Scientist believe bubbles could solve energy problems


Boris Djuric
1 Jan 2015 Tokyo - When you opened a bottle of champagne to celebrate the New Year, you probably didn't think the complicated physical process that launched the cork into the sky. Scientists, however, believe that understanding these principles can lead to more efficient energy production; but it requires a supercomputer. The bubbles that give the sparkling wine its texture and sometimes cause the liquid spray from the bottle are carbon dioxide, which is still in solution when under pressure, but reveals itself by returning to its gas phase after the cork pops.

The basics of the process are well known, but the exact laws that regulate how bubbles appear and merge are not yet fully understood, partly because the bubbles grow from micron and nanometer sizes to those measured in millimeters and centimeters.

This evolution of bubble, discovered in 1896, is scientifically called Ostwald Ripening after researcher Wilhelm Ostwald. Apparently, the small bubbles are 'eating' larger ones, because the larger bubbles are in more stable energy state.

The same principle stands for soda or even ice cream, where the formation of ice crystals from molten mixture, however, Ostwald ripening is also encountered in industrial equipment.

Understanding exactly how Ostwald ripening works may allow better design of boilers and turbines. A team of scientists from the University of Tokyo, Kiusiu University and Riken described they work on using Ostwald ripening to produce energy, in a report published in theJournal of Chemical Physics.

The researchers, however, didn't use a bottle of champagne, but complex animated particle system models. Because of its mathematical complexity, they use the fastest computer in Japan and the fourth fastest in the world, Riken's K supercomputer to render animation. The computer uses about 4,000 processors to help the team to simulate 700 million particles and follows them through a million intervals.

"A huge number of molecules, however, are necessary to simulate bubbles - in the order of 10,000 are required to express a bubble", stated researcher Hiroshi Watanabe, one of the authors of the report.

He added the research team "needed at least this many to investigate hundreds of millions of molecules - a feat not possible on a single computer".

Despite some work that disputes the classic 1960s Lifshitz-Sliozov-Vagner ( LSV ) theory, which explains how bubbles form in the foam, scientists have confirmed that LSV theory actually does describe Oswald ripening properly.

"Honestly speaking, our present study is quite fundamental and it cannot be applicable to improve the efficiency of real devices right now", Hiroshi Watanabe stated. "This is the first step to understand how bubbles appear and how bubbles interact with each other during the bubble formation from the molecular level."
Source: University of Tokyo