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heat source with time and temperature coupled load

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I have a battery with many cells in it, these are relatively sensitive to temperature. that is, 250 ° C, there is a sudden internal heat generation lasts about 30 seconds. I am now interested in the overall temperature distribution and development of battery if one after another cell due to the high temperature of the surrounding cells, self-developed heat. So a thermal runaway of a larger battery if someone including what can imagine.

Have now with the Comsol a colleague can play, but I myself, unfortunately, can not ask for more. while I have discovered something like ramp and square definitions, yes that would fit if I could link the definitions with a heat load. Maybe someone knows a tutorial.

thanks jojo

2 Replies Last Post Jan 19, 2015, 2:32 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 10 years ago Jan 19, 2015, 2:01 a.m. EST
Hi Joaquim

When you start a new model with COMSOL (and even when you are a specialist ;) start with some simple models, that you might check by a simple hand calculation and one physics at the time, to check you get the BC well defined.

For your case, make a simple bar, put one end at a fixed temperature and apply a time dependent heat source on the other end (by a time dependent function you might define under Definitions>Functions, and check what happens. Be sure you get the relations correct, that you understand the heat conductance and identify the heat diffusion. Then you might apply some other dissipations BCs such as surface air convection cooling ...
You might then try a frequency domain case, to be sure you master and understand fully the heat diffusion equation case.

Only then you can go confident into a more complex model with several heat sources, conducting and convection heat exchange, perhaps also radiative (if the latter is of interest, try out a few of the Model library cases, as radiative exchange can be quite tricky due to the Form/View Factors, and their calculations

--
Good luck
Ivar
Hi Joaquim When you start a new model with COMSOL (and even when you are a specialist ;) start with some simple models, that you might check by a simple hand calculation and one physics at the time, to check you get the BC well defined. For your case, make a simple bar, put one end at a fixed temperature and apply a time dependent heat source on the other end (by a time dependent function you might define under Definitions>Functions, and check what happens. Be sure you get the relations correct, that you understand the heat conductance and identify the heat diffusion. Then you might apply some other dissipations BCs such as surface air convection cooling ... You might then try a frequency domain case, to be sure you master and understand fully the heat diffusion equation case. Only then you can go confident into a more complex model with several heat sources, conducting and convection heat exchange, perhaps also radiative (if the latter is of interest, try out a few of the Model library cases, as radiative exchange can be quite tricky due to the Form/View Factors, and their calculations -- Good luck Ivar

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Posted: 10 years ago Jan 19, 2015, 2:32 a.m. EST
thanks for your answer. they still have a tip for me might realize heat source as I applying the coupled (time, temperature)?

best regards jojo
thanks for your answer. they still have a tip for me might realize heat source as I applying the coupled (time, temperature)? best regards jojo

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