Prediction Capabilities of Two Reynolds Stress Turbulence Models for a Turbulent Wake Subjected to Adverse Pressure Gradient

Abstract

The present contribution focuses on the behavior of two RANS Reynolds stress turbulence models in the prediction of flow reversal occurring in turbulent wakes subjected to strong adverse pressure gradients. RANS results are compared to a high-fidelity RANS-IDDES solution for an experimental set-up from Driver and Mateer. The tested models are the JHh-ϵh v2 and the SSG/LRR-ω. Additionally, the comparison includes a modified version of the SSG/LRR-ω model where the sensitivity to pressure gradients is enhanced by the Sϵ4 term, which is already present in the JHh-ϵh v2 model. None of these RANS approaches was able to capture the flow recirculation as shown by the IDDES. The analysis aims at characterizing the wake flow and identifying possible sources of the RANS shortcomings, such as departure from dynamic equilibrium and strong Reynolds stress anisotropy.