The mesh , which in this case has been generated with polymesh, is named contr41.msh. It is included in the box x=[0,4], y=[-20,20]. It is composed of 128 nodes for pressure.

Four boundary sets have been defined, named BS1 to BS4; BS1 will be an Inflow region; BS2 will be a zero velocity wall an outflow; and BS4 will be an axis of symmetry.