激波诱导矢量喷管流场的数值模拟及试验

Computational and experimental analysis of the flow field in shock vector control nozzle

关键词:  火箭发动机  激波  推力矢量喷管  数值仿真

Key words:  Rocket engine  Shock wave  Thrust vectoring nozzle  Numerical simulation

摘要:

为研究固体火箭发动机激波诱导矢量控制效率的影响因素,及验证数值模拟方法的准确性,对激波诱导轴对称推力矢量喷管模型进行了壁面测压试验,采用二阶精度Roe格式和k-ω SST两方程湍流模型求解强守恒型Navier-Stokes方程对矢量喷管复杂干扰内流场进行数值模拟。根据试验和数值模拟结果分析了喷管内主流和次流相互作用产生的复杂流场结构,比较了在不同喷管落压比NPR和次主流压力比SPR下喷管壁面静压的分布情况。结果表明,数值计算和试验结果基本吻合,验证了计算方法的准确性；在一定范围内减小喷管落压比,增大次主流压力比可以增大喷管周向壁面静压差,提高喷管的推力矢量偏角。

Abstract:

In order to study the influencing factors for the efficiency of shock vector control system in solid rocket engine, and verify the accuracy of the numerical method, an experimental investigation has been conducted to determine the static pressure on the wall of the shock vector control axisymmetric nozzle. The complex inner flowfield of the nozzle was numerically simulated by solving three-dimensional average Reynolds Navier-Stokes equations using second-order precision Roe scheme and the k-ω shear stress transport two equations turbulent models. The structure of the flow-field of the vectoring nozzle, induced by the interaction of primary inflow and secondary inflow, and the distribution of the static pressure on the wall of different nozzle pressure ratio and secondary pressure ratio were analyzed and investigated. The results indicated that the computational results show good agreement with experimental data, which validates the veracity of numerical method; the static pressure differential on the circumference wall and the thrust vectoring efficiency increases with the decreasing of the nozzle pressure ratio and increasing of the secondary pressure ratio in some range.