Open Access

ARTICLE

Phase Distribution of Bubbly Flows under Terrestrial and Microgravity Conditions

Asghar Esmaeeli¹

1 Corresponding author: Tel.: 618-453-7001; Fax: 618-453-7685, E-mail address: esmaeeli@engr.siu.edu, Department of Mechanical Engineering and Energy Processes, Southern Illinois University, Carbondale, IL 62901

Fluid Dynamics & Materials Processing 2005, 1(1), 63-80. https://doi.org/10.3970/fdmp.2005.001.063

Abstract

We use direct numerical simulations to study phase distribution of bubbles under terrestrial and microgravity conditions. The full Navier-Stokes and energy equations, for the flows inside and outside the bubbles, are solved using a front tracking/finite difference technique. Both nearly spherical and deformable bubbles are considered. For buoyancy-driven flows, spherical bubbles at Re = O(10) and deformable ones at Re = O(100) exhibit a uniform spatial distribution at quasi steady-state conditions, while nearly spherical bubbles at Re = O(100) form horizontal rafts. Bubbles, driven by thermocapillary effects in microgravity, also form horizontal rafts, but due to an entirely different mechanism. When thermocapillary and buoyancy forces act in opposite directions, the raft formation is prevented and the bubbles form a large cluster that moves in the direction of buoyancy.

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