Hi,

I would like to simulate passage of ammonia gas thru compacted sand. I am only interested in how the gas flows in the domain. Can someone let me know how to set up the problem in CFX 11? Can this be performed by using Sand as a porous medium and use particle tracking for the gas?

Thanks, Sans

Depends on what exactly are you seeking from CFD.

1) If you just want to see effect of sand on gas flow in terms of pressure drop & change in velocity, but do not want to see effect of gas flow on sand particles, then you can model sand portion as porous domain. Define volume porosity for this porous domain. Keep rest of the domain as only gas domain. That's it. Nothing else is required. No need to even go for particle tracking. Solve this physics and plot streamlines in post to see change in velocity & check pressures at inlet/outlet of your porous domain to check effect on pressure.

2) But, if you also want to see effect of gas flow on sand particles, then probably it's nearly impossible. I have never tried that.

This is want I think. Hope it helps.

Best luck,

Chirag