Hello Deal.II Users,

I am working on setting a constraint: (V - v_s ) \cdot n = \phi_f (v_f - v_s) \cdot n on three vector variables at the interface with affine constraint class in Deal.II's library. (Where, V, v_s, and v_f are velocity vectors on two different domains, and they are coupled with each other at the interface; n is the normal vector; \phi_f is the volume fraction.) I decided to constrain either V_x= -(...) / n_x or V_y= -(...) / n_y depending on the absolute values of n_x or n_y (n_x and n_y are the components at x, y directions of the normal vector n). Now, I have a problem with getting the normal vectors *at nodes *when playing with affine constraint within the fe_nothing and hp:finite element framework. The relevant function/class I have found in Deal.II's library all return the normal vector *at quadrature points,* not at nodes. Have you ever encountered a problem like this? Could you kindly share me your idea of handling this problem? Thousand of thanks. Best, Lei Li -- 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 dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/d0e78c60-d0d0-4748-8252-de28d7ef5a8co%40googlegroups.com.