With just a single measurement, a new model may deftly describe turbulent fluid flows near an airplane wing, ship hull or cloud, researchers report in the July 9 Science. If the long-sought model proves successful, it may lead to more efficient airplanes, better ways to curb pollution dispersal and more accurate weather forecasts.
Fluid dynamicist Alexander Smits of Princeton University calls the new model “a very significant advance” that opens up a new way of thinking about chaotic, energy-sapping turbulence.
Turbulence is a problem that extends far beyond a bumpy plane ride. Fluid flowing past a body — whether it’s air blowing by a fuselage or water streaming across Michael Phelps’s swimming suit — contorts and twists as it bounces off an edge and interferes with incoming flows, creating highly chaotic patterns. Airliners squander up to half of their fuel just overcoming the turbulence within a foot or so of the aircraft, and turbulent patterns in the bottom 100 meters of the atmosphere confound weather and climate predictions.
Physicists and engineers have had a good grip on the basic behaviors of fluids since the mid-1800s, but have been baffled by the complexity of the tumultuous flows near a boundary. “We don’t really have a handle on the physics,” says study coauthor Ivan Marusic of the University of Melbourne in Australia. “So even though the problem is over a hundred years old, we still really haven’t had a major breakthrough.”