RBCC引射性能对飞行器入轨运载特性影响分析

Influence analysis of RBCC ejector mode performance on transportation capacity of launch vehicle

为给火箭基组合循环动力系统(RBCC)引射技术研究提供参考,在性能指标和技术可实现性上实现平衡,对不同引射模态性能下的飞行器两级入轨运载特性变化规律进行了研究。设计两级入轨飞行器构型,并给出飞行剖面,对其180 km近地轨道入轨运载特性进行计算。研究表明:在动力系统性能均取基准值时,150 t级飞行器赤道平面入轨时可以将4.409 t有效载荷送入180 km近地轨道;有效载荷随引射模态比冲或推力的增加均会提高;考虑到引射模态比冲的可实现性及有效载荷对其敏感性,引射模态比冲并非越大越好,存在合理的取值范围,对于RBCC火箭发动机的两级入轨飞行器来说,合理有效的比冲取值范围在300~400 s之间;在一定范围内提高引射模态推力是更为合理的选择,当推力高于一定值后,推力提高带来的有效载荷增益越来越小。

In order to provide a reference for the research on ejecting technology of RBCC,as well as balancing the performance and realizability,the variation law of the transportation capacity for TSTO launch vehicle under different ejecting mode performance was studied.The configuration of the TSTO launch vehicle was designed,and the flight profile was given.Then the TSTO transportation capacity to low-earth-orbit at 180 km was calculated.The results show that when the propulsion system is set as the baseline values,4.409 t payload can be delivered into 180 km LEO from the equatorial orbit for 150 t launch vehicle.The payload increases along with the increase of specific impulse or thrust in ejector mode.Considering the realizability of specific impulse and the sensitivity of the payload to it,the larger specific impulse of the ejector mode is not the better,and there is a reasonable value range of specific impulse.For the TSTO launch vehicle with RBCC engine,the reasonable and effective range of specific impulse is between 300~400 s in ejector mode.It is a more reasonable choice to increase the thrust in ejection mode.Thrust should be as big as possible in ejector mode within a certain range.When the thrust is higher than a certain value,the payload gain becomes smaller and smaller along with the increase of thrust.