GENERATION OF A VORTEX RING WITH HIGH REYNOLDS-NUMBER BY AN EXPLODINGWIRE IN WATER

A method is presented for generating a vortex ring in water by an expl oding wire installed in a metal pipe. As a vapor bubble accompanied by wire explosion grows, water starts to flow with a high speed resultin g in a formation of a vortex ring at the outlet of the pipe. The growt h speed of a vapor bubble by the exploding wire in water is measured a s 10 similar to 20 m/s, in consistent with measurements of the transla tional velocity, 4 similar to 5 m/s, of vortex ring and the rotational velocity, about 10 m/s, of fluid at the edge of vortex core. The Reyn olds number based on the diameter of orifice, the velocity of vortex r ing and the kinematic viscosity reaches the order of 10(5). The magnit ude of vorticity and the circulation are in the order of 10(3)/s and 1 0(-1) m(2)/s. These values are larger by about 10 times than those rep orted previously.