Study of the compressible mixing-layer correction for the SST k-omega model and for the SSG/LRR-omega model and application to the simulation of plumes

To calculate infrared (IR) signatures generated by plumes, CFD simulations using RANS tur-bulence models can be used to predict species and temperature distribution as input data for the subsequent tools. RANS models were mainly developed for subsonic flows, and in some flow situations, compressibility corrections need to be applied. One such situation is compres-sible free-shear-layer flow relevant for the simulation of plumes. The growth of the spreading rate of high-speed mixing layers is reduced significantly compared to the incompressible regime, leading to a much longer extent of the region effected by the plume. The present work describes the validation and application of the compressibility correction by Wilcox (2006), which was developed for the Wilcox k-omega model, for the SST k-omega model and for the SSG/LRR-omega RSM in the DLR TAU code. For the functional testing and for the validation of the method, a mixing-layer test-case was developed based on the incompressible planar mixing layer case by Delville provided at the NASA turbulence modeling resource webpage. The results show the validation with respect to experimental and LES data as well as a first application to plumes.