Generation of a Vortex Ring with High Reynolds Number by an Exploding Wire in Water

Abstract

A method is presented for generating a vortex ring in water by an exploding wire installed in a metal pipe. As a vapor bubble accompanied by wire explosion grows, water starts to flow with a high speed resulting in a formation of a vortex ring at the outlet of the pipe. The growth speed of a vapor bubble by the exploding wire in water is measured as 10-- 20, m/s, in consistent with measurements of the translational velocity, 4-- 5, m/s, of vortex ring and the rotational velocity, about 10, m/s, of fluid at the edge of vortex core. The Reynolds number based on the diameter of orifice, the velocity of vortex ring and the kinematic viscosity reaches the order of 10⁵. The magnitude of vorticity and the circulation are in the order of 10³/s and 10^-1, m²/s. These values are larger by about 10 times than those reported previously.