Comparison of hybrid turbulence models for a circular cylinder and a cavity

Three hybrid Reynolds-averaged Navier-Stokes/large-eddy simulation turbulence models are applied to the flow over a three-dimensional circular cylinder and a generic weapons bay. Time-step and grid sensitivity studies are performed. The time-step study indicates that 100-200 steps per primary shedding cycle are required for temporal accuracy using a second-order implicit algorithm. The grid study indicates that these new turbulence models - can achieve a reasonably grid-independent solution in simulation of unsteady turbulent flows. As the mesh resolution is increased, smaller scale turbulent structures become visible. A computational mesh with a grid resolution resulting in a ratio of the turbulent length scale to grid length scale greater than 2 produced a reasonable simulation with all three hybrid models for both cases.