Hybrid Reynolds-Averaged Navier-Stokes/Large-Eddy Simulation Investigating Control of Flow over a Turret

This investigation explores the flow over a turret atM1 0:4 and ReD 2:4 10 using both hybrid Reynoldsaveraged Navier–Stokes/implicit large-eddy simulation (RANS/ILES) and k-based unsteady Reynolds-averaged Navier–Stokes (URANS) simulations. Additional hybrid RANS/ILES simulations were performed to compare the effectiveness of two steady-suction flow control approaches. The hybrid RANS/ILES computations were obtained using awell-validated high-orderNavier–Stokes flow solver employing a fourth-order compact spatial discretization in conjunction with a sixth-order low-pass spatial filter. The URANS simulations were performed using a secondorder version of the flow solver and kturbulence model. The turret configuration consisted of a half-foot radius hemisphere atop a 4.5-in.-tall circular cylinder base. Both steady suction through a slot and a leeward porous turret shell were explored as forms of flow control. Time-mean hybrid RANS/ILES results, obtained on a 23 10-point mesh, compared reasonably well to experimental pressure coefficient and velocity profiles for the baseline flow. The separation angle was predicted to within 3 deg of experimental observations. The instantaneous hybrid RANS/ILES solutions display complex three-dimensional flow phenomena in the wake of the turret that the kURANS model was unable to resolve. Both steady-suction flow control approaches successfully attached the flow over most the turret dome and significantly reduced the size of the wake.