In continuum mechanics, the vorticity is a pseudovector field that describes the local spinning motion of a continuum near some point (the tendency of something to rotate), as would be seen by an observer located at that point and traveling along with the flow.
Conceptually, vorticity could be determined by marking parts of a continuum in a small neighborhood of the point in question, and watching their relative displacements as they move along the flow. The vorticity vector would be twice the mean angular velocity vector of those particles relative to their center of mass, oriented according to the right-hand rule. This quantity must not be confused with the angular velocity of the particles relative to some other point. Wikipedia, Vorticity
Schauberger
With explosions vorticity (turbulence) always occurs, resulting in a reduction in the velocity of the through-flowing substance, leading in turn to cavitation, viz. the corrosion on [a] ship propeller or pressure screws in turbines. In particular when snow meltwater or glacier water is centrifugated. In such cases radar-like retroactive reactions takes place, which as detonating events, have a shattering effect. The detonation velocity can be a thousand times greater than the normal combustion velocity, which explains, for example, why the resistance to motion increases by the square in all explosion and expansion machines, which also increases by the square of the velocity of an increase in heat. It therefore acts to impede motion. [The Energy Evolution - Harnessing Free Energy from Nature, Explosion and Implosion - Expansion and Impansion]
See Also
Angular Momentum
Orbit
Spin
Spiral
Swirl
Triplet Swirl
Vortex