双组元高室压脉冲火箭发动机工作特性分析

Study on the characteristics of bipropellant-fueled pulse rocket engine with high combustion chamber pressure

为了研究高室压脉冲火箭发动机的工作特性,在分析其工作原理的基础上建立了数学模型,其中燃烧室和挤压腔采用零维模型,喷管采用一维准稳态模型,采用四阶Runge-Kutta法进行了求解.结果表明,燃烧室的最大压强和平均压强都高于推进剂供给压强,而挤压过程中进出燃烧室的质量不守恒是压强升高的原因.与常规液体火箭发动机相比较表明,脉冲火箭发动机的真空比冲提高了7.5%,而喉部面积仅为其10.2%.

By using a moving injector, the combustion chamber pressure of pulse rocket engine is much higher than feed system supply pressure. In order to analyze the characteristics of bipropellant-fueled pulse rocket engine, a mathematics model was presented. The zero-dimensional models were used for combustion chamber and extrusion rooms, and the onedimensional, quasi-steady model was used for nozzle flow. Using N2O4 and MMH as propellant, the equation sets were calculated with fourth-degree Runge-Kutta method. According to calculated results, the maximal pressure and average pressure of combustion chamber are much higher than supply pressure, on account of the nonequivalent mass flow rate in combustion chamber. The performance difference between pulse rocket engine and conventional constant-pressure liquid rocket engine （LRE） was compared. Results show that, under the same supply pressure, the same mean thrust and area ratio, the vacuum specific impulse of pulse rocket engine has increased by 7.5 %, but the throat area is only 10.2% of LRE.