RT Journal Article
SR Electronic
T1 The structure of the blue whirl revealed
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP eaba0827
DO 10.1126/sciadv.aba0827
VO 6
IS 33
A1 Chung, Joseph D.
A1 Zhang, Xiao
A1 Kaplan, Carolyn R.
A1 Oran, Elaine S.
YR 2020
UL http://advances.sciencemag.org/content/6/33/eaba0827.abstract
AB The blue whirl is a small, stable, spinning blue flame that evolved spontaneously in recent laboratory experiments while studying turbulent, sooty fire whirls. It burns a range of different liquid hydrocarbon fuels cleanly with no soot production, presenting a previously unknown potential way for low-emission combustion. Here, we use numerical simulations to present the flame and flow structure of the blue whirl. These simulations show that the blue whirl is composed of three different flames—a diffusion flame and premixed rich and lean flames—all of which meet in a fourth structure, a triple flame that appears as a whirling blue ring. The results also show that the flow structure emerges as the result of vortex breakdown, a fluid instability that occurs in swirling flows. These simulations are a critical step forward in understanding how to use this previously unknown form of clean combustion.