[Geopdes-users] solution gradient times geometry gradient at a given side in a multipatch geometry

[Are S. <Are...@si...>]

I am doing some multiplication of the gradient of a scalar with the normal vector of the surface in a multipath geometry. I see that I can use the "msh_eval_boundary_side" to calculate the normals at the desired side while "sp_eval_boundary_side" can be used to calculate the  values and the geometry points. As far as I understand I will then have to give the correct weights for the solution (lets call these weights u) for that specific side into "sp_eval_boundary_side". That is I have to extract the correct local values for the side  from the global solution weights, u. If this is correct how do I find the correct u's for a given side in a multipatch geometry. If I am not correct and there is a much easier way to do this I would appreciate your advice!

I know another strategy is to use "sp_eval" at the correct side. Then I would have to calculate the normals of the geometry. This is done in already in "msh_eval_boundary_side" which is why I thought this would be a good way to do this...

What is the rule for global numbering of solution weights (u's) in a mp geometry?

Best regards,
Are Simonsen



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####    Are J. Simonsen, PhD.
####   Research scientist
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####    SINTEF MATERIALS&CHEMISTRY, Process technology
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