纳米流体近场辐射与消光作用的光谱特性

SPECTRUM CHARACTERISTICS OF NEAR-FIELD RADIATION AND EXTINCTION EFFECT IN NANOFLUID

以Al纳米流体为例,运用涨落电动力学方法计算球形纳米颗粒间的单色近场辐射换热量,运用Rayleigh散射近似方法计算纳米流体的消光系数,并对两者峰值光谱区间进行比较。结果表明:对于Al纳米颗粒,近场辐射偏长波区域,而消光系数偏短波区域,且消光系数透射波峰随颗粒半径增大而偏短波区域移动,这可为纳米流体非独立散射区的吸热特性研究提供参考。

In this paper, aluminum nanofluids was taken as an example for calculating its spectral characteristics of near-field radiation, using the fluctuating electrodynamics method, and of extinction effect using the effective medium method based on the Mie scattering theory. The spectrums for them indicated that the near field radiation tends to be dominant in the long-wave range, comparing with the extinction coefficient. However, the spectrum of the maximum value for the extinction coefficient shifts to larger wavelength region while increasing the nanoparticle radius. This can provide fundamental basis for further analysis of heat adsorption characteristics in the dependent regime for nanofluids used in direct solar collector.