Measurements and Prediction of Air Entrainment Rates of Pool Fires.
Measurements and Prediction of Air Entrainment Rates of
Zhou, X. C.; Gore, J. P.; Baum, H. R.
Combustion Institute, Symposium (International) on
Combustion, 26th. Proceedings. Volume 1. July
28-August 2, 1996, Napoli, Italy, Combustion Institute,
Pittsburgh, PA, 1453-1459 pp, 1996.
Available from: National Technical Information Service
ON BOOK SHELF: QD516.S92 1996
ISSN ISSN 0082-0784
combustion; pool fires; air entrainment
Motivated by the various applications of entrainment
rate correlations in fire research and the large
uncertainty in the efficacy of existing correlations and
experimental data, the first particle imaging
velocimetry (PIV)-based measurements of fire-induced
flow field around pool fires burning methanol, heptane,
and toluene were obtained. Air entrainment rates for
15-cm and 30-cm pool fires burning the three different
fuels were calculated based on the mean velocity field.
The entrainment data for the six fires could be
correlated well using the fire Froude number as the
nondimensional parameter. An existing kinematic
approach to the prediction of the fire-induced flow
field was extended to the present fires. The driving
processes for the entrainment flow, namely, the
volumetric heat release and the baroclinic vorticity
generation, were evaluated based on correlations of
buoyant diffusion flame structure in the literature.
The predicted entrainment elocities were substantially
higher than the measurements but were in qualitative
agreement with the data. On this basis the heat release
rate and vorticity correlations used in the analysis
were corrected by using a smaller radius for the 1/e
point in the velocity profile. The modified predictions
were in better agreement with the experimental data.
Therefore, further evaluation of the kinematic approach
with proper heat release rate and vorticity
distributions is warranted.