关键词: 固液火箭发动机, 二次喷射, 推力矢量控制, 喷管效率, 数值模拟

Abstract:

According to the characteristics of a hybrid rocket motor, the complex inner flow-field of the secondary gas injection is numerically simulated by using the two-dimensional average Reynolds equations and the k-ε turbulent model. Considering the nozzle efficiency, the influences of the injection position, injection mass flow rate and injection angle on the flow-field of the secondary gas injection are investigated. The results show that the optimal nozzle efficiency and the optimal vector control performance could not be achieved at the same time. The trend of the effect of the injection position on the vector control performance increases firstly and then tends to decrease. The effect of the injection mass flow rate and injection angle on the vector control performance has an increasing trend. Combined with the specific impulse loss, the ideal injection position is located from 1/2 to 3/4 of the nozzle expansion section; the ideal injection mass flow rate is 6% of the primary mass flow rate, and the ideal injection angle is 140°.

Key words: Hybrid rocket motor, Secondary injection, Thrust vector control, Nozzle efficiency, Numerical simulation