Brilliant bubble breakthrough

While the observation of bubbles in action is endlessly fascinating for children and adults alike, the understanding of their formation and movement is a topic of intense scientific research - a field in which the University of Technology, Sydney has reached a new landmark.

Adjunct Professor John Reizes and Dr Matt Gaston of the Faculty of Engineering have succeeded in creating a computer model for the formation and interaction of six air bubbles in water - a world first in computational fluid dynamics.

The applications for such work are as diverse as household refrigeration, the production of world-class champagne and the effectiveness of bazookas that fire rockets at armoured tanks.

Despite the widespread use of bubbles in industry, virtually nothing is known of the mechanisms that govern their movements or shapes.

"When I got into this field, I was amazed that nobody understood the initial formation of a bubble, how it moves through liquids, or what shapes it takes," Prof. Reizes said. "We're looking at the detail of what's happening and developing techniques to enable us to model lots of individual bubbles."

With sophisticated software tools they have designed and developed themselves, the researchers have modelled air bubbles passing through water and, in the process, have identified for the first time a broad spectrum of bubble movement and growth characteristics.

Two bubbles released simultaneously side by side, for example, behave differently; and a bubble on top not only coalesces with the bubble underneath but later can break up into several bubbles.

As part of their study, the team has also simulated a slow jet of air in a column of liquid that required seven weeks of intensive calculations to generate and release a bubble.

"UTS is now recognised as a pioneering centre for the numerical study of bubbles," Prof. Reizes said. "We are especially interested in what causes bubble motions so that we can explain and control them."

Item provided courtesy of UTS