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Heat Transfer in Solids Convergence Issues

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Hello,

I am trying to model the temperature within a copper cylinder that has some power density within it, but can not seem to get the model to converge.

Any help/advice would be greatly appreciated.

Very Respectfully,

Will.


7 Replies Last Post 24.09.2015, 16:04 GMT-4

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Posted: 9 years ago 24.09.2015, 13:38 GMT-4
Hi,

You have heat coming in but nothing going out. Mayby heat flux from outer walls will handle the problem.

Best regards

Tero Hietanen
Hi, You have heat coming in but nothing going out. Mayby heat flux from outer walls will handle the problem. Best regards Tero Hietanen

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Posted: 9 years ago 24.09.2015, 13:58 GMT-4
Hello,

I defined that around the edge, it will not allow me to define it anywhere else.

It will still not converge. I tried putting a heat flux of 0, and a non-zero value.

Very Respectfully,

Will
Hello, I defined that around the edge, it will not allow me to define it anywhere else. It will still not converge. I tried putting a heat flux of 0, and a non-zero value. Very Respectfully, Will


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Posted: 9 years ago 24.09.2015, 14:23 GMT-4
Hi,

I added heat flux with convective heat transfer coefficient. Check model.

Best regards

Tero
Hi, I added heat flux with convective heat transfer coefficient. Check model. Best regards Tero


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Posted: 9 years ago 24.09.2015, 14:42 GMT-4
Hello,

Thank you!

So this kind of modelling assumes that the temperature within the heat source is constant? Wouldn't there be a greater internal temperature than what is on the surface?

Very Respectfully,

Will.
Hello, Thank you! So this kind of modelling assumes that the temperature within the heat source is constant? Wouldn't there be a greater internal temperature than what is on the surface? Very Respectfully, Will.

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Posted: 9 years ago 24.09.2015, 15:37 GMT-4
Hi,

In your current model air is defined as fluid but is not moving (no buoyancy flow). Due to this your block is between solid air which is quite good insulator. If you want to add flow, check this:

www.comsol.com/blogs/using-the-boussinesq-approximation-for-natural-convection/

Best regards

Tero
Hi, In your current model air is defined as fluid but is not moving (no buoyancy flow). Due to this your block is between solid air which is quite good insulator. If you want to add flow, check this: https://www.comsol.com/blogs/using-the-boussinesq-approximation-for-natural-convection/ Best regards Tero

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Posted: 9 years ago 24.09.2015, 15:42 GMT-4
Hello,

That's interesting. Thank you again for the help.

One last question, by any chance do you know if I can simulate the cylinder of copper as a coil of copper wiring and how I would go about doing that?

Very Respectfully,

Will.
Hello, That's interesting. Thank you again for the help. One last question, by any chance do you know if I can simulate the cylinder of copper as a coil of copper wiring and how I would go about doing that? Very Respectfully, Will.

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Posted: 9 years ago 24.09.2015, 16:04 GMT-4
Hi,

Hmm... maybe defined as solid block but different heat transfer to every axis direction (effective heat conductivity). If wiring is very thin, define coil directly to solid copper.

Best regards

Tero
Hi, Hmm... maybe defined as solid block but different heat transfer to every axis direction (effective heat conductivity). If wiring is very thin, define coil directly to solid copper. Best regards Tero

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