DNS of Compressible Turbulent Boundary Layers with Adverse Pressure Gradients

First direct-numerical-simulation results of compressible subsonic adverse-pressure-gradient turbulent boundary-layers are presented with self-similar boundary-layer profiles in their streamwise evolution, which represents the most general canonical form of the adverse pressure gradient case. Only few results are available in literature for this problem even in the incompressible regime, since the achievement of such canonical flows requires very costly iterative procedures in order to find the correct pressure distribution which has to be prescribed at the top of the simulation domain. Additionally, preliminary result are presented for the detection of turbulent superstructures in the unsteady flow field, which can be denoted to be the most dominant global events in wall-bounded turbulent flows. All results have been calculated with a new version of our numerical in-house code NS3D, which now also allows MPI decomposition in the spanwise direction of the simulation domain. A scaling study shows a maximum increase in the efficiency of up to 300% compared to the previous code version where only OpenMP decomposition has been available for the spanwise decomposition.