A fire phenomenon, known as the blue vortex, can arise from fire tornadoes. This week, scientists reported new details about the structure of the mysterious clean-burning flame.
Why it matters: Researchers hope to one day use the blue shrinkage as a source of energy and clean up fuel waste. To do so, they need to understand the shape of the flame – and how it can be controlled.
Background: A team at the University of Maryland discovered the blue vortex in 2016 while testing the idea of using fire vortices, products of intense heat and wind, to spill oil on water.
- Fire vortices generate soot (though not as much as typical fires) – small particles of carbon produced when fuel is not completely burned and that gives a flame its yellow color.
- In a lab, the vortices can turn into blue vortices, in which the fuel is completely burned and no soot is produced.
What they did: Joseph Chung, Xiao Zhang and their colleagues at the University of Maryland made a computer simulation of the blue whirl and compared it to video of the flame forming in the lab.
- They found that the whirl consisted of “a diffusion flame and pre-mixed rich and lean flames – all coming together in a fourth structure, a triple flame appearing like a hot blue ring,” they write in Science Advances.
- Blue whirls are not seen in nature. Why and under what conditions they can occur in nature are still open questions, Chung says.
What follows: “This is a first step in applying the blue vortex to a more practical application,” says Zhang. There are more questions, she adds, for example: if a larger blue whirl can be created so that it can burn more effectively (it is currently only a few inches in size) and whether it can burn faster.
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