3D simulation of airflow through small objects
 

Dear All,

I model in Ansys Fluent a scenario where the air flows through a bunch of little balls. I send a drawing.

The air is delivered to the container (through a single inlet) that is filled with little balls, as per the attached drawing. Once the air comes out from the inlet, the majority of air is 'distributed' inside the container underneath the perforation plate (through a void, see drawing). The air gets to balls through a perforation plate, it flows between balls, and gets out through a single outlet.

My problem is that:

1. The conditions of the air penetrating the perforation plate and balls is different near the inlet and far from the inlet.

2. Consequently, the velocities of air penetrating balls are different around perforation plate (e.g. in locations number 1-6, shown in Section A-A).

3. I am not sure how to deal with this scenario effectively. I cannot perform any experiments (no empirical data available).


My only idea is to

A. Start modeling with use a small box/cube (central cross section of this box is represented in the drawing - View C), which would include a small part of perforation plate near inlet, a few hundreds/thousands(?) of balls (not porous media), void between external wall of container/perforation plate and inlet.

B. Run several simulations inside the cube and get my plot(s) of velocity vs pressure drop, and then try 3D porous media modeling.

This little cube would need to be large enough to accommodate the perforation plate and balls located 'in front-of' the inlet as well as those located left/right of the inlet and above/underneath the inlet. This gives me probably thousands of balls that I would need to draw.

Also, the characteristics of air penetrating balls may be different in up, down and straight direction.

Do you have better ideas how to approach this problem?
Please help.
Regards