后效期火药燃气加速弹丸的数值研究

 弹丸出膛后受高压火药燃气作用将继续加速并达到最大速度，后效期内弹丸增速大小及增速规律对于武器系统的设计和射击精度等具有重要的影响。采用基于动网格的有限体积方法，对不同装药量、弹丸质量和口径等9种条件下的发射过程进行了数值模拟，讨论了弹丸出膛后的受力状况和运动过程，对最大速度出现的时间、位置和增速量及其变化特点、影响因素等进行了详细的分析。计算结果显示，后效期弹丸增速率最大可超过3%，且加速过程受弹丸质量和装药量的影响很小。

Numerical Investigations on Acceleration of Projectile in Post-Effect Period

After exiting the muzzle, the projectile continues being accelerated to maximum velocity by the propellant flow. The increasing of velocity in post-effect period has a great influence in the design of weapons and weapon firing precision. The process of firing under different conditions was numerically studied using finite volume method based on moving grids. Force on the projectile and the movement of the projectile were discussed. When and where the projectile reach its maximum velocity as well as the velocity increasing rate and the factors influences it was analyzed in detail. The result shows that the rate of increasing velocity may be over 3%, and is hardly affected by bullet mass and explosive charge.