Modeling Compressibility Effects on Turbulent Flows

Abstract

This paper proposes a three-equation (k-ε-F) model for compressible turbulence. Recent direct simulations of homogeneous turbulence show that compressibility effects depend more on the initial conditions than on the turbulent Mach number. This implies that the level of compressibility in turbulence may not be predicted only by solving the equations of k and ε. In this study therefore the variable F, which is defined by the dilatational components of turbulence, is introduced and the equation of F is also solved. We also focus on modeling the pressure-dilatation correlation. An analysis of shocklike structures reveals that this correlation is strongly related to the dilatation dissipation. The proposed model is validated by previous direct simulations of compressible turbulence.