Simulation RANS des écoulements dans une tuyère supersonique avec l’effet de compressibilité

Abstract

The subject of this dissertation concerns the modeling and numerical simulation of compressible turbulent flows from converging-diverging nozzles of different shapes (conical or profiled). Previous work showed that standard turbulence models were unable to correctly predict compressible flows with adverse pressure gradients. In this work, we propose to introduce Menter's two-equation SST-V turbulence model which does not require damping functions to improve the predictions of such flows. This model was then applied to study the following problems: - Simulation of compressible turbulent flows in nozzles. - Simulation of supersonic shock wave/turbulent boundary layer interactions. - Simulation of the transition between free separation and restricted separation. - The study of heat transfer through the wall of a nozzle in flows Supersonic. These phenomena play a fundamental role in the design and operation in many situations both in internal and external aerodynamics, thus heating by turbulent friction in supersonic is important and external cooling becomes necessary to maintain the integrity of the surface of the nozzle. The comparison of the results obtained with the experiment reveals a very satisfactory agreement; the SST-V turbulence model provides a clear improvement in the prediction of such flows.