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Surface-to-Surface Radiation
Posted Apr 14, 2020, 3:34 p.m. EDT Heat Transfer & Phase Change Version 5.4 1 Reply
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Hello! Tell me please different between boundary conditions: heat flux and external radiation source. I have two COMSOL project with thermal analysis: 1) Heat Transfer in Solids; 2) Heat Transfer With Surface-to-Surface Radiation. In both cases, the geometry (solid cube) and mesh are the same. In the first case my model has boundary conditions as heat flux on one side: 1000 W/m^2. In the second case my model (solid cube too) has boundary conditions on one side as external radiation source - infinite distance - posotion Y (-1) - Source Heat Flux: 1000 W/m^2 too. In the both analysis a Surface Emessivity is 0.6 on all outer sides of cube. Study: Stationary. As a result, the calculation results: temperatures, are differ from each other. Why?!!! I thought I would get the same results. What is the reason for this difference? Thank tou
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Hi,
There might be difference in the material in both cases. Did you set the boundaries differently, such as thermal insulation / emissivity? You can check if all other conditions are exaclty the same.
I am confused that when I add External Radiation Source it does not seem to work. When I disable that External Radiation Source the result does not change. Is there anything that I have missed?
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