LES of turbulent boundary layers and wakes

Results of Large-Eddy Simulations (LES) of transitional boundary layers (Grenoble) and wake flows behind flat plates with rectangular and circular trailing edge (Aachen) are presented. With improved inflow conditions that take into account the weakly non-linear development of perturbations upstream of the domain K- and H-type transitions were simulated with good agreement concerning the streamwise evolution of the perturbation amplitudes. The vortex dynamics during the transition process is analyzed using the data of simulations based on 5 million grid points. The influence of spanwise grooves is investigated for the fully turbulent boundary layer. The main effect to partially isotropize the vortical structures in the near wall region is confirmed by statistical results. So far findings for the wake flow have been obtained using laminar boundary layer profiles as inflow conditions. Solutions with turbulent boundary layers are presently carried out in cooperation with Grenoble. The algorithm applied for the wake flow simulation is a second-order accurate mixed central-upwind scheme for compressible flows. Non-reflecting boundary conditions are used for the lateral and outflow boundaries. The simulations are performed for a free stream Mach number of 0.3 and a Reynolds number of 5.000 based on the trailing edge thickness. The presented results include the visualization of the vortex dynamics and the turbulence statistics of the near wake.