On Mon, Jun 13, 2016 at 2:43 PM, Ryan Woodall <rwood...@utexas.edu> wrote:
> Hi everyone, > > I've got a problem where I'm try to implement 2 types of boundary > conditions on a FEM model. The first type of BC i have is a zero-flux BC, > which is pretty easy to implement. However, I'm also trying to implement > time-dependant Neumann BC's, and I'm not sure how to do that. They are > essentially of the following form: > > grad(C) = P*(C_p(t)-C(t)) > > where P is a time-invariant constant, and C_p(t) is known at every time > step. > I think you left out the "dot n" on the left. > > I'm new to C++ and libmesh, so very basic level help would be the most > helpful. > There are several examples of how to do something similar to this in the examples. One is in examples/transient/transient_ex1. There we are imposing a Dirichlet BC, but it's done weakly via a penalty by computing a surface integral contribution. Look at the code around the "fe_face->reinit(elem, s);" line. -- John ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
