A new kinematic criterion for vortex ring pinch-off

This study lays out a methodology whereby conditions necessary for vortex ring to separate from the shear flow can be identified by relationship between characteristic velocities of jet and along axis symmetry. criterion identifies pinch-off take place when velocity induced at origin forming surpasses maximum feeding centerline, defined twice piston velocity. A strategy determining these purely driving programs (i.e., without direct knowledge state leading ring) is presented. variety conditions, including different nozzle geometries (converging radial velocity) programs, are examined validate velocities. These parameters adjusted independently each other so that effect jetting parameter observed independently. Nozzles which induce converging decrease formation number approximately two (for nearly constant programs), due large increase in vorticity flux increasing volume flux. Accelerating compensate growing substantially increases both parallel flows. The new centerline coincided very closely with all cases tested, validating this as predictive tool.