Time similarity analysis of unsteady buoyant plumes in neutral surroundings
- 26 July 1979
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 93 (02) , 241-250
- https://doi.org/10.1017/s0022112079001877
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.Keywords
This publication has 5 references indexed in Scilit:
- Fire growth rates in wood cribsCombustion and Flame, 1976
- Radiative energy transfer from turbulent diffusion flamesCombustion and Flame, 1976
- The asymptotic behaviour of a starting plumeJournal of Fluid Mechanics, 1975
- The ‘starting plume’ in neutral surroundingsJournal of Fluid Mechanics, 1962
- Forced plumesJournal of Fluid Mechanics, 1959