Modification of the SSG/LRR-omega RSM for Turbulent Boundary Layers at Adverse Pressure Gradient with Separation Using the New DLR VicToria Experiment

Abstract

We present a turbulent boundary layer flow experiment at a high Reynolds number and at a significant adverse pressure gradient leading to separation, which was performed within the DLR project VicToria. We describe the design of the test case, the set-up in the wind-tunnel, and the measurement technique using particle imaging and particle tracking with the novel Shake-The-Box technique. We present the experimental results for the mean velocity profiles and a wall-law for adverse pressure gradients. Then we consider RANS turbulence modelling and propose a modification of the equation for the dissipation rate ω in the SSG/LRR-ω model, so that the modified model can predict the proposed wall-law at adverse pressure gradients. Finally we show numerical results using the modified SSG/LRR-ω model. The modifications cause a reduction of the near-wall flow velocity at adverse pressure gradients making the modified model more susceptible for flow separation. Both observations are in good agreement with the experimental data.