# THEORETICAL STUDY OF MOTION OF SMALL SPHERICAL AIR BUBBLES IN A UNIFORM SHEAR FLOW OF WATER

• MEHDI, SYED MURTUZA (Department of Mechatronics Engineering, Jeju National University) ;
• KIM, SIN (School of Energy Systems Engineering, Chung-Ang University)
• Accepted : 2014.10.23
• Published : 2015.02.25

#### Abstract

A simple Couette flow velocity profile with an appropriate correlation for the free terminal rise velocity of a single bubble in a quiescent liquid can produce reliable results for the trajectories of small spherical air bubbles in a low-viscosity liquid (water) provided the liquid remains under uniform shear flow. Comparison of the model adopted in this paper with published results has been accomplished. Based on this study it has also been found that the lift coefficient in water is higher than its typical value in a high-viscosity liquid and therefore a modified correlation for the lift coefficient in a uniform shear flow of water within the regime of the $E\ddot{o}tv\ddot{o}s$ number $0.305{\leq}Eo{\leq}1.22$ is also presented.

#### Acknowledgement

Supported by : National Research Foundation of Korea (NRF)

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