Accession Number : AD0707149

Title :   CONVECTION IN A ROTATING ANNULUS UNIFORMLY HEATED FROM BELOW,

Corporate Author : COLORADO UNIV BOULDER

Personal Author(s) : Davis-Jones,Robert P. ; Gilman,Peter A.

Report Date : APR 1970

Pagination or Media Count : 37

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)

Descriptors :   (*SUN, ROTATION), (*CONVECTION(HEAT TRANSFER), *HYDRODYNAMICS), PERTURBATION THEORY, RINGS, STABILITY

Subject Categories : Astrophysics
      Fluid Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE