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BC convergence criterium or Stop condition

Posted 17 août 2011, 05:00 UTC−4 Heat Transfer & Phase Change, Computational Fluid Dynamics (CFD), Parameters, Variables, & Functions Version 4.3b 1 Reply

Paolo Mesolella
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Hi to all,

i'm trying to solve a problem of heat transfer in porous medium in non local thermal equilibrium.

I use 2 ht modules linked by a source term to compute fluid and solid phase equations.

This model is ok when i use a BC like Tf=Ts=cost.

Now i want to apply this condition:

On fluid phase an heat flux: 100[W/m^2]-ht2.tfluxx where ht2fluxx is the flux on solid phase and is unknown.

On solid phase Tf=Ts where Tf=Ts is unknown

The model runs and reach a solution.

When I check this one i should find that ht.tfluxx+ht2.tfluxx=100 W/m2 indeed i find 90 W/m2.

So i would personalize a convergence criterium on BC or use a stop condition...i don't know.

I tried to use finer meshes and strong tolerance to check convergece (1e-10) but this unbalance still remain.

Thanks in advance.

Paolo
1 Reply Last Post 11 déc. 2013, 15:02 UTC−5
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Hello Paolo Mesolella

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Marco Zanoni
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Posted: 1 decade ago 11 déc. 2013, 15:02 UTC−5
Hi Paolo,

I'm trying to apply local thermal non-equilibrium as well, but I would like to relate Ts and Tf in both equations by a heat loss in the source therm. For example h(Ts-Tf) for the energy equation for solid phase and h(Tf-Ts) for the energy equation for fluid phase. But I'm getting some problems about boundary conditions.

Do you have any idea about how to relate Tf and Ts?

Thanks

Marco
Hi Paolo, I'm trying to apply local thermal non-equilibrium as well, but I would like to relate Ts and Tf in both equations by a heat loss in the source therm. For example h(Ts-Tf) for the energy equation for solid phase and h(Tf-Ts) for the energy equation for fluid phase. But I'm getting some problems about boundary conditions. Do you have any idea about how to relate Tf and Ts? Thanks Marco

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