Local Implications for Self-Similar Turbulent Plume Models

Scase, M. M. and Caulfield, C. P. and Linden, P. F. and Dalziel, S. B. (2007) Local Implications for Self-Similar Turbulent Plume Models. Journal of Fluid Mechanics, 575 (-1). pp. 257-265. DOI 10.1017/S0022112007004740

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Abstract

The local implications of the well-known flux conservation equations of Morton et al. (Proc. R. Soc. Lond. A, vol. 234, 1956, p.1) for plumes and jets are considered. Given the vertical velocity distributions of a model plume or jet, the divergence-free radial velocity distributions are calculated. It is shown that in general the velocity of the plume boundary is not described by the local total fluid velocity in this way. A two-fluid model tracking the evolution of both ‘plume’ and ‘ambient’ fluid is proposed which resolves this apparent inconsistency and also provides a way of explicitly describing the mixing process within a model plume. The plume boundary acts as a phase boundary across which ambient fluid is entrained, and the plume boundary moves at the velocity of the plume fluid. The difference between the plume-fluid radial velocity and the total fluid velocity quantifies in a natural way the purely horizontal entrainment flux of ambient fluid into the plume across the phase boundary at the plume edge.

Item Type:	Article
Uncontrolled Keywords:	BPI
Subjects:	99 - Other
Journal or Publication Title:	Journal of Fluid Mechanics
Volume:	575
Page Range:	pp. 257-265
Identification Number:	10.1017/S0022112007004740
Depositing User:	Sarah Humbert
Date Deposited:	08 Jul 2010 13:45
Last Modified:	23 Jul 2013 09:57
URI:	http://eprints.esc.cam.ac.uk/id/eprint/1448

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