ALOFT-PC: A Smoke Plume Trajectory Model for Personal Computers.
ALOFT-PC: A Smoke Plume Trajectory Model for Personal
Walton, W. D.; McGrattan, K. B.; Mullin, J. V.
NIST SP 995; Volume 2; March 2003.
Environment Canada. Arctic and Marine Oilspill Program
(AMOP) Technical Seminar, 19th. Volume 2. Proceedings.
June 12-14, 1996, Alberta, Canada, Environment Canada,
Ottawa, Ontario, 987-997 pp, 1996.
oil spills; in situ burning; computer models; heat
release rate; crude oil; plumes; pool fires; wind
velocity; temperature profiles
As the understanding of the capabilities and limitations
of in situ burning of oil spills increases, in situ
burning continues to gain acceptance as an oil spill
mitigation tool. One widely imposed criteria for the
use of in situ burning is limiting the exposure of
downwind populations to smoke particulate. Since the
downwind distribution of smoke particulate is a complex
function of the fire parameters, meteorological
conditions, and topographic features, a computer based
model is required to predict the smoke plume trajectory.
Measurements and observations at experimental burns have
shown that the downwind distribution of smoke is not
Gaussian and simple smoke plume models do not capture
the observed plume features. To resolve these problems,
NIST has developed a smoke plume trajectory model that
solves the fundamental Navier-Stokes equations using an
eddy viscosity over a uniform grid which spans the smoke
plume and its surroundings. This large eddy simulation
smoke plume model has been refined over a period of
years using a computer workstation and the results have
compared favorably with the limited data available from
experimental burns. ALOFT-PC (A Large Open Fire plume
Trajectory model) is the public domain version of the
model for windows based personal computers. The model
inputs include wind speed and variability, atmospheric
temperature profile, and fire parameters and the output
is the average concentration of smoke in each of the
computational cells from ground level to the top of the
plume. ALOFT-PC is designed to aid in the in situ burn
planning process. For this purpose a "foot print" of
the ground level smoke concentration is the most
commonly used model output.