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Flux continuity along inner boundary

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COMSOL community,

I have a simple 2D square as my geometry and a circle within the square. The electrical conductivity inside the circle is different from the rest of the square.

I need to make ensure that there is flux continuity (i.e. current density is continuous) along the boundary of the inner circle c1/VE1. How do I do that?

I also need a finer mesh just along the inner boundary. How do I do that?

Model attached.

Thanks
Deepika


1 Reply Last Post Aug 1, 2014, 11:42 a.m. EDT

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Posted: 1 decade ago Aug 1, 2014, 11:42 a.m. EDT
If you put no boundary conditions at the edge of the inner circle there shoud be no net consumption or production of current there. Is that what you mean by flux continuity?

About the mesh: first do a physics-controled mesh that has the appropriate density for 'normal' areas. This will create a 'free triangular' subnode on the 'mesh' node. To this free triangular node, add a 'distribution' node, and select for this operation the edges of your circle. You can now use the settings of this node to separately play with the mesh density at your edge. Also, in the 'size' subnode of the 'mesh' node you can play with the 'maximum element growth rate' to tune how fast the mesh becomes coarser away from your edge.
If you put no boundary conditions at the edge of the inner circle there shoud be no net consumption or production of current there. Is that what you mean by flux continuity? About the mesh: first do a physics-controled mesh that has the appropriate density for 'normal' areas. This will create a 'free triangular' subnode on the 'mesh' node. To this free triangular node, add a 'distribution' node, and select for this operation the edges of your circle. You can now use the settings of this node to separately play with the mesh density at your edge. Also, in the 'size' subnode of the 'mesh' node you can play with the 'maximum element growth rate' to tune how fast the mesh becomes coarser away from your edge.

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