This simulation shows ice spreading through a water droplet. The image is a real scientific model that’s being developed on Titan, the #1 ranked supercomputer in the U.S. Video credits: Mike Matheson (Oak Ridge National Lab)
In early 2011, a tide of icy weather smothered the Caribou Wind Farm in New Brunswick in Canada and shut down the farm’s 33 turbines for a month. “The cold weather is not an issue,” Mark Hachey, the farm’s manager told CBC News. “They can run in rain, they can run in snow. It’s when you get an accumulation of ice, much similar to an airplane.” Caribou has the capacity to power 30,000 homes and Hachey told the CBC that he was looking for solutions like non-stick coating to the turbine blades to crack the persistent problem.
Scientists at GE Global Research (GRC) are already on the case. According to a recent blog post, they’ve been running ice forming simulations on the U.S. top-ranked supercomputer, Titan Cray XK7, at Oak Ridge National Laboratory to study how ice grows. Masako Yamada from GRC’s Advanced Computing Lab said that she can model water droplets that are 50 nanometers in size, far smaller than actual droplets, over incredibly short fragments of time called femtoseconds. (One femtosecond is to one second is what one second is to 31.7 million years.) “It’s analogous to creating a high-speed video using an atomic microscope,” Yamada said. “Titan is one of the few resources in the world that can handle our needs.”
Yamada and her team are using the research to develop icephobic surfaces that prevent ice creation and build up. This can be done by reducing “stickiness” between ice and surface, bouncing water droplets before they can freeze, delaying the onset of freezing, and lowering freezing temperature. “We can see exactly how the water molecules interact with the surfaces,” Yamada said. “This is simply impossible using any physical test. In addition, in the virtual world, the results are not impacted by dirt, defects and other random sources of noise.”
The research has applications everywhere, from windshields to the ideal ice cream scooper. “We have observed that certain types of surfaces hinder ice formation, but the exact mechanism was unknown,” says Rick Arthur, who leads the Advanced Computing Lab at GRC. “We use simulations as a means to gain insight into the conditions under which ice can be suppressed. Many industrial systems that operate in cold environments stand to benefit from resisting ice including wind turbines and offshore oil and gas drilling and production rigs operating in extremely cold environments.”
Ice stopped turbines at Caribou again in 2012, for the third year in a row. But if GE’s simulations work out, Hachey’s winter headache could be over.