Buoyant plumes and vortex rings in an autocatalytic chemical reaction
Buoyant plumes and vortex rings in an autocatalytic chemical reaction
Physical Review Letters, 95, 024505 (2005).
Michael C. Rogers and Stephen W.
Morris
Department of Physics,
University of Toronto, 60 St. George St., Toronto, Ontario, Canada M5S 1A7.
Buoyant plumes, evolving free of boundary constraints, may develop
well-defined mushroom shaped heads. In conventional plumes, overturning
flow in the head entrains less buoyant fluid from the surroundings as the head rises,
robbing the plume of its driving force. We consider here a new type
of plume in which the source of buoyancy is an autocatalytic chemical
reaction. The reaction occurs at a sharp front which separates reactants from less
dense products. In this type of autocatalytic plume, entrainment assists the reaction, producing new buoyancy which fuels an accelerating plume head. When the head has grown to a
critical size, it detaches from the upwelling conduit, forming an accelerating, buoyant
vortex ring. A second-generation head then develops at the point of detachment.
Multiple generations of autocatalytic vortex rings can detach from a single
triggering event.
Movies:
Autocatalytic chemical smoke ring, the movie [YouTube].
The Experimental Nonlinear Physics Group / Dept. of Physics / University of Toronto / 60 St. George St. Toronto, Ontario, Canada, M5S 1A7. Phone (416) 978 - 6810