空间光学镜头可适应边界温度的CAE计算方法

A calculating method for temperature tolerance of space telescope

提出了空间遥感器温度场的描述方法,建立了某空间遥感器光学镜头的热光学分析模型,计算得到了该空间光学遥感器温度水平和温差要求的热控指标。在对遥感器在轨运行热载荷状态进行假定描述的基础上,用有限元方法进行了温度场及热弹性变形分析,得出假定温度载荷作用下光学遥感器各光学表面的变形量及刚体位移量。利用Zernike多项式进行波前差拟合,得到Zernike多项式系数,代入光学系统,利用CODEV光学计算软件计算热载荷作用下光学镜头的传递函数(MTF)。通过迭代,得到光学系统满足传递函数指标>0.4要求的各温度场临界值,完成了从光学指标到热控指标的转换,避免了热控设计的过设计或设计不足,可以在设计方案阶段作为遥感器结构的热适应性设计的参考,同时为制定合理的热控设计指标提供数据依据。

A calculating method for the permissible temperature tolerance of the space telescope is studied and the temperature fields including every temperature state that the telescope is on orbit are described. The temperature field and thermal elastics based on a coupling model of the space telescope are analysized to abtain the displacement of optics surface and then its corresponding deformation is fitted as Zernike polynomial to use in a optical system. The MTF of telescope is calculated by transforming the coefficient of the polynomial into software CODE V. Experiment results show that when the MTF meets to the optical target, the ultimate temperature tolerance of the space telescope can be obtained, which is the aim temperature scope for the thermal design.