大水深火箭发动机尾流场数值模拟

Numerical simulation of tail flow field for underwater solid rocket motor

针对火箭发动机在深水环境下工作的燃气射流特性,采用VOF(Volume of Fluids)方法建立了二维轴对称两相数值计算模型,对深水长尾喷管火箭发动机点火初期的过程进行了数值模拟。模拟了长尾喷管喷管燃气射流的气泡的形成、发展及断裂过程,获得了气液两相流场中压强、马赫数、温度等参数的变化规律。计算结果表明,长尾喷管出口出现周期性的压力脉动,气液相互作用过程中形成含涡结构的边界层。水深越大时,环境压力越大,长尾喷管出口的压力、速度波动越大,射流稳定后长尾喷管轴线上的压力、速度保持不变。研究结果可为深水火箭发动机的设计提供参考。

For gas jet characteristics of rocket motor working in deep underwater,two-dimensional axisymmetric two phase numerical model has been built by means of the volume of fluid(VOF)method,based on which the initial stage of deep underwater rocket motor ignition has been simulated.The results show the growth and evolution of gas bubble by gas jet.The distribution laws of pressure,mach number and temperature in two-phase flow field are obtained.The calculation results show that the phenomenon of periodic pressure fluctuations and boundary layer with vortex structure in the process of gas-liquid interaction are captured.The greater the water depth,the higher the environmental pressure is.It results also in greater the pressure fluctuation at the outlet of the nozzle,and the pressure and speed in the long tail nozzle remain unchanged.The analysis of the calculated results can provide information for design of underwater rocket motor.