直接加热对固冲发动机地面模拟性能影响的理论分析

为了模拟飞行状态下进入补燃室的空气总温,在地面模拟试验中要对空气加热。通过直连模拟计算,研究了常用加热器燃料(氢气、煤油、甲烷和酒精等)对含硼贫氧推进剂固体火箭冲压发动机性能的影响。结果表明,当按照气流中含氧量与纯净空气一样进行补氧时,气流中的含氧量能模拟纯净空气中的含氧量;直接加热、补氧的直连模拟计算所得的发动机真空比冲相对偏差与加热空气的燃料种类有关,以氢气为燃料的相对偏差大于0,而其它3种燃料的相对偏差小于0;从污染空气对真空比冲相对偏差的影响分析,污染空气对发动机性能的影响很小。

Theoretical analysis on effect of direct heating on ground simulation performance for solid ducted rocket motor

In order to simulate the air temperature in the afterburning chamber,the air used by the ground simulation test shound be heated.By direct-conncted simulation calculation,the effects of common heater fuel (hydrogen,kerosene,methane and alcohol) on performance of solid ducted rocket motor with low-oxygen boron-based propellant were investigated.The results show that oxygen content in the air flow is consistent with that in the ambient air,and can be used to simulate that in the ambient air.Relative deviation of motor vacuum specific impulse from direct-conncted simulation calculation have relation with fuel kind.Relative deviation is more than 0 when H_2 is taken as fuel,and less than 0 when other three matters are taken as fuel.Through analyzing the effect of polluted air on relative deviation of vacuum specific impulse,the results show that polluted air has small effect on motor performance.