, it was shown that increasing canard

leading edge sweep increased incremental lift at high angles of attack.

This, however, is not the case with incremental moment. Canard C3, the

25-degree high aspect ratio canard had the largest incremental moment at

a 25 degrees, but had the lowest incremental lift. This was also the

case at a - 22 degrees. Since the lift was lower for this canard and the

moment greater, the canard had less of an effect on the wing than the

higher sweep canardb.

At low angles of attack the incremental moment decreases with increas-

ing canard sweep angle. This is to be expected since, as was shown at

subsonic speeds in Volume 2, the moment contribution due to the canard is

proportional to the individual lift curve slope CL• of each canard; the

low sweep canards have a higher CL

DEFLECTION

The effect of both positive and negative canard deflections on the

incremental moment characteristics are presented in Figure 33. Data are

presented for position P3 on the 50-degree wing model, and positions P1

and PF for the 25-degree wing model. The canard is C0 for both models.

As indicated in the figure, at low angles of attack the increment due to

deflection is approximately the same for either positive or negative

42

S. . "V..' • ,- qI-- . .• .. ,.. ... , - . . . . . . , . . . . .. . .. ... ,.. ,.• ... . . . . .

Figure 32 - Effect of Canard Shape on IncrementalMoment for the 50-Degree Wing

0.2 Cc•' ,3 . "-i - C o

&.-A. c2

0.1 0,3

0 0.2

0-.- 0,1•~I NCREASI NG

LEADING

EOGE 8WEEP*; 0 I 0

0 10. 0.2

0 I 0.1

o -- I - - 01 -4

0 1010.4 0.0 0.8 1 0 0.4 0.6 0.8 1.0MACH NUMBER MACH NUMBER

Figure 32a - Position P3

43

*1 "*,"

-,.~

Figure 32- (Continued)

a.: - 04 3i~00.2 OA-

a.I 0,2

c0*- 25

0.1 - a12 0.1

INCREASINGLEADING EDGE'WEEP

0 0-a

0.1 a " -0.2

0- 2 0.1

-4

St I - 01

0.4 0.8 0.3 1.0 0,4 0.6 0.3 1.0


Figure 32b - Postion P

44L -.- - - -. .-. -:- . .

L

Figure 33 - Effect of Canard Deflection on Incremental Moment

0.4

-er a 5

0.3 i. -10

0.2 au2S

0.1

0.2 22

DECREASING DEFLECTION

0.1

0.1,," 16

0

0.1 12 am

-. w-

0 0w --- -

0.4 0.6 0,9 1.0

MACH NUMBER

Figure 33a Position P on 25-Degree Wing

45

|•.Mani


6c

- 0

* 0.2 20 - +10

0.1

0

0.2 - ""Now

0,1

• II

S,0,1 - - - - m . -

!;, a " 25

0

0 0.1

0- 0-- 00.4 0.6 0.8 1.0 0.4 0.6 0. 1.0


Figure 33b - Position P3 on 25-Degree Wing

m m46

1.:


0.2 2 -

0.1 -20

-h~ -lili - ÷10

o • I

a 0 0

0.1

0

0 I I

a 1

0 a =0

0.4 0.6 0. l 1.0MACH NUMBER

Figure 33c - Position P on 25-Degree Wing

47

•' ...

deflection. As angle of attack is increased, there is a reduction in in-

cremental moment for the positive deflection when compared with the corre-

sponding negative deflection. This is particularly true for the 25-degree

wing model.

At the far canard location Pl, on the 25-degree wing model, there is

a sizable reduction in the magnitude of incremental moment when the angle

of attack is increased. A comparison of the increment at 0 degrees ACM N

0.1 and 12-degrees angle of attack ACM N 0.02 indicates a probable canard

stall. Beyond 12-degrees angle of attack &CM due to positive deflection is

larger.

It is interesting to note the difference in behavior between the 25-

degree and 50-degree wing models with increasing Mach number. The 25-

degree wing model shows only small changes in ACM with increasing Mach

number. The 50-degree wing model, however, exhibits a rise in ACM with

Mach number at low angles of attack and a decrease in AC with Mach numberMat high angle@ of attack. Thus it appears that the canard on the 25-degree

wing is relatively insensitive to Mach number, whereas the 50-degree wing

model exhibits significant changes. These changes, however, are due to

the canard on the 50-degree wing having a more favorable effect on delaying

outer wing panel separation, thus moving the overall vehicle center of

pressure further aft.As proof of these statements data for the incremental center of pres-

sure shift with Mach number are presented in Figure 34. The incremental

center of pressure is defined as AC -a C , where Cp M CM/CL.PM=0.6

Data are presented at constant angle of attack for both 25- and 50-degreesweep models. As shown, deflection of the canard has only minimal effect

on the incremental Cp shift for the 25-degree sweep model. The 50-degreemodel exhibits significant changes in AC p between positive and negative

canard deflections and these changes increase with increasing angle of

attack. An shown, positive deflection causes an increase in aft center of

pressure travel and thib increase is greater than the basic wing-body.

Since it is unlikely that the canard stall angle would be less for the 50-

degree wing than for the 25-degree wing, the difference between the two

48

,-i.a 6.6

0.-

A- 8-io

€-0.

0 -,- , 109, ,

-0., "

-o,01 __ _ __ _ _ _ _ 1 1

0

0.4 0.6 e Ole 1.0 0.4 0Fu 0.B 1.02


Figure 34a - Deflection for Figure 34b - Deflection for50-Degree Wing 25-Degree Wing

Figure 34 - Effect of Canard Deflection on Center of Pressure

49

center of pressure movement6 must be due to the main wing shape. In order

to have an aft Cp shift, the canard on the 50-degrre wing must be delaying

stall over the outboard panel of the 50-degree wing, thus moving the over-

all wing center of pressure aft.

The remaindir of the incremental moment data d-ie to canard deflection

are presented in Figure 35. These data are for the three canards C21, C2 ,and C3 located at positions P3 and P6* The deflection angles are 0 and -5

degrees for these two positions. The deflection angles are 0, -5, and -10

degrees for the C0 canard located at position P6' Data for the C0 canard

at position P3 have already been presented in Figure 33. In general,

canard deflection does not change the trend of incremental moment with

Mach number for any of the canards, Differences do occur with angle of

attack for the various canard shapes. The low aspect ratio canards C0 and

C1 exhibit a larger reduction in moment at high angles of attack than at

low angles of attack.

This behavior is in keeping with the previous discusnion in that the

low aspect ratio canards have a greater influenchs on the wing center of

pressure. This influence is diminished somewhat by negative deflections.

The higher aspect ratio canards C2 and C3 show only small changes in

incremental moment with deflection. The incremental moment is reduced by

negative deflection, but the trends with Mach number are approximately the

same for either deflection angle.$ The variation of canard control power C with angle of attack is

c

presented in Figure 36. Data are presented for Much numbers of 0.6 and0.8 for both 25- and 50-degree sweep models. The data were obtained from

Figures 33 and 35, and are based primarily on 6. a 0 and -5 degrees, In

general, canards C 0 and C1I show very little difference with Mach number atpositions P3 and P ' In,:reasing Mach number improved CM at position P2

0' 6c

for canard CI on the 50-degree wing and position Pl for the 25-degree wingwith canard C. Canard control power, CM tended to increase with angle

"0i ' H6 • ••

c

50

-. !

Figure 35 - Incremental Pitching Moment Due to Canard Deflection

0.4 0.4

0V ---- 0S-5-

0.3 0.3-

a - 25

0.2 0.2

~0.3 ~0.3

ftft a 22 a- 220.2 0.2

0.2 ' 0.02

a-Is

0.1 0,.01

a 12

0.1 --- -- 0.1 -r 12

00- - ----€• •0 - - "--" a - 0

0.4 0.6 0.8 1.0 0.4 0.0 0.8 1.0


Figure 35a - Canard C1 on 50- Figure 35b - Canard C1 on 50-

Degree Wing at Position P2 Degree Wing at Position P 3

51


0.3

"- 0 -2. ..

0.3~*w22

0.2

~0.2

+.

0.1 12

0 aoi*Sm -m iO -am

I0.4 0,6 0.6 1.0

MACH NUMBER

Figure 35c - Canard C:1 on 50-

Degree Wing at Position P 6

52


0.3 0,3

~u35 mm 25

-0.2 0.2

0.1 o,'0.1

S0 6"0

'5'" mm =00a. -a2202 mm40.2 6=1 m f

a* 22

0.1 0,1 I 1

0.1 0.

012

0.1 so d -o 60 a-12 0.1

0 0

•am00,1*n -t aw # 0'201 - m m° '

Im m -ii - a., mm a-mm amm mm m m

0.4 0,6 0.3 1,0 0.4 0.6 0.8 1.0MACH NUMBER MACH NUMBER

Figure 35d - Canard C2 on 50- Figure 35e - Canard C2 on 50-Degree Wing at Position P Degree Wing at Position P

3 6

53

Figure 35 .Continue,_

0.4 0.4 8

00

-5 -5

0.3 0.3 •* 10

-25~ e-26

a.: ~0.2 ~

'6 0.1 I0.1

0.2 - 0.2- -22

DECREA.ING DEFLECTION

0,1 0.1 I

0..1 0.1

0 I 0

it -12

o., - 0 - .., -. .... ... .0.1 0,2 c-12 ~ -

0 --. 0.1 -

J.IoI I

0.4 C.6 0.8 1.0 0.4 0.6 0.8 1.0


Figure 35f - Cpnard C3 on 5C- Figure 35g - Canard C0 on 50-

Degree Wing at Position P, Degree Wing at Position P6

54

Wil

Figure 36 -Canard Control Power versus Angle of Attackat Mach Numbers of 0.6 and 0.8

0.02

*0

S0.02 ~oo

p 3p00

0.02 00

002 P3 ON

0 0 P

0 0

C.0 on the2 50Dge ig5-ereWn

55


0.02M - 0.6M-0.8

0 cope

0.02

0

0.02

CoP2 + DEF

0

0.02

CoP3 - OEF

0 16 24

Figure 36c - Canard C0 on the 25-Degree Wing

56

of attack for canards C and C on the 50-degree wing, however, CM,0 1 C

C

decreased for the 25-degree wing. With increasing angle of attack, CMc

decreased for the high aspect ratio canards C2 and C3 . Canard control

I,: power based on positive and negative deflections are presented in Figure

36c for canard C on both models. There are no significant differences0

between the data for either positive or negative deflections until high

angles of attack. At 0 - 25 degrees the positive deflection had a slightly

higher CM for the 50-degree wing and a lower value for the 25-degree wing.6

TRISURFACE CONFIGURATION

The basic pitching moment characteristics of the horizontal tail,

canard, and trisurface configurations are presented in Figure 37 for both

models at M = 0.6. The canard is deflected to -5 degrees on the 50-degree

sweep model. As shown, the canard configuration exhibits no nosedown

break, whereas the horizontal tail configuration breaks the stability at

lift coefficient of 0.73 and 0.93 for the 25- and 50-degree models.

respectively. Angles of attack for the nosedown break are 12 degrees for

the 25-degree model and 19 degrees for the 50-degree model. Stable pitching

moment breaks also occur, however, for the trisurface configurations at

higher lift coefficients and higher angles of attack. In addition, the

magnitude of the pitching moment change is not as severe for the trisurface

configuration as those experienced by the horizontal tail configurations.

