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HTC calculation

Posted 27.06.2011, 05:36 GMT-4 Heat Transfer & Phase Change Version 4.1, Version 4.2 7 Replies

alirod
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Hi,
I'm trying to simulate a model of heat transfer between two solids.
I have, through experimentation, data on the variation of temperature at different points, density, etc.
Is it possible to calculate with Comsol the Coefficient of Heat Transfer (h) from these data?.
I work with Comsol 4.1: Could you please recommend the best module for this model?.
Thanks
7 Replies Last Post 14.02.2013, 08:56 GMT-5
Edgar Kaiser
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Posted: 1 decade ago 27.06.2011, 07:14 GMT-4
Alicia,

I would suggest the heat transfer module. However, thermal conductivity is a parameter in the model, not a dependent variable that is solved for. I see two possible approaches:

You can do a parameter study of thermal conductivity and see which value fits your measurement best.

Another approach would be to re-write the PDEs in order make the parameter into the dependent variable and use your measurent data as boundary conditions.

Cheers
Edgar
Alicia, I would suggest the heat transfer module. However, thermal conductivity is a parameter in the model, not a dependent variable that is solved for. I see two possible approaches: You can do a parameter study of thermal conductivity and see which value fits your measurement best. Another approach would be to re-write the PDEs in order make the parameter into the dependent variable and use your measurent data as boundary conditions. Cheers Edgar
alirod
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Posted: 1 decade ago 28.06.2011, 07:09 GMT-4
Thank you for you reply!!

One question: If I decide to re-write the PDE, Should I use the "PDE Interface" module or is there some way to do it in the "Heat Transference Module".

Thanks a lot,
Alicia
Thank you for you reply!! One question: If I decide to re-write the PDE, Should I use the "PDE Interface" module or is there some way to do it in the "Heat Transference Module". Thanks a lot, Alicia
Edgar Kaiser
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Posted: 1 decade ago 28.06.2011, 07:25 GMT-4
Alicia,

I am not completely sure but I don't think it is possible to modify the equations in the application modules.

So you probably need to do it in the PDE module. If I am wrong, I ask the forum to correct that.

Cheers
Edgar
Alicia, I am not completely sure but I don't think it is possible to modify the equations in the application modules. So you probably need to do it in the PDE module. If I am wrong, I ask the forum to correct that. Cheers Edgar
Jeff Hiller COMSOL Employee

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Posted: 1 decade ago 28.06.2011, 08:55 GMT-4
Hi Edgar,
It is possible to modify the pre-implemented equations. One way consists in modifying the weak expressions in the Equation View. You will need to turn on the Equation View first. In v4.2 you can do that through Options>Preferences>Show (if you want to do this permanently) or alternatively through the Show button located near the top right corner of the Model Builder window (if you want this turned on only for the current model).
Jeff
Hi Edgar, It is possible to modify the pre-implemented equations. One way consists in modifying the weak expressions in the Equation View. You will need to turn on the Equation View first. In v4.2 you can do that through Options>Preferences>Show (if you want to do this permanently) or alternatively through the Show button located near the top right corner of the Model Builder window (if you want this turned on only for the current model). Jeff
Ed Frank
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Posted: 1 decade ago 13.02.2013, 14:54 GMT-5

Hi Edgar,
It is possible to modify the pre-implemented equations. One way consists in modifying the weak expressions in the Equation View. You will need to turn on the Equation View first. In v4.2 you can do that through Options>Preferences>Show (if you want to do this permanently) or alternatively through the Show button located near the top right corner of the Model Builder window (if you want this turned on only for the current model).
Jeff


Can you give an example? I'd like to modify the electroneutrality equation in the NP interface. When I look under "Equation view" I see 7 entries in the variables table and the tables for shape functions, weak expressions, and constraints, are empty.
[QUOTE] Hi Edgar, It is possible to modify the pre-implemented equations. One way consists in modifying the weak expressions in the Equation View. You will need to turn on the Equation View first. In v4.2 you can do that through Options>Preferences>Show (if you want to do this permanently) or alternatively through the Show button located near the top right corner of the Model Builder window (if you want this turned on only for the current model). Jeff [/QUOTE] Can you give an example? I'd like to modify the electroneutrality equation in the NP interface. When I look under "Equation view" I see 7 entries in the variables table and the tables for shape functions, weak expressions, and constraints, are empty.
Ed Frank
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Posted: 1 decade ago 13.02.2013, 15:17 GMT-5
Oh, wait. I was looking in the wrong equation node. Looks like I need to understand the test() operator in COMSOL.
Oh, wait. I was looking in the wrong equation node. Looks like I need to understand the test() operator in COMSOL.
Niklas Rom COMSOL Employee

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Posted: 1 decade ago 14.02.2013, 08:56 GMT-5
I think this model does exactly what Alicia wants to do:
www.comsol.com/showroom/gallery/3903/
Niklas


Hi,
I'm trying to simulate a model of heat transfer between two solids.
I have, through experimentation, data on the variation of temperature at different points, density, etc.
Is it possible to calculate with Comsol the Coefficient of Heat Transfer (h) from these data?.
I work with Comsol 4.1: Could you please recommend the best module for this model?.
Thanks


I think this model does exactly what Alicia wants to do: http://www.comsol.com/showroom/gallery/3903/ Niklas [QUOTE] Hi, I'm trying to simulate a model of heat transfer between two solids. I have, through experimentation, data on the variation of temperature at different points, density, etc. Is it possible to calculate with Comsol the Coefficient of Heat Transfer (h) from these data?. I work with Comsol 4.1: Could you please recommend the best module for this model?. Thanks [/QUOTE]

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