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Vorticity dynamics of a convective swirling boundary layer

Published online by Cambridge University Press:  19 April 2006

Richard Rotunno
Richard Rotunno
Affiliation:
Cooperative Institute for Research in Environmental Sciences, University of Colorado/NOAA, Boulder 80309
Present address: National Center for Atmospheric Research, P.O. Box 3000, Boulder 80309. The N.C.A.R. is sponsored by the National Science Foundation.
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Abstract

The vorticity dynamics of a convective swirling boundary layer are studied from the viewpoint of steady, inviscid fluid-dynamics theory. Attention is confined to the region of flow lying directly below and within a circularly shaped updraft. Fluid enters the updraft region without vorticity save for that in the boundary layer upstream of the updraft radius. Solutions of the equation \[ r\eta = r^2\frac{dH}{d\psi}-\frac{d}{d\psi}\bigg(\frac{\Gamma^2}{2}\bigg) \] (e.g. Batchelor 1967, p. 545) are presented. By the nature of this approach it allows one to compute the ‘outer’ flow together with the outer boundary-layer structure and hence side-step the interaction problem. A drawback is that the inner viscous structure is not captured. These solutions are compared to some numerical solutions of the time-dependent, viscous axisymmetric Navier-Stokes equations which are reported elsewhere (Rotunno 1979). Although the agreement is not perfect, model results are close enough whereby a number of useful deductions concerning the effects of viscous diffusion and time-dependence may be made.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 97 , Issue 3 , 15 April 1980 , pp. 623 - 640
Copyright
© 1980 Cambridge University Press

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