Hybrid LES/RANS Simulation of a 10-degree Double-Fin Crossing Shock Flow at Mach 8.28

Abstract

The simulation of a Mach 8.28 10-degree double-fin crossing shock flow using a hybrid large-eddy ⁄ Reynolds-averaged Navier-Stokes (LES⁄RANS) solver is presented in this work. The solver blends a Menter two-equation model for RANS with a Yoshizawa one-equation subgrid model for the LES calculations. The solver uses a flow-dependent

transition function based on wall distance and a modeled form of the Taylor microscale. Turbulent boundary layers are initiated and sustained in the inflow region using a recycling⁄rescaling technique applied to the fluctuation fields. The hybrid LES⁄RANS model is tested using both Menter's Baseline (BSL) and Shear Stress Transport (SST) models for the RANS closure. These results are compared to pure Menter BSL and SST RANS results as well as with the experimental data of Kussoy and Horstman(1992). This study concludes that while the hybrid LES⁄RANS model outperforms RANS calculations in the inflow region where the flow is nominally two-dimensional, it significantly overpredicts the wall heat transfer rates in the region of the crossing shock interaction. Possible explanations for this behavior as well as plans for future attempts at solutions to these shortcomings are provided.