Vortex Cannons Types
A vortex cannon is a device that produces vortex rings which is nothing more than a swirling toroidal form of air, it consists in doughnut shaped a mass of air revolving over his circular geometry. The vortex wave can travel long distances as it moves through atmosphere almost without friction, transporting energy from the vortex device to a target. We can say that a vortex cannon shots an invisible ball of air, but when the cannon tube is filled with smoke, smoke rings is produced and this is one common form we see the operation of vortex cannons. The vortex cannon structure is formed by a tube with an aperture smaller than the tube diameter in one end (the vortex aperture) and a propulsive way in the other end that forces the air inside the tube through the vortex aperture. The ring vortex is formed when the air pass through the aperture with high velocity, the air in contact with the inner edge is slowed down while the air near the center moves faster, the result is a swirling annular structure that detaches from the tube extremity when the air movement ceases. What differs one type of vortex cannon from another is the mechanism used to propels the air inside the tube, there are basically three types:
- The propulsive membrane
- The combustible chamber
- And the piston
The propulsive membrane is the more simple mechanism and consists basically of a flexible membrane, like a thin plastic sheet, that is attached to tube´s border with an elastic on it . When the elastic is stretched the air is admitted inside the tube and when the elastic is quickly released, it pulls the membrane violently and forces the air out through the hole in front of the tube producing the vortex wave. That is the type used in many different toys, and that is the principle behind the knew DIY vortex cannon made of a trash can and also of the very simple office toy made with a coffee cup and rubber balloon.
The other vortex cannon type has a more elaborated mechanism were the flexible membrane is substituted by a piston mechanically actuated. This kind of mechanism enables the use of an auxiliary release system in handle devices making it more easy to control because after loaded the vortex cannon can be operated with just one hand. This is also a more robust design as it is almost all solid state, even the elastic rubber band can be substituted by a a metallic spring to produce a more powerful and quickly pump of air.
The most powerful vortex cannons uses some kind of flammable gases or even explosives to produces a strong air compression and generates the vortex. These devices normally has big dimensions and are used in shows as special effects and constitutes a spectacular physics demonstration.
A portable vortex cannon that operates with a piston mechanism can be easily built following the DIY plans available here at innovationview.com.