Compressible Turbulence Model Consistency for Separated High-Speed Flow Regimes

摘要

Fluid compressibility can remarkably modify the behavior of turbulent flow with respect to the incompressible case. The presence of strong pressure-induced density changes adds to the turbulence phenomenology new specific processes and mechanisms, such as new pathways for energy exchanges and a strong coupling between momentum and energy exchanges, significantly altering the flow behavior. Many research groups are working on methods to include these compressibility effects in conventional turbulence models to predict the flowfield for compressible conditions more realistically. This work aims at the assessment and validation of several compressible corrections to an in-house hypersonic multigrid reactive Navier-Stokes code within the "baseline" Spalart-Allmaras turbulence model. The base pressure enhancement for supersonic afterbody flow computations is first addressed. Then, the shock/turbulent boundary-layer interaction at the junction of a cone/flare configuration is dealt with. The analysis of the numerical results and their comparison with the experimental data show that, in most cases, the proposed corrections produce a significant simulation improvement. Finally, an in-house hypersonic wind-tunnel test campaign is performed on generic blunt-cone/flare configurations. The pressure distributions along the model as well as the forces and moments are used to calibrate the numerical calculations in the range of Mach numbers of 4.8 to 6.2.