NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Measurements and Prediction of Air Entrainment Rates of Pool Fires.


pdf icon Measurements and Prediction of Air Entrainment Rates of Pool Fires. (581 K)
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

Keywords:

combustion; pool fires; air entrainment

Abstract:

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.