Study of RANS Turbulence Models for Turbulent Wake Flow in Adverse Pressure Gradient

Abstract

We present an analysis of RANS turbulence models for a new turbulent wake flow case in adverse pressure gradient. The reference data are obtained from an LES. RANS simulations using the Spalart-Allmaras model, the SST model and the SSG/LRR-ω model show a tendency to underpredict the onset of flow reversal in the wake. The comparison with the LES data reveals that the SSG/LRR-ω model underpredicts the turbulent transport of the Reynolds stresses and overpredicts the ratio of production to dissipation. Therefore two modifications of the SSG/LRR-ω model are studied, i.e., the modification of the coefficient of the gradient diffusion hypothesis for the turbulent transport of the Reynolds stresses and the sensitization of the dissipation rate to irrotational strains. Both modifications improve the agreement with the reference data.