It is a horizontal drum with a circular hole at the bottom.
If you hit an ordinary diaphragm, an air whirl in the shape of a torus (a circle resembling, for example, an inflated inner tube) will form next to the hole. The air whirl moves along the drum axis at a distance of multiple meters. The Air Cannon helps to observe this effect.
1. Problem: the diaphragm often bursts
Solution: change the tension mechanism
We replaced the rubber diaphragm with a fabric one. We also changed the tension mechanism. Now you just pull lightly instead of pummelling it as hard as you can. We also ensured that we really got a circular (torus-shaped) whirl after firing the cannon with the new tension mechanism. As the air whirl was invisible, we filled the drum with spray smoke and released it. We did receive a beautiful smoke torus.
2. Problem: how to make the effect more spectacular than before
Solution: use a different mounting of the curtain with metal tiles.
The Air Cannon fires at the wall in front of it where a curtain with hanging metal rings is located. We wanted to see if we could achieve a better result. We tested different surfaces. We tried using squares instead of rings and applied different mounting method and materials. We were inspired by the works of Ned Kahn, an artist whose designs on the building façades undulate in the wind.