velocity field from pressure distribution

[drir]

Hi,

I have calculated the pressure distribution over a 2D porous material with the finite difference method. However, now I want to calculate the velocity field or streamlines of the air flowing through this porous material from my pressure distribution. I have thus the pressure value on each node of the grid. How can I do this?

Thanks

 

[btrueblood]

As a starting guess, I'd use:

http://en.wikipedia.org/wiki/Stokes_flow