Fluid Dynamics of Fire Whirls: An Inviscid Model.
Fluid Dynamics of Fire Whirls: An Inviscid Model.
(1371 K)
Battaglia, F.; Rehm, R. G.; Baum, H. R.
NISTIR 6427; 18 p. February 2000.
Available from:
National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
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Order number: PB2001-104051
Keywords:
fire whirls; fluid dynamics; methodology; fire plumes;
entrainment; combustion; buoyant plumes; equations
Abstract:
Whirling fire plumes are known to increase the danger of
naturally occurring or post-disaster fires. In order for
a fire whirl to exist, there must be an organized source
of angular momentum to produce the large swirl
velocities as air is entrained into the fire plume.
These vorticity-driven fires occur over a large range of
length and velocity scales, and significantly alter the
entrainment and combustion dynamics. A new model that
incorporates angular rotation and neglects dissipation
is derived for a buoyant plume; the result is a form of
the steady state Euler equations. Included is a general
solution for large density and temperature variations.
Results that identify the mechanisms and their effects
on the creation of a fire whirl are presented.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899