SimScale CAE Forum

Conjugate Heat Transfer with Heat Source Inside Fluid


I’ve recently been working on a problem in which a solid object inside a pipe is emitting X watts of heat. Water flows around that objecting, cooling it. However, I can’t find a good way to simulate this. The only way I can see to do this is to place an external wall heat flux boundary condition on the bottom of the solid object as a wall boundary condition. But, if I do this, the temperature distribution of the solid object would not be accurate.

I have tried to impose the external wall heat flux boundary condition on the interfaces between the solid and the water, but that does not work either.

Can anyone think of a good way to accomplish this? Is it possible to have my solid completely surrounded by water and still emitting heat?


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Hi @taustinOCC,

have you had a look at the project from @sjesu_rajendra? Click: CHT Simulation

You can also define a.heat source in CHT simulation. See: Heat Source CHT

Another example that might be interesting for you is: Heat sink-Electronics cooling using CHT

Tell me if that helped!

Good luck and happy simulating!


Hi @taustinOCC, just to clarify. You are really after a volumetric heatsource (W)? I think this is the way I would want to run this simulation. Not sure if this is available yet if this is what you need, remember seeing a post about it somewhere.

You could attach a heat flux with definition q, this would allow you to calculate heat flux by the area of the plane you are using. So make some kind of plane in the solid, do this by splitting the solid in two? might have to give it a go, I’ve never tried it, but that would pump heat into the solid at your required value. This would allow some kind of planar source?

If you are able to put a link of the model up I could see better how to do this,

@taustinOCC, @jousefm, @1318980 - Relevant for this case, we are planning to add volumetric heatsources to the Platform in our release next Wednesday.



Hi @AnnaFless, great to hear!! Thanks.


Thank you for the responses.

@jousefm, I have been using at least two of those examples as guides in my efforts. With their help, I at least have meshing down and good understanding of the Numericals and Simulation Control.

@1318980, That is what I have been trying to do in the meantime. My only concern with splitting the model in half is the inaccuracy of the mixing at the back side of the solid heat source, particularly in the case of turbulent flow modeling. Although, this shouldn’t greatly affect my results focused in the heat transfer. I do believe the Symmetry boundary condition would be helpful for such a split down the center of the geometry, but am not sure if this boundary condition is helpful for 3D geometry. Also, I’m having difficulty figuring out how to apply both the symmetry and external wall heat flux conditions to the cross-section of the solid heat source after being split. Is the symmetry boundary condition only for symmetry in fluid properties at each reflected point across the plane?

@AnnaFless, That is outstanding news! I look forward to this release.


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@taustinOCC, is there any chance I could see your model to better understand your setup? I just want to see if we can put together a custom boundary for this but without seeing the problem I’m finding it hard to imagine.

Kind regards,

Hi Anna
Any news on Volumetric heatsources?

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Hi David (@DavidKing) ,

Yes, my apologies for not posting an update in this thread - Volumetric heat sources are now available for CFD Analysis Types: Conjugate Heat Transfer and Convective Heat Transfer (without boussinesq approximation). We are still developing the content for this feature release (ie example projects and documentation) - but it will be coming soon.




And a video for more context with this volumtric heat source feature:


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