外场热环境作用下地基望远镜温度分布预测

为研究外场复杂热环境对望远镜温度分布的影响，采用有限单元法，建立某全天候工作的激光通信地面站地基望远镜数值仿真模型。首先对望远镜主体进行稳态热分析，研究其在外场热环境作用下温度分布；再对主次镜进行瞬态热分析，研究其在通信时段与非通信时段温度变化。分析表明：冬夏两季望远镜最大温差为25.839℃,小于设计指标，证明望远镜能够在动态变化的外场环境中稳定通信；主次镜温度变化相较于舱内环境温度具有明显滞后性且幅值更低，在后续热分析中能够针对不同时刻正确设置主次镜温度边界条件，避免使用较高的舱内环境温度等效主次镜温度；通信前半小时打开舱门主次镜与环境温差不足以降低到2℃以下，建议设计合理热控措施，缩小舱内环境温度与外场环境温度差距，以保障望远镜通信质量。

Prediction of temperature distribution of ground based telescopesunder the influence of external thermal environment

To study the influence of the complex thermal environment of the external field on the temperature distribution of the telescope,the finite element method is used to establish a numerical simulation model of a ground based telescope for an all weather laser communication ground station.Firstly,a steady state thermal analysis of the main body of the telescope is carried out to study the temperature distribution under the influence of the external thermal environment.Then,a transient thermal analysis of the primary and secondary mirrors is carried out to study the temperature variation during the communication and the non communication periods.The analysis results show that the maximum temperature difference of the telescope in winter and summer is 25.839°C,which is lower than the design index,which proves that the telescope is able to communicate stably in the dynamically changing external field environment.The temperature changing of the primary and secondary mirrors has a significant hysteresis compared with the ambient temperature in the cabin,and has lower amplitude.Therefore,in the subsequent thermal analysis,the temperature boundary conditions of the primary and secondary mirrors can be set correctly for different times,which can avoid using a higher cabin ambient temperature instead of primary and secondary mirror temperature.Open the cabin door half an hour before the communication and the temperature difference between the primary and secondary mirrors and the environment is not enough to reduce the temperature to below 2°C.It is recommended to design reasonable thermal control measures to narrow the gap between the ambient temperature inside the cabin and the ambient temperature in the external field,in order to ensure the communication quality of the telescope.