Research on the Impact of Embedded Weapon Release Characteristics

Compared with the traditional way of loading external arms, the embedded weapon bay has the characteristics of low drag and high stealth performance. However, due to the coupling of the cavity, bulkhead and weapon, the flow field in the embedded weapon bay is very complex. It is necessary to avoid the adverse effects of the flow in the cavity and to effectively control the process of the weapon separation in order to ensure the launch accuracy and launch safety. In this paper, several sensitive factors affecting the trajectory and attitude of the weapon are simulated according to the model of the embedded weapon, and the influence mechanism of the key flow field parameters is analyzed. The control measures are designed, and the control effects are studied. It is found that the height and the height-to-length ratio will affect the trajectory and attitude of the weapon. Gravity drop weapon is affected by the moment of rise during weapon separation. In the condition of different height and same Mach number, the dynamic pressure difference is very big because of the difference of density and velocity. The effect of shear layer on weapon is more obvious with the increase of dynamic pressure when the dynamic pressure of 7 km is up to 11 km. The force of weapon is greater when it is close to the shear layer. The attitude is more easily changed. At the same time, the pressure gradient is different. The pressure gradient increases with the height drop, with the surface pressure of the weapon changing obviously. The attitude changes more acutely. With the increase of the ratio of length to depth, the type of the cabin flow transitions to the closed cavity, the more uneven the pressure distribution in the cabin, the greater the range of high pressure formed in the rear bulkhead, the greater the deflection of the cabin flow line to the cabin, the closer the weapon to the shear layer, the more vulnerable to the influence of the shear layer, the more unstable the falling attitude, the greater the pitch angle, and the more volatile the yaw angle. It is even more detrimental to the safe delivery of weapons. The control measures of the leading edge jet and bilge discharge pipe will affect the trajectory and attitude of the weapon. The leading edge jet opens a small opening at a certain distance from the leading edge of the bay, and shoots air into the flow field. After adding the jet, the disturbance velocity is introduced in z direction. The thickness of the shear layer is increased. The pressure gradient is reduced. The moment of the weapon is decreased and the attitude angle of pitching is reduced. The longitudinal and transverse characteristics of the weapon are improved. With the increase of jet strength, the falling attitude of the weapon becomes more stable. The bilge discharge pipe through the installation of pipeline at the bottom of the weapon bay, connecting the front and rear bulkhead, so that the rear bulkhead high-pressure air flows forward, the cabin pressure distribution is more uniform, more conducive to the safe separation of weapons.