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How to express the difference in temperature between two elements? (Lumped radiation)

Posted 25 juin 2012, 09:59 UTC−4 Heat Transfer & Phase Change, Materials, Mesh, Parameters, Variables, & Functions Version 4.2a 1 Reply

Raymond Ruigbaard
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Hello dear colleagues,

I am modeling heat transfer in a porous packed bed and I want to avoid T^4 terms (numerical stability), so, I want to model radiation in a simple way. The idea is to either lump radiation into conduction or make a simple source term for it.

The latter option would yield something like:
Radiation heat transferred = Boltzmann_constant * emissivity * surface_between_elements * average_temperature * (temperature_element_1-temperature_element_2)

OR: Q_rad = sigma * epsilon * T_av^3 * (T_1 - T_0)

But for this I need the temperature of the neighboring elements. How do I call those? Is there a better way to describe this idea? Is there a way to properly describe this using dT/dx (like conduction) ?

Thanks for any suggestions. Kind regards,

Ray
1 Reply Last Post 26 juin 2012, 04:04 UTC−4
Raymond Ruigbaard
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Posted: 1 decade ago 26 juin 2012, 04:04 UTC−4
Has no one else ever had to do something like this in COMSOL?
Please, if you know anything, let me know.

Thanks you and kind regards,

Ray
Has no one else ever had to do something like this in COMSOL? Please, if you know anything, let me know. Thanks you and kind regards, Ray

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