On Mon, Feb 29, 2016 at 5:42 PM, Boyce Griffith <[email protected]> wrote:
> > On Feb 29, 2016, at 5:36 PM, Mark Adams <[email protected]> wrote: > > >>> GAMG is use for AMR problems like this a lot in BISICLES. >>> >> >> Thanks for the reference. However, a quick look at their paper suggests >> they are using a finite volume discretization which should be symmetric and >> avoid all the shenanigans I'm going through! >> > > No, they are not symmetric. FV is even worse than vertex centered > methods. The BCs and the C-F interfaces add non-symmetry. > > > If you use a different discretization, it is possible to make the c-f > interface discretization symmetric --- but symmetry appears to come at a > cost of the reduction in the formal order of accuracy in the flux along the > c-f interface. I can probably dig up some code that would make it easy to > compare. > I don't know. Chombo/Boxlib have a stencil for C-F and do F-C with refluxing, which I do not linearize. PETSc sums fluxes at faces directly, perhaps this IS symmetric? Toby might know. > > -- Boyce >
