Numerical and experimental investigation on effect of primary rocket flow on performance of RBCC

Under different inflow rates, the effects of primary rocket flow on motor performance were investigated by using 3D two-phase numerical calculation method and ground direct-connect test system. The numerical results show that under different inflow conditions, the increment of primary flow has different effects on thrust and special impulse; under lower inflow rate, the increment of primary rocket flow can accelerate inflow air heating and shorten atomizing evaporation time and distance of secondary combustion, which can improve motor performance; under higher inflow rate, excessive primary rocket flow can choke flow path, which may weaken the influence of primary flow on thrust and special impulse. The experimental results validate numerical investigation law of primary flow and RBCC performance. Especially under the higher Mach number inflow condition, the effect of increment of primary flow on RBCC performance can decrease with the increase of the inflow rate. Under either lower Mach number or higher Mach number inflow condition, there exists the optimized primary flow, which can improve RBCC performance.