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How can I have the value of the total heat flux passing through an element

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I am simulating a simple concrete wall junction and i've created a temperature difference between the exterior and the interior.
Now I need the total heat flux passing from the interior to the exterior, I am only able to visualise the progress the heat flux through the wall, but I need the value of the heat flux passing through it. Can anyone help me?

3 Replies Last Post 28 avr. 2011, 08:36 UTC−4

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Posted: 1 decade ago 27 avr. 2011, 11:34 UTC−4
Try to go to Equation View, maybe you' ll find the variables you want
Try to go to Equation View, maybe you' ll find the variables you want

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Posted: 1 decade ago 28 avr. 2011, 03:29 UTC−4
Actually the equations are right and I am getting coherent results but I need to find the total heat flux and this I can't figure out how to do this, in the 3.5 version there is the post treatment where you can get the values of the heat flux passing through any surface you want but how can I do the same thing in the 4.0 version?
Actually the equations are right and I am getting coherent results but I need to find the total heat flux and this I can't figure out how to do this, in the 3.5 version there is the post treatment where you can get the values of the heat flux passing through any surface you want but how can I do the same thing in the 4.0 version?


Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 28 avr. 2011, 08:36 UTC−4
Hi

I do not have 4.0, but here is an example in 4.1

You need ti integrate the normal heat flux. But for good/best results, you should set the fixed temperature boundaries to "use Weak form". Then in the Solver Enable "Direct mode" (requires more ram than an iterative solver). And integrate "T_lm" over the boundary. T_lm (the lagrange multipliers) is given without units, but in HT its W/m^2 see the doc

Check also the page on the KB about heat fluxes

--
Good luck
Ivar
Hi I do not have 4.0, but here is an example in 4.1 You need ti integrate the normal heat flux. But for good/best results, you should set the fixed temperature boundaries to "use Weak form". Then in the Solver Enable "Direct mode" (requires more ram than an iterative solver). And integrate "T_lm" over the boundary. T_lm (the lagrange multipliers) is given without units, but in HT its W/m^2 see the doc Check also the page on the KB about heat fluxes -- Good luck Ivar

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