[petsc-users] Neumann BC with non-symmetric matrix

[Boyce Griffith]

> On Mar 1, 2016, at 10:08 AM, Jed Brown <jed at jedbrown.org> wrote:
> 
> Mark Adams <mfadams at lbl.gov> writes:
> 
>> 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? 
> 
> Depends on scaling.  Refluxing versus evaluating fluxes once on the fine
> faces should give the same result.  Note that you can make a symmetric
> FV discretization (for elliptic problems) by writing it as a mixed FE
> method and choosing a quadrature so that fluxes can be eliminated.

Jed, can you also do this for Stokes?  It seems like something like RT0 is the right place to start.

Thanks,

-- Boyce