Turbulence modeling

Abstract

This chapter focuses on modeling compressible wall-bounded turbulent flows. We first make the distinction between variable-property effects and intrinsic compressibility effects. Variable-property effects are associated with changes in density, viscosity, etc., primarily due to heat transfer, while intrinsic compressibility effects are associated with volume changes induced by pressure fluctuations. Both phenomena significantly impact turbulence and thus complicate turbulence modeling. The focus is on adapting Reynolds-averaged Navier-Stokes (RANS) models to account for these effects, which can also be applied to wall-modeled large eddy simulations (WMLES). Canonical flows are examined to illustrate the necessary modifications needed to incorporate compressibility effects into general RANS models. These improvements are applicable to many turbulence models and for complex flow geometries.