In both cases the increase in stability is delayed approximately 3-

degrees angle of attack beyond the corresponding angle of attack of the

horizontal tail.The variation of the incremental pitching moments with Mach number for

the three difference configurations is presented in Figure 38. Data are

presented for both wing sweeps. The incremental moment data for the hori-

zontal tail and the 25-degree wing model are relatively constant with Mach

number, however, this is not the case for the 50-degree wing model. Between"0- and 8-degrees angle of attack, the variation with Mach number ia

57

,L

04

0.3

0.2 -- M 0.2 25215-DEGREE WING a 1 €"2

0.1 ;. J

""11 *+0K

0.1 .•.:o -, lo/ p+aw

i•:,o.,.00 .,""'00"J'.' 00 ,. , /

00 . -0 .0 41• °

M a0.8 • HT

50-DEGREE WING-0.1-

l I tlI . I0 0.2 0.4 0.6 0. 1.0 1.2 1.4 1.6

CL

Figure 37 - Pitching Moment Characteristics of Tail,Canard, and Trisurface Configurations

58

r',•...Nowilr • ~

__ _ _ _ ___4_ __ _ _

0 Ck

44I41

Iit

00 w

fn. I I

4* 0

NMOW

irN 9 10"ifl II *

I-I

o' . (

I III II I

q r•q

relatively constant. At 12 to 16 degrees the model begins to pitchup and

the magnitude of this pitchup becomes more severe with increasing Mach

number. Similarly, after the pitching moment break (a 'ý.19 degrees) the

magnitude of the nosedown moment is increased with increasing Mach number.

The canard configurations show relatively constant incremental moment

variation with Mach number.

The trisurface configuration behaves in a manner simila- to the hori-

zontal tail on the 50-degree wing model, i.e., increasing pitchup tendency

between 12- and 16-degrees angle of attack with Mach number and increasing

nosedown moments with Mach number after the nosedown break. The trisurface

ccnfiguration on the 25-degree model behaved in a manner similar to the

horizontal tail configuration.

To determine the amount of interference between canard-wing horizontal

tail and the incremental changes due to the addition of the separate sur-

faces, Figure 39m is presented. Shown is a comparison of the measured

increment due to the trisurface configuration and the sum of the increments

of the horizontal tail and canard. Data are presented at Mach numbers of

0.6 to 0.8. As shown, the measured increments are consistently higher for

the 25-degree wing than the sum of the increments indicating a reduction

in the moment contribution due to the horizontal tail. This reduction is

perhaps due to a change in wing downwash over the horizontal tail. This

change is a result of the changed loading over the inboard portion of the

wing due to the canard. The trend of the incremental moment with increas-

ing angle of attack is the same for the measured and summed increments,

and the nosedown break occurs at approximately the same angle of attack.

After the break, the curves are approximately parallel indicating that

superposition of individual components is possible.

Similar trends are noted for the 50-degree wing model, however, the

differences between measured and summed incret nts are smaller at low

angles of attack. The nosedown break is shifted to the higher angle of

attack for the measured values rather than for the summed values, indi-

cating changes of the characteristics of the horizontal tail due to the

canard.

61

II

.4 to L .•/ /o - aI -i

/I

62

0% j.S. . . .. , " ;-; ; "iS

The trend with increasing angle of attack is approximately the same

for both measured and summed increments.

In the section on lift it was stated that the close-coupled canard is

a poor trimming device. This is due primarily to two reasons; the first

reason. being the proximity to the wing necessary to obtain beneficial

interference and the second reason being the large increment in drag due

to positive canard deflections at low angles of attack. Figure 40 presents

comparison data between the canard located at three longitudinal stations

and the horizontal tail located at 1.5 wing chords aft of the wing center

of gravity. The geometry of the canard and horizontal tail are the same,

corresponding to canard C.. The data are in the form of CM at lift

coefficients of 0, 0.6, and 0.9. To take out the differences in longitudi-

nal position, the data have been divided by the ratio of the corresponding

longitudinal distance divided by the wing mean aerodynamic chord, kc/c.

At low lift coefficients the tail ham the better ability to generate pitch-

ing moments and it is only at the higher lift coefficients that the canard,

located at position P3 , has an advantage.

The canard at position P3, however, only has a nondimensional moment

arm Zc/ý of 1.0 versus the tail moment arm of 1.5 for position PV. indi-

cating that the horizontal tail is better or equal to the canard even at

the high lift coefficient.

A further measure of the efficiency of the canard or horizontal tail

as a trimming device is the ratio of moment generated to drag produced by

surface deflection.

These data are shown in Figure 41. Here again, the horizontal tail

has an advantage at lift coefficients of 0 and 0.6 until a Mach number of

0.9 is reached. It is only at the higher lift coefficients where the

canards show a distinct advantage primarily due to the large lift loss re-

sulting from tail deflection, which, in turn, causes a large increase in

drag.

Negative deflections of the canard do not cause large drag increments,

and CM is approximately the same as that for positive deflections. Thus,6

the penalty of using the canard for trim is small or can even be slightly

63

I.L

• •= - J . .. . . " " ' " " "" . . . - I ... , ,... . . . . .. =c . . ... ,. .. .. • . 1., ,-, *.'- , . • . .. .. ' - ' .. " - "

- ' HTP8

CON BASED ON

COPS. J POSITIVE DEFLECTION

--- �k CoP7

? 0.01'U

;- - I

.. 0.01 - ,

'I. 13

0. I I

U -r

0•01 .. 2

0 I I

0.4 0.6 0,1 1.0 1.2

MACH NUMBER

Figure 40 - Normalized Control Power

64

6 ~HT Pe

5 1.C

. h_ i cop,

43'0 2

/11

o -U--

3

2k.. - ......

S

0• .4 0.6 0.8 1,0 1.2"• ~MACH NUMBER

:: Figure 41 Control Surface E.fficiency

N ,

,,,. .o

'18

beneficial. The horizontal tail, however, when deflected positively,

generates increased lift and, thus, performance is benefited by small posi-

tive deflections. Data on positive tail deflections are not available for

the two models used in this volume, however, data are available on the F-4

aircraft which indicate significant drag reductions for positive tail de-

flection. These drag reductions are larger than those exhibited by nega-

tive canard deflections. Thus, it is felt that whether the aircraft is

stable (positive canard deflections, negative tail aeflections to trim) or

unstable (negative canard, positive tail deflec.ions) the horizontal tail

is the more efficient trimming device at low-to-moderate lift coefficients.

At high lift coefficients, where negative tail deflections cause large

lift losses and the likelihood of horizontal tail stall is possible due to

positive tail deflections, the canard can be used for trim purposes in con-

junction with the horizontal tail.

The canard, in conjunction with the horizontal tail, improves the

control power of the horizontal tail at moderate to high angles of attack

as shown in Figure 42. Horizontal control power is presented for the hori-

zontal tail on the 25-degree wing model both with and without the canard.

As indicated in the figure, at low angles of attack, CM is slightly re-

duced when the canard is on the aircraft. With increasing angle of attack,

the canard on configuration exhibits larger values of CCM than the canard

off data. This is primarily due to the delay of separation on the main

wing due to the canard. These same data are presented as a function of

angle of attack at Mach numbers of 0.6 and 0.8 in Figure 43.

DRAG

The primary effect of the canard on drag is to reduce wing neparation

thus improving the induced drag of the configuration. The improvement in

"drag is shown in Figure 44. Figure 44 presents the lift-to-drag ratio

variation with Mach number for both 25- and 50-degree models evaluated both

with and without canards. The data are presented at constant lift coeffi-

cients of 0.9 and 1.0 for the 25- and 50-degree wing models, respectively.

66

,"-0,02 -

216-DEGREEWING COP 3

i.% CANARD OOF-- -- CANARD ON

S -0.01 1 2

oI 10.02

--0,01 -0.01

0 ] I ... . 0

W-mm-mm'W a,4•"no

""0,01 -0.. 2 10

0 0

i•,~to o |-, '

OA 0.6 0,8 1,0 0.4 0,6 0,8MACH NUMBER

MACH NUMBER

Figure 42 - Effect of Canard on Horizontal Tall

control Power at Constant Angle of Attack

67

~JL -

(4-

44 F0 t

(4Hw

I 00

0(4

68

As shown, the lift-to-drag ratios (L/D) are relatively constant with Mach

number up to the point where strong compressibility effects occur.

These cumpressibility effects occur at a Mach number of 0.7 for the

25-degree wing model and there is a steady increase in L/D for the basic

25-degree wing model beyond this point. This increase in L/D is primarily

due to a reduction in the angle of attack to obtain C1 0.9. The varia-

tion of acquired angle of attack is shown in Figure 45.

As indicated in the figure, the required angle of attack fox the basic

25-degree wing-body drops off fairly rapidly, whereas, the required angle

of attack for the canard configurations is relatively constant up to a Mach

number of 0.85.

The 50-degree model exhibits relatively constant L/D for both canard

off and OIL zonfiguiations and the angle of attack required is almost con-

stant for the canard. The required angle of attack for the canard off

configuration is beginning to drop off at the higher Mach numbers and as

wac shown in Figure 6 at higher Mach numbers (H '1 1.0). The difference

between canard on angle of attack required and the wing-body angle of

attack will be approximately the same in a similar manner to that of the

25-degree wing at M - 0.9.

The remainder of the discussion on drag will involve canard position,

shape, and deflection and will be presented in the form of minimum drag

coefficient CD , induced drag factor kl, and lift-to-drag ratio L/D.0

POSITION

The effect of canard position on the zero lift drag is presented in

Figure 46 for the 50-degree wing model at Mach numbers between 0.6 to 1.10.

Th~ree positions are represented PI. P3F and P7 as well as the basic wing-

body. As expected from Volume 2, the forward position has the largest drag

value throughout thq Mach number range. Positions P3 (most aft) and P 7

(lowest) have approximately the same value up to M - 1.0 where position P3

has the lowest value.

Figure 47 presents the wave drag of the configurations presented in

Figure 46. This wave drag was determined by subtracting the drag value at

69

LnB

qW

41 co'

LA

A ;ju be

Im.

700

0.06 - We

S.... c0 IP /*0.04

0.2 dof

OA 0.6 Ol, 1.0 1.2

MACH NUMBER

Figure 46 -Effect of Canard Positionon Minimum Drag

0.04[• -,-,.--- we '

,.--. Cop,a -.-- Cops

0.02 Ar-A c*p,

0.4 0.6 0, 1.0 1.2MACH NUMBER

Figure 47 - Effect of Canard Positionon Wave Drag

71

M m 0.6 from the values at the other Mach numbers. The canard at position

P3 has approximately the same wave drag as the basic wing-body, with posi-

tion P1 causing an earlier drag rice. These results were discussed some-

what in Volume 1, and are due to the good fairing of the canard at positidn

P into the overall aircraft area distribution, whereas position P1 caused

a distinct hump in the area distribution.

Canard longitudinal position did not have any appreciable effect on

the minimum drag of the 25-degree wing model as shown in Figure 48. The

canard does, however, delay the drag rise Mach number to a limited extent

on the 25-degree sweep model as shown in Figure 49.

