A Comprehensive Study of the Sigma Model in Low- and High-speed Flows

Paper in proceeding, 2023

The -DDES model has been explored in low- and high-speed flows. Results are compared to simulations using DDES with the shear layer adaptive LES length scale ΔSLA. It is shown that the use of the -DDES model accelerates the transition from RANS to LES in both low- and high-speed flows. Results from simulations of a low speed free shear layer flow and a supersonic base flow using -DDES is comparable to results of DDES with ΔSLA for the time-averaged velocity field and resolved Reynolds stresses. In simulations of transonic flow over the generic M219 cavity -DDES shows favorable results with regards to the prediction of sound pressure levels, overall sound pressure levels and Rossiter modes frequencies compared to DDES with ΔSLA.