Effects of optimized bleed system on supersonic inlet performance and buzz

Abstract

This paper details the numerical investigations of bleed effects on supersonic inlet performance and buzz under various bleed conditions, including location, width, plenum static pressure, and inlet conditions (for example, inflow Mach number and throttling ratio). A bleed boundary condition model that reflects the effects of local flow expansion and porosity variation is proposed and validated. Flows around a supersonic inlet with bleeds are computed to show bleed effects on the inlet performance and buzz. By employing metamodeling in conjunction with a genetic algorithm, an optimal bleed condition maximizing the total pressure recovery is obtained, for each Mach number and throttling ratio, in the air chamber. A bleed condition that provides better performance for all Mach numbers and throttling ratios in the subcritical inlet operating range is then obtained by multipoint design optimization. Numerical results show that the optimal bleed condition, obtained by the multipoint design optimization, provides a much wider subcritical stable range for enhanced inlet operation by substantially increasing the total pressure recovery and suppressing inlet buzz.