Figure 50 presents minimum drag as a function of canard longitudinal

position at constant Mach number for both 25- and 50-degree wings. Canards

C0 and C1 are used for the 50-degree wing and C0 for the 25-degree wing.As at subsonic speeds drag is minimized at an ic/c of approximately 1.2

which is the location where the canard exposed trailing edge is slightly

ahead of the wing leading edge.

The figure graphically illustrates the penalty which is paid at high

transonic Mach numbers (0.95 < M < 1.10) for poor canard location, unless

the area distribution is modified to account for the canard. This penalty

is on the order of 50 to 80 counts of drag (0.0050 to 0.0080).The effect of canard vertical location on minimum drag is presented in

Figure 51. In general, canard vertical position has a minimal effect on

CD min however, lowering the canard increased minimum drag for canards C0

and C2 on the 50-degree wing model; the lower position had slightly lessor equal minimum drag on the 25-degree wing model.

These trends with vertical position are the same as those observed at

subsonic speeds and discussed in Volume 2.

The effect of canard longitudinal position on the induced drag factor

kit at constant lift coefficient, is presented in Figure 52. Data are

presented for lift coefficients of 0.5 and 1.0 at Mach numbers from 0.6 to

1.1. At the low lift coefficient the forward position P1 has slightly

less induced drag than the aft position P 3 at the low Mach numbers.

72

0.04

0.03

S0.02

I,, -mmmp 1

0.01 -* *pa

0.4 0.6 0.3 1.0MACH NUMBER

Figure 48 - Effect of LongitudinalCanard Position on Minimum Drag

for the 25-Degree Wing

0.04

0.03 - /

0C o3o0

BASIC

0.01

o I I

0.4 0.6 0.6 1,0

MACH NUMBER

Figure 49 - Minimum Drag of the 25-Degree Wing with and without Canard

73

0.03

0.02- M a 0.6" .

0.06M- 1.1 0.01 10-DEGREE WING

•/'C160 P2,3

0.05 1.1 we 0

Figure 50b - Canard C1 on1.0 50-Degree Wing

0.04 - 0.04

/7 1.0'1' }0.03 - . 0.013-"09 _

10.0 7 0. 0 .00.2 O.OAS ......

0.02 0.0.* 0.60.02 m~~s 0.6 c0.0. ________0

0.0 0.

0.01 0.0150-DEGREE WING 25-DEGREE WING

P 1, P3, P7 C060

"P I, P2 , P3

0I I II I I 40.6 0. 1.0 1.2 1A 1.0 0.0 0.6 1.0 1.2 1.4 1.6

Figure 50a - Canard C0 on Figure 50c - Canard C on50-Degree Wing 25-Degree Wing

Figure 50 - Effect of Canard Longitudinal Position onMinimum Drag at Constant Mach Number

74

Figure 51 - Effect of Canard Vertical Position on Minimum Drag

0.03--p 3 S• Pe

0.02 -

0.01

0 I __ _ _ _ _ _ __ _ _ _ _ _

0.03 - 0.03

0.02 - 0.02 ,

0.01 Cl 0.01 Co

oI I a0.4 O.6 0.e 1.o 0.4 0.6 0.3 1.0


Figure 51a - Position of 50-Degree Wing

75


0.04 ,

0.03

10.02 P.i

0.01

0

(0.04

* 0.03

II

0.02

0.01

\Pt

0,01

0 I .i

0.4 0.6 0.1 1.0

MACH NUMBER

Figure 51b - Position of 2 5-Degree Wing

76

0.5 SHTrnm - CP3

CL- 1.0

0.4

0.3- • -''•----. __

o.2- c. .- -1,,0

0.2 CL 054:

0.1

a I I0.4 0.6 0.9 1.0 1.2

MACH NUMBER

Figure 52 - Effect of Canard Position on Induced Drag

77

This trend was also evident in Volume 2, and is due, in part, to the

unfavorable interference of the canard at position P3 at low lift coeffi-

cients. in the Mach number range between 0.75 to 0.95 the aft position had

lower induced drag. Beyond M - 0.95, there is little effect of canard

position.

At the higher lift coefficient, CL - 1.0, the aft pobition has lower

induced drag up to M - 0.95 but beyond M - 0.95 positio-, has little or no

effect.

Induced drag factor at constant angle of attack for canards C0 on both

50- and 25-degree models and canards C1 on the 50-degree model is shown in

"Figure 53. The trends noted for Figure 52 also occur in Figure 53. At low

angles of attack and Mach number, the canard in the forward position has

less induced drag factor than the aft po6ition; however, as angle of attack

is increased, the aft position has the lowest induced drag factor. It is

evident that at speeds near the sonic velocity, canard position has minimal

effect on induced drag factor. The data in Figure 53 show that moving the

C1 canard forward to position P 2 generates lower induced drag factors than

at position P. This phenomena was discussed in Volume 2, and is due to

the fact that position P2 for the 60-degree delta canard C1 corresponds to

position P3 for canard C0 in terms of canard-wing overlap position.

The effect of canard vertical position on induced drag factor is shown

in Figure 54 for canards C0 , CI, and C2 at positions P3 and P6 for the 50-

degree wing and canard C0 at positions P20 P3' P6' and P7 for the 25-degree

wing. Induced drag factor was, in Leneral, increased by lowering the

canard on the 50-degree wing. On the 25-degree wing the canard nearest to

the plane of the wing P' exhibited the highest induced drag factor over

most of the angle of attack range. When the canard was at the proper

longitudinal station t/c % 1.0, lowering the canard improved the induced

drag at high angles of attack.

The variation of L/D with Mach number for the canards at various

longitudinal stations is presented in Figure 55. Data are presented for

maximum lift to drag ratio (L/D)max and L/D at lift coefficients of 1.0

78

-EEEE

A¸.

Figure 53 - Effect of Canard Position on InducedDrag at Constant Angle of Attack

0.5

P1

INORIASING Vie P

mJ 0.4 -a-

0.2 I

OA

0,1J'

0.20

0.3 -

0.2

1..

0.1 . . I

MACH NUMIER

Figure 53a - Canard C0 on 50-Degree Wing

79


OA

058

.2 GA .....~

INCREASING 2/1

0.3 10.2 - - -

CA0.4 O

0,2 0. -

0.3-'--_ 0.2 I

i

0.2

0.0

0.3 -

l0.1

0,1 0.1 - 0-4i

0 1 1 .Li

0.4 01 0.. .0 A 0.6 0.,


"Figure 53b - Canard C on Figure 53c - Canard C0 on50-Degree Wing 25-l1egree Wing

80

Figure 54 - Effect of Vertical Position on Induced Drag Factor

0.1 0.5

p2

OA Gs A

1ra~a' 25w¶*. .20.3 0.3

Co

0.2 I 0.2

0.4 0O 4 --!GA

22 wm-0-00" 0.3 - et' 220.3

!0.2 I . ,

0.3 - 0.3 .hr ._2Ii I, 1 .. . . -

S0.2 - 0._ __ __ _ __ _ __ ___-_ _

I0.2 a- 1212a-s

0.2 a* p ~ r0.2 a4 =mw~m~j= F-ý;.m..

ti0.10, - CIt3

0.11

0.4 0.1 O.0 1.0 0.4 0.6 0..MAC" NUMBiER MACH NUMBER

Figure 54a - Canard COi on Figure 54b - Canard C on50-Degree Win& 50-Degree Wing

81

b..j


0.,

0~ o4 ___ .. f

0,4- -

0.A Ii I

0. 0.0 -.

0. -0.1 ......

0.2

CA 1

0.3 a22'w 1

7" a-12•. ~0.2 l

0.3 -- 06 - - a -0.2

INCREASING z/u

i 12

0.2 -

0,. --

0.1

,i0. Pi - - P•-- PS

0 3

0.4 0.6 0.8 1,0 0.4 0.6 0.8 1.0


Figure 54c - Canard C2 on Figure 54d - Canard C0 on50-Degree Wing 25-Degree Wing

82

m . .

60

Io to-

* ((1r. IMfly 011/4

0

to

to

N.0/-I1I

'A 1K83

and 0.9 for the 50- and 25-degree sweep models, respectively. Figure 55

presents data for the C0 canard at positions P1 and P 3 at hach numbers from

0.6 to 1.1. Presented on the figure are the corresponding canard off

values. The canard located at position P3' most aft, had the highest L/D

except at M - 0.6 where the most forward canard P1 had a slightly higher

value.

Both canard positions had lower values of (L/D)max than the basic

wing-body at Mach numbers up to 0.95. At Mach numbers above 0.95 the

maximum L/D for the canard at position P 3 exceeded the value of the basic

wing-body, thus indicating that carrying the canard at transonic speeds

does not penalize performance. The most forward canard had larger values

of (L/D)max at Mach numbers greater than 1.0, however, the values were

lower than those obtained at position P3.

At the higher lift coefficient, LID was approximately double that of

the basic wing-body for the canard at position P3 at low Mach numbers. As

the Mach number increased, LID remained relatively constant for the canard

at position Py3 The basic wing-body, however, had a rapid increase in LID

due to the aforementioned decrease in required angle of attack in order to

attain CL = 1.0. This rapid increase in L/D brought the value of L/D to

approximately the same value as that of the canard at position P3' The

L/D for the basic wing-body was slightly lower, however.

The forward canard position had lower values than the aft position and

exhibited a rise in L/D between Mach numbers of 0.8 to 1.0 to bring the

value up to that of the aft location.

It thus appears that at high transonic speeds (M > 1.0) and high lift

coefficients, canard location has little effect on performance.

Similar characteristics are shown in Figure 55 for the 25-degree wing

model. For (LID)max the middle position P2 had the highest value of LID,

with the aft position having the lowest value. At Mach numbers up to 0.87

the basic wing-body had larger values of (LID)max than the canard configu-

rations; above this Mach number the middle and aft locations P2 and P had2 3

equal or greater values of (L/D)max*

84

.. A.

LrAt the higher lift coefficient, CL - 0.9, the most aft positi~on

doubled the value of L/D of the basic wing-body. Lift-to-drag ratio falls

off with forward canard movement. As with the 50-degree wing data, L/D is

relatively constant for the most aft canard location. The data for the

other canard locations and the basic wing-body exhibit a rapid increase in

L/D between Mach numbers of 0.7 to 0.9. At the highest Mach number, M *

0.9, there is little discernable difference between L/D for any canard

position or the basic wing-body.

Figure 55c presents data for the 50-degree canard C1 , at positions

P2 and P Position P2 was the optimum position at subsonic speeds and is

also the optimum position at transonic speeds. As indicated in the figure,

L/D is relatively constant with Mach number as was the case of the canard

CO, at position P3 in Figure 55a.

The effect of canard vertical location on L/D is presented in Figure

56. Data are presented for canards CO, C1, and C2 at positions P3 and P6

for the 50-degree model and canard C0 at positions P39 P6 $ P20 and P7 for

the 25-degree model. As at subsonic speeds, lowering the canard reducesboth (L/D) max and L/D at high lift coefficients. The incremental lose in

L/D is relatively constant with Mach number.

CANARD SHAPE

The variation of minimum drag with canard shape is presented in

lLgure 57. The low aspect ratio, high sweep canards C0 and C1 exhibited

the lowest drag throughout the Mach number range presented.Canards Co, C1 , and C2 all exhibit the same increase in drag with Mach

number. Canard C3 had the highest minimum drag and also exhibited an early

drag rise. This early rise is expected and is due to the low sweep of the

canard.

