How to Write Boundary Conditions?

Numerical methods and mathematical models of Elmer
sunyuan
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Re: How to Write Boundary Conditions?

Post by sunyuan »

Can I ask one more question? What is the meaning of "3,9,12,15" in the line "Physical Surface("ends1", 24) = {3, 9, 12, 15};"? I didn't find any related numbers in the ".geo" file...
kevinarden
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Re: How to Write Boundary Conditions?

Post by kevinarden »

You can always ask one more question, but there may not be one more answer, The geo is created automatically in gmsh using the gmsh menus. So the exact meaning of the numbers I do not know,. However I believe they are the line numbers that make up the surface.

The gmsh manual is online.
sunyuan
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Re: How to Write Boundary Conditions?

Post by sunyuan »

Ah, I see. Actually I'm just confusing that how to write a boundary condition like "0 potential at infinity"? Since I can't define a surface represents the infinity right?
kevinarden
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Re: How to Write Boundary Conditions?

Post by kevinarden »

If you look at tutorials 12, 14, 15 you can see how they created an air body around the bodies and defined the fairfield boundary condition to the outer surface

https://www.nic.funet.fi/pub/sci/physic ... orials.pdf
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