Convection induced by centrifugal buoyancy

Abstract

The onset of convection is observed in a cylindrical annulus which is heated from the outside, cooled from the inside and rotating about its vertical axis of symmetry. The dynamical constraint exerted by the dominating Coriolis force inhibits the instability when the top and bottom boundaries of the annulus are conical so as to make the vertical height vary with distance from the axis. The experimental observations are in good agreement with the theoretical predictions by Busse (1970a). This confirmation indicates the absence of subcritical finite amplitude instabilities and suggests that the annulus experiment provides a close dynamical model for convection in the liquid core of the earth.

Three-dimensional quasi-geostrophic convection in the rotating cylindrical annulus with steeply sloping endwalls

“…Laboratory experiments in the rotating cylindrical annulus (Busse & Carrigan 1974), spherical shells (Busse & Carrigan 1976;Cardin & Olson 1994;Aubert et al 2001) and hemispherical shells (Cordero & Busse 1992;Cordero 1993;Sumita & Olson 2000) have all demonstrated that columnar motions can persist well above the onset of convection even in the presence of top and bottom boundaries with order-one slopes. This fact is also well-observed in the many numerical simulations of rotating convection in spherical shells (e.g.…”

Centrifugally driven convection in the rotating cylindrical annulus with modulated boundaries

“…In particular, the annulus model exhibits all basic dynamical features of convection in rotating spherical shells which represents a fundamental problem in astrophysics and planetary science. The rotating annulus system can easily be realized in the laboratory (Busse and Carrigan, 1974) and several experimental studies have been performed (Azouni et al, 1986;Busse et al, 1997). Among the theoretical investigations we mention only some recent ones Busse, 1992, 1997), in which realistic no-slip boundary conditions have been used.…”

New patterns of centrifugally driven thermal convection

“…There is also the Coriolis force, of course, which causes differences with respect to the ordinary Rayleigh-Bénard layer. In fact the Coriolis force is typically a dominating force ensuring that convection assumes the form of rolls aligned parallel to the axis of rotation (2). But for fluids of sufficiently large Prandtl number a limit can be reached in which the Coriolis force can be regarded as a small perturbation in the balance of forces in Rayleigh-Bénard convection.…”