火箭发动机尾焰流场注水降温效果初探

Exploring on Cooling Effect of Water Injection on Rocket Motor Exhaust

为了对超声速高温燃气射流的注水降温机理进行探索,对该类流场进行了数值模拟和实验研究。气-液两相流场采用Mixture多相流模型进行计算,液态水的汽化过程通过耦合水的汽化方程来模拟。实验现象采用高速摄影和红外热像仪进行拍摄,并且在冲击平板上布置了热电偶温度测点。通过对仿真计算得到的温度云图与实验结果进行比较发现,无论是流场形态还是温度场分布,两者都十分吻合,证明了计算模型的适用性。结果表明:液态水和燃气的掺混汽化吸热效果显著,高温区域由于注水影响缩小到一个类锥形区域;迎气面温度大大降低,热冲击烧蚀效应得到有效缓解,尤其是中心部位降温效果最为明显,注水后温度仅为原温度值的60%左右。

To study mechanism of cooling high temperature supersonic jet by water injection, the numerical simulation and experiments were carried out. Gas-liquid two phase flow field was calculated by Mixture muhiphase model. Vaporization mech- anism of water was simulated by coupling equation of water vaporization. The phenomena were photographed by high-speed photography and infrared thermograph. Several temperature monitor points were sensed by thermocouples on the bottom plate. The temperature contours calculated agree well with experimental results in flow structure and temperature distribution. The availability of Mixture multiple model is proved. It can be concluded that the weakened thermal impact and ablation effect ac- companying the temperature of head face can be decreased by water injection.