Stephan thinks there are a few things missing for DG support, both in the coupled_sw_solver and the ipcs_sw_solver. Shouldn't the advection term have interior facet integrals as well? Also, in case of weak eta bcs, you seem to integrate the pressure gradient term by parts which is only possible if you would add jump terms in u. I actually don't think it's necessary to integrate by parts here in the first place.
Stephan thinks there are a few things missing for DG support, both in the coupled_sw_solver and the ipcs_sw_solver. Shouldn't the advection term have interior facet integrals as well? Also, in case of weak eta bcs, you seem to integrate the pressure gradient term by parts which is only possible if you would add jump terms in u. I actually don't think it's necessary to integrate by parts here in the first place.