The induced drag factor for the various canard shapes is presented in

Figure 58. As at subsonic speeds, induced drag is minimized by low sweep

and high aspect ratio at low angles of attack and Mach number. With in-

creasing angle of attack the reverse is true; induced drag is minimized by

the higher sweep canards.

85

•'. .. ..... ,* -• •

00

L I IL'-4

W dn

8 a 86

.all

"0

10

C..,

LM

I " I •

#I

k-. 87

- I

- II

87

C3

0.02 C2Cl

I,; IC 0.01P3 -

040.6 0.9 1.0

MACH NUMBER~

Figure 57 - ffact of Canard Shape en Minimum Drag

88

-O 0.4

CI - - - aI

C3 0. 3 -

'OA

"a..

0.2

0.3 w 0.4

INCREASItJGLEADINGEgEa SWEEP al22

0.2 I0.3

0.4 16al

0.2

0.3 - * 22 0.3

0.2 I0.2I

0.32 0.32

0.2 - 0.2-

0.4 .5 0.w.

"0. INCREASING INCREABIAN.LEADING1 LEADING

gol $WEEPEDGE SWEEP

0 .- 1 0.3 1- - d - 1 "

0.0 I I

0.4 0.6 0.6 1.0 0.4 0.6 0.8 1.0


Figure 58a ,Poition P Figure 58b - Position P3 6

Figure 58 -Effect of Canard Shape on Induced Drag Factor

89

The variation of L/D for the various shapes is presented in Figure 59.

Data are presented at positions P and P6 . At both positions the 45-degree3 6

high aspect rario canard had the highest value of (L/D)max up to a Mach

number of 0.8, beyond this Mach number the high sweep canards had a higher

value. The low sweep canard C3 , had a rapid drop off in (L/D)max with Mach

maxnumber due to the aforementioned early drag rise. Behavior of (LID)max, at

low transonic speeds was similar to that described in Volume 2 at subsonic

speeds. Low sweep, high aspect ratio canards perform better. At the higher

CL, canard C2 was slightly better than the other three canards, and canard

C3 was the poorest. There is, however, little difference between any of

the shapes at the higher lift coefficient. This behavior is in keeping

with that observed at subsonic opeeds.

DEFLECTIONThe parameter which has the greatest influence on drag of the close-

coupled canard is deflection. A 10-degree deflection of the canard can

increase the minimum drag of the aircraft by as much as 100 counts (0.01)

thus causing a large reduction in the maximum L/D. In addition, deflection

haM a large infl1aiice on the Induced drag factor. These changes will be

discussed in the following section.

Minimum drag coeffitient CD , as a function of canard deflection, is

presented in Figure 60.

The data are for the C0 canard located at posltion P on both 25- and0 3

50-degree models.

The range of deflections is from -10 to +10 degrees. Figures 60a and

60b present data for the 50-degree wing. As indicated, the increment in

minimum drag is relatively constant with Mach number. Minimum drag occurs

at zero deflection as expected with small negative deflections causing

only a sligat drag increase. Figure 60c presents data for the 25-degreewing. Here, drag due to deflection Is not constant but rather increases

for positive deflections. This increase is shown in Figure 61 where the

incremental drag is plotted against Mach number at constant deflection. A

definite decrease in drag rise Mach number is observable for the positive

90

10-

INCRIAIING C3 I 'CANARD LEADI NG L/bMAXEDGE SWEEP LODqMAI

P6 P

4-

0 4g1.

_ _ _ _ _ _ _ _ _ _ ,i I I ,.

0,4 0.6 0.6 1.0 0.4 0.8 0.1 1.0

MACH NUMBER MACH NUMIBR

Figure 59a - Position P3 Figure 59b - Position P6

Figure 59 - Effect of Canard Shape on Lift-to-Drag Ratio

911

1

S9mltIIi

Figure 60 - Minimum Drag as a Function of Canard Deflection

0.07M 1.1

.1 0.08

0.05 1.0

0,04 -

0.950.9

0.02 0.02 GOP 0.6

0.01 S0-DEGREE WING 0.01COPN 50-DEGREE WING

CoP3

0 - I i 0-10 -6 0 5 10 1i -15 -10 -B 0 6 10

68c 6c

Figure 60a - Positive Deflection on Figure 60b - Positive and Negative50-Degree Wing Deflections on 50-Degree Wing

92


0.04

0.03 /M - 0.180.03S

M0.60

0.I 2DEGREE WINGO

0.01

-10 0 10 20

Figure 60c -Positive and NegativeDeflections on 25-Degree Wing

93

F A,

0.02

0.01 50-DEGREE WING

0.62

0 I 25-DEGREE WING

0.01 6c - +10

01.

0.4 0.6 0.8 1.0 1.2MACH NUMBER

Figure 61 - Incremental Drag Due to Canard Deflection

94

10-degree canard deflection. A slight drag rise is also evident for the

positive 10-degree deflection on the 50-degree wing, however, it is only

about half the magnitude of the rise on the 25-degree wing and not as

abrupt.The second major effect of canard deflection is to modify the induced

drag factor of the overall configuration. Negative canard deflections

reduce the induced drag factor k1 while positive deflections increase kI.

This variation in induced drag factor is presented in Figure 62. The data

are for both positive and negative deflections and the canard is C0 located50at position P3 for both wing sweeps.The effect of deflection on the higher sweep wing is relatively con-

stant with Mach number and decreases with increasing angle of attack. The

25-degree wing shows a larger variation with Mach number primarily due to

the lower critical Mach number. There is also little decrease in the

magnitude of induced drag factor change with angle of attack. From the

data presented, it is clear that negative canard deflections can improve

the overall configuration efficiency.

The majority of the remaining data on indvced drag variation due to

deflection are concerned with negative deflections and are presented in

Figure 63. Data are presented for the four canard shapes at position P3

and canards CO, C1 , and C2 at position P6. The canard C1 is also presented

at position P2" In general, deflection angle was limited to -5 degrees.

Data for the 25-degree wing are for canard C0 at position P6 and posi-

tion P1 for -10 and +10 degrees, respectively. The variation of induced1Idrag factor with deflection is similar to that discussed previously, withone exception. This exception is the data for canard C1 located at posi-

tion P2. This configuration had a reversal in induced drag factor at

angles of attack of 20 degrees or larger. The deflected canard had larger

values of k than the undeflected. In Volume 2 it was shown that there

was a lower gap ratio boundary in which lift was lost. The data from

Figure 19 for this configuration Indicate that there is perhaps an upper

boundary also where the favorable effects of the canard begin to diminish.

The behavior is analogous to a slat in which, if the gap is too large,

95

Figure 62 - Effect of Deflection on Induced Drag Factor

[CA0.4 %

.; 0.2ck ( 17

0.2

"0.4

S• ac

0.3 0-0

a-'12

,•,,----,-.,-

0.2

0.3 [, CANARD C0 , POSITION P3

0.2 * 0.5

0.1 CA a-25

m. 0.3

0.2 0.50.

0.1 0.4A

o 0 ... o0.2 _-0.4 0.6 0.C 1.0 0.6 0.8 1.0


Figure 62a - Deflection on 50-Degree Wing

96


0.30

0.2

0.3.0. - - l

a 120.3

~- ----0.3 -l

0.2

0.2 -5 ma ,f--

-. M m. -..10 oam,INCREASING a - CCANARD CANARD Co. POSITION P3DEFLECT!ON

0.1 0.4

0.3 0- .

S0.3

0.2 0.4 -

0.1 - 0.3 -

. . _. o,* a 22

0.4 0.0 0.o 1.0 0.4 0.6 o. 1.0MACH NUMBER MACH NUMBER

Figure 62b - Deflection an 25-Degree Wing

9I

* .Figure 63 -Effect of Canard Deflection onInduced Drag Factor

0.3

0 .2 a -1 2

.0.

0,2

0.4 -

0.2

0.14O

0.3~ -- mo

0.2 0.4

0..3

01~~~ -4 - 0.-11 02

040.6 0.1 1.0 0.4Ol 0.9 1.0


Figure 63a -Deflection for C 0 p6on 50-Degree Wing

98


OA OA

INCREA8ING DEFLECTION

0,3 a25

0. 22 0.3p"

0.2 Ii0.2

0.3-0.3o.s

O,8- o --

0.2 I Io. -I

*0.20.INCREAOING DEFLECTION

0.3 -I 0.

0.2 •" o.2--

0.3-20.3

0.2 - ~ ~ * 0.2 - - -

",1 IN C R E AIINN I I Z " -" "-DEFLECTION 0.1

0.4 0.6 0.8 1.0 0MCNUBR.00.4 0.6 0.E 0.1

MACN NUMBER MACH NUMBER

Figure 63b - Deflection for Figure 63c - Deflection forC1 p2 on 5 0-Degree Wing C1 P3 on 50-Degree Wng

99

-. . .. ..

Figure 63 (Continued)OA

a29J 0.2- *-22

5C

0

o.i I

0.2

0.38 "'

0.3 1- - -

INCRIASING DEFLICTION0.2 I

0.2 -;

0.2 a.ýmp-t"fif

0.1

0.4 0.6 0.8 1.0

MACN NUMBER

Figure 63d - Deflection forC1 P6 on 50-Degree Wing

I 10


6c0

0=250.4 0.4

au2.5 f.,i '.. - " o,- • '

0.2I 0.2 ....I

0.3 0.30.2 I o,2 I

0.2 0.3

0.3 0.30.2 0.2

0.2 -- -0. __8 __--..*" " "

0.1 0.1

INCREASING DEFLECTION INCREASING DEFLECTION

0r -...

.o__ I I I0.4 0.6 0.5 1.0 OA 0.6 0.8 1.0


Figure 63e - Deflection for Figure 63f - Deflection forC2 P3 on 50-Degree Wing C2 P6 on 50-Degree Wing

101

i"i

Figure 63 (Continued)0.4

S---25 -

0.2 *w2 I0 pa

i6.C

0.

0.2

0.3

0.2 ,-12 _ _ - .

0.3

0.2 I

!0,1 -- -em -ml - -a -m -

INCREASINGDEFLECTION

0 I I0,4 0.6 0.8 1.0

MACH NUMBER

Figure 63g - Deflection forC3 P 3 on 50-Degree Wing

102

NOT.


0.I

6C

aa2

OA 0. - 25 0.4 21~

a21

0.3

OA -04- a1

0.3 a-

0.20.

0.2 -- 0.2 -

a-Um4

am4{ 0.1

oi- 010.4 0.6 0.8 1,0 OA 046 0.8 .MACN UMBERMACH NUMBER

Figure 63h - Deflection for Figure 631 - Deflection forC 0 P 6 on 2 5--Degree Wing C0 P1 on k5-Degree Wing

103

the slat effectiveness is reduced. At present, data are not sufficient to

determine the actual magnitude of the distance of this critical gap height.

The final segment of this discussion on drag due to canard deflection a

is on the L/D variation.

The effect of a positive 10-degree deflection on the maximum L/D for

the 50-degree wing is presented in Figure 64. Deflecting the canard causeda reduction in (L/D) of approximately 30 percent when compared to the

maxnondeflected canard. The magnitude of thiw loss is relatively constant

until the drag rise, when it is reduced significantly due to the large in-

crease of drag on the overall configuration. Thus, the additional drag due

to the deflection is a smaller percentage of the total minimum drag.

