Effect of Inclination on the Convection of Air in a Cubic Enclosure under Both Magnetic and Gravitational Fields with Flow Visualization

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Hiroyuki Ozoe¹  Shu-Shen Lu³  Toshio Tagawa¹  Ben Hua²  Masayuki Kaneda¹  Riki Noda¹ 

[1] Institute of Advanced Material Study, Kyushu University;The Key Lab on Enhanced Heat Transfer and Energy Conservation, Ministry of Education, Chemical Engineering College, South China University of Technology;School of Chemistry and Chemical Engineering, Sun Yat-Sen University

关键词: Magnetic Convection;    Inclination of Enclosure;    Numerical Analysis;    Flow