Most of you have probably uncorked a bottle of champagne at some point. Or, opened a bottle of soda. As the pressure is released, bubbles start rapidly forming. These bubbles then start a process known as Ostwald ripening. Basically, bigger bubbles continue to grow larger as smaller bubbles dissolve and their molecules are redistributed.
Ok, so what does this have to do with energy? Ostwald ripening also happens in power plants, on a much larger scale of course. Many of these power plants use boilers to convert water into steam. Until now, scientists were not entirely sure what was going on inside the boiler. Like how many bubbles form for example.
According to a new study, a team of researchers from the University of Tokyo, Kyusyu University and RIKEN in Japan were able to simulate bubble nucleation from the molecular level. To do this, the researchers used the K computer at RIKEN, one of the most powerful systems in Japan.
Researchers ended up simulating an incredible 700 million particles and followed their collective motions through a million time steps. It took massively parallel simulations using 4,000 processors on the K computer to make the simulation possible.
“In the past, while many researchers wanted to explore bubble nuclei from the molecular level, it was difficult due to a lack of computational power,” explained Hiroshi Watanabe, a research associate at the University of Tokyo’s Institute for Solid State Physics.
“But now, several petascale computers — systems capable of reaching performance in excess of one quadrillion point operations per second — are available around the world, which enable huge simulations.”
By expanding understanding of the behavior of bubbles, engineers may one day design more efficient power plants.
Watanabe and his fellow researchers will be looking at the boiling process next.
“Bubbles appear when liquid is heated as ‘boiling,’ or as ‘cavitation’ when the pressure of the liquid decreases,” said Watanabe. “Simulating boiling is more difficult than cavitation at the molecular level, but it will provide us with new knowledge that can be directly applied to designing more efficient dynamo.”