空间核反应堆异常再入高温高速撞击模拟试验中热响应特性研究

Research on Thermal Response Characteristics of Space Nuclear Power in High-Temperature and High-Velocity Impact Experiment under Accidental Reentry

高温高速撞击模拟试验是考核空间核反应堆异常再入大气层撞击地面事故安全性的重要项目。本文针对试验热加载和高速飞行阶段,建立了耦合传导、对流和辐射的有限体积模型,数值研究了试验中空间核反应堆堆芯模拟件的热响应特性,分析了加载温度变化速率和径高比的影响。结果表明,热加载阶段,堆芯模拟件最高温度和最低温度分别位于侧面及底面的交界处和模拟件中心;达到热平衡的时间除受加载温度变化速率的影响外还取决于模拟件径高比。高速飞行阶段,堆芯模拟件最高温度和最低温度所在位置与热加载阶段相反,且最低温度随着径高比和飞行时间的增加而减少。研究成果能够支撑高温高速撞击模拟试验系统研制及试验设计。

High-temperature and high-velocity impact simulation test is a significant experiment to evaluate the safety of space nuclear power reactor in the accident impact on ground after accidental reentry.In this paper,a finite volume model coupling conduction,convection and radiation is established for the heat loading and high-velocity flight phase of the test,and the thermal response characteristics of the core simulator of the space nuclear reactor in the test are numerically studied,and the effects of loading temperature change rate and diameter-height ratio are analyzed.The results show that during the heat loading phase,the highest temperature and the lowest temperature of the core simulator are located at the junction of the side surface and the bottom surface and at the center of the simulator respectively.The time to reach thermal equilibrium is not only affected by the change rate of loading temperature,but also depends on the diameterheight ratio of the simulator.In the high-velocity flight phase,the highest and lowest temperatures of the core simulator are opposite to those in the heat loading phase,and the lowest temperature decreases with the increase of the diameter-height ratio and flight time.The research results can support the development and experimental design of high-temperature and high-velocity impact simulation test system.