On Wed, Jul 22, 2015 at 7:13 PM, Sahai, Amal <sah...@illinois.edu> wrote:
> I have a system with 3 variables, representing the x,y,z component of a > quantity. I solved this system to obtain the component wise distribution in > a given domain. I would now like to calculate the divergence of this > distribution at the node points and then output this along with the > previous 3 variables. How do I compute the divergence at the node points? What finite element basis are you using? Depending on the basis, the divergence isn't going to be continuous across elements, so the nodal value is well defined. (I'm pretty sure we don't even have an FE that would have continuous divergence implemented in libMesh.) You could do something like patch recovery to extrapolate the quadrature point values to the node. Also, you could treat the divergence as a cell value and output it as an element quantity with ExodusII. The latter will be quickest and easiest to accomplish (checkout examples/systems_of_equations/ex6 which computes the average stress over the element and outputs it as a cell value). Best, Paul ------------------------------------------------------------------------------ _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
