I have a problem with direction-dependent diffusion (that is, the diffusivity \nu depends on the derivative direction but not spatial location) such that the horizontal diffusivity and vertical diffusivity are different, leading to a Laplacian as follows:
I am discretizing the problem with a mixed method, which defines the auxiliary variable L = ∇u such that So in my weak form, I end up with terms like the following: (please excuse the abuse of index notation with repeated j three times). phi_ij here refers to each scalar basis function in the tensor-valued finite element space. It seems using the deal.ii FEValuesExtractors, I can access the divergence of each tensor-valued basis function, but I need to multiply each term in the divergence with the appropriate value of \nu by component. I suppose I could ask for the gradient of each phi and do the sum manually,but I was wondering if there's a way to do it directly. Is there a standard way of doing this in deal.ii? Any pointers would be appreciated! -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/65594873-33d7-44c2-834b-ba398fd9fb1bn%40googlegroups.com.
