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On the motion of turbulent thermals

Published online by Cambridge University Press:  29 March 2006

M. P. Escudier  and
T. Maxworthy
M. P. Escudier
Affiliation:
Division of Engineering and Applied Mechanics, University of Southern California, Los Angeles
T. Maxworthy
Affiliation:
Division of Engineering and Applied Mechanics, University of Southern California, Los Angeles
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Abstract

An analysis is presented of the motion of a turbulent thermal in an unstratified environment. Although based upon the entrainment hypothesis introduced by G. I. Taylor (see Morton, Taylor & Turner 1956), the analysis differs from previous work in that it is not limited to small density differences between the thermal and its surroundings. Also, the influence of the virtual mass of the unsteadily moving fluid, ignored by previous investigators, is included and shown to be of significance for any density difference.

Calculations of the temporal variations of size, velocity and density are presented in non-dimensional form for thermals with initial density ratios covering the practically attainable range. It is shown a posteriori that losses of momentum and buoyancy to a wake are probably of negligible influence in any real case.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 61 , Issue 3 , 20 November 1973 , pp. 541 - 552
Copyright
© 1973 Cambridge University Press

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