* mesh size has been slightly adjusted in nonlift test case to ensure proper convergence * Dirichlet BCs have been kept in bli test case due to lack of robustness with all Neumann BCs, they will have to be removed at some point * the solver is slightly slower (2%) when only Neumann BCs are used (consistent, because it takes more time to compute and assemble a Neumann BC than a Dirichlet BC)