Similar trends occur for the 25-degree sweep model as indicated in Figure

65. Figure 65 includes data for both positive and negative canard deflec-

tions for both models. With increasing Mach number, the penalty in L/D

for positive deflections is significantly reduced, this is due, however,

to the large increase in drag due to compressibility.

Negative deflections increase (L/D)max for both wing sweeps. The in-

crease in (L/D)max occurred at both negative deflections on the 25-degree

wing but only at -5-degrees deflection on the 50-degree wing. At the

higher lift coefficients, canard deflection does not significantly change

L/D.

The remaining data on the variation of L/D due to deflection is pre-

sented in Figure 66. Data are presented for canards C1, C2, and C3 at

position P for the 50-degree model and canards CO, C1 , and C2 at position3 CP6'

Canard C0 was evaluated at positions P3 and P6 for the 25-degree wing

model. As in the previous discussion, light negative deflections, 6c " -5

degrees, increased (L/D)max over the (L/D) max of the undeflected configura-

tion. At the higher lift coefficient, deflection made little difference in

L/D for the 50-degree wing. A negative 10-degree deflection at position

P6 for the 25-degree wing model, however, reduced L/D at CL 0 0.9 by 0.5.

This reduction alao occurred at position P for the 25-degree wing as pre-3

sented in Figure 65.

104

I,

~r.we CA 'I we

8- 0 ....... -.-- -

6 -i- - - - - -* %-- --- a• WL/DMAX "'

,C,

4 4-

W0DEONEEWING PCL 0-.

2 p,~ we

0.0 0. 1.0 1.2 04 0.6 0.3 1.0MACH NUMBIR MACH NUMSCR

Figure 64a - Positive Canard Deflec:tion Figure 64b - Positive and NegativeDeflections :

Figure 64 - Effect oi Conard Deflection on Lift-to-DragRatio for the 50-Degree Wing

,I

1'1

100

12/

La. 0.

100

AFigure 66 - Effect of Canard Deflection on Lift-to-Drag Ratio

i 64

II

0

Cap 10

LlOMAX

6 Io

t

I S.

4 4

CL * 1,0

2 weB

CL 1.0

0 _0.4 0.0 0.6 1.0 4 , L.0SMACH NUMB ER .00.8 1.0MA-Cn NUMI on

MACH NUMBER

Figure 66a - Canard C0 on Figure 66b - Canard C on5:-Degree Wing 5 0 -De~ree Wing

107

!0


P$60

P06¶0

•;' we

C2 C3

4 44

CL 10. CL "1,0

2 -2

o . ... I , I o I I0.4 0.6 0.6 1C.; 0,4 0.6 0.1 1.0


Figure 66c - Canard C2 on Figure 66d - Canard C3 P3 on50-Degree Wing 50-Degree Wing

103


14 141

8--l

f 10 -10

a - 10

CL *

80 CL '0-9

5 - 1

6--0

2

CL C 0 0 -

04 0.5 0.8 1.0 0.4 0.6 0.3 .


Figure 66e - Canard C0 P6 on Figure 66f - Canard C P on0 6 0 125-Degree Wing 25-Degree Wing

109

TRISURFACE CONFIGURATIONS

The carrying of a canard on a normal aircraft configuration consisting

of wing-body-tail incurs a drag penalty. This penalty is primarily due to

friction drag or C . This penalty is shown in Figure 67. The configu-Dmin

rations presented in Figure 67 are that of the basic wing-body, wing-body-

tail, wing-body-canard, and trisurface configurations. Data are presented

for various canard and horizontal tail deflections for both wing

configurations.

As with the canard alone, adding the canard to the wing-body-tail

configuration causes a small drag increment which is relatively constant.

This increment is slightly smaller than that due to the canard alone,

thereby indicating that the canard is reducing the drag of the horizontal

tail.

This increase in minimum drag due to the addition of the canard is

offset by the lower values of induced drag f.actor of the trisurface con-

figuration which is presented in Figure 68. This reduction is most signifi-

cant at the higher angles of attack, where the trisurface configuration

had consistently lower values of k1 than the canard alone at angles of

attack of 16 degrees or better.

The penalty in minimum drag caused by the additional surface results

in a reduction in maximum L/D as shown in Figure 69. The data in Figure

69 are untrimmed and, as will be discussed in Volume 4 of this report when

the configuration is trimmed, the penalty in (L/D)max due to carrying the

canard can be reduced almost completely. At the higher lift coefficient

there is no penalty for carrying the canard and the trisurface aircraft

has approximately the same value as the canard alone.

The data in Figure 69 are at O-degree tail deflection. In order totrim at higher l1ft coefficients negative tail deflections are required

for a stable configuration. Lift-to-drag ratios for the wing-body-tail

and trisurface configuration at tail deflection of -10 degrees are pre-

sented in Figure 70. As shown, adding the canard to the configuration in-

creases L/D by approximately 50 percent for both wing sweeps.

110

"Figure 67 - Comparison of Minimum Drag of Canard,Horizontal Tail, and Trisurface Configurations

W0-010111 WING

0.04 -

C. NY

0.02I--

SC .6j

0.4 0.6 0.6 1,0

"MACH NUMSIA

Figure 67a. 6 0, 6" -5iH T

SO-DEGRAE WING

0.06

1 0.04

HT +C

MACH NUMBER

Figure67b6 -- 10,6c -0:• AH NUI c

111


NY0.04

3;H-D|ONIII WING

a II0.4 0.' 0 .1 1.0

MACH NUMEIR

Figure 67c - 0, 6c -THc

0.0O

:1-D10"ll WINGJ

8"00I I _0002 0

Figure 67d - --10,6$ 0<1s O 1.0H T C,

112

Figure 68 - Induced Drag Factor for Canard, HorizontalTail, and Trieurface Configurations

- HTPg80

0.5 m~-COP 36.6HTPe8o4CoP3 6..*

OA -

50-DEREE WING

CA ~ .250. ---

0.3

t0. ari oil

a1 * 12 aI 1

*-113

S0.2 also 0.4

a4

0.10.

0-22

0.4 0.6 0.8 1.0 0.4 016 0.3 1.0MACH NUMBER MACH NUMBER

Figure 68a -Induced Drag for 50-Degree Wing

113

r


TRI8URFACE 5-.DEORIE WING

li CoP• 0.4

COPS + HTPo

0.3

0. 4 - 4I ft'% *Ma

0.3 0.4

0.2 -12 C\

0.2

4,

0.1 a-4 0.4 -

S, , o,?O... e,0 0.1.0.4 0.6 0.3 1.0 04 0.6 O.E 1.0

MACH NUMBER MACH NUMBER "

Figure 68b -Induced Drag for 25-Degree Wing

114

EI

14 14TRISURFACE 25-DEGREE WING0-D.)EGREE WING COP360

om.iiCoPa8.4 HtP880

12 12 .... TPUO, COP•8 HNTPo60CoP38-- + NTP86 0 1W

HT

10Ca 0

We &UMJMSLLJUi AuA...4,, 0 -- 10 , HT HT

6 a;i~4 C + H7 , .

4 C -Hr040,.o

,No,, CL O,6

2,a CI

We

,,I ._I, I , I_OA 0.6 0.8 1.0 0.4 0.6 0.3 1.0


Figure 69a -Lift-to-Drag Ratios for Figure 69b - Lift-to-Drag Ratios forS50-Degree Wing 25-Degree Wing

Figure 69 - Lift-to-Drag Ratios for Canard, HorizontalTail, and Trisurface Configuztions

11.5

C+HTr

2_

CL m 1.050-0EGRIE WING

0 0.6 0.6

4

C + H1- ,,, i,, i.,,,.,., ,

SHTCL -0.9

26-DEGREE WING

00.4 0.6 0.8 1.0

MACH NUMBER

Figure 70 - Lift-to-Drag Ratio& at CL - 1.0 and 0.9 for

50- and 25-Degree Wings, Horizontal Tail, andTrisurface Configurations with Horizontal

Tail Deflected -10 Degrees

116

BUFFET

The close-coupled canard has a favorable effect on buffet onset lift

coefficient and intensity. Both 50- and 25-degree sweep models were fitted

with wing root bending moment gages, and root mean square (RMS) values of

wing bending moment were taken.

A discussion of and means of obtaining these data are given by4

Ottensoser. He indicates that the canard had little favorable effect on

the 25-degree wing primarily due to the early onset of buffet (B.O.) caused

by the low wing sweep. The present discussion will, therefore, be limited

* to the 50-degree sweep model.

Several methods are available for obtaining the buffet onset lift

coefficient. These methods include RMS data, axial force data, and lift

data. With an actual aircraft, RMS data can be taken in small increments

at constant load factor, one "g" in most cases, and buffet onset can be

reasonably determined. In the wind tunnel, however, in order to obtain one

" itg condition, i.e., constant normal force with varying angle of attack, it

is necessary but not practical to vary the dynamic pvessure. Thus, RMS

data for a tunnel model does not give a true indication of wheu buffet

onset actually occurs, but rather an indication of the dynamic contribution

of a varying normal force. In addition, for a wind tunnel model, the

tunnel turbulance and compressor acoustics can excite the model.

The axial force characteristics often used for buffet onset determi-

nation include the zero values of the first and second derivatives of axial

force with lift coefficient BCA/8CL and a2CA/aCL. An additional means of

buffet onset determination is the deviation of the actual lift curve from

the ideal or low angle lift curve slope. It is this method, in conjunction

with tha axial force methods, which has been used to determine buffet onset

lift coefficient in this report.

Buffet onset lift coefficient is taken to be that value which deviates

5 percent from the predicted low angle of attack value. The lift cu1-ve

slope for prediction was taken between 0- and 5-degrees angle of attack.

An example of this technique is presented in Figure 71 for both baslc

wing-body and canard-wing-body. Shown in the figure are the axial force

variations for both configurations and the values of aCA/ CL - 0 and

117

1.0 We wECP 381 /I S~ PERCENT DEVIATION //

CIaETEE7 0, +4 DEGREES

5 r-RACENT DEVIATION

act

3 12 IS Mr 0 -0.020.02~.ANGLE OF ATTACK IDEOREESI) CA, AXIAL COP FIRICIENY

I:.Figure 71 -Comparison of Lift Curve Deviation and AxialForce Techniques for Buffet Onset Determination.

118

a2CA/C - 0 for each. As indicated, the lift curve deviation method gives

A Lvalues of buffet onset lift coefficient approximately the some as those at

the second derivative zero values and lower values than the first derivationA.

values. The incremental difference between each method, however, is

approximately the same (0.2 < AC < 0.3). Thus, while the exact buffetB.0.

onset lift coefficient may not be known, it is felt that the observed

trends are valid.

The effect of canard position on buffet onset lift coefficient and

angle of attack is shown in Figure 72. Data are presented for canards C0

and C2 at positions P 3 and P 6 and for canard C1 at positions P 2 ' P3, and

P6" The deflection angle is -5 degrees for all canard shapes. As indi-

cated in Figure 72, buffet onset lift coefficient and angle of attack are

larger for the canard configurations than for the basic wing-body. The

magnitude of this increase rapidly diminishes with Mach number, however.

In general, the high-aft position P 3 gave better results than the low

position P 6' iThe increase in buffet onset lift coefficient varied from a AC' of

L0.40 at M - 0.6 to 0.10 at M - 0.9. It should be noted that these data

are based primarily on the 5-percent lift curve deviation.

