Three Dimensional Simulations of Fire Plume Dynamics.
Three Dimensional Simulations of Fire Plume Dynamics.
(796 K)
Baum, H. R.; McGrattan, K. B.; Rehm, R. G.
International Association for Fire Safety Science. Fire
Safety Science. Proceedings. Fifth (5th) International
Symposium. March 3-7, 1997, Melbourne, Australia, Intl.
Assoc. for Fire Safety Science, Boston, MA, Hasemi, Y.,
Editor(s), 511-522 pp, 1997.
Keywords:
fire research; fire safety; fire science; fire plumes;
aircraft hangars; large eddy simulation; pool fires;
roofs; temperature; velocity; computational fluid
dynamics; convection
Abstract:
The velocity and temperature fields of fire plumes are
studied theoretically and computationally using the
authors' large eddy simulation techniques. A version of
the Navier-Stokes equations specialized to the study of
fire dynamics is used as the basis for the analysis. No
empirical turbulence modeling parameters are introduced
into the computations. these simplifications permit
high resolution solutions to the three dimensional
time-dependent Navier-Stokes to be directly compared
with experimental correlations of the time-averaged
properties of an isolated vertical plume. Comparisons
are made by averaging the time-dependent numerical
results rather than the governing equations. Computed
mean velocities and temperature are shown to be in close
agreement with McCaffrey's correlations. The
methodology is then applied to the study of a large pool
fire in an aircraft hangar with a complicated roof
geometry. A simple cell masking scheme permits the
inclusion of the building geometry into the calculation
without sacrificing computational efficiency. The plume
structure in the hangar is compared with the isolated
plume properties.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899