关键词: 激波/边界层干扰, 高超声速, 湍流模型, 湍动能, 涡黏性模型

Abstract: Shock wave/boundary layer interaction in hypersonic turbulence flows can cause significant changes in key parameters such as aerodynamic force and aerothermal environment, therefore drawing extensive attention in the design and optimization of high-speed vehicles. The most widely used approach for turbulent simulation of such vehicles is RANS modelling with eddy viscosity models. Many studies have focused on the modification and improvement of the turbulence models to obtain better prediction in such flows. Nevertheless, studies on the RANS equations, particularly those on the role of the Turbulent Kinetic Energy(TKE) in the transport equations of mean variables, are rare. We investigate the influence of three TKE terms on the RANS equations using the k-ω SST model in the simulation of a hollow cylinder-flare flow of Mach number 7.05. The action mechanism of each individual TKE term on the prediction of hypersonic shock wave boundary layer interaction is analyzed qualitatively and quantitatively. The results show that these TKE terms have a significant impact on the flow prediction in the Shock Wave/Boundary Layer Interaction (SWBLI) area, particularly on the size of the separation region. Omission of one TKE term could lead to shrink of the separation bubble to only 40% of that without omission; in contrast, ignoring another TKE term would enlarge the separation length by more than 30%. The theoretical analysis of the mean momentum and energy equations indicates that this strong influence is mainly introduced by the significant change of the effective mean pressure field when the TKE terms are ignored. This will, consequently, lead to a change in the adverse pressure gradient near the separation point, resulting in a clear variation in the predicted length of flow separation.

Key words: shock wave/boundary layer interaction, hypersonic, turbulence model, turbulent kinetic energy(TKE), eddy viscosity modelhttp