- Numerical simulations of normal sonic gaseous injection through diamond shaped orifices into a Mach 5.0 freestream were performed using RANS and DES turbulence models. The GASP and Cobalt flow solvers were used in this work. A detailed study of the secondary turbulent flow structure was performed. Flow structures predicted by RANS solutions were compared with instantaneous and time-averaged DES solutions. Results indicate that RANS and DES predict similar flow structures. Turbulent kinetic energy results show higher predictions by DES in the downstream shear layer and lower prediction near the injector as compared to RANS model results. Also, clear connection to secondary flow structure was observed; for example, a TKE peak was observed downstream of the injector and was concluded to be due to the interaction of the wake vortices. Copyright 2005 by the American Institute of Aeronautics and Astronautics, Inc. All right reserved.