The growth dynamics (inception → departure) of isolated gas bubbles, emanating from a capillary-tube orifice submerged in isothermal pools of different liquids is computationally investigated. The complete set of continuity and transient Navier-Stokes equations are solved, and the gas-liquid interface during the bubble growth process is tracked using a volume of fluid (VOF) method. Computational solutions that describe the dynamic behavior — incipience, growth, and pre-departure necking — of a single bubble growing from tips of sub-millimeter-to-millimeter-scale capillary orifices in stagnant pools are presented. The parametric effects of liquid properties (surface tension and viscosity, in particular), capillary diameters, and air flow rates on the bubble shape, its equivalent diameter, and growth times are described. Furthermore, these results are shown to be in excellent agreement with the available experimental data, and they fundamentally highlight the ebullience structure and the role of liquid-gas interfacial tension on the bubble evolution.

This content is only available via PDF.
You do not currently have access to this content.