Smoke Plume Trajectory From In Situ Burning of Crude Oil in Alaska: Field Experiments.
Smoke Plume Trajectory From In Situ Burning of Crude Oil
in Alaska: Field Experiments.
(4870 K)
McGrattan, K. B.; Walton, W. D.; Putorti, A. D., Jr.;
Twilley, W. H.; McElroy, J. A.; Evans, D. D.
NISTIR 5764; NIST SP 995; Volume 2; 40 p. November
1995.
Sponsor:
Alaska Department of Environmental Conservation, Juneau,
AK
Available from:
National Technical Information Service
Order number: PB96-131560
Keywords:
crude oil; oil spills; in situ combustion; pool fires;
smoke; fire plumes; smoke movement; in situ burning
Abstract:
As part of their effort to assess the impact of smoke
plumes from in situ burning of crude oil on nearby
populations, the Alaska Regional Response Team and the
Alaska Department of Environmental Conservation
established a Cooperative Research and Development
Agreement with the National Institute of Standards and
Technology (NIST) in 1993 with the intent of developing
predictive methods to estimate the downwind
concentration of particulate matter from a burning oil
spill. The first phase of the study consisted of
laboratory-scale burns of North Slope and Cook Inlet
crude oils, the results of which were used to define the
source terms for the LES (Large Eddy Simulation) plume
trajectory model. A number of different fire sizes and
weather conditions were considered with the aim of
estimating the extent to which concentrations of smoke
particulate matter would exceed ambient air quality
standards. Recommendations were made in a previously
published report. In the present report, experimental
data collected at two sets of mesoscale burns are
compared with the results of the LES model run using the
recorded meteorological and physical conditions. The
two experiments are the Newfoundland Offshore Burn
Experiment (NOBE), August 1993, and the Alaska Clean
Seas Burning of Emulsions, September 1994. Each series
of burns was conducted under different conditions, and
different data collection techniques were employed at
each. The results show that the predictions of the LES
model are in good agreement with the experimental
measurements, given the uncertainty of the input
parameters. This increases confidence in the accuracy
of the predicted results reported in the original study,
and it also provides guidance on how to assess the
undertainty of model predictions. The original report
was written without the benefit of field data to
validate the physical assumptions of the model; thus it
was suggested that a factor of safety of 2 be applied to
a model prediction to account for both the uncertainties
in the input parameters and the physical assumptions of
the model. The results of the field experiments,
however, suggest that the uncertainty of the model
prediction is commensurate with the uncertainty of the
input parameters. This is not to say that the model is
perfect, but rather that the uncertainties due to the
physical assumptions of the model are outweighted by the
uncertainties due to the input parameters.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899