固体火箭发动机径向加质流局部稳定性分析方法研究

A Study of Analysis Method for Hydrodynamic Stabilities of Solid Rocket Motors with Side-Induced Flow

应用局部非平行流动稳定性理论研究了大长径比固体火箭发动机内的表面涡脱落现象。分析了由主变量公式和流函数公式导出的扰动方程的差异,以及流动参数对稳定性的影响,发现两种扰动方程对最不稳定波频率的预估值小于2%,且该频率沿流向逐渐增加。比较了基于空间发展模式的理论结果与大涡模拟计算结果,发现在不发生共振的情况下,理论方法可以较好地预估发动机内的流动不稳定频率。

A local non-parallel（LNP） hydrodynamic stability approach was applied to investigate the partial vortex shedding phenomenon observed in solid rocket motors with side-induced flow with large length to radius ratio.Two disturbance equations based on stream function formulation and primitive variable formulation were solved and results were compared.The effects of flow parameters on stability results are obtained.It is showed that the predicted values of the most unstable frequencies by two disturbance equations differ less than 2% and the frequencies increase along streamwise.Large Eddy Simulations were performed on two different configurations and compared with the results obtained by the LNP method based on spatial evolution of the flow instabilities.The comparison shows good agreement in a certain degree in terms of amplified frequency range when no resonance happens.