固体火箭发动机点火药颗粒点火过程流固耦合特性研究

Fluid-Solid Coupling Characteristics Study on Ignition Process of Ignition Powder Particle in Solid Rocket Motor

关键词:  固体火箭发动机  点火药颗粒  点火激波  流固耦合  数值仿真

Key words:  Solid rocket motor  Ignition powder particle  Ignition shock wave  Fluid-solid couple  Numerical simulation

摘要:

为了研究点火药颗粒点火瞬态过程中流动与燃烧特性及点火喷流冲击对自由装填药柱结构的影响，以N-S方程、k-ε湍流模型为基础，采用颗粒轨道模型建立点火药颗粒点火模型，结合流固耦合方法分析点火喷流冲击对自由装填药柱结构的影响。通过与相关试验结果对比证明计算模型可靠，然后对固体火箭发动机点火药颗粒点火过程进行仿真计算，计算结果表明：点火药颗粒主要分布在药柱内通道且点火药颗粒之间存在点火时间差，并出现持续高压现象，导致内外通道压强差高达1.4MPa；由于点火燃气的传播特性，将整个点火过程分为点火激波正向传播阶段和反射阶段，其中在正向传播阶段，点火冲击对药柱结构具有显著影响，最大位移高达8.0mm。

Abstract:

In order to study the flow and combustion characteristics of ignition powder particles and the effects of ignition shock on the structure of free loading grain during ignition of ignition powder particles， based on the N-S equation and k-ε turbulence model， the ignition model of ignition powder particles is established by particle trajectory model. Combined with fluid-solid couple method， the effects of ignition shock on the structure of free loading grain are analyzed. Compared with the relevant test results， the calculation model is reliable， then the ignition process of ignition powder of solid rocket motor is simulated.The results show that the ignition powder particles are mainly distributed in the channel of the grain， and there is ignition time difference between the ignition powder particles， and the phenomenon of continuous high pressure appears ，which leads to the pressure difference between the internal and external channels as high as 1.4MPa. Due to the propagation characteristics of ignition gas， the whole ignition process is divided into normal shock wave stage and reflected shock wave stage. In the normal shock wave stage， ignition shock has a significant effect on grain structure， and the maximum displacement is as high as 8.0mm.