2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

Time domain sound field analysis by finite element method-Comparison of iterative methods and analysis of small hall-

○奥園　健 大鶴　徹 岡本　則子OKUZONO Takeshi OTSURU Toru OKAMOTO Noriko

末吉　俊秀SUEYOSHI Toshihide

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L◉

研究の背景

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

FEM FDM BEM・Their applications is generally limited to low frequencies and/or simple room shape.

・Finite- and boundary-element methods can be ..., and work well for small rooms with

arbitrary geometry at low frequencies.◉A. Wareing et al., J. Acoust. Soc. Am. 118 (4), pp 2321-2331, 2005

研究の背景

◉ S. Sakamoto et al., International Symposium on Room Acoustics : Design and Science 2004.

◉ , AA-2005-12 2005.

◉ T. Otsuru et al., Proc. ICA 2004(Kyoto), I-479-I-482, 2004.

FDTD

FMBEM

FEM

6000 m3 1.4 kHz

3000 m3 500 Hz

12000 m3 1k Hz

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

TDFEM◉ T. Otsuru et al., inter noise94,

◉ , 1996

FEMLarge-scale Finite Element Sound Field Analysis : LsFE-SFA

◉ Okamoto N et al., The 9th Western Pacific Acoustics Conference, 2006

◉ Otsuru T et al., J. Acoust. Soc. Jan(E), 21(2), 87-95 2000

◉ T. Otsuru et al., Proc. ICA 2004(Kyoto), I-479-I-482, 2004.

27

研究の背景

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

本研究の目的

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

KrylovCG, GMRes, QMR, BiCGStab etc...

[A]{x}={b}

◉ T. Okuzono et al., Inter noise2006, 2006.

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

0

25

50

75

100

0 10,000 20,000 30,000 40,000

Required memory, RM [GByte]

Room's volume, V [m3]

fmax=250 Hz

fmax=500 Hz

fmax=1 kHzfmax=2 kHz

fmax=4 kHz

＃27

＃

＃＃

RM 1600V/ d fmax

c

3

fmax

c/ d

V

[Hz]

[m/s]

[m3]

[Byte]

/ d > 4.4

16 GByte

38000 m3

必要記憶容量の概算式

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

解析例 1 小ホール内音場解析

zn =zn = 1.0

8926001300 ms

13,230

6(250 Hz),8(500 Hz)

OpenMP

27

FE解析の設定SS (-7.558, 0.0, 1.50)

x

yz

zn

12 , fc = 250, 500 Hz

0.04 s

[Pa]

SS

x

y

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

小ホール内音場解析における反復解法の収束性

0

5

10

15

20

25

0 5000 10000 15000

fc = 250 Hz

fc = 500 Hz

Nmv

Time step

13.814.7

250500

fc [Hz] Average of iteration number

Iteration number

94 h (250 Hz)

101 h (500 Hz)

14 GByte

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

解析例 2 大規模多目的ホール内音場解析

37,184 m3

2,844 m2

2,572y

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

FE解析の設定

1960901000 ms

20000

27

-1

-0.5

0

0.5

1

0.00 0.05 0.10 0.15 0.20

Time [s]

Amplitude

0.2

0.4

0.6

0.8

1.0

0 200 400 600 800 1,000

Frequency [Hz]

Apmlitude

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

sound source

xx

y -1

-0.5

0

0.5

1

0.0 0.2 0.4 0.6 0.8 1.0

P1

FEM Meas.

Time [s]

Normalized sound pressure

127 h4.9 GByte

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

まとめ

TDFEM

今後の課題TDFEM

2007. 5 Architectural Acoustics lab., Oita Univ., Japan, O2L

今後の課題