CONVECTION IN A ROTATING ANNULUS UNIFORMLY HEATED FROM BELOW,
Abstract
The report discusses a linear stability analysis, to second order in initial amplitude, of Benard convection of a Boussinesq fluid in a thin, rotating annulus, for modest Taylor numbers T (= or < 10,000). The work is motivated in part by the desire to study further a mechanism for maintaining, through horizontal Reynolds stresses induced in the convection, the sun's 'equatorial acceleration', which has been demonstrated for a rotating convecting spherical shell by Busse and Durney. The annulus is assumed to have stress free, perfectly conducting top and bottom (which allows separation of the equations) and nonconducting, nonslip sides. Annuli with gap-width to depth ratios a of order unity are considered. The close, nonslip sidewalls produce a number of effects not present in the infinite plane case, including overstability at high Prandtl numbers P, and multiple minima in Rayleigh number R on the stability boundary. The latter may give rise to vacillation. The complete second order solutions for the induced circulations indeed give faster rotation in the outer half, except for large P (> 100), in which case thermal stresses dominate. At all P, this differential rotation is qualitatively a thermal wind. Overstable convective cells, and stationary cells at higher T induce more complicated differential rotations. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1970
- Accession Number
- AD0707149
Entities
People
- Peter A. Gilman
- Robert P. Davis-jones
Organizations
- University of Colorado Boulder