基于铝片取向的复合热控涂层吸收发射比调控  

Regulation of ratio of absorptivity to emissivity of composite thermal control coating via orientation of aluminum flakes

作　　者：费天皓 张文杰 郑崇 董健 刘林华 Fei Tianhao;Zhang Wenjie;Zheng Chong;Dong Jian;Liu Linhua(School of Energy and Power Engineering,Shandong University,Ji'nan 250061,China;Science and Technology on Optical Radiation Laboratory,Beijing 100854,China)

机构地区：[1]山东大学能源与动力工程学院,山东济南250061 [2]光学辐射重点实验室,北京100854

出　　处：《红外与激光工程》2023年第3期322-330,共9页Infrared and Laser Engineering

基　　金：国家自然科学基金(52006127)。

摘　　要：金属颗粒掺杂型复合涂层是重要的航天器热控材料,除了粒子材料、尺寸、体积分数、几何形貌、涂层厚度等常规调控手段,颗粒的取向也是影响涂层辐射特性的重要因素。颗粒取向可以通过改变工艺参数或使用定向剂控制,然而目前关于颗粒整体取向对涂层吸收发射比的影响规律尚不清晰,而且现有的采用二流法的研究中大多都将散射假定为各向同性。以热控涂层中常用的大尺寸铝片粒子掺杂型复合涂层为计算模型,采用考虑衍射的几何光学方法和考虑各向异性散射的二流法研究了铝片取向角对热控涂层吸收发射比的调控规律,同时考虑了铝片体积分数和涂层厚度等因素。结果表明:通过调节粒子取向可实现涂层吸收发射比在0.48~1.69范围内的调控。涂层平均吸收率和平均发射率在铝片取向角超过45°时明显增大。涂层吸收发射比在铝片取向角45°附近最小,并且随铝片体积分数的增大而减小。研究表明:通过控制粒子的整体取向可有效实现吸收发射比的调控,为热控涂层的设计和调控提供了新的思路。Objective Metal particle pigmented coatings play a vital role in the thermal control of spacecraft.The ratio of absorptivity to emissivity of coating is one of the important properties of thermal control performance.Besides the conventional factors of particle material,size,volume fraction,morphology and coating thickness,particle orientation is also an important factor in the regulation of radiative properties of the coating.It is important to study the regulation method of the ratio of absorptivity to emissivity of the coating for the design of thermal control coating.The orientation of the particles can be adjusted by operating parameters or alignment agents.The effect of particle orientation on the ratio of absorptivity to emissivity of coating is not thoroughly explored yet.Moreover,the scattering in two-flux theory is usually assumed to be isotropic in the literature.Therefore,it is necessary to investigate the regulation of the ratio of absorptivity to emissivity of the coating by flake orientation.Methods As the commonly applied heat dissipation coating,the composite coating pigmented with large-size aluminum flakes was studied.The flakes were assumed to be randomly distributed and identically oriented.Due to the limitation of computer resources,it is infeasible to calculate the radiative properties of randomly distributed non-spherical large particles through strict solution of electromagnetic theory.The radiative properties of aluminum flake at different orientation angles were calculated by geometrical optics considering diffraction,and then the radiative transfer of the coating was solved by two-flux theory considering anisotropic scattering.The geometrical optics and the two-flux theory are suitable for the rapid calculation and analysis of the radiative properties of composite coating pigmented with large-size particles.The effects of orientation angle of aluminum flake,volume fraction and coating thickness were investigated.Results and Discussions The spectral radiative properties of aluminum flake

关 键 词：热控涂层 铝片取向角 几何光学 各向异性散射 二流法 吸收发射比 

分 类 号：TK121[动力工程及工程热物理—工程热物理]