Thibault Bridel-Bertomeu <[email protected]> writes: > Hi everyone, > > I was wondering if it was possible to build a solver based on PetscFV > without using ghost cells for the boundary conditions ? > Would it be possible to call PetscDSAddBoundary with DM_BC_ESSENTIAL and so > on instead of DM_BC_NATURAL_RIEMANN ?
Are you thinking this sets the value in a ghost cell or the value in a cell adjacent to the domain? For the former, the value in a ghost cell must typically be set to a (nonlinear for nonlinear PDE) function of the value in the adjacent cell to implement desired BCs. > Mostly in the case of an hybrid problem with FVM and FEM (like for instance > ex18.c from the TS tutorials), it would make sense that the boundaries > shared by the two discretizations be set at the same locations, i.e. for > FEM the quadrature points, wouldn't it ? You either have a surface integral (NATURAL boundary condition, with the integrand specified at quadrature points) or an ESSENTIAL condition, which is implemented nodally (with some lifting for non-Lagrange bases).
