Perforated plates are plates with pattern of holes, slots, or decorative shapes. They have a wide area of usage in industrial applications, such as filters, silencers, radiator grilles, ventilation or separator plates.
If a perforated plate needs to be involved in model, and if the thickness of the plate is bigger than the hole diameter, using porous media feature might be computationally cheaper than actually modeling the plate itself.
How to use Porous Media Future
You can check this project as an example.
Under Advanced Concepts, choose one of the porous media
Assign the Darcy and Forchheimer resistance coefficients with respect to local coordinates.
Assign the Unit vector 1 and Unit vector 2 with respect to global coordinates.
Choose the porous media region:
- If you created the region in CAD model and defined it as zone, then pick the volume
- If not, then create a cartesian box, using geometry primitives and select the box
While the sponge like structures permit the flow evenly in every direction (isotropic), perforated plates transmit the flow in a particular direction (anisotropic). To simulate an isotropic structure, dx, dy, dz and fx, fy, fz should have been same. However, fluid will flow only on 1-direction in perforated plates. Therefore add higher resistance should be added to the other 2 directions (as an example, multiply d and f by 10).
If you would like to learn how to predict Darcy and Forchheimer Coefficients for perforated plates, check the following pages
- Predict Darcy and Forchheimer coefficiens, using experimental data
- Predict Darcy and Forchheimer coefficiens, using empirical equations
How to Define Inclined Perforated Plate
Following pictures represents an inclined perforated plate inside a pipe. Assuming the perforated plate has the identical properties as the previous one, same Darcy and Forchheimer coefficients can be applied.
In this example, Darcy and Forchheimer coefficients for perforated plate are calculated as 2.53e+7 and 3.03e+3 respectively. Since coefficients d and f need to be defined in local coordinate system, just assign the corresponding values to dx and fx. Flow won’t pass through the closed surfaces, therefore we need to add a higher resistance to the other two directions (2.53e+8 and 3.03e+4). These will be assigned to dy, dz, fy and fz.
The following picture represents pressure gradient on the cross section of the pipe and perforated plate. Velocity vectors show how the flow aligned through the perforated plate.