Plume Spreading Due to Floor Conditions of A Plunging Liquid Jet Using Stereographic Backlit Imaging

Abstract Plunging liquid jets are a multiphase flow studied to understand how gas is entrained in a liquid and the resulting mixing capabilities. From existing literature, it has been hypothesized that rising bubbles play a noticeable role in the multiphase hydrodynamics of the plunging liquid jet bubble plume, and that separating the rising bubbles from the incoming liquid jet can result in a significant increase in the depth of the bubble plume. This study explores the effects of separating the incoming liquid jet from the rising bubble plume through floor interactions and compression effects due to a finite tank depth. This configuration is found in many natural and industrial systems, but not within published literature. Using existing theoretical models of infinite depth plunging liquid jet systems, which align reasonably well with captured baseline data, two models are developed for when floor interactions are present, one theoretical and one empirical. The models show a correlation between plume spread and floor interaction with the incoming plunging liquid jet bubble plume. Data acquired through stereographic backlit imaging over a range of flow rates show a reasonable agreement with the proposed models.