底排装置瞬态泄压过程数值模拟

为了研究底排弹出膛口到自由飞行阶段膛口流场发展过程以及弹丸底部参数变化,采用二维轴对称平均N-S方程和一方程S-A湍流模型研究了底排弹出膛口过程中近膛口以及底排装置内腔的流场特性。同时为了进行验证对比,研究了普通弹丸出膛口过程的近膛口流场特性,底排弹以及普通弹丸的运动通过FLUENT软件中网格的动态铺层得以实现。获得了清晰的外流场波系结构以及底排装置内腔的压力及温度的变化规律,计算结果表明,普通弹丸出膛口过程的近膛口流场波系结构与实验图片相符,证明了本文采用的数值方法的可行性,计算结果为底排装置内（燃烧室）固体燃料的非稳态燃烧过程以及固体燃料的力学性能的分析提供了丰富的数据参考,同时为膛口流场的研究提供了参考。

Numerical Simulation of Transient Depressurization Process of Base Bleed

In order to study the arguments of bottom of base bleed projectile, when it flies away from muz- zle, in this paper, two-dimensional axisymmetric average navier-stokes equation and a equation S-A turbu- lence model were adopted to numerical study the flow field characteristics near the muzzle and in the base bleed unite during the process of out of the muzzle. For the propose of validation and comparison, the flow field characteristics near the muzzle in the process of common projectile out of muzzle were numerical stud- ied, the movements of base bleed projectile and common projectile were achieved by using grid dynamic layer in FLUENT software. Clear wave structures of flow field outside, and change rule of the pressure and temperature in the base bleed unite were got. Calculation results show that the wave structures of the flow field near muzzle in the process of common projectile out of muzzle are consistent with the experiment, the numerical method used in this paper is feasible, and the wave structures of the flow field outside of base bleed projectile are almost the same as common projectile. The results provide references for studying the combustion process and mechanical properties of base bleed propellant, and the flow field of muzzle.