综合考虑非线性气温环境和主镜视宁度表面“气刀”强制对流换热,对地基望远镜主镜瞬态温度场理论模型进行研究,结合分离变量法和格林函数法求解出温度场的解析表达式。以4m主镜为例,运用温度场理论模型解析解,对主镜视宁度进行了分析计算。分析了“气刀”对主镜视宁度的改善效果;讨论了“气刀”风速与主镜视宁度的关系;分析了不同径厚比对主镜视宁度的影响。利用有限元方法分析4m主镜温度场,与所推导的温度场理论结果进行比较,二者获得了较好的一致性。主镜温度场理论解在望远镜主镜设计中具有普适的应用价值。 Considering the nonlinear temperature environment and the primary mirror surface, the “air knife” forced convection heat transfer, the theoretical model of the transient temperature field of the primary mirror of the ground-based telescope is studied. The temperature field is solved by the method of separating variables and Green’s function Analytic expression. Taking the 4m primary mirror as an example, the temperature field theory model analytic solution was used to analyze and calculate the primary mirror sighting degree. The effect of “air knife ” on the main mirror viewing degree is analyzed. The relationship between the air knife ’s wind speed and the main mirror viewing angle is discussed. The influence of different aspect ratio on the main mirror viewing angle is analyzed . The finite element method is used to analyze the temperature field of the 4m primary mirror, which is in good agreement with the theoretical results of the temperature field deduced. The main mirror temperature field theory solution in the telescope primary mirror design has universal value.