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Simulatneous temperature distribution...!

Lele, Dipl.-Phys. & Msc.

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Dear Comsol Users,

I am willing to come over to you again, this time with some questions I would like to be enlighted.
I've built a 3D heat exchanger (coil) inside a material (cylinder) and with Comsol, I would like to figure out the temperature distribution in the coil and on the material (cylinder). For this purpose i used "conjugate heat transfer" thinking that could give the both temperature distribution. Unfortunately, I only have velocity/pressure and temperature distribution
of the fluid inside the coil and nothing regarding the material...!!!!

- So I ask to you which other physics should I apply or did I used the previous module in the wrong way?
- What can I do to have the temperature distribution in the cylinder?
- Which physics moduls should I apply together in order to evaluate both fluid and maerial?
- Please, how to evaluate then the heat transfer coefficient?

Thanks in advance for your replies and look forward to hear from you guys.

--
A. Fopah Lele

5 Replies Last Post 7 mars 2013, 17:21 UTC−5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 28 févr. 2013, 02:21 UTC−5
Hi

you must have missed something in the coupling, you needa domain fluid and a domain solid node for each, and check that the default "wall" is at the correct interface. For me t works. Check the examples in the model library

--
Good luck
Ivar
Hi you must have missed something in the coupling, you needa domain fluid and a domain solid node for each, and check that the default "wall" is at the correct interface. For me t works. Check the examples in the model library -- Good luck Ivar

Lele, Dipl.-Phys. & Msc.

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Posted: 1 decade ago 28 févr. 2013, 11:11 UTC−5
Thanks Ivar for your suggestions. Indeed, I have my fluid and solid domains. The idea is to address the heat (temperature) from the fluid to the solid, but I found that there are "thermal insulation" on fluid wall. This boundary condition is generated by default in Comsol I think.
So what can I do to remove those thermal insulation. This is maybe the reason of non-communicative heat from fluid to solid!

What tips (if there exist) can I use here?

Regards,
--
A. Fopah Lele
Dipl.-Phys. & Msc.
Thanks Ivar for your suggestions. Indeed, I have my fluid and solid domains. The idea is to address the heat (temperature) from the fluid to the solid, but I found that there are "thermal insulation" on fluid wall. This boundary condition is generated by default in Comsol I think. So what can I do to remove those thermal insulation. This is maybe the reason of non-communicative heat from fluid to solid! What tips (if there exist) can I use here? Regards, -- A. Fopah Lele Dipl.-Phys. & Msc.

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

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Posted: 1 decade ago 28 févr. 2013, 11:33 UTC−5
Hi

difficult to say without seeing the model or at least an image of the model tree developed.

the NITF can be addresses from the fluid to solid but also from the solid to the fluid (direction of main flux), I suspect you have something wrong in the order of the nodes (up down), but it could be something else too ...

--
Good luck
Ivar
Hi difficult to say without seeing the model or at least an image of the model tree developed. the NITF can be addresses from the fluid to solid but also from the solid to the fluid (direction of main flux), I suspect you have something wrong in the order of the nodes (up down), but it could be something else too ... -- Good luck Ivar

Lele, Dipl.-Phys. & Msc.

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Posted: 1 decade ago 7 mars 2013, 10:26 UTC−5
Hi Ivar,
In attached is a picture file of my model. It's too heavy for uploading.
Now I've adjust some parameters and I could see the solid temperature distribution, but with no variation. And there is an error: Solution did not converge! What can I do here? I've checked all the used parameters, adjust and run but still obtained same wrong results.

Regards,
--
A. Fopah Lele
Dipl.-Phys. & Msc.
Hi Ivar, In attached is a picture file of my model. It's too heavy for uploading. Now I've adjust some parameters and I could see the solid temperature distribution, but with no variation. And there is an error: Solution did not converge! What can I do here? I've checked all the used parameters, adjust and run but still obtained same wrong results. Regards, -- A. Fopah Lele Dipl.-Phys. & Msc.


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

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Posted: 1 decade ago 7 mars 2013, 17:21 UTC−5
Hi

one thing for uploading, clea the solutions and the mesh (Edit clear all solutions ...) and File reset history, then save (with a new name) and upload the almost "empty" model file, then it will fit ;)

Also, if the model is big, try to start with a much simpler one, set up the model, palay with it until it gives reasonable results (simple model = one you can really and easily guess the results) then build up your more complex model

--
Good luck
Ivar
Hi one thing for uploading, clea the solutions and the mesh (Edit clear all solutions ...) and File reset history, then save (with a new name) and upload the almost "empty" model file, then it will fit ;) Also, if the model is big, try to start with a much simpler one, set up the model, palay with it until it gives reasonable results (simple model = one you can really and easily guess the results) then build up your more complex model -- Good luck Ivar

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