基于CFD软件的桁架式望远镜遮光筒扰流分析  

A Study of Baffle Turbulence in Open Truss Telescope Based on CFD Software

作　　者：李陶然[1,2] Taoran(Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China, Email： [e-mail] University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院光学天文重点实验室(国家天文台),北京100012 [2]中国科学院大学,北京100049

出　　处：《天文研究与技术》2017年第1期70-77,共8页Astronomical Research & Technology

摘　　要：遮光筒会影响主镜上方的空气流动,不利于主镜表面与周围空气的热交换。以兴隆基地50 cm望远镜为例,应用CFD软件分析了两种消杂散光装置(遮光筒和独立挡光环结构)对主镜区域气流运动和温度的影响。同时根据温度数据计算主镜视宁度。分析结果表明,遮光筒会造成温度分布不均匀、湍流影响范围大、非对称的漩涡绕流等影响。独立挡光环结构的情况下,主镜视宁度减小74%。由此说明,在主镜散热和空气流通方面,主镜遮光筒有较大弊端。将该分析方法与杂散光分析结合,可合理选择杂散光抑制方案,对望远镜设计及改造具有一定参考和应用价值。Primary baffle would influence the airflow above the primary mirror, which is not conducive to heat exchange between the mirror＇s surface and the ambient air. The 50cm Telescope at Xinglong Observatory is influenced by two kinds of stray light suppression devices--baffle and vanes. In this paper, an analysis of airflow and temperature around the primary mirror of the 50cm Telescope has been carried out with CFD software. Mirror seeing has also been calculated with CFD data. Analysis results indicate that, the primary baffle will cause nonuniform temperature distribution, large area of turbulence and asymmetry vortex. In the case of independent vanes, mirror seeing decreases by 74%. These results show that the primary baffle has major disadvantages in respect of mirror cooling and air circulation. With the help of airflow and stray light analysis, plans for stray light control can be chosen more reasonably. The CFD analysis method could be helpful to telescope design and transformation.

关 键 词：桁架式望远镜 CFD 遮光筒 湍流模型 主镜视宁度 

分 类 号：P111.21[天文地球—天文学]