LABORATORY OBSERVATION ON THE SPREAD OF BUBBLE PLUME IN THE WATER OF DENSITY STRATIFICATION

摘要

The air jet discharging upward into the stratified water is observed in the water tank. The air takes the form of bubbles which rises up owing to buoyancy and which impart an upward velocity to the surrounding water. Different air discharge rates and ambient water density stratification cases are run to observe the spread of the bubble plume. Experiments were conducted on the water tank of 67.5 cm by 60 cm with 60 cm of height. The images of bubble plume were grabbed by using the CCD camera with the resolution of 256 by 256 pixels. Observational results indicate that: (1) For the homogeneous ambient water, the air discharge rate does not significantly affect the growth of the bubble plume. (2) When the ambient water becomes density stratification, intrusion of the bubble plume occurs around the layer density difference interface. And the inhibition on the intrusion of the bubble plume increases and enlarges the intrusion length as the layer density difference increases.