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Mirror temperature field on x,y-plane (General extrusion coupling)

Posted Feb 4, 2014, 4:20 a.m. EST Parameters, Variables, & Functions Version 4.4 2 Replies

Joerg Schwieger
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Hello,
I would like to simulate a stationary heat transfer problem in a first step and the Eigenmodes (with the pressure acoustics modul) in a second step. Because the heat transfer problem is symmetrical to the x,y-plane (and to save computing time), I only simulate it in one half of the model. Then I would like to mirror this temperature field on the x,y-plane to calculate Eigenmodes in the whole model.
I tried the "General Extrusion coupling" to mirror the temperature field of the half model onto the other side to get a temperature field that is defined in the whole model. My problem is that the "General Extrusion coupling" mirrors the temperature field but does not keep the original temperature field on the side so that I do not have a temperature field in the whole model.
I attached the file to my problem (version 4.4).

I appreciate any helpful ideas!

Best regards, Joerg
2 Replies Last Post Feb 4, 2014, 7:39 a.m. EST
Nils Malm COMSOL Employee

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Posted: 1 decade ago Feb 4, 2014, 7:19 a.m. EST
Dear Joerg,
The extrusion coupling operator genext1() in your model only evaluates correctly at locations such that the source and destination transformations together map the location on a point in the source domain. This only happens at destination locations with z>0.

The trick to make your model solve is to use a Varables feature with the destination domain as selection to define "T" as "genext1(T)" in the destination domain. This makes the variable name T available everywhere in your model; it doesn't matter that it is a dependent variable in one domain and an expression variable in another. Then you can write your acoustic density expression naturally as a function of "T". And as a side effect, you can plot "T" on the complete geometry if you want to.

best regards
Nils Malm
Dear Joerg, The extrusion coupling operator genext1() in your model only evaluates correctly at locations such that the source and destination transformations together map the location on a point in the source domain. This only happens at destination locations with z>0. The trick to make your model solve is to use a Varables feature with the destination domain as selection to define "T" as "genext1(T)" in the destination domain. This makes the variable name T available everywhere in your model; it doesn't matter that it is a dependent variable in one domain and an expression variable in another. Then you can write your acoustic density expression naturally as a function of "T". And as a side effect, you can plot "T" on the complete geometry if you want to. best regards Nils Malm
Joerg Schwieger
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Posted: 1 decade ago Feb 4, 2014, 7:39 a.m. EST
Dear Nils,
Thanks for your answer. That works perfectly!
Dear Nils, Thanks for your answer. That works perfectly!

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