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Time similarity analysis of unsteady buoyant plumes in neutral surroundings

Published online by Cambridge University Press:  19 April 2006

M. A. Delichatsios
M. A. Delichatsios
Affiliation:
Factory Mutual Research, 1151 Boston-Providence Turnpike, Norwood, Massachusetts 02062
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Abstract

A time similarity formulation of the flow equations for unsteady plumes is shown to exist only when the buoyancy flux at the source varies as a power function of time. The time similarity equations for unsteady plumes are solved numerically. It is shown that the velocity of the leading edge of the plume is less (at most the 0·42 fraction) than the velocity inside the plume behind its leading edge; this observation is consistent with Turner's (1962) results on the behaviour of a starting plume with constant buoyancy flux at the source. Finally, experimental results of axial temperature histories in the buoyant plume generated by a fast-growing fire are compared with the theoretical predictions.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 93 , Issue 2 , 26 July 1979 , pp. 241 - 250
Copyright
© 1979 Cambridge University Press

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References

Delichatsios, M. A. 1976a Fire growth rates and sprinkler response in small-scale stored plastics tests. FMRC Tech. Rep. no. 22503, Factory Mutual Research Corporation, Norwood, Massachusetts.Google Scholar
Delichatsios, M. A. 1976b Fire growth in wood cribs. Combustion and Flame 27, 267.Google Scholar
Hansen, A. G. 1967 Generalized Similarity Analysis of Partial Differential Equations in Nonlinear Partial Differential Equations (ed. W. F. Ames), p. 1. Academic Press.
Heskestad, G. 1972 Similarity relations for the initial convective flow generated by fire. A.S.M.E. paper no. 72-WA/HY-17.
Heskestad, G. & Delichatsios, M. A. 1977 Environments of fire detectors. Phase I: Effect of fire size, ceiling height and material, vol. 1, Tests; vol. 2, Analysis. F.M.R.C. Tech. Rep. no. 22427, Factory Mutual Research Corporation, Norwood, Massachusetts.
Markstein, G. H. 1976 Radiative energy transfer from turbulent diffusion flames. Combustion and Flame, 27, 51.Google Scholar
Middleton, J. H. 1975 The asymptotic behaviour of a starting plume. J. Fluid Mech. 72, 753.Google Scholar
Morton, B. R. 1959 Forced plumes. J. Fluid Mech. 5, 151.Google Scholar
Turner, J. S. 1962 The starting plume in neutral surroundings. J. Fluid Mech. 13, 356.Google Scholar
Witham, G. B. 1965 Nonlinear dispersive waves. Proc. Roy. Soc. A 283, 238.Google Scholar
Yokoi, S. 1960 Report of the Building Research Institute, no. 34, Ministry of Construction. Japan.