Simulation des écoulements turbulents compressibles par une ...

Title of the thesis:
"Simulation of compressible turbulent flows by a mixed finite elementi finite volume method".
Summary:
Compressible turbulent flows are a subject of considerable importance in aeronautics. The aim of this
investigation is to develop a code to compute compressible turbulent flows in complex geometries.
The classical k-epsilon model has been used to describe the turbulent flow. In the vinicity of the solid
boundaries, wail laws are used to impose the boundary conditions at a small distance from the wail.
The k-epsilon modelisation has been introducted in a mixed finite element /finite volume method
developped to compute compressible flows. In order to compute the flow in complex geometries,
unstructured meshes are used. The time derivative and the advection terms are integrated by finite
voJumes, whereas the source and the viscous terms áre interpolated with a classical finite element
formulation. The stabilization of both acoustic and convective waves is realised by applying flux splitting
technics. The wall laws are imposed within the variational formulation.
This method has first been validated for low Mach number flows; comparisons with both experiments
and numerical simulations have been performed. Then, this method has been applied to simulate higher
Mach number flows, (supersonic mixing layers, compression corners and a transonic flow over a
bump).
Key-words:
mixed finite element/finite volume method - flux splitting technics - internai compressible turbulent
flows - k-epsilon model - wall laws