Oxygen transfer characteristics of bubbly jet in regular waves

Abstract

The dissolved oxygen level is an important index of the water environment, and in this paper, the oxygen transfer of the bubbly jet in regular waves is investigated numerically and experimentally. The Reynolds-averaged Navier-Stokes equations, the re-normalisation group k-e equations, and the volume of fluid (VOF) technique are used along with a 2-D CFD model to simulate the wave and bubble motions as well as the turbulence, and a dissolved oxygen transport equation is used to model the oxygen transfer behavior both through the bubbly interface and the wave surface. A series of experiments are conducted to validate the mathematical model, with good agreement. In addition, a group of dimensionless parameters are defined from the wave parameter and the aeration parameter, and their relationships with the total oxygen transfer coefficient are explored. Furthermore, the dimensional analysis and the least squares methods are used to derive simple prediction formulas for the total oxygen transfer coefficient, and they are validated with the related experimental data.