Alternating Bubbles Emerging from Two Interacting Vertical Gas Jets in a Liquid

Boyuan Chen

Boyuan Chen, SEAS '23, Chemical Engineering, Columbia University

Supervising Faculty, Sponsor, and Location of Research

Dr. Christopher Boyce, Bonomi Summer Scholarship, Columbia University

Abstract

Optical imaging experiments of two vertical gas jets injected into a liquid demonstrate that bubbles pinch off from these jets in an alternating (180 degrees out of phase) pattern. Image analysis demonstrates that this alternating pattern occurs only at sufficiently high Froude numbers and sufficiently low ratios of the separation distance between orifices to the orifice diameter. Otherwise, the bubbles from the two jets breakoff at uncoordinated times relative to one another. A physical mechanism is proposed in which the alternating pattern occurs due to a growing jet pushing liquid between the two jets towards the second jet, such that the second jet pinches off, forming a bubble. This mechanism is used to formulate a simplified coupled harmonic oscillator model which predicts qualitatively the transition from uncoordinated to alternating bubble breakoff.

Keywords

Gas jets, asynchronous break-off, coupled oscillator

Alternating Bubbles Emerging from Two Interacting Vertical Gas Jets in a Liquid (pdf)