多级活塞缸式燃气弹射内弹道的研究

Based on computational fluid dynamic method,a multi-stage piston cylinder gas ejection model was established and a dynamic zone mesh motion method was adopted to simulate the missile's motion.The process of expansion of multi-stage piston cylinder was studied.The change of flow field and the characteristics of internal trajectory were investigated.The results show that during the ejection, the distribution of pressure in low pressure chamber is uniform, but the temperature is equal to total temperature, resulting in a bad thermal environment. With the expansion of multi-stage piston cylinder,the acceleration of missile declines stepwise. It takes 0.74 seconds for expansion of multi-stage piston cylinder.The acceleration overload is less than 8 g.In addition,the results of multi-stage piston cylinder ejection and zero dimensional internal trajectory are almost the same.Besides,on the same initial conditions,compared to ordinary gas-steam ejection,the velocity and acceleration of missile ejected by multi-stage piston cylinder devices are smaller.As a result, with multi-stage piston cylinder ejection,the missile has a smaller acceleration and the process of ejection is more stable.The space can be used more efficiently and the structure is more reasonable.