Suppression of cavity loads using leading-edge blowing

We present hybrid Reynolds-averaged Navier--Stokes/large eddy simulation-based analysis of the suppression of fluctuating pressure loads on the walls of a complex nonrectangular cavity using leading-edge mass blowing. The unique aspect of the concepts discussed here is the very low mass flow rates used to achieve significant suppression. The simulation results are used to gain insight into the mechanism governing the effectiveness of these jets. The jets are applied to an L/D = 5.6 cavity at supersonic conditions of Mach 1.5. The simulation results show excellent agreement with experiments demonstrating an overall reduction in fluctuating pressure levels on the order of 50% with the control concepts. The primary mechanism of reduction is the break up of the spanwise coherence in the shear layer into smaller vortical structures thus reducing the shear layer flapping and leading to a smaller imprint on the wall pressures.