为了掌握500m口径球面射电望远镜(FAST)在太阳辐照下的温度分布,弱化它的"太阳灶"问题,保护馈源舱内相关仪器,对太阳辐照FAST温度场进行了研究,包括太阳相关参数研究、"太阳灶"问题解析及热流计算、台址地貌对FAST的阳光遮挡及不同工况下的FAST温度分布等。结果表明,FAST馈源舱温度分布不仅与反射面反射率、孔隙率和辐照时间有关,而且与馈源舱防护罩的反射率、材料、焦舱位置、微波入口直径等因素有关。当反射面反射率为0.2、孔隙率为0.4时,馈源舱最高温度为47.56℃,时间约在12∶00;反射面最高温度为68.34℃时,时间是在14∶00,此时与反射面最低温度为35.03℃时的温差为33.31℃。文章还计算了形成太阳灶的时间域,最后为FAST的相关设计及使用提出了意见和建议。
To master the temperature distribution and "Solar cooker" of a Five-hundred-meter Aperture Spherical Radio Telescope(FAST) and to protect instruments in a feed cabin under the solar radiation,the temperature distributions of the FAST are studied in detail,which includes sun parameters,"Solar cooker" calculation,heat flows and the temperature distribution of the FAST under different work conditions.The results indicate that the feed cabin temperature distribution is not only relevant to the reflector reflectivity,porosity rate,and the radiation time,but also to the reflectivity of the shield,materials,the diameter of microwave inlet and other factors.The analysis results of work conditions show that the reflector reflectivity is 0.2,porosity rate is 0.4 and the maximum temperature of the feed cabin is 47.56 ℃ at 12∶00.Furthermore,the temperature of reflector surface reaches maximum 68.34℃ at 14∶00,in which the minimum temperature is 35.03 ℃,and the temperature difference of reflector is 33.31 ℃.Moreover,the time domain of solar cookers is simulated.Finally,it gives the comments and suggestions for the design and use of FAST.The research in this paper not only obtains the temperature distribution of the FAST,but also provides references for the design and use of the FAST.