Gas entrainment rate and flow pattern of vertical plunging liquid jets

Abstract

Abstract For a vertical plunging liquid jet system using various liquids, the effects of the operating conditions including the nozzle length‐to‐diameter ratio on the gas entrainment rate Q g were evaluated experimentally. The differences in Q g were related to the changes in the jet shape before plunging and the velocity of the plunging liquid jet at the point where the gas sheath breaks up. Empirical relationships were also presented to predict the maximum depth Z of bubbles entrained by the diffusing jet. The changes of Z were further discussed in terms of the downward liquid velocity distribution in the submerged two‐phase region, which depends mainly on the size of entrained bubbles.