地外天体上航天器起飞瞬时羽流对主发动机干扰效应影响

The effect of plum on main engine of ascending spacecraft launched from extraterrestrial bodies

与地面运载/导弹发射相比,地外天体起飞航天器的主发动机在受限空间内点火瞬时,将短时处于非自由流态的工作环境条件下;羽流激波进入喷管内部且可能产生“激波贴壁”,对发动机喷管造成力、热综合效应,影响发动机工作的安全可靠性。文章从地外天体受限条件下羽流对发动机的影响要素出发,完成地外天体受限条件下的羽流建模和仿真分析,给出激波在喷管内的分布形态和变化规律并进行试验验证。所得结论可对地外天体起飞航天器的构型布局设计、导流设计和主发动机工作安全性评估提供参考依据。

In comparison with vehicles or missiles launched from the ground,an ascending spacecraft launched from an extraterrestrial body is generally obstructed by a limited firing space for its main engine.Therefore,the main engine will be forced to stay in a non-free flow state when the generated plume shock squeezed inside the nozzle jet becomes an“adherence plume shock”,with both heating and impacting effects on the nozzle and with potential threats to the safety and reliability of the engine and its peripheral equipment.In this paper,the possible influencing factors of the generated plume on the engine under limited conditions are analyzed.By the modeling of the engine plume and the related simulation analysis,the distribution pattern and the transformation of the plume shock in the nozzle jet are proposed and testified by experiments.The results may help the design of the spacecraft configuration,the plume diversion,and the safety evaluation of the main engine for spacecraft to be lifted off from extraterrestrial bodies.