Peaceful guns shooting smoke rings

What is it about?

This experiment is a scaled up version of cigarette smoke rings. The Vortex Cannon shoots thick rings of foggy air which move quickly trough the air. The incredibly stable rings stay in the air for up to a minute and travel around 7 meters distance.

Details and Theory

The flow is visualized by nebulising the air. One can describe the stream profile at the front hole as follows: in the centre of the opening, the molecules of the air move outwards fast. Closer to the edge of the opening the movement is slower, and the molecules in direct contact with the barrel are static. This causes the smoke ring to rotate. As it moves away from the barrel the faster particles from the inside of the barrel circulate around the vortex. The ring remains stable until it reaches its destination or vanishes for the eyes as the smoke gets increasingly thinner.