带喷流扰流片的火箭发动机推力特性分析

Analysis on the Rocket Motor Thrust Vector Provided by a Jet Tab

采用试验结合数值仿真手段,研究了位于火箭发动机拉瓦尔喷管出口处单片喷流扰流片相对喷管出口径向位置的变化对发动机轴向力和侧向力的影响。研究结果表明:随着喷管出口面积堵塞比的增加,发动机侧向力增大,轴向推力损失增加;发动机轴向推力损失约为侧向力的30%到50%。仿真分析表明:喷流扰流片在发动机喷管扩张段内造成超声速燃气的激波与边界层相互作用,喷管扩张段内壁面形成的非对称压力分布是发动机侧向力产生的基础;喷流扰流片造成的燃气激波和粘性损失是发动机轴向推力损失的根源。

The gas dynamic of a rocket motor affected by inserting a jet tab into the exhaust plume at the nozzle exit plane was investigated by experimental and numerical methods. Variations of the axial thrust loss and the side force of the rocket motor with the insertion of the jet tab were analyzed. The results show that both the axial thrust loss and side force increase with the insertion of the jet tab. The ratio of the axial thrust loss to the side force ranges from 0. 3 to 0. 5. The jet tab provides thrust vectoring by creating a shock- pattern inside the nozzle that results in a high- pressure region along the nozzle wall directly upstream of the jet tab. Shock and viscous loss of the exhaust induced by the jet tab form the axial thrust loss of the motor.