Coalescence of Co-Axial Bubbles in a Stagnant Water Column

EasyChair Preprint 6275

Abstract

The bubble formation and dynamics in the liquid phase affect the heat and mass transfer mechanism between phases, which is crucial in determining the equipment's performance. The commercial applications include floatation, absorbers, reactors, and distillers. Thus, it is vital to understand the bubble hydrodynamics such as bubble rise velocity, residence time, shape formation, coalescence and break-up, better equipment design, and enhanced process optimization. The specifics of the bubble hydrodynamics and the coalescent combination of the co-axial and lateral engagements of individual bubbles are essential factors to analyze the bubbles' flow in the column. The present work focuses on examining two bubbles' motion characteristics co-axially (in the vertical direction) with a center-to-center distance of 50 mm. The width and height of the column are 100 mm and 300 mm, respectively. It can be seen that for larger diameter bubbles, the bubble collapses before merging into the leading bubble. This is because of the flow field around the bubble that causes instability. Furthermore, the change in the pressure field below the leading bubble changes the rising velocities. The present study outcomes help understate the fundamentals of bubble rise and can be used in large-scale problems. This work sets a basis for examining the mass transfer mechanisms such as bioreactors, bubble columns, etc.

Keyphrases: Bubble rise, CFD, VOF, air-water, multiphase flow

@booklet{EasyChair:6275,
  author    = {Furqan Tahir and Hassan Tahir and Binash Imteyaz},
  title     = {Coalescence of Co-Axial Bubbles in a Stagnant Water Column},
  howpublished = {EasyChair Preprint 6275},
  year      = {EasyChair, 2021}}