I am building an air-hockey table. Essentially, a rectangular wooden box with holes on the top surface. I am fitting a blower fan on the bottom and wondering how affects the airflow, if at all.
From my understanding, air is sucked from under the table and pushed in the box, increasing pressure and forcing air out of the holes on top. Is pressure uniform within the box with air flowing in? Or will the area around the fan have a higher pressure compared to the corners, for example?
In case of air hockey, the holes should be tiny enough, that the difference in pressure should be negligible - the differential between different parts of the surface should be much lower than differential between sub-table and surface/outside. (otherwise, your puck will just plug the holes it's over, instead of floating on air pushed out) I'm not sure if common fan is sufficient for that; the large open area between the fins makes any pressure build-up very difficult. you might want to use a radial turbine, the sort used in a vacuum cleaner.
The area near the fan usually has higher pressure. But by adding fins and or partitions you can try to achieve a more even pressure distribution for high flow situations. If you just have a deep box and fan at the bottom near the center and the dimensions of the holes are small, you can get a better balanced distribution of pressure.
However if the holes are rather large the box will act as a manifold and the holes nearer to the fan will carry an unproprtionally large share if flow.
There are numerical simultiin softwares that can plot a very good estimate if flow.
The idea is to have a head pressure consistently one order higher than the total drain. Like a Scottish bagpipe.
