Discussion: Boundary condition types in new staggered implementation
While re-implementing the staggered grid scheme, I thought it might be good to discuss which types of BCs we
want to offer. So far, I could implement most of the tests using only dirichlet
and neumann
BCs and some helper classes.
We could have additionally (as in the old implementation)
- symmetry (technically a combination of Dirichlet with v*n = 0 and zero shear stress)
- beaversJoseph (technically a solution dependent Dirichlet for the tangential velocity)
Symmetry can already be easily achieved by combining dirichlet
and neumann
.
This is not so easy for beaversJoseph because we do not support solution dependent Dirichlet BCs.
The old implementation circumvents that by not calling dirichlet
but beaversJoseph
with sol-dep arguments in the local residual.
It could be possible to implement beaversJoseph in terms of a Neumann BC, but that might become cumbersome, especially if inertia terms are considered.
Edited by Kilian Weishaupt