典型弹道升力式火星进入器性能比较分析

Performance comparison of typical semi-ballistic Mars entry vehicles

进入器的减速效率和着陆精度是火星进入、下降、着陆过程的关键问题,利用数值方法分析了火星科学实验室、"龙飞船"和"猎户座"飞船三种典型弹道升力式火星进入器的气动特性和进入轨迹,研究气动参数、进入姿态和进入器质量等参数偏差对开伞状态的影响,比较典型弹道升力式火星进入器气动特性和着陆性能,讨论几何构型对弹道升力式火星进入器性能的影响。研究结果表明:钝锥前体外形可以产生更高的阻力系数,但与球冠大底相比气动热环境也更严酷;同样的进入条件的前提下,三种进入器进入过程的最大过载和开伞高度相差不大,"龙飞船"的开伞动压相对较低,有利于降低减速伞系的开伞载荷。相关研究结论可为我国后续火星探测任务进入器气动外形设计提供有益参考。

The deceleration of the entry vehicle and precision landing are some of the key challenges during the Mars entry,decent and landing(EDL)stage.The aerodynamic characteristics and entry performances of three typical lifting Mars vehicles were analyzed,including Mars Science Laboratory,SpaceX’s Dragon capsule and Orion Multi-Purpose Crew Vehicle.The entry trajectories were analyzed with trajectory simulation program.In the present work,the aerodynamic characteristics and entry performances of three typical lifting Mars vehicles,and the impact of geometry configurations on the performances of Mars lifting entry vehicle were discussed.Results showed that sphere-cone heatshield will produce larger drag and more severe aerodynamic heat.Under the same conditions,there is not much difference between maximum load factor and opening height and the Dragon capsule has the lowest opening dynamic pressure,which is beneficial to decrease the opening load.The research results can provide valuable reference for aerodynamic design of future Mars entry vehicles.