Influence of nonlinearity within the RANS approach on modelling of vortex structures in supersonic turbulent flows

The results of numerical studies of the influence of turbulence anisotropic properties on the formation of vortex structures in supersonic turbulent flows are presented. The studies were carried out within the RANS approach, where two test cases were considered as validation problems: flow in a channel of square cross-section and flow in a model configuration of a backward ledge. As a result of the numerical studies, the advantage of using a nonlinear turbulence model in comparison with a linear one is shown, which consists in a qualitatively correct description of the spatial structures of currents and in a better quantitative agreement between computational and experimental data. Additional confirmation that the experimentally observed asymmetry of flows arises due to turbulence anisotropy has been obtained, and the use of models with a nonlinear form of the turbulent stress tensor in the computational model allows us to obtain experimentally confirmed structures of such flows.