Adaptive wall treatment for the elliptic blending Reynolds stress model

Abstract

International audienceWall functions are widely used in CFD in order to significantly reduce the computational cost compared to so called Low-Reynolds number formulations. They are, however, particularly restrictive in terms of meshing as they require the first calculation point to fall into the logarithmic region. Industrial simulations of internal flows, such as the ones encountered in nuclear applications, are particularly challenging due to their inherent complexity that makes it difficult to satisfy those conditions everywhere.The present study focuses on a new algebraic adaptive wall treatment for the Elliptic Blending Reynolds Stress Model (EB-RSM) by extending some of those recently proposed approaches. Blending functions that ensure a correct asymptotic behaviour at the wall for the velocity and the turbulent variables are introduced and boundary conditions are prescribed at the first near-wall cell. The approach shows very promising results on fully developed channel flows, comparable to what is obtained using a numerical integration down to the wall