Akamatsu Masato, Higano Mitsuo, Ogasawara Hitoshi
Faculty of Systems Science and Technology, Akita Prefectural University, 84-4 Tsuchiya-Ebinokuchi, Yuri-Honjo, Akita 015-0055, Japan.
Ann N Y Acad Sci. 2006 Sep;1077:613-28. doi: 10.1196/annals.1362.052.
Two-dimensional numerical computations were carried out in order to elucidate the effect of a Kelvin force on the air in two coaxial circular pipes with open ends under both gravitational and nongravitational fields. The outer pipe with open ends corresponds to the bore space of the superconducting magnet. The inner pipe with open ends is assumed to be placed inside this bore space. The sidewall of the outer pipe is cooled isothermally. The central region of the inner pipe is heated isothermally and the other region is thermally insulated. The magnetic gradient that was produced by the electric current circulating within the circular electric coil was applied to air in two coaxial circular pipes with a thermal gradient. Moreover, the present numerical computations were carried out by changing the relative positions of the circular electric coil and the inner pipe. In both gravitational and nongravitational fields, when the circular electric coil was placed at the end of the heated region of the inner pipe, the Kelvin force was produced in the inner pipe and the magnetothermal air jet was created. As a result, the hotter air rapidly flowed out from the end of the inner pipe. These phenomena could be successfully explained by considering the temperature dependence of the mass magnetic susceptibility of air according to Curie's law.
为了阐明开尔文力在重力场和非重力场下对两端开口的两个同轴圆形管道内空气的影响，进行了二维数值计算。两端开口的外管对应于超导磁体的孔空间。假设两端开口的内管放置在该孔空间内。外管的侧壁被等温冷却。内管的中心区域被等温加热，其他区域隔热。由圆形电线圈内循环的电流产生的磁梯度被应用于具有热梯度的两个同轴圆形管道内的空气。此外，通过改变圆形电线圈和内管的相对位置进行了当前的数值计算。在重力场和非重力场中，当圆形电线圈放置在内管加热区域的末端时，在内管中产生了开尔文力并形成了磁热空气射流。结果，较热的空气迅速从内管末端流出。根据居里定律考虑空气的质量磁化率对温度的依赖性，可以成功地解释这些现象。
