Formation of thermomagnetic convection of stratified magnetic fluid in a Hele ̶ Shaw cell
P. N. Kazantsev, B. L. Smorodin
Perm State National Research University, Perm, Russia
Keywords: magnetic fluid, magnetophoresis, thermal diffusion, convective stability, Hele---Shaw cell, Galerkin method
Abstract
This paper touches upon the formation of thermomagnetic convection in a stratified magnetic colloid filling a Hele---Shaw cell placed in an external nonuniform magnetic field and heated from the side of a narrow edge in such a way that the constant field strength gradient is co-directed with the temperature gradient. The Galerkin method is applied to obtain critical magnetic Rayleigh numbers for the cases of monotonic convection and oscillatory convection arising due to the nonuniformity of the concentration of magnetic nanoparticles caused by thermal diffusion and magnetophoresis. In the case of oscillatory instability, the dependence of the neutral oscillation frequency on the mixture separation parameter and the concentration Rayleigh number is determined. For supercritical monotonic and oscillatory convection conditions, the current function, temperature, and concentration distributions are presented, and the behavior of the amplitudes of various spatial harmonics is investigated
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