Mobility of air bubble entrapped through jet impingement

Abstract

Problems associated with air bubble entrapped in another liquid media find many practical applications in engineering and science (e.g. air bubble formation in molten metal during metallurgic processes, air bubble entrainment at hydraulic jumps, self-aeration of free jets and slug flow when gas formation within slug occurs). The study of motion of air bubble may lead to understand and control the highly complex processes like nucleate boiling and safety of nuclear reactors. Therefore it is clear that the study of air bubble motion in any liquid medium plays an important role to avoid defects and to enhance the efficiency of various engineering processes. In the present dissertation, a numerical investigation has been made to study the behavior of entrapped air bubble and to understand the combined effect of jet force and buoyancy on it. The Finite Volume Method (FVM) with 3D Volume of Fluid (VOF) model has been adopted to formulate/simulate the present problem. Different combinations of Reynolds number, initial position of bubble and number of bubbles have been considered for better understanding about the mobility of air bubble in water. The effects of various fluid properties and turbulence on its motion and shape have also been studied. For each of the case studies, the contours of phases, velocity and velocity vectors have been evaluated.