High-order large eddy simulations of high-speed boundary layer transition

High-order Large Eddy Simulations (LES) of high-speed boundary layer transition are performed for a cone-slice-flap geometry and two benchmark problems. The fully compressible Navier-Stokes equations for an ideal, calorically perfect gas are discretized using a hybrid scheme based on fourth-order summation-by-parts (SBP) finite-difference operators for turbulence and fifth-order WENO for shocks with explicit fourth-order Runge-Kutta for time marching. The code employs either structured curvilinear body-fitted grids or Cartesian grids with the immersed boundary method (IBM) for handling complex geometries. The code is parallelized with MPI and scales on thousands of CPU cores. Predictions are compared to previously published Direct Numerical Simulation (DNS) and experimentally measured data. The cone-slice flap geometry was simulated and subsequently broken down into two model problems: high-speed transitional flow over a flat plate with an impinging shock and high-speed turbulent flow over a compression corner. These cases were used to assess the feasibility of coarse grid wall-modeled LES (WMLES) in the context of turbulence, shock/boundary layer interactions (SBLI), and SBLI with flow separation. Transition was successfully predicted in the flat plate case albeit with oscillations resulting from the shock. In the compression corner case, the predicted wall pressure was found to have good agreement with previous DNS data. Unsuccessful attempts were then made to validate the implementation of the wall model using a high-speed turbulent Couette flow case. Future works aim to successfully implement the wall model and ultimately simulate the cone-slice-flap geometry using coarse grid WMLES.