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Heat Transfer

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I'm trying to model a thin strip of aluminum, in 3d, using the heat conduction module. In the lab, we are trying to drive heat through one face of the aluminum and model the changing temperature throughout the plate, given the plate is in a vacuum and the walls of the vacuum are about 13K. The initial temp of the plate is 273K and we are driving it to 410K. My question is, I'm assuming the boundaries of the faces are heat flux boundaries, but what type of boundary is the face that the heat is being driven through? It seems like it's be a heat flux boundary as well, but I'm unsure where to enter in the temperature, 410K, that we are driving the aluminum to. Therefore, would that face be a temperature boundary?

1 Reply Last Post 29 juil. 2010, 16:27 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 29 juil. 2010, 16:27 UTC−4
Hi

it sounds for me that you have heat flux onto the layer where you have physical contact to another material of known temperature (perhaps also Joule heating ? in the film). And then most probably radiation exchange if you have vacuum around, not that then you need to know surface absorption and emissitivity (integrated over the wavelength) and use the sigma*T^4 relation in ABSOLUTE temperature "Kelvin" of the radiation exchange. And finally for radiative exchange you must define the "view factors" or apparent surface exchange solid angles, either by COMSOl calculations or by assumption. Check the doc

--
Good luck
Ivar
Hi it sounds for me that you have heat flux onto the layer where you have physical contact to another material of known temperature (perhaps also Joule heating ? in the film). And then most probably radiation exchange if you have vacuum around, not that then you need to know surface absorption and emissitivity (integrated over the wavelength) and use the sigma*T^4 relation in ABSOLUTE temperature "Kelvin" of the radiation exchange. And finally for radiative exchange you must define the "view factors" or apparent surface exchange solid angles, either by COMSOl calculations or by assumption. Check the doc -- Good luck Ivar

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