The axial force criteria give larger improvements for che canard on

data as shown in Figure 73. Figure 73 presents the variation of BCA/ 3CLwith lift coefficient for Mach numbers 0.6, 0.7, 0.8, and 0.9. Canard

on and off data are both shown. As indicated, the range of aCA/aCL w 0.0

is between CL's 0.73 and 0.44 for the basic wing-body versus a range of

1.16 to 0.84 for the canard configuration.

This range is shown in Figure 74. The axial force criteria predicts

a larger, more constant increment in buffet onset lift coefficient than the

lift deviation method; this increment is on the order of 0.4. It thusappears that the data in Figure 73 are somewhat conservative in determining

the buffet onset C1 particularly at the higher Mach numbers.

The effect of canard shape on buffet onset is presented in Figure 75.

Data are presented for the four shapes at position P 3' At low Mach

numbers the higher sweep canards generated the highest buffet onset lift

119

Figure 72 - Effect of Canard Position on Buffet Onset LiftCoefficient and Angle of Attack

01.2 .1 .

p 3

pg \a.,

0.4

074 0.6 0.1 1.0 CA CIO 0.8 1'.0MACH NUMBER MACH NUMBER

Figure 72a -Position for Canard C 0

P2

1. - -P-1

1.0 C16-5 12

ci .s - ,4

0.\,

0.4- I0.. I0.4 0.6 0.6 1.o 0.4 .06 0.6 1.0


Figure 72b - Posttion for Cenard C1

120

•... - .,0--...--

:'t'


. 16

1.0 12

0..

0.,4 - 11

* 0.4 I0'I0.4 •.6 0* 1.0 0.4 0.6 0.- 1.0


* Figure 72c -Position for Canard C2

121

-0..

"-4A - M 0.7 -0.?

-OA CANARD OFF-0.3 -4.1 4 - - 0.3CANARD ON

S-0.3 \ 03- .

-0.1 0.- f .82

0.1 0

0.2 0.80.1

CL, LIFT COEFFICIENT 0.2 0-0.5 0.2 I% 01104

- /. M 04O CL, LIFT COEFFICIENT

NI M 0.

.-.3I -0.3

-0..1

0.1 0.1 1.-

0 0.4 0.5 1.2 0 0., 0.,

CL, LIFT COEFFICIENT CL, LIFT COEFPICIENT

Figure 73 - Variations of Axial Force Slope with Lift Coefficient

1 32

%!A--

0A CANARDI

GAW --0I .I

0.6 0.8 1.0

MACH NUMBER

Figure 74 -- Comparison of Buffet Onset LiftCoefficient Based on Axial Force Criteria

for Canard and Wing-Body

16.1.2 2

0.6 B.J.

0.6 -

GA 0 I0.4 0.6 0.6 1.0 OA 0._ .. 8 1.0


Figure 75- Effect of Canard Shape on Buffet Onset LiftCoefficient and Angle of Attack

123

$ '

,'rw- -f-&-, -

coefficient. As Mach number is increased, the lowest sweep canard C3 per-

formed best. This is due to the fact that canard C has the highest values3

of CLa at low angles of attack (Ot < 12 degrees), thus higher overall con-

figuration lift coefficients are possible. Angle of attack for buffet

onset is not significantly different for any of the canards at high Mach

numbers. In an overall sense, canard C2 performed best.

Canard deflection is presented in Figure 76. The negative canard

deflection configuration had lower values of buffet onset lift coefficientover most of the Mach number range based on the lift curve deviation

method presented. Based on the axial force criteria this was not the case.

Positive canard deflections exhibited very little negative change in

axial force with Increasing lift coefficient, whereas negative deflections

exhibit reductious in axial force. This difference in axial force behavior

may be due to flow separation of the canard when positively deflected.

Thus the canard itself may be buffeting at an early lift coefficient,

whereas the canard is still preventing separation of the main wing.

The last data on buffet onset to be presented are shown in Figure 77.

Comparison data on the horizontal tail and canard are presented. As

shown, the presence of the horizontal tail has little effect on buffet

onset lift coefficient whereas the canard has a significant effect. Thus

the increase in buffet onset lift coefficient is net due merely to the

additional area of the canard or horizontal tail, but rather due to the

favorable interference between canard aid wing.

BUFFET INTENSITY

It was mentioned earlier that it is often difficult to estimate buffet

onset from RMS data in the wind tunnel. The RMS data does, however, give

an excellent representation of the buffet intensity. Since the model Inthe wind tunnel is not at constant load factor, or in nonturbulent air,

incremental buffet intensity will be presented. This incremental intensity

*i was obtained by subtracting the RMS value at zero lift coefficient and

dividing by half the total value of the lift force on the model, lift -

qSw CL/ 2.

124

S. . . .' t m m i i Ii i

1.2 1s

•.a -+ we -

8 -0

0.4 a.. . 1.0 4 .0.4 0.6 " 0!, 1,0 AJ 0.6 0,8 ,,0

MACH NUMISR MACH NUMBER

Figure 76 - Effect of Canard Deflection on Buffet OnsetLift Coefficient and Angle of Attack

1.01

we21.o-0 12--\:

a'0.3

0.4 4

0* MACH NUMBER 0MACH NUMBSER10

Figure 77 - Comparison of Buffet Onset Lift Coefficientand Angle of Attack for Horiz.ontal Tail, Canard,

and Basic Wing-Body

125

o,, .. - ., -*

It was found that the data from the four Mach numbers evaluated for

each configuration when plotted as incremental RMS, collapsed into a single

line, albeit with a deal of scatter. Examples of this form of plot are

shown in Figure 78 for the basic wing-body and the wing-body-canard.

The following discussion is based on the mean value curve of the

various configurations.

The plots fror /a'sich the mean lines were obtained are given in

Appendix B. Actual RMS bending moment values are given in Reference 4.

A comparison of the buffet intensity between the canard, wing-body and

horizontal tail is given in Figure 79. Data are plotted both as functions

of CL and angle of attack. As shown, buffet intensity is reduced for the

canard configuration when compared with either basic wing-body or wing-body-

horizontal tail. This is true, whether plotted versus angle of attack oz

lift coefficient. Thus the canard configured aircraft can pull higher load

factors for equal buffet intensity.

Canard position had only a minimal effect on buffet intensity (as

shown in Figure 80) for canard C0 . Strong influences arc shown for the

high aspect ratio canard C2 , where lowering the canard had a beneficial

effect. Similarly, moving the canard aft improved the buffet intensity

for the 60-degree canard C1 .

Figure 81 presents the effect of canard shape. The 45-degree canard

C0 had the lowest level of buffet intensity over moat of the CL range

evaluated; however, intensity increased rapidly in the CL range between

1.0 and 1.3. Beyond a lift coefficient of 1.15 the low sweep canard had

the lowest level. Data, however, arc not available for this canard beyond

a CL of 1.28.

Positive deflection of the canard appears to have a beneficial effect

on buffet intensity as shown in Figure 82. Data are, however, insufficient

to verify this effect in further detail.

126

L. ~ ..... ~¶r1:'zu::I

*r a 0.16 -

* 0.06

01 0.2w4OP6.

•;~0

WB

0.06

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

CL

Figure 78 - Incremental Buffet Intensity for BasicWing-Body and Wing-Body Canard

127

" I. . .. . .• I ' i-•,

0.24

0.16

-- 40o 12 16 20 24 26

0,24

KwZ-- / / '0.06 000-00

0,8 -,-" *.* --------

0.2

0.0.4.60. 10 1. ,

CL

Figure 79 - Comparison of Incremental Buffet Intensity for

Horizontal Tail, Canard, and Wing-Body as Functionsof Lift Coefficient and Angle of Attack

128

..........................

i.£ , /

*IPiNC OF P0ImoN

0 .FP

Figure 80 -Effect of Canard Positi0n on Increm.ntal

Buffet Iftnety,,

129

C . ;, a

* .0.06 - $wow'-* OP1EA I

0.0

0 0.2 0O4 0.6 0.6 1.0 1.2 1.4

Figure 81. Effect of Canard Shape on Incremental Bufifet Intensity

0.16

0.06

0.

0.2 0.4 oll 0.1 1.0 1.2 1.4 1.6CL

Figure 82 -Effect of Canard Deflection on IncrementalBuffet Intensity

130

SUPERSONIC SPEEDS

The. previous discussion in this volume was based on three wind tunnel

entries in the DTNSRDC 7- x,10-foot Transonic Wind Tunnel. The data to be

discussesd in this section were obtained in the DTNSRDC 18-Inch Blovdown

Supersonic Tunnel. Data were taken at Mach numbers of 0.67, 1,88, and 2.48.

The model used was a geometrically similar half model of the 50-degree

model. Both canard and horizontal tail were evaluated separately and in

conjunction with each other. Canard and horizontal tail shapes were the

45-degree truncated delta canard, C0. No variation of position was

attempted and the canard was located at position P3. Horizontal tail was

located at position P9.

The raw data, from which the previous analysis at transonic speeds

was obtained, has been publishid.I1- The supersonic data, however, have

not been published; therefore, both incremental and complete coafiguration

data will be presented in this section.

Lift, drag, and pitching moment of the basic wing-body, wing-canard,

and wing-tail are presented in Figure 83 at Mach numbars of 1.88 and 2.48.

In contrast to the data at subsonic and transonic speeds the canard has

less lift than the horizontal tail. The horizontal tail generates more

than double the incremental lift at M - 1.88 and no incremental lift isevident for the canard at M - 2.48. Examination of the pitching moment

shown in Figure 83c indicates, however, that the canard is lifting duo tothe forward shift in neutrai point. It thus appears that the shock wave

interference between canard and wing causes a significant lift loss on the

main wing. Similarly, this loss in lift causes an increase in drag as re-

flected in the lift-to-drag ratio data presented in Figure 83b. The hori-

zontal tail is clearly superior in performance at both Mach numbers.

The only significant incremental data which can be obtained from

Figure 83 are those of incremental moment which are presented in Figure 84.

As iihown, incremental moment slope is relatively linear at both Mach

numbers.

Stability characteristics in the form of center of pressure, CM/CN,

neutral point DCM!/CN and pif:ching moment slope CM are presented in Figure

85. As shown, the center of pressure shift for the canard is approxnmately

131

r

Figure 83 - Longitudinal Characteristics of the Canard,Horizontal Tail, and Wing-Body at H - 1.88 and 2.48

0

J. W14T _0

08 - W 0. 4 - W NT

CA. - 0.4

0.2 -. -

Mc 1.3 M - 2.4

0 4 12 l 0 4 8 1 16

Figure 83a - Lift

0.6 w - 0.8 6

SWHT\

wc\

,'y 0.4 - CA 0,4 _/i/.0.2 0.2 -

M - 1.66 -M2A8

0 0 - 00wo ! ! , ,o- -- 'rI 0 _

0 1 2 3 4 0 2 4LID LtO

Figure 83b - Lift-to-Drag Ratio

132

I •, I, i


0. 1.M

M * 2.48 W

j 00 -0.04

-0.08 -0.12 -W

\,WH., r

-0.121 -0.16 1I0 0.2 0.4 0.6

CL-0.20

-0.24

-o , . .. . .. l0 0.2 0.4 0.6 0.0

CL j

Figure 83c - Pitching Moment

11133 :

j•

.... ....... - ....

