  Graphene has generated a lot of research interest due to its special
properties, which include a hydrodynamic regime. It is not yet clear however
which boundary condition such a hydrodynamic current flow satisfies. The aim of
this paper is to investigate the effect of different boundary conditions on the
potential in an infinite strip of graphene, in which the electrons can be
treated hydrodynamically. The boundary conditions on the current range
continuously from no-slip to a free boundary. We analyse the situation for two
different orientations of the source and sink, inspired by recent papers. We
discuss which geometry is better suited for identifying the hydrodynamic regime
and experimentally determining the boundary conditions.
