PLUME ANALYSIS OF PLUNGING LIQUID JETS WITH FLOOR INTERACTIONS USING STEREOGRAPHIC BACKLIT IMAGING

Plunging liquid jets occur when a liquid jet travels through a gas and enters a liquid pool. They are studied in order to understand and model the highly efficient gas-liquid mixing in the resulting bubble plume. Among the aspects of plunging jets studied, compression effects at the bottom or within the pool, while relatively common in application, remain less understood in current literature. The presence of a tank floor spreads the resultant bubble plume which reduces the flow resistance between the rising bubble plume and the incoming liquid jet. The effect of the tank floor on the overall entrainment and mixing is unknown. In order to understand the compression effects of the plume-floor interaction, a liquid-filled tank was designed to simulate multiple tank depths. This work describes the apparatus used to produce a plunging jet with floor effects, as well as the image analysis methodology for identifying and comparing plume formations. Data were collected for multiple liquid flow rates encompassing different entrainment regimes as well as multiple plate positions, varying the level of plume and base interaction. Stereographic backlit images were acquired and several different identification methods are described to better define and compare bubble plume features. Limitations in the image analysis procedures are also described.