一种热网络方程计算方法的改进

通过热网络离散节点群控制方程的敏感性分析,提出了一种新的热网络方程求解改进方法———分离变量参数系数方法,用于分析航天器表面材料性质对温度场分布的影响.同时,采用蒙特卡罗射线踪迹法求解太阳直接入射面积和太阳辐射传递系数,考虑了航天器几何遮挡关系对热网络系数的影响.计算结果表明:航天器虚拟模型主体部位的最大温度值要高于太阳电池板的温度.在开始阶段,冷却速度迅速增加至最大值,然后再慢慢降低并有17K温度的偏差.为了分析材料表面的太阳吸收系数对温度分布的影响,以a=0.35为算例原值,对于与原值的吻合程度,太阳吸收系数增大的影响优于其减小的影响.

An improved solution to thermal network equation

Based on the sensitivity analysis of discrete node group control equation for thermal network,a new improved solution,detached variables-parameters coefficient(DVPC) method,is proposed to solve thermal network problem in heat-transfer analysis of spacecraft.It emphasizes analyzing the spacecraft surface material properties′ influence on the temperature field distribution.Monte Carlo ray tracing method is used to solve solar direct incidence area and network radiation transfer coefficient.Meanwhile,effects of spacecraft geometry sheltering on thermal network coefficient are discussed.Numerical simulation results indicate that the maximum temperature value of satellite main body in simulation model is larger than that of solar array.At the beginning stage,cooling velocity increases rapidly and gets to its maximum value,then descends slowly and reaches up to steady stage with 17 K discrepancy.For analyzing the impact of solar absorption coefficient,the calculating results of a=0.35 is employed as original value.Meanwhile,influence of increasing solar absorption coefficient is better than that of decreasing to true value.