Abstract :

Training in the basics of compressible turbulence including astrophysics medium.

Distribution CM/TD:

approximately 4 CM (6h), 4 TD (6h), 6 CM/TD (9h) and 1 TP (3h).

Compressible turbulence in the interstellar medium (ISM): * Role of turbulence in star formation * Feedback of star formation on galaxy evolution * Toward the gravo-turbulence framework
The ISM: a very brief introduction * Composition * ISM phases: thermodynamics of the ISM and the bistable equation of state * Pieces of evidence of interstellar turbulence - Pressure: thermal, magnetic, cosmic-rays, non-thermal - Scaling laws (in ionized and neutral medium) - Reynolds number - What is ISM turbulence?
Observation of ISM turbulence * Power spectrum * Structure function analysis and intermittency
Theory and numerical simulations * Modifications to K41 for compressible turbulence * Comparison between compressible and incompressible - Power spectrum - Structure functions and (multi-)fractal models * Magnetized turbulence: challenges * Predictions from numerical simulations
Open questions in ISM turbulence

transonic compressible fluid mechanics
- Kovasznay entropic, acoustic, vortical waves. Morkovin hypothesis Non-hypersonic turbulence
- compressible Navier-Stokes equations - adimmension of Reynolds and Mach numbers
- compressible numerical methods: conservative schemes (Mac Cormak, shock capture...), non-reflective boundary conditions,
- oblique shocks - Rankine Hugoniot relations
- compressible turbulence - dynamic and thermal boundary layer: SRA Reynolds analogy, Crocco Busemann relations
- Numerical experiments: shock tube, turbulent compressible plane channel, turbulent compressible plane jet
compressible turbulence and instrumentation
- nozzle, oblique shock type air intake, shock tube,...
- Experimental demonstration of linearized modes of compressible turbulence (Kovasznay) by using the hot wire and fluctuation diagrams.