Investigation of store separation characteristics by leading edge spoilers before supersonic cavity

Abstract

Abstract The internal cavity is widely used on new generation aircraft. However, there are some new aerodynamic and acoustic issues accompanied with the internal cavity. Store separation is a challenge when separated from a high-speed cavity, the store usually generates nose-up pitch moment due to the separated flow and large static pressure gradient, which is a threat to store separation safety. Leading edge spoiler is an effective passive flow control method to improve the store separation characteristics, however the effects of varisized leading edge spoiler on store separation characteristics are still unknown. In this paper, a parameterized leading edge spoiler model is established to investigate the store separation characteristics by leading edge spoilers flow control before supersonic cavity, a small aspect ratio fly-wing aircraft and a simplified store model are employed to simulate the store separation characteristics. Numerical results show that the leading edge spoiler lifts the shear layer and significantly changes the pressure distribution inside the cavity, which makes the store a nose down pitch angle during separation. The height of leading edge spoiler greatly influences the store separation characteristics for it changes the shear layer and vortex structure. The angle of spoiler and the gas between spoiler and aircraft also have great effects on store separation, larger angle and smaller gas lead to less nose-up angle.