0.05 -.M I'm ,- W M m 2.41.wc-wwc-w

0.04 ml 0 0.04 --

X---110

-0.04 00

-0.0 - -0.8U

WT-W-0.12 -o,1,12-U 20 4 8 12 IS 4 a 12 Is

a a

Figure 84 - Incremental Pitching Moment of Canardand Horizontal Tail

"134

• .

rmm,. WHT

- n WC0.01 0.01

M w 1.88 .- M- 2.4

0 0 op- ~ .~m

K 0.02 002

0.2 0.2

0 0

-0.1 -0.0

-0,.4 I •-0.40

S0.1 0.1

0 a

" i at o McN b s f .

.0.4 -0..o

Figure 85 -. Stability Characteristics of Canard Horizontal Tail •anC, Wing-Body at Mach Numbers of 1.88 and 2.48 ,_

135

the same at both Mach aumbere and is parallel to the basic wing-body.

Similarly, the neutral point shift due to the canard is approximitely

constant with Mach number. This is not the case for the horizontal tail as

indicated in Figure 85. Figure 86 presents the incremental changi in

neutral point for both canard and tail. The canard is relatively constant.

The contribution of the horizontal tail, however, is reduced with increas-

ing Mach number. The data in Figure 86 have been normalized wlth respect

to moment arm and are presented in Figure 87. At the low Mach numben the

horizontal tail is the more efficient stability modifying device. This is

also true at the high Mach number but to P lesser extent.

The majority of the data taken from the supersonic wind tunnel program

were based on the trisurface configuration and the basic characteristics

of this configuration are presented in Figure 88. Data are presented for

Mach numbers of 0.67, 1.88, and 2.48.

The lift data at all thret: Ma-h numbers are similar to data discussed

previoxusly. At the low Mach number the canard has a significant affect by

increasing lift, however, at the supersonic Mach n'Lmuers very little incre-

mental lift is being generated. SinilArly, lift-to-drag ratio is increased

by the presence of the canard at lift coefficients greater than 0.45 at

the low Mach number but little change is noted at the higher Mach numbers.

Incremental lift and moment are presented in Figure 89. As shown,

both incremental moment and lift decrease with increasing Mach number.

Pitching moment does not decrease at the same rate as incremental lift

thereby indicating the cLnard is causing a lift loss on the MZin wing.

The model used in vbtaining these data was a half-model. By using t'-e

rolling moment gage of the balance it is possible to obtain Lhe latý_r.l

center oL pressure CJ/CN of the configuration. This variation iG presented

in Figure 90.

At the low Mach number (M-0.67) the late:al C is fui.ther out for theP

canard off configuration up to a normal force coefficihnt of 0.6. Be>ond

this value of normal force coefficient the canard on configuration has the

largest value. In general, as the stall on a swept wing progresses the

lateral center of pressure moves toward the wing root at,.l the wing becomes

lews efficient. It can be seen, however, that the canard delay,: this

136

-- M- 1.8

M 2.480.2 -.-

CANARD

•o<)

-0.2

-0.41 S I0 4 812 is

Figure 86 - In•remental Neutral Point ChangeDue. to Canard and Horizontal Tail

M" 1.88

w Ow "a - TAIL

-. CANARD

M -2.46

K 0.2w- TAIL

I ~~~CANARD\IoI , I L. ...0 4 8 12 16

Figure 87 - Normalized Absolute Incremental Neutral Point Change

137

Figure 88 - Longitudinal Characteristics of Horizontal Tailand Trisurface Configurations

