Dear all While a solving a conservation law with DG, I find that total mass is not conserved. To get total mass conservation, we need
sum_(i=0,1,...ndofs-1) grad(phi_i(xq, yq, zq)) = 0 where phi_i are shape functions and ndofs = fe.dofs_per_cell and above equation must hold at every quadrature point (xq,yq,zq). I have checked in my application that above sum is O(1e-14). While this is small, it seems to lead to slow mass loss as it gets multiplied by a large number. This can be easily fixed by taking grad(phi_0(xq, yq, zq)) = - sum_(i=1,...ndofs-1) grad(phi_i(xq, yq, zq)) I want to test if this really solves my conservation problem. Can you help me by pointing out in which function I have to put this fix ? Somewhere in FEValues class ? Thanks praveen -- 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. For more options, visit https://groups.google.com/d/optout.
