Scientists from University of Maryland have discovered a new type of fire tornado called the “blue whirl’.
“Blue whirl” the beautiful new flame, inspired by fire tornadoes, is surprisingly eco-friendly and can even help in reducing pollution as it vastly reduces those harmful emissions and could clean up oil spills.
Fire whirls—also called fire devils and fire tornadoes—can form in urban or wildland fires and generate powerful winds that pick up and hurl burning debris. The authors describe these whirlwinds as “powerful, spinning disasters for people and surroundings.” In their new research, the team was attempting to study fire whirls that burn over water, with an eye to improving oil-spill cleanup, when they discovered the new phenomenon.
SEE HOW THIS DISCOVERY TOOK PLACE:
- Poured liquid fuel on the surface of water in a steel pan, then ignited it to make what’s called a pool fire. These flames can burn on any flat surface smeared with fuel, including oil spills, and can evolve into fire whirls.
- Over the fire, a pair of quartz half-cylinders formed a sort of tube with slits to pull cold air up into the chamber and coax the flame into a whirl about 2 feet high.
- Then, unexpectedly, the fire whirl continue to evolve to a different, unexpected fire structure: a small, intensely whirling blue flame.
- The blue whirl is very stable, it is also small (up to 3 or so inches), and quiet. To keep it dancing, the team used a copper tube to pump more fuel in. Under the right conditions, they could keep it going as long as it had fuel, up to 8 minutes.
- The yellow color of most flames comes from soot particles, which form when there isn’t enough oxygen to completely burn a fuel. The blue whirl’s hue indicates that it has enough oxygen to com-bust without making soot.
Somehow, the flame’s intense, oxygen-hungry swirl and the presence of a watery border instead of a solid surface seem to allow it to reach the newly discovered “blue whirl state”.
But the researchers admit that there’s still a lot they don’t understand about the blue flame they’ve created, including exactly why it burns the way it does.