Ii ~~~LATEAAL POSITION_________________________

WHP6 M, 0,67

14 NTP40 PY3o 0

#40

12.•

1.0

0.4

0.2

0 4 12 18

S 16 20is t 24

Figure 88a -U~ft

138


r EFECT OF CARRYING CANARO

IAI14.4

WH.rTP960

SiIIWHTP060 +CoP3I60

1.2 - \%

0o.a

0 .1

I

M. 2.48 M .. ".M. 0.0

0.2-

1 2 3 4 7L/D

Figure 88b - Lift-co-Drag Ratio

139

~~~~~~. .. . .. ., , .•. . . .~il~ z ; ,' ..:

S__ . U. .. . ... .!... . .

.,q


0.11

0.12.- WHTP96 0 * CoP 3 60 WHT

' 0.08 3 0

/ ~~M.O."7~

0.04 - 0

~/Slow

I0

-0.0 - M -248

J7 WH,

-0.12

-0.16 - 0.67

-.0.20

-0.24 M 1.88

-0.29 I I I0 0,2 0.4 0,9 0,8 1.0 1.2 1A4 1.6

CL


140

0.4

0.2

MnY INCREASINGM2.41 8 MACH NUMBER

0 1 # 1 1d -j

0 4 8 12 Is 20 24 U 2

Figure 89a -Incremental Lift

0.34

M -0.6

0.20

0.16 - VCT - WT

0.12

0.08

M -15

0.04 ..-- M -2.48 INCREASING

- - MACH NUMBER

Figure 89b - Incremental Pitching Moment

Figure 89 -Incremental Lift and Pitching Moment Due to Canard

141

r .,-

ia

II SI - ,I

WI

3/ 0

II I-I

I)N /,.

/4

aj

inward movement of the center of pressure to higher normal force values.

As Mach number is increased, little canard effect is noted on lateral center

of pressure and at the highest Mach numbers the effect is detrimental. The

canard on data also indicates an oscillatory change in lateral center of

pressure with increasing CN. The exact cause of this oscillatory change is

unknown but may be due to the changing position of the canard trailing edge

shockwave on the main wing.

The stability characteristics of the wing-body-tail and trisurface

configurations are presented in Figure 91. As expected, installation of

the canard moves the center of pressure forward at all Mach numbers as shown

in Figure 91. Similarly the canard causes a forward movement of the air-

craft neutral point as presented in Figure 91b. Examination of the varia-

tion of neutral point and pitching moment slope indicates the surprising

result that there are regions of angle of attack where the trisurface con-

figuration is more stable than the canard off configuration. This is shown

most clearly at the low Mach number between 27- and 31-degrees angle of

attack and at lower angles of attack with increasilLg Mach number. This

increase in stability is due not only to delay of flow separation over ths

outer wing panels but also to a modification of the downwash over the tailthereby delaying the horizontal tail stall angle.

The effect of canard deflection at supersonic speeds is presented in

Figure 92. As at transonic and subsonic speed, deflection has little

effect on the lift characteristics.

Zero lift drag is increased by both positive and neg&tive deflections

as shown in Figure 92b, however, with increasing angle of attack drag, due

to negative deflections, is negligible.

Negative deflection caused a lower incremental change in moment than

did the corresponding positive deflection at M - 1.88. At M - 2.48 the

incremental change is approximately the same for either positive ornegative deflection.

Canard deflection has only a minimal effect on the stability charac-

teristics of the configuration as shown in F~gure 93. Negative deflection

tended to make the stability more oscillatory in nature than did the posi-

tive deflection.

143

Figure 91 - Stability Characterieticm of Horizontal

Tail and Trisurface Configurations

- - - W H V C

r - -n.• -, nn-

-0.2.

M M IN

.o. 1 I ,Is Is n I2 , .a

Figure 91a - Center of Pressure

"144

... ... ... . .. . ..,, ,-

.

Figure 91 (Continued)0.0

.....--. WrHC

-WHT

OA -

0,-

0

_•.-; -.,4 - I-". ,W

-0.6

0 12 10 20 26 U 32 1

Figure 91b - Neutral Point

-L - -WH 1 C

-WN 1

• "r'' i UNIT ABII'

0.01 OO M- -,40,01 - ' •"

-0.02 - M I. STAILI

0 4 I 12 1 20 24 26 32 36 40

Figure 91c - Pitching Moment Slope

145

Figure 92 -Effect of Canard Deflection on theLongitudinal Characteristics

CANARD DIFL. AT SUSPKNIBON OPEEDS

0.6 ac +~10-

0~0.4

M - I'

0.26

0..4.1

ri.ur Beb - Dag

A. 146

.............

M-1.0- M 2.4


0.06M- -

M * 1.43 aft-ý e -.10

h. -8a .10"0.04 ,

M * AS

-0.34 -

%b%

"0.12.

-0.16

-0.20

-8.24 __ _ _

0 0.2 0.4 0 0.2 0.4 0,ICL


147

r"-'"T-im' -" ........ ..J'i" J' i 1 ..... "' "l i:"! .. .. . ... .. .. . .. .. .

04

- 0- - - 10

-0.02 Z

0S0.-, -10

M.Ae

0 0-

WN1C

• -- -. - -.

-a,. -0.2

-0...- -0.

0 .. ,, 2 Is 204,,I

Figure 93a - M a 1.88 Figure 93b - M - 2.48

Figure 93 - Effect of Canard Deflection onStability Characteristics

146

. . . 2: '- l ,. ., .. . ... . .. ... .. .... , , ..... "

10

* \CANARO

17TAIL M IM

4 M 2ASw 4

M"~204 M1

SCANARD a M-2.48

2 M-2.41

GA. 0.' 0 0.2 OA .0.!(f0 4120, CL

CLEfficiOUCY re 95 - Normalized Trim EfficiencyFigure 94 T rim &~~inc iur

.1 .

i °-"- ---" --Sw46 CANARD

•" ,-0.3-

Wi TAIL

. 0. a ll 1.2 1.4 1,* 1. 8

MACH NUMBIR

Figure 96 - Neutral Point Variation !or Canard, Uorizontal Tail,

and Win&-Body at Mach Numbers from 0.6 to 1.88

7 149

.-.-..-.-----.----.----.--.--

A comparison of the trimming efficiency of the canard and horizontal

tail is presented in Figure 94. Data are for positive canard deflection

and negative tail deflection; the deflection angle is 10 degrees for both

tail and canard. The efficiency is equal to incremental moment divided bydrag due to deflection /CM Over most of the lift coefficient range

the horizontal tail is the superior trimiing device. This is particularly

-rue at M - 2.48.

Normalized trim efficiency is presented iG Figure 95. At H - 1.88 the

canard is superior to the horizontal tail, however, at M - 2.48 the canard

is inferior. The canard exhlbita a large decrease in surface efficiency

with Mach number, due perhaps to canard-ifing shock interaction. The hori-

zontal tail has only a minimal decrease in surfaue efficiency with Machnumber.

The final data to be presented arc frow the transonic section of this

volume and also include supersonic data and are shown in Figure 96. Figure

96 presents the variation of neutral point (B/•cL) evaluated at a lift

coefficient of 0.0 with Mach number. The configurat~ons represented are

the basic wing-body, wing-body-tail and wing-boei-nanard. As shown, therate of neutral point shift with Mach number is ..,proximately the same for

both wing-bod, and wing-body-canard.

The horizontal tail configuration, however, becomes slightly more

stable (Wh-0.04c) between subsonic and supersonic speeds.

SUMMARYThe preceeding volumes of this report have enumerated certain improve-

ments on the lift, drag, aný pitching moment due to the preoence of a

close-coupled canard on the basic aircraft characteristics at subsonic

speeds. These improvements also occur at transonic speeds albeit somewhat

modified. In general, the effectiveness of the canard in increasing lift

and decreasing drag is reasonably independent of Mach number at Mach

numbers below that Mach number where strong compressibility effects occur.

When strong compressibility effects are present, the magnitude of the aero-

dynamic improvements diminishes with increasing Mach number. When true

150

supersonic speeds are reached M > 2.0 the effect of the close-coupled canard

on the aerodynamics is negligible and, in fact, may be unfavorable.

The effect of such canard variables as position, shape, and deflection

on lift, drag, pitching moment, and buffet at transonic and supersonic Mach

numbers is given below.

LIFT

1. Increasing Mach numbers had little effect on the canard configura-

tions, but increased the lift at constant angle of attack for the canard

off configurations. The Mach number at which this occurred was a function

of the wing sweep angle.

2. The canard position which optimized lift at subsonic speeds also

was the best position at transonic speeds. Position does not, however,

have a strong influence when strong compressibility effects are present.

3. High sweep canards maximize lift.

4. Lift changes due to canard deflection are relatively constant with-- Mach number.

5. Shock wave interaction between close-coupled canard and wing

caused lift losses to the wing at supersonic speeds.

PITCHING MOMENT

1. The rate of neutral point aftward shift with Mach number is

approximately the same for either canard on or off.

2. Incremental moment due to the canard decreased with increasing Mach

number at high angles of attack. This behavior was particularly severe

for forward mounted canards.

3. When the canard was located close to the wing (Zt/c"_O), the pitch-

ing moment effectiveness was severely reduced with increasing Mach number.4. For canards located further forward or lower than the optimum

position, the rate of neutral point shift with Mach number was greater than

the basic wing-body.

5. The canard position which exhibited the greatest incremental liftexhibited the greatest incremental moment change regardless of canard

volume coefficient.

151

6. Low sweep canards exhibited greater incremental moments than high

sweep canards.

7. Deflection does not effect incremental moment variation with Mach

numbers.

8. Adding a canard to a configuration consisting of wing-body-

horizontal tail increases the angle of attack at which pitch down occurs

and increases horizontal tail control power.

9. The horizontal, tail is a more efficient trimming device at: low-

to-moderate angles of attack when compared with a close-coupled canard.

At high angles of attack the canard is more efficient. This is true for

both stable and unstable configurations.

DRAG

1. Canard configurations exhibit relatively constant lift-to-drag

ratios at high lift coefficients. Canard off configurations had a rise in

lift-to-drag ratio with incriasing Mach numbers.2. Forward and downward movement of the canard causes an increase in

minimum drag coefficient and induced drag.

3. Canard position has only a minimal effect on induced drag at Mach

numbers greater than 0.95.

4. At low Mach numbers, low sweep, high aspect ratio canards maximize

lift-to-drag ratio, with increasing Mach number, high sweep, low aspect

ratio c4nards perform best.

. 5. Positive canard deflections cause a decrease in the drag rise

Mach number and increases in both minimum drag ano induced drag.

6. Small negative deflections increase the maximum lift-to-drag ratio.

Negative deflections have little effect on lift-to-drag ratio at high lift

coefficients.

7. The trisurfaced configuration had lower values of induced drag

than either canard slono or horizontal tail configurations at angles of

attack greater than 16 degrees.

8. At satpersoni. speedu, the penalty for carrying the canard is

small.

152

S. , .

9. Both positive and negative deflections increase minimum drag at

supersonic speeds. Drag due to negative deflections reduces with increasing

angle of attack.

BUFFET

The close-coupled canard delayed buffet onset and buffet intensity on

the high sweep research model (A - 50 degrees).

ACKNOWLEDGMENTS

The author wishes to thank John R. Krouse and Jonah Ottensoser for

their help in obtaining and evaluating the data presented in this report.

Additional acknowledgment is given to James H. Nichols and Dr. Roger J.Furey for their guidance and support.

153,

APPENDIX A

MODEL GEOMETRY

The data presented in this report are based on two research models.The models concist of steel wings and a steel central core. Fuselages

are wooden fairings surrounding tbe central core. The canards and hor-

zontal tall are wood and fiberglass fairings built up around a steel spar.

Attachment of the canards and horizontal tail is provided by steel plates

flush with the fuselage. Seven canard and three horizontal tail mounting

pobitions are provided. Each canard can be rotated through a deflectionrange from -10 to +25 degrees in 5-degree increments. Horizontal tail

deflection range in from -25 to +10 degrees. Potation point for both

canards and horizontal tail is 40 percent of the exposed surface rootchord. Moment reference point for both research models is 0.27 c.

Detailed dimensions of the wings are given in Table 1. Table 2

presents dimensions of the four canards. Figure 97 shows the commonfuselage shape for both models. Wing planform geometries are given in

Figure 98. Canard geometry is given in Figure 99. Canard locations are

presented in Figure 100. A photograph of the various model components is

shown in Figure 101.

155

Qin0mmrn OU

TABLE 1 - GEOMETRIC CHARACTERISTICS OF THE WINGS

W1 (A - 50 Degrees) W2 (A - 25 Degrees)

Airfoil Section (NACA) * 64A008

* Projected Area, square inches 304 295

Span, inches 35.50 42.00

Chord, inches

Root (centerline) 15.38 12.20

Tip 1.90 1.90

Mean Aerodynamic Chord, inches

Length 10.30 8.30

Spanwise Location from 6.70 7.90Body Centerline

Aspect Ratio 4.15 6.00

Taper Ratio 0.12 0.16

Sweepback Angle, degrees

Leading Edge 50.0 25.0

Quarter Chord 45.5 20.0

Trailing Edge 23.5 -1.5

Incidence Angle, degrees 0 0

Dihedral Angle, degrees 0 0

Twist Angle, degrees 0 0

"*64A008 Airfoil swept 25 degrees around 0.27 c chord line.

156

156

TABLE 2 - GEOMETRIC CHARACTERISTICS OF THE CANARDS

C0 C1 C2 C3

Airfoil Section (NACA) 64A008 64A006 64A008 64A008

Exposed Area, square inches 39.8 39.8 47.2 49.3

Projected Area, square inches 76.0 89.5 76.0 76.0

Exposed Semi-Span, inches 5.74 4.79 7.60 7.60

Total Span, Inches 16.28 14.38 20.00 20.00Chord, inches

Root (centerline) 8.73 12.45 6.70 6.12

Root (exposed) 6.33 8.30 5.31 5.00

Tip 0.59 0 0.90 1.48

Aspect Ratio 3.50 2.31 5.26 5.26

Taper Ratio 0.07 0 0.13 0.24

Sweepback Angle, degrees

Leading Edge 45 60 45 25

Trailing Edge 0 0 22.8 0

Dihedral Angle, degrees 0 0 0 0

157

.,

NOTE: VERTICAL TAIL WAS NOT TESTED WITH THE25-DEGREE LEADING.EDGE SWEEP.WING (W2)

A

Figure 97a - Top View

SECTION A-A

D ALL DIMENSIONS ARE IN INCHES (CENTIMETERS)

WIDTH - 4.75 (12.00). HEIGHT = 4.15 (10,54)UPPER CORNER RADIUS - 1.00 (2.54)LOWER CORNER RADIUS - 0.25 (0.64)

I.. ~ 25.12 •

I _ __ __(___ __ ._ __o _ __ ___ ,___ __..... __ __ __

(63.,0)

(115.87)

Figure 97b - Side View

Figure 97 - Research Aircraft Fuselage

158

L _ _ _

10.77 (27.35)

9iiAA* 50 DEGREESAR a 4.15. 0.12-- i

I.,

A - 26 DEGREES

AR 0.00x - 0.16AIRFOIL:NACA 64A006 W2

Figure 98 - Planform View of the Wings

1591

S159 Ar• w•..

A "4S DEGREESAR m 3.50 A 45 DEGREESA " 0.07 AR 5.,20AIRFOIL: A a 0.13NACA 64A00$ AIRFOIL:

I :NACA 64A009

-: AIRFOIL:

r•Am

A 20 DEGREES "• NACA64A

AR m 2.31 "

A0AIRFOIL:NACA 64A000

C-,

Figure 99 - Planform View of the Canards,.6

= 160

,I,

U I I

[ .. '-

261

Figure 101 - Wind Tunnel Model Components

162

APPENDIX B

BUFFET INTENSITY

*, Presented in this appendix are the actual data used in obtaining the

values of buffet intensity presented in the section on buffet.

The data as presented have the value of a (root mean square bending

moment, RMS at zero angle of attack) removed from each data point. All

data are for the 50-degree sweep model. Data for the basic wing-body are

presented in Figure 102. Data for the horizontal tail are presented in

Figure 103. Canard C0 is shown in Figure 104. Figures 105, 106, and 107

present data for Canards C1 , C2 , and C3 , respectively.

t

is.

163

-i~ a, .. . .. . , , • .. t .2 a .. ".

0 0.2 0.4 0.6 P'.8 1.0 1.2 1A

C4

Figure 102 -Incremental Root Mean Square Data for the50-Degree Wing-Body

0.16

0.01

~~ HT PI6Q

a . . ;e0.3 1.0 1.2 1.4

Figure 103 -Incremental Root Mean Square Dataf or the Horizontal Tail

164

44

0.16.

0.2 p OA 0.6 0. 8 1.0 1.2I 1.4

CL

Figure 104a Position P, -5-Degree Deflection

O @2 OA 0.6 0.8 1.0 1.2 I.A 1.6CL

Figure 104b Position P6 -5-Degree Deflection

Figure 104 - incremental Root Mean Square Data for Can..rd C 0

165

0.16

0.2 0.4 0l6 0.6 1.0 1.2 I.A 1.14 CL

Figure 105a.- Position P 2

0.2 all0, 0.6 1.0 1.2 1A 1.6CL

Figure 105b -Position P3

0.16-

0.0

0 0.2 0.4 0.6 0.3 1.0 1.2 1.4CL

Figure 105c -Position P 6

Figure 105 - Incremental Rtoot Mean Square Data for

Canard C, at -5-Degree Deflection

1566

0106

0 0.2 0.4 0.6 0.6 1.0 1.2 1.4CiL

Figure 106a -Position P3

3.0.16

0.09 C098-6

00.2 0.4 O.6 0.8 1.0 1.2 1.4

C1L

Figure 106b - Position P 6

Figure 106 -Incremental Root Mean Square Data forCanard C2 at -5-Degree Deflection

0.16

00

0.2 0.4 0.6 0.3 1.0 1.2 1.4CL

Figure 107 - Incremental Root Mean Square Data for Canard C3at Position P 3and -5-Degree Deflection

167

REFERENCES

1. Lacey, D.W., "Transonic Characteristics of Close-.Coupled

Canard and Horizontal Tail Inatalled on a 50-Degree Sweep Research

Aircraft Model," NSRDC ASED AL-81 (Aug 1972).

2. Ottensoser, J., "Test Data on the Transonic Aerodynamic Character-

itstics of Close-Coupled Canards with Varying Position and Deflection

Relative to a 25* Swept Wing," NSRDC ASED AL-87 (Jan 1972).

3. Ottensoser, J., "Test Data on the Transonic Aerodynamic Character-

istics of Close-Coupled Canards with Varying Planform Position and

Deflection Relative to a 500 Swept Wing," NSRDC ASED AL-88 (Hay 1972).

4. Ottensoser, J., "Parametric Analysis of Close-Coupled Cane rd

Transonic Aerodynamics for a Generalized Wing-Body Configuration," DTNSRDC

ASED 399 (May 1977).

p.

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