气体二次喷射矢量喷管混合流场数值模拟

Numerical Simulation of the Mixed Flowfield in Secondary Gas Injection Vector Nozzle

采用二维雷诺平均方程和k-ε湍流模型对气体二次喷射矢量喷管复杂干扰内流场进行数值模拟。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。数值模拟得到矢量喷管二次射流的激波系结构,以及复杂的主/次流干扰流动图像。二次喷射流场包含复杂的涡系结构和波系结构,还存在着边界层与激波的相互干扰、自由剪切层、激波、膨胀波和大尺寸分离。数值模拟还表明,二次冷喷流对喷管扩散段出口附近壁面有非常明显的冷却作用。

The complex inner flow-field of secondary gas injection for solid rocker motor were numerically investigated using two-dimensional average reynolds equations and the κ-ε turbulent models. Two-order upstream scheme and explicit Runge-Kutta algorithm were used to solve these equations. Ir gained the structures of shockwave series of secondary gas injection vector nozzle and complex main/secondary flow image by numerical simulation. The secondary flow field includes complex vortices and shockwave series. It also has interaction by the boundary layer and shockwave, free shearing layer, shockwave, rarefaction wave and heavy gauge separation. The numerical simulation also indicated that secondary cold gas injection had very obvious effects on the surface wall about the exit of the nozzle diffuse.