To read the full version of this content please select one of the options below:

Numerical simulation of the interaction between a vortex ring and a bubble plume

Van Luc Nguyen (Graduate School of Information Science, Nagoya University, Nagoya, Japan)
Tomohiro Degawa (Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya, Japan)
Tomomi Uchiyama (Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya, Japan)

International Journal of Numerical Methods for Heat & Fluid Flow

ISSN: 0961-5539

Article publication date: 11 July 2019

Issue publication date: 11 September 2019

Abstract

Purpose

This paper aims to provide discussions of a numerical method for bubbly flows and the interaction between a vortex ring and a bubble plume.

Design/methodology/approach

Small bubbles are released into quiescent water from a cylinder tip. They rise under the buoyant force, forming a plume. A vortex ring is launched vertically upward into the bubble plume. The interactions between the vortex ring and the bubble plume are numerically simulated using a semi-Lagrangian–Lagrangian approach composed of a vortex-in-cell method for the fluid phase and a Lagrangian description of the gas phase.

Findings

A vortex ring can transport the bubbles surrounding it over a distance significantly depending on the correlative initial position between the bubbles and the core center. The motion of some bubbles is nearly periodic and gradually extinguishes with time. These bubble trajectories are similar to two-dimensional-helix shapes. The vortex is fragmented into multiple regions with high values of Q, the second invariant of velocity gradient tensor, settling at these regional centers. The entrained bubbles excite a growth rate of the vortex ring's azimuthal instability with a formation of the second- and third-harmonic oscillations of modes of 16 and 24, respectively.

Originality/value

A semi-Lagrangian–Lagrangian approach is applied to simulate the interactions between a vortex ring and a bubble plume. The simulations provide the detail features of the interactions.

Keywords

Acknowledgements

This study was supported by a grant from the Project of Creation of Life Innovation Materials for Interdisciplinary and International Researcher Development of the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Citation

Nguyen, V.L., Degawa, T. and Uchiyama, T. (2019), "Numerical simulation of the interaction between a vortex ring and a bubble plume", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 29 No. 9, pp. 3192-3224. https://doi.org/10.1108/HFF-12-2018-0734

Publisher

:

Emerald Publishing Limited

Copyright © 2019, Emerald Publishing Limited