被动式引射器内流场数值研究

采用二维轴对称雷诺平均方程和Spalart-Allmaras湍流模型。研究了被动式引射器稳定工作时其内流场结构及高空试验舱压强的变化。空间上采用二阶迎风格式进行耦合求解。时间上采用显式Runge-Kutta方法进行迭代推进，直至流场收敛。结果表明，引射马赫数越大。要求的启动总压越高，为了降低启动压比，可以适当缩小混合室收缩比，增加第二喉道长径比。引射马赫数与引射总压对引射器内流场结构和高空试验舱真空度影响极大，发动机出口燃气参数对高空试验舱真空度有一定的影响．但其作用十分有限。

Numerical study on inner flow filed in passive ejector

The inner flow field in the passive ejector and the pressure of experimental cabin during steady working condition were investigated by using two-dimensional axial symmetry average Reynolds equations and standard Spalart-Allmaras turbulent models.Two-order upstream scheme and explicit Runge-Kutte algorithm were used to solve these equations.The results show that bigger ejecting Mach number requires higher total start-up pressure.Reduction of the ratio of start-up pressure can be realized by decreasing the contraction ratio of the mixing chamber and increasing the L/D ratio of second throat appropriately.The ejecting Mach number and total pressure have great effects on the structure of the inner flow-field in ejector and the vacuum degree of experimental cabin.The gas parameters of nozzle exit have certain effects on the vacuum degree of experimental cabin,but the effects are limited.