Empirical equations for bubble formation frequency from downward-facing nozzle with and without rotating flow effects

Abstract

Bubble formation from a downward-facing single-hole nozzle immersed in a still circular water bath has been observed with a high-speed video. An empirical equation is derived for the frequency of bubble formation, f B0, as a function of gas flow rate Qg, the inner and outer diameters of the nozzle, dni and dno, the acceleration due to gravity, g, and the physical properties of fluids. A cross-flow is imposed on the nozzle by rotating the bath around its vertical axis. The frequency of bubble formation in the presence of the rotating flow, fB, is predicted using fB0 and the rotating flow velocity. vH. © 2005 The Japan Institute of Metals.