[Ankur]

Hi all,

I am trying to model the air flow in a torrefaction chamber and I would be glad of any assistance.

This is the Geometry of the Chamber that I am trying to model. As you can see there are two rectangular boxes - one inside the other.
The external box has three circular pressure outlets for the air to be sucked out.
The inner box has a rectangular face at the front, as a velocity inlet for the air to come in.
The top of the inner box has plenty of holes for the air to enter the outer box from the inner box. (Like a zero thickness perforated sheet)

What i want to know is what boundary type do I denote the top of the inner box and the holes as?

Thanks a lot

[skris2009]

It looks like the top of the inner box has too many holes and it might not be feasible to give boundary conditions to each of these holds. You could try the porous boundary condition in Fluent. It allows you to specify a porosity and a thickness of a material.
I used this BC for a similar problem once, and I didnt know the porosity of the material I was using, but I knew that air was flowing easily through the material. So I assumed a very thin material of porosity comparable to cotton cloth.
If you can get a porosity for your material then great. If not, you can approximate it depending on the physics of the flow through the material.

Hope this helps.