关键词: 燃气弹射；压力冲击；环形腔；内弹道；流场；载荷

Abstract: On the basis of comparison with experimental data verifying the reliability of model， two-dimensional axisymmetric numerical model with secondary combustion and trail cover movement was established for double pressure peaks shock of missile low-temperature gas-ejection. The flow field mechanism of the ring cavity smoothing missile bottom pressure curve was studied， and the influence of structural parameters on the pressure impact smoothing effect was analyzed by decoupling， and the idea of ordinal optimization was put forward. The numerical results show that the ring cavity with the function of storage of oxygen can effectively prevent gas from diffusing upward， making the secondary combustion expand along the time dimension， thereby smoothing the impact of missile bottom. After the arrangement height and annular radius of ring cavity are established by geometric constraints of initial chamber space， the length can be taken as the main structural parameters to control the curve of missile bottom pressure， and expansion or contraction of angle as the structure parameter to fine tune， then the pressure curve can approximate the ideal design curve. After arranging the optimal ring cavity， the peak acceleration is reduced by 9.26%， and out of the cylinder speed is reduced by 4.13%， and out of the cylinder time is extended by 2.5%.

Key words: Gas-ejection；Pressure shock；Ring cavity；Interior ballistic；Flow field；Load