thermal expansion

General discussion about Elmer
kevinarden
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Re: thermal expansion

Post by kevinarden »

You go to github.com sign up for an account or sign in if you have one. Create a new repository, make it public. Go to add file, upload. Share repository link.

I believe it is possible to solve first the EM and then solve the HT (with the EM_Joule heating beeing the HT body force), and at last the LE (with the thermal expansion coming from the HT temperature)

You could do it with restarts using the previous saved step as the inital starting point for the next one.
kevinarden
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Re: thermal expansion

Post by kevinarden »

There is a detailed discussion on joule heating located here

viewtopic.php?f=7&t=7021&hilit=joule+heating
kevinarden
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Re: thermal expansion

Post by kevinarden »

I took the harmonic wire tutorial, then added heat and displacement to it. I seems to yield reasonable results.
joule1.tar.gz
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Roland
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Re: thermal expansion

Post by Roland »

Hi Kevin, thanks a lot for this test which I will look at! But my wish is to have it work with my spiral inductor, as you can understand... What is your opinion about why it does not work in this spiral inductor configuration for the moment?
We keep us informed
Thanks again!
Roland
Rich_B
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Re: thermal expansion

Post by Rich_B »

Hello Roland,

What happens with your spiral model, when you increase the number of elements in just the aluminum/insulator sheet? The width of the inductor element looks like it is almost equal to the width of each sheet element. What happens if the sheet elements were one quarter (or smaller) of the inductor width?

Than
kevinarden
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Re: thermal expansion

Post by kevinarden »

I think there is a mesh density issue, the mesh is too coarse. However, Roland when I use your case.sif with the wire.grd tutorial model the temperatures and displacements are extremely large.
Roland
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Re: thermal expansion

Post by Roland »

Hello Rich and Kevin, yes I think you are completely right, the problem comes very probably from the too coarse mesh in the plate! I will try to get a finner mesh in the plate in the Gmsh file. I don't master Gmsh very well, so if perhaps you know how to get a finer mesh selectively just in the the plate(and not in the other domains) please could you explain me how to do that the in Gmsh?
Again many thanks and we keep us informed
Roland
kevinarden
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Re: thermal expansion

Post by kevinarden »

In gmsh you can go mesh, define, transfinite, then you can specify the number of elements on a curve, surface, or volume.
Rich_B
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Re: thermal expansion

Post by Rich_B »

Another option when using gmsh: after loading the geometry, and generating a mesh, select 'Mesh -> Refine by splitting'.

A third option is to add a command similar to this: Mesh.MeshSizeMax = 0.01. The way to add the command is to 'edit script' under geometry, then type in the command anywhere in the script, save and reload the script. The attached file shows the use of the command.

Rich.
Spiral_ind_2.geo
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kevinarden
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Re: thermal expansion

Post by kevinarden »

I believe these operate on the entire mesh whereas the transfinite you can select specific curves, surfaces, and volumes.
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