摘要
为研究添加遮光剂对SiO2气凝胶热辐射特性的影响,分别采用考虑基质吸收的改进的Mie散射理论和经典的Mie散射理论计算了气凝胶基质中单个粒子的热辐射特性和遮光气凝胶总的热辐射特性,并将两种方法的计算结果与已有实验数据进行了对比。分析了遮光剂粒子尺寸、分布规律对遮光气凝胶热辐射特性的影响,计算了遮光气凝胶的辐射热导率和不同温度下的最优粒径。结果表明:气凝胶基质的吸收作用对基质内的粒子散射影响较小,在计算遮光气凝胶热辐射特性时可以忽略。采用TiO2均一粒子系作为遮光剂,温度为300、500、700、900 K时的最优粒子半径分别为1.4、1、0.75、0.6μm。
To study the effects of adding opacifier to silica aerogel on its thermal radiation characteristics,the ther-mal radiative characteristics（TRC）of a single particle embedded in the aerogel matrix and the TRC of the opaci-fied aerogel were calculated by using the modified Mie scattering theory that takes the absorption of the matrix into account and the classical Mie scattering theory. The calculated results were compared with the experimental data in the literatures. The influence of the particle′s size and distribution of the opacifier on the TRC of the opacified aero-gel was analyzed. The radiative thermal conductivity（RTC）and the optimum particle size at different temperatures of the opacified aerogel were also computed. It was shown that the influence of the absorption of the aerogel matrix on the scattering of the particle embedded in the matrix is very small and can be neglected when calculating the TRC of the opacified aerogel. For the TiO2 opacified aerogel with a uniform TiO2 particle size distribution,the opti-mum particle radii are 1.4,1 ,0.75 ,0.6 μm at temperatures of 300,500,700,900 K,respectively.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2014年第5期642-648,共7页
Journal of Harbin Engineering University
基金
国防科学技术工业委员会基金资助项目(401030603)
关键词
遮光剂
气凝胶
热辐射特性
粒子散射
辐射热导率
吸收基质
二氧化硅气凝胶
opacifier
aerogel
thermal radiation characteristics
particle scattering
radiative thermal conductivity
absorption matrix
silica aeragel
