为分析长尾管固体火箭发动机的内部流动特性,编制微分内弹道程序进行发动机内弹道解算;同时采用自定义函数建立质量进口条件、动网格技术模拟燃面推移、欧拉-拉格朗日模型结合粒子随机游走模型,对无长尾与有长尾结构固体火箭发动机三维两相瞬态内流场展开对比研究,对比了发动机的性能,分析了长尾结构对气相流动特性与不同直径颗粒的运动分布的影响。分析结果表明:内弹道与流场仿真的发动机平衡压力基本一致。有长尾结构带来了沿程阻力损失,内部平衡压强要高于无长尾结构发动机压力,导致了装药燃烧加快,输出推力反而减小;燃气流经长尾区域流速增加明显,但粒子作用会导致轴线附近流速与温度的震荡,温度整体变化小,故此区域热防护应该重点考虑;由于惯性,粒子在长尾区域先汇集后发散,随粒径增加,粒子汇集区越靠前,散布程度越大,气流对粒子运动作用越小。

In order to analyze the internal flow characteristics of SRM with tail-pipe nozzle, a differential interior ballistic program is developed to solve the interior ballistic of the motor, and meanwhile the mass inlet condition established by using the custom function, the combustion surface displacement simulated by a dynamic grid technique, and the Euler-Lagrange model combined with the particle random walk model are used to conduct a contrastive study on the three-dimensional two-phase transient internal flow field of SRM with tail-pipe and no tail-pipe. The study compares performance of the SRMs and analyzes influence of the tail-pipe nozzle on gas phase flow characteristics and motion distribution of particles with different diameters. The results show that: the tail-pipe nozzle can cause frictional drag, and its internal equilibrium pressure is higher than that of the motor without tail-pipe nozzle, which leads to acceleration of the charge combusting and decrease of the output thrust; Flow velocity of the gas flowing through the tail-pipe area increases obviously, but the particle action will cause oscillation of the flow velocity and temperature near the axis, and the change of temperature is small, so the thermal protection in the area should be considered. Because of inertia, particles converge first and then diverge in tail-pipe area, with the increase of particle size, the particle convergence area goes further forward, the degree of dispersion is greater, and the effect of turbulence on particle motion is smaller.