薄膜二次表面镜热控涂层的辐射物性分析

Radiative properties of second surface mirror type thermal control coatings

认识热控涂层的热辐射物性对航天器热控制设计具有重要指导作用。文章根据薄膜二次表面镜涂层的吸收与反射过程分析,建立模型方程,结合已有的太阳吸收比、红外发射率等表观数据,采用非线性参数最小二乘法获得了薄膜材料的吸收系数和反射率等辐射物性,并分析了厚度对热控涂层太阳吸收比和红外发射率的影响。研究结果表明,聚酰亚胺薄膜对太阳光的表面反射率为0.571,吸收系数为19.343 mm-1,对红外辐射的表面反射率为0.227,吸收系数为39.615mm-1;F46薄膜对太阳光的表面反射率为0.744,吸收系数为0.757mm-1,对红外辐射的表面反射率为0.111,吸收系数为9.240mm-1。

The radiative properties of thermal control coatings are important parameters in the thermal control design of spacecraft. On the basis of analyzing the absorbing and refecting process of the second surface mirror of plastics, a radiative model is established. By combining the radiative model with the apparent radiative parameters such as the solar absorption and the infrared emissivity, the surface reflectivity and the medium absorption coefficient are obtained by the non-linear least squares method. The effects of thickness on the solar absorptivity and the infrared emissivity of the thermal control coatings are analyzed. The reflectivity and the absorption coefficient of the Kapton film are calculated to be 0.571 and 19.343 mm-1 for the solar spectrum, and those for the infrared spectrum are 0.227 and 39.615 mm1. The reflectivity and the absorption coefficient of the F46 film are 0.744 and 0.757 mm-1 for the solar spectrum, and those for the infrared spectrum are 0.111 and 9.240 mmt.