using distributed arrays;
Transient nonlinear driven cavity in 2d.
The 2D driven cavity problem is solved in a velocity-vorticity formulation.
The flow can be driven with the lid or with bouyancy or both:
-lidvelocity <lid>, where <lid> = dimensionless velocity of lid
-grashof <gr>, where <gr> = dimensionless temperature gradent
-prandtl <pr>, where <pr> = dimensionless thermal/momentum diffusity ratio
-contours : draw contour plots of solution