Fluid Dynamics Analysis On Missile Launching And Separating From Weapon Bay

Along with the developing of new generation of fighter aircraft such as F-22, F-35, Russia's Mig1.44, Su-47, the fourth-generation fighter-related technology has become a hot spot, with the characters of stealth, supersonic cruise, high mobility, over the horizon and short take-off and landing operations. Since the traditional way of weapon loading caused high RCS, disturbed the smooth shape of the aircraft, and increased the aircraft's aerodynamic drag, the fourth generation fighter aircraft weapons must be buried.In this paper, the application of weapon bay on various types of aircrafts, such as long-range bombers, fourth generation fighter aircrafts and new generation of UAVs, is introduced. The layout, form of cabin door's open and launch system of weapon bay on U.S.F-22 aircraft is mainly demonstrated. Meanwhile, a main weapon bay's three-dimensional model of F-22 aircraft is built, and the fluid analysis grid of the main weapon bay, folding doors, spoiler, and AIM-120C missiles is divided.In this regard, the steady flow characteristics of the F-22 weapon bay is analyzed and calculated based on nested grid. With a spoiler set in front of the weapon bay, a passive control method used to improve the flow field and the cabin door's opening to the dynamic flow field is analyzed. Based on this method, we can get the influence of the weapon bay's flow field which caused by the cabin doors speedy opening. Through the flow field's analysis in the 6DOF motion of AIM-120C missile, we determined the safety of the pylon's ejection parameters on this situation.This research may contribute to determine cabin door's form and the ejection control law for the pylon, and offered help for the design of weapon bay.