一种火箭基组合循环动力空天飞行器总体设计分析

Overall Design and Analysis of Rocket based Combined Cycle Powered Launch Vehicle

针对将2t有效载荷送入200km低地圆轨道的任务需求,通过定性分析明确了水平起飞、两级入轨的运载模式,建立火箭基组合动力(RBCC)空天飞行器的任务剖面。考虑RBCC空天飞行器复杂的耦合关系,建立一套基于弹道优化的总体设计流程,并形成相应的基准方案。在基准性能基础上,分析分离点状态、气动性能和发动机性能的影响。结果表明:低空高马赫数分离能有效发挥RBCC发动机的优势,提升运载效率,但需解决高动压分离的问题;阻力、推力、比冲是影响RBCC飞行器的重要性能参数,在性能较差的引射段,推力的影响尤为明显。设计方法和参数分析结果可为未来的空天飞行器设计提供参考。

Assuming the mission requirement of launching 2 tons payload into 200 km low earth orbit, a two-stage-to-orbit (TSTO) mode with horizontal takeoff was defined by qualitative analysis, and the mission profile of rocket-based combined power (RBCC) vehicle was established. Considering the complex coupling relationship in the RBCC aerospace vehicle, a set of overall design method based on ballistic optimization was established, and a set of benchmark scheme was formed. Based on the benchmark performance, the parameters of takeoff and landing speed, the fuel selection, the separation state, the aerodynamic performance and the engine performance were analyzed. The results showed that: High takeoff speed could effectively reduce the overall fuel consumption of RBCC aerospace vehicle, but it would lead to the increase of the size and weight of the landing gear, which will affect the overall cost of the vehicle. The drag, the thrust and the specific impulse were important performance parameters affecting RBCC vehicle, especially in the ejection mode with poor performance. The method and the results of parameter analysis in this paper may provide certain references for the design of aerospace vehicles in the future.