Analysis of liquid circulation in a rectangular tank with a gas source at a corner

Abstract

Abstract In this work, we investigate experimentally and numerically the hydrodynamics induced by a bubble plume introduced at a corner of a rectangular tank. Such gas–liquid flows are inherently unsteady. Particle Image Velocimetry (PIV) was used to experimentally determine transient velocity fields in the system. For this gas–liquid flow system, both the fluctuating and mean liquid velocities were determined experimentally by PIV. This technique enables us to determine velocity fields in a 2D plane. The behavior of the system was simulated in FLUENT 6.2 using a two fluid Euler–Euler model with a constant bubble size of 3 mm. Water is treated as the continuous phase and the gas bubbles are treated as the dispersed phase. The motion of the bubbles renders the flow turbulence and this effect is captured by the mixture k–ɛ turbulence model. Two and three-dimensional simulations were carried out to predict the flow behavior. The predictions of the time averaged flow field, turbulent intensity etc. are compared with experimental observations. We also calculate the magnitude of the turbulent viscosity from our model. For the case of corner injection of bubbles, we conclude that the velocity at a point does not show sustained periodic oscillations in time.