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Define subdomains with MATLAB

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Hello everyone,

I don't understand how the definition of subdomains and subdomains groups works with MATLAB.
I've saved the Comsol 2D example "coil inductance" as an M-File to see how it works. The geometry of this example is a half circle with a smaller circle in it. But then in the code, I find these lines:

bnd.type = {'A0','cont','ax'};
bnd.ind = [3,1,1,2,2,2,2];

The second line allocate for each subdomain a number of subdomain group. So we have here 3 subdomain groups, but 7 subdomains. But I would like to know: how to define the subdomains after we build the geometry ?

Thanks
Ronan

2 Replies Last Post 16 set 2009, 11:02 GMT-4

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Posted: 2 decades ago 15 set 2009, 11:33 GMT-4
I think these are boundary conditions if im not mistaken. 3 boundaries for the half circle and 4 for the inner circle. I think the numbers in the bnd.ind line refer to one of the 3 boundary condition types in the above line, i.e. on boundary 1 there is an 'ax' condition, boundaries 2-3 have an 'A0' condition and on boundary 4-7 there is continuity ('cont'). You will find information relating to each subdomain in the equ. lines below where the boundary conditions are stated. Hope this helps, Ive only recently started using the Matlab functionality myself

Adam
I think these are boundary conditions if im not mistaken. 3 boundaries for the half circle and 4 for the inner circle. I think the numbers in the bnd.ind line refer to one of the 3 boundary condition types in the above line, i.e. on boundary 1 there is an 'ax' condition, boundaries 2-3 have an 'A0' condition and on boundary 4-7 there is continuity ('cont'). You will find information relating to each subdomain in the equ. lines below where the boundary conditions are stated. Hope this helps, Ive only recently started using the Matlab functionality myself Adam

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Posted: 2 decades ago 16 set 2009, 11:02 GMT-4
Hello Adam,
Thanks for your answer.
Hello Adam, Thanks for your answer.

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