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Fire whirls are devastating, incompletely understood pyrodynamic events. They happen when a wildfire is so advanced that it makes its ain wind. When building a campfire, if you've laid it well, you'll often notice that the smoke and sparks brand a lazy spiral as they ascension. Fluid dynamics and fire science haven't still nailed down exactly what makes a feather of smoke rising in a screw, but it'due south like shooting fish in a barrel to see that information technology often does. That phenomenon, writ large, is what makes fire whirls: the spiraling updraft in a higher place an out-of-control fire tin fling burning droppings through the air, roughshod trees, and even burn people alive.

Now, a grouping of researchers from the University of Maryland are bending the firenado to their ain, more benevolent uses. This makes my inner pyromaniac intensely happy.

Yellow spiral vortex evolving into a blue whirl. Credit: Xiao, Gollner and Oran, 2016

In much the same way as rocket stoves are physically arranged to command the currents of air through a combustive center, scientists figured out how to induce a fire whirl by simply putting two quartz half-cylinders in a higher place their fire. What they produced was a pure, spiraling blue flame, smokeless and silent. They've named it a blue whirl. "A fire whirl is usually turbulent, simply this blue whirl is very quiet and stable without visible or audible signs of turbulence," said Huahua Xiao, coauthor.

"Blue whirls evolve from traditional yellow fire whirls. The yellow colour is due to radiating soot particles, which class when there is non enough oxygen to burn the fuel completely," said professor of engineering Elaine Oran, coauthor. "Bluish in the whirl indicates there is plenty oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn."

These results represent a new way to control how fire does what it does, both by irresolute the vortex mode of the flame and past altering the behavior of the fuel. When the researchers tested out their technique over a scaled-down oil spill, the bluish whirl made the whole oil slick start to rotate and describe inward toward the flame, sometimes removing any visible oil. After the vortex had exhausted its fuel, the researchers leaned down with a butane torch, but found that at that place was nothing left to burn.

Think virtually that: a stable, controlled vortex of flame that can burn rough oil completely, and exploits surface tension and viscosity to feed itself in lieu of a physical wick.

A cleaner burn is really important, for reasons that go across air quality in the lab. During oil spills like the 2010 Deepwater Horizon disaster, in-place burning is ane tactic cleanup crews use to reduce the volume of the spill. But oil fires are so bad they're well-nigh unreal, because of the huge plumes of bulletproof, toxic blackness smoke, and in situ burning is no exception. The fact that information technology's over h2o might fifty-fifty make it worse, because the waves move around all the toxic crap left when the oil burns. The blue whirl might be exactly the thing for oil spills: information technology burns hot, smokeless, and steady, even when information technology'south burning crude oil. And it draws up the oil every bit information technology burns.

The researchers are conscious of the need to run into whether we can make the blue whirls stay lit over the open ocean, and they hope that publishing their technique can brand fire more accessible to research. "A burn down tornado has long been seen equally this incredibly scary, destructive thing," said fire protection engineer and coauthor Michael Gollner. "But, like electricity, can you harness it for good? If nosotros can understand it, then maybe we tin can control and use it."

You really should go read the original (and freely available!) paper, because these people articulate some fascinating things about how fire behaves.

doi:10.1073/pnas.1605860113