发动机点火过程中压强振荡对人工脱粘的冲击分析

Analysis on effect of pressure oscillation shock on stress-release boot of SRM during ignition

针对固体火箭发动机点火过程,采用流固耦合的方法数值模拟了点火过程中发动机内流场以及药柱人工脱粘附近应力应变的变化情况。计算表明,点火初期发动机内部出现激波,并在药柱通道内振荡传播,随时间减弱为压强振荡。压强波动对人工脱粘缝隙的冲击会影响脱粘缝内流场的分布和应力应变,人工脱粘层尖端应力变化与升压梯度变化存在对应关系。激波对人工脱粘缝隙的冲击会引起装药明显变形,但是不会使缝隙增大。

The flow field and stress-strain behavior about the stress-release boot of a solid rocket motor in ignition process were studied by means of the flow-structural-interaction numerical method. The results show that shock wave occurs and spreads in the tunnel of the grain at the beginning of ignition process, which will be attenuated as pressure oscillation. Pressure fluctuation impacts the stress-release boot and affects its the internal flow field distribution and stress-strain. The stress variation at stress-release boot tip corresponds to gradient variation of pressure. Although the impact of shock wave on the stress-release boot may lead to obvious grain deformation, the gap of stress-release boot will not be extended.