空间同位素热源故障再入极端环境条件分析  

Extreme Environmental Conditions Analysis of Space Radioisotope Heat Unit during Accidental Reentry

作　　者：魏昊功 马彬[1] 刘振玉[1] 刘中玉 朱安文[1] WEI Hao-gong;MA Bin;LIU Zhen-yu;LIU Zhong-yu;ZHU An-wen(Beijing Institute of Spacecraft System Engineering,Beijing 100094,China)

机构地区：[1]北京空间飞行器总体设计部,北京100094

出　　处：《科学技术与工程》2020年第21期8829-8834,共6页Science Technology and Engineering

基　　金：国家自然科学基金(11702020);民用航天技术预先研究项目(D020216)。

摘　　要：空间核动力源是支撑人类探索宇宙空间的关键技术,但安全问题始终是空间核动力源设计和应用的重要部分。以中国未来月球探测任务为背景,针对可能发生的典型的事故场景,建立三自由度动力学模型,并引入基于化学非平衡方程、完全气体方程的计算流体力学方法,开展空间同位素热源故障再入情况下的极端环境条件分析,分析空间同位素热源故障再入情况下气动力/热环境、海平面高度飞行速度和弹道倾角等极端环境条件。研究结果表明:同位素热源阻力系数为1.6左右,无量纲纵向压心系数约为0.5,再入过程0°攻角驻点热流密度峰值约为8.1 MW/m^2,总加热量约为101.55 MJ/m^2;从80 km开始经178.3 s到达海平面高度,此时同位素热源的飞行速度为86.5 m/s,弹道倾角为-89.9°。为后续放射性同位素热源结构热响应分析、高温高速撞击试验等安全性分析与验证工作的开展提供了必要条件。While space nuclear power source is a key technology for humankind to explore the universe,yet safety is always an important part of the design and application of space nuclear power source.Based on China s future lunar exploration missions,extreme conditions were analyzed for typical accident scenarios.A three degrees-of-freedom dynamic model was established and the computational fluid dynamic method based on chemical non-equilibrium equation and complete gas equation was introduced.Extreme environmental conditions analysis of space radioisotope heat unit during accidental reentry was conducted.Factors as aerodynamic force,aerothermal environments,flight velocity and trajectory inclination angle at sea level of space radioisotope heat unit during accidental reentry were analyzed.The results show that the drag coefficient of radioisotope heat unit is about 1.6 and the dimensionless longitudinal pressure center is 0.5.The peak heat flux rate of stagnation point at the angle of attack of 0 degree is 8.1 MW/m^2,and the total heat transfer is 101.55 MJ/m^2 during accidental reentry.Starting at an altitude of 80 km,it takes 178.3 s for the radioisotope heat unit to reach sea level,and the velocity and trajectory inclination angle are 86.5 m/s and-89.9°,respectively at that time.These results are essential for subsequent safety analysis and validation such as thermal response analysis of radioisotope heat unit and high temperature,high speed impact experiment.

关 键 词：同位素热源 故障再入 极端环境 弹道倾角 气动热 

分 类 号：V528[航空宇航科学与技术—人机与环境工程]