红外涂层的辐射热转移和选择性辐射

本文通过辐射热转移理论对热基质平面涂层的光谱辐射进行厂分析,并给出了在限定厚度范围内,该涂层光谱辐射的一般方程。由此可以判定在不同基质上,当涂层达到热力学平衡时,其红外辐射是属于黑体辐射或选择性辐射体系。本文同时还讨论了涂层厚度、涂层材料及不同基质性质对红外辐射特性的影响。

Radiative Heat Transfer and Selective Emission in Infrared Coatings

The spect.ral radiance of infrared ratiation emitted from a smooth planar coating in thermal contact with a hot substrate is analyzed by radiative transport theory. The solution of the radiative transfer equation which governs the spectral radiance within the coating is used to determine whether selective emitter coating in infrared banded regions can be obtained in the limiting cases of optically thin or thick regimes. If a coating of a selective emitter applied to a blackbody substrate forms a nonscattenng .absorbing and emitting layer in thermodynamic equilibrium with the substrate. the composite system can emit as a metallic (low emissivity) substrate and form a nonscattering,absorbing.emitting layer in thermodynamic equilibrium with the substrate .then the spectral radiance of the composite system will be dominated by the emissive properties of the coating.The composite system in which optical thickness approaches infinity can emit as a blackbody. The results are presented in a summary that shows how varing the optical thickness of the coatings,the coating material.and the substrate parameters to affect the emitted radiation.