As eighth-grade teachers have been insisting since the beginning of time, science can be fun. And surely nothing appeals more to the eighth-grade sensibility than the promise of a laboratory engineered fire tornado! Jules Suzdaltsev has the details in today's DNews special.
Scientists at the University of Maryland recently published an intriguing paper concerning the phenomenon of the "blue whirl" -- a kind of supercharged fire tornado that has potential applications in several industries.
First things first: What is a fire tornado? Well, it's just like it sounds. With certain intense conflagrations -- like forest fires -- rising heat and wind conditions produce eddies of air that result in a whirlwind of flame. These are called fire whirls or fire tornadoes. A fire tornado can also occur when an actual tornado runs into an existing blaze. Either way, fire tornadoes are hugely destructive but also highly interesting, from an engineering point of view.
That's where the Maryland study comes in. While studying new ways to deal with oil spills, the research team discovered a way to turn the typical, unruly fire tornado into a narrow whirl with a pure blue coloration. The upshot on the so-called blue whirl is that it burns fuel with an extremely high efficiency and produces almost no byproducts at all.
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To create the blue whirl effect, the research team filled a pan with water, poured liquid fuel on top, lit it, then pulled cold air through the mixture. After some time, the two-foot-tall bright yellow tornado condensed into a three-inch-tall blue flame, producing almost no byproducts at all. From the abstract:
Whereas fire whirls are known for their intense and disastrous threat to life and surrounding environments, their swirl properties and thus higher combustion efficiency imply an unexploited potential for highly efficient, low-emission combustion. In studying fire whirls over water for oil-spill cleanup, we discovered a beautiful, swirling flame phenomenon, the "blue whirl," which evolves from a fire whirl and burns with nearly soot-free combustion.
Check out Jules' report for more details on the new discovery, and its potential impact on everything from tiny cigarette lighters to giant rocket ships. Jules also gets into the molecular mechanics of oxidation and makes a surprisingly persuasive case that rust is actually just fire in slow motion.
-- Glenn McDonald
PNAS: From Fire Whirls To Blue Whirls And Combustion With Reduced Pollution
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