2014 年 62 巻 1 号 p. 31-37
Transient three-dimensional numerical computations were carried out to clarify the heat transfer rate characteristics of magnetothermal convection of paramagnetic air created by the magnetic force alone in a shallow cylindrical enclosure with the thermal and magnetic gradients in a non-gravitational field. The enclosure filled with a paramagnetic air was fixed at the location which is subjected to a more uniform axial magnetic force and a minimal radial magnetic force. This configuration was devised to compare the heat transfer rate for the Rayleigh-Benard convection generated in a uniform gravitational force and the heat transfer rate for the magnetothermal convection by the application of the magnetic Rayleigh number proposed by Braithwaite et al. The computed heat transfer rates, i.e., the average Nusselt numbers on the heat transfer wall, for various numerical conditions were plotted versus the magnetic Rayleigh number with the classical experimental data for the Rayleigh-Benard convection under a nonmagnetic field reported by Silveston. When the average Nusselt numbers were evaluated using the magnetic Rayleigh number Ram, our data computed in the range 1,000 < Ram < 11,430 were found to distribute along the averaged curve obtained experimentally by Silveston.