Delayed Detached Eddy Simulations of Compressible Turbulent Mixing Layer and Detailed Performance Analysis of Scientific In-House Code TASCOM3D

In the present paper a compressible turbulent mixing layer is investigated using Delayed Detached Eddy Simulation (DDES). Thereby two compressible flows are divided by a splitter plate which join downstream of the plate and form a mixing and shear layer. The simulations are performed with the scientific code TASCOM3D (Turbulent All Speed Combustion Multigrid Solver) using a fifth-order upwind biased scheme combined with an improved multi-dimensional limiting process (MLP) (Gerlinger, 2011) for spatial discretization. The inviscid fluxes are calculated using the AUSM+-up flux vector splitting. DDES is a hybrid RANS/LES approach which uses a traditional Reynolds averaged Navier-Stokes (RANS) approach for wall-bounded regions and a Large Eddy Simulation (LES) approach for the mixing section. The simulations show a quasi two-dimensional flow field right after the splitter plate and a following conversion to a turbulent and highly unsteady flow field after short distance. Furthermore the performance of TASCOM3D on different HPC systems is analyzed: a vector (NEC SX-9) and a scalar processor based (Cray XE6) system, both installed at the High Performance Computing Center Stuttgart (HLRS). The investigation points out the challenges and problems in HPC and may serve other researchers as comparison and assistance to achieve good performance on the different architectures.