Title Modellistica di flussi turbolenti

Turbulent flow modelling

Degree Corso di Laurea Magistrale in Ingegneria

Meccanica (DM 270/04) Year

1Teaching Period

2Credits

6

Teacher: Cristian Marchioli Academic year: 2013/2014

Objectives:

The course provides the basic physical concepts and mathematical tools required to (1) understand the fundamentalphenomenology of single-phase and two-phase turbulence, and interpret experimental data and simulations; (2) analyzesingle-phase and two-phase turbulence processes of interest for environmental and industrial applications; (3) use state-of-the-art computational models to optimize fluid mechanics system design.

Acquired skills:

- Basic understanding of turbulence processes

- Modelling of turbulence processes

- Basic computational skills for computational modelling

Lectures and exercises hours

Topics Specific contents

IntroductionBackground and basics concepts. Conservation equations (continuity, Navier-Stokes). Non-dimensionalization. Kinetic Energy Transport Equation

10

Vorticity Dynamics

Definitions of vorticity, physical significance of mathematical definition Circulation Birth, diffusion, and death of vorticity Viscous flow inside and outside a rotating cylinder, diffusion length scale Vorticity Equation, potential and stream functions Biot-Savart Law, Helmholtz's Theorem, point Vortices, 2-D vortex motions, basic vortex interactions Discrete Vortex Method

10

Boundary LayerLaminar Boundary Layer Blasius problem, Stokes problem Free plane jet Integral momentum method

8

Turbulence

Reynolds-averaged conservation equations (RANS). Reynolds stress tensor.Closure problem for RANS equations: closure laws and scaling. Law of the wall Inner variables. Statistical description of turbulence. Introduction to Multiphase Turbulent Flows

18

Turbulence ModellingTurbulence modelling for computational fluid mechanics. Zero, one and two equation models. Large Eddy Simulation and Direct Numerical Simulation

10

InstabilityInstability and transition to turbulence. Hydrodynamic instability. Introduction to linear stability analysis. Large Scale Structures.

4

Total hours for lectures and exercises 60

for exercises only 18

Further educational activities hours

Labs 0

Tutorials / Seminars 0

Workshops 0

Guided tours 0

Total hours for further educational activities 0

2

Total hours 60

Type of exam: Written and oral

References:

- P. Andreussi, A. Soldati; Fluidodinamica di Processo; Ed. ETS, 2000.

- S.B. Pope, Turbulent Flows, Cambridge University Press, Cambridge, U.K., 2000

- R.L. Panton; Incompressible Flow; Ed. Wiley & Sons, 1960

- Lecture notes

Additional material or information on line http://158.110.32.35/fluid-turb.html

2