Large-eddy simulation of supersonic turbulent flow in axisymmetric nozzles and diffusers

Effects of extra strain and dilatation rates on the turbulence structure in nozzles and diffusers with fully developed supersonic pipe flow as inflow condition are investigated by means of LES using high-order numerical schemes. Results from a DNS of pipe and nozzle flow validating the LES are also shown. It is found that weak pressure gradients already strongly inhibit or enhance the Reynolds stresses via corresponding changes of production and pressure-strain terms. The results constitute a database for the improvement of second-order turbulence models for compressible flow.