- a stable perturbation in a fluid that takes the form of a torus in which the flow rotates in the section of the torus so that the pressure difference between the inside and outside of the torus balances body forces. The best-known vortex ring is a smoke ring
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for vortex ring
Through a vortex-ring or tube, the fluid circulates in closed lines of flow, each one of which is laced through the tube.Lord Kelvin
A vortex-ring produced in the air behaves in the most surprising manner.
Such a vortex-ring is made by the smoker who purses his lips into a round hole and sends out a puff of smoke.
Now this is just what a vortex-ring would do in an incompressible frictionless fluid.
It is certainly possible roughly to conceive how such a structure as a vortex-ring in the ether might be formed.