| Abstract: | The axisymmetric and stationary basic flow due to the unstable stratification in the lower region of a spherical annulus cooled from inside has already been investigated in some detail ([5], [4]). The same applies to the columnar cell flow regime of high Taylor numbers dominated by the force component perpendicular to the rotation axis ([2] and [3]). Yet the question of the initial mechanism of symmetry breaking at medium Taylor numbers has still not been investigated. Therefore the present paper investigates the onset of natural convection in a differentially heated wide spherical gap. The stability curves for radius ratio η = 0.4 and a silicon oil fluid with Pr = 39 are determined by varying Rayleigh and Taylor number. The m = 2 vortex is investigated in detail using quasi 3D Particle Image Velocimetry (PIV). (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
