Steps towards a Reynolds Stress Model for the Prediction of Separated Flows

Abstract

A tailored strategy based on Reynolds stress modelling is suggested for improving the prediction of separated flows. The strategy is based on the observation that the turbulence structure differs between different flows. A full description of the turbulence structure requires the full information about the Reynolds-stress anisotropies rather than the invariants alone. Success of the strategy is demonstrated by applying a zonally modified Reynolds stress model for improved prediction of a plane mixing layer to separating flows, leading to shorter separation bubbles. Combination with a recently developed length-scale correction maintains the pressure distribution, but moves the reattachment point downstream again.