Behavior of magnetothermal RayleighBenard convection of air visualized by 3D simulations
We conducted transient three-dimensional numerical computations to scrutinize the behavior of magnetothermal convections of air created by a steep magnetic gradient, i.e., the magnetic force, in RayleighBenard configuration (a shallow cylindrical enclosure heated from below and cooled from above). First, the behavior of RayleighBenard convection generated by the gravitational buoyant force alone was observed. Second, the behavior of magnetothermal RayleighBenard convections was observed for the different initial conditions and magnetic gradients. In concrete terms, we investigated the behaviors of the enhanced RayleighBenard convection and the suppressed RayleighBenard convection formed by the influences of the magnetic and gravitational buoyant forces. To clarify the effect of the magnetic force alone, we studied the behavior of the magnetothermal convection created in a nongravitational field using different initial conditions. Finally, we compared the computed average Nusselt numbers in both gravitational and nongravitational fields with the classical experimental data for RayleighBenard convection reported by Silveston, by applying the magnetic Rayleigh number first proposed by Braithwaite et al.
rayleighbenard convection air magnetothermal convection magnetic force paramagnetic fluid superconducting magnet