Experimental investigations on the effects of grid-screen, sand bed, and nozzle orientation on the dynamics of bubble plumes

Abstract

A bubble plume is defined as a column of air that flows through a liquid ambient due to the density difference between air and the ambient liquid. Bubble plumes have been utilized in wastewater treatment and oxygen transfer in civil and environmental engineering projects. Based on the injection pressure of air flow, bubble plumes can be converted to jet plumes or bubbly jets. A bubble plume is generated by the injected pressurized air/gas, and a bubbly jet is generated by injection of gas-liquid mixture in the ambient. In addition, bubble plumes can be generated by injecting air through a nozzle, airborne stone, or a group of diffusers into the ambient water. Bubble plumes are classified as two-phase air-liquid flow in which the ambient hydrodynamics and initial conditions dictate the motion of air bubbles and their sizes. Bubble plumes are extensively used in civil, environmental, and chemical engineering fields in many different industrial applications (Beutel et al., 2008). In recent years, there has been an increasing interest in using bubble plumes for mixing or aeration in lakes to improve water quality by adding oxygen. [...]