The dynamics of bubble deformation has significant impacts on two-phase flow fundamentals such as bubble induced turbulence and flow regime transition. Despite the significant progress achieved by experimental studies on bubble deformation, certain limitations still exist especially for wide-range datasets. To significantly expand the flow conditions available from experiments, direct numerical simulation (DNS) is utilized to study the bubble-liquid interactions using finiteelement solver with level-set interface capturing method. Different from conventional investigations of bubble rising and deforming in stagnant liquids, a proportional-integral-derivative (PID) bubble controller is leveraged to maintain the bubble location in uniform liquid flow. This paper evaluates the reliability and reproducibility of the PID bubble controller for complex bubble deformation studies through a comprehensive set of verification and validation studies. An improved bubble deformation map is developed, based on Weber number and bubble Reynolds number, showing six zones for different deformation and break-up mechanisms. This research aims at producing virtual experiment level data source using interface resolved DNS and shedding light into the physics of interface dynamics. The insights obtained can be further incorporated in improved multiphase CFD models to guide the engineering designs and industrial processes where bubble deformation and break-up play a pivotal role.

No abstract

The article “Complex bubble deformation and break-up dynamics studies using interface capturing approach” written by Yuqiao Fan, Jun Fang, and Igor Bolotnov, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 18 July 2020 without open access. After publication in Volume 3, Issue 3, page 139–151, the author(s) decided to opt for Open Choice and to make the article an open access publication. Therefore, the copyright of the article has been changed to © The Author(s) 2021 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.