Apparatus for Studying Convection under the Simultaneous Action of a Magnetic Field and Rotation

Abstract

An apparatus for the study of the instability of a layer of mercury heated from below and subjected to the simultaneous action of a magnetic field and rotation is described. The equipment is designed to examine the mode of convection and the dependence of the critical Rayleigh number (=αgβ_cd⁴/κν, where g denotes the acceleration due to gravity, β_c the critical adverse temperature gradient, α the depth of the layer, κ the thermometric conductivity, ν the kinematic viscosity, and α the coefficient of volume expansion) for the onset of instability on the values of nondimensional parameters Q₁ (=σH²d²/π²ρν, where H is the strength of the magnetic field, σ the electrical conductivity, and ρ the density of fluid) and T₁ (=4Ω²d⁴/π⁴ν², where Ω denotes the angular velocity of rotation), the features proven to be essential in such studies. By using a reconditioned cyclotron magnet as a part of the experimental arrangement, this apparatus covers wide ranges of parameters Q₁ (from 10 to 10⁶) and T₁ (from 10⁵ to 10¹⁰). Typical results that can be obtained by this apparatus are discussed with a few illustrative examples.