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本文讨论一种确定固体材料比辐射率的方法.在被测材料的表面开一个圆柱形空腔,并在其背面均匀加热.联立求解腔壁的辐射换热和体内的热传导方程,求得温度场分布和腔底的有效辐射.结果表明,腔底的有效辐射是比辐射率、腔深和半径之比以及一个表示温度梯度的参数的函数.文中讨论了能量辐射和光子辐射两种情况.在实验中,用热象仪测量材料表面和腔底的有效辐射.由理论分析结果和实验测定的有效辐射,求得材料的比辐射率.
This article discusses a method of determining the emissivity of a solid material by forming a cylindrical cavity on the surface of the material under test and heating it evenly across the back of the material to determine the radiative heat transfer of the cavity wall and the heat transfer equation in the body The distribution of temperature field and the effective radiation at the bottom of the cavity.The results show that the effective radiation at the bottom of the cavity is a function of the ratio of emissivity, cavity depth and radius and a parameter that represents the temperature gradient.In this paper, two cases of energy radiation and photon radiation In experiment, the effective radiation of material surface and cavity bottom was measured by thermal imager, and the emissivity of the material was obtained from the theoretical analysis results and the experimentally measured effective radiation.