On the flow phenomena associated with liquid plunging jets: effect of jet velocity

Plunging liquid jets effectively entrain and disperse gas into a liquid pool. They are favoured in industry for mixing fluids and distributing gas without the need for an agitator. The effectiveness of gas entrainment and dispersion depends on various parameters such as nozzle geometry, jet length, and jet velocity. This study focuses on the effect of jet velocity, with parameter studies stretching up to values resulting in highly turbulent flow regimes. This study examines the impact of jet velocity on bubble size distribution in a turbulent water–air system. A three-dimensional, full-Eulerian simulation coupled with a large-scale interface- capturing method and a method-of-moments population balance is employed to simulate the plunging jet. Important modelling aspects include turbulence modelling and population-balance modelling. We spatially resolve the bubble sizedistribution within the reactor to derive empirical correlations. We also investigate the impact of jet velocity on bubble velocity, bubble penetration depth, and gas hold-up. Results are validated against experimental data from the literature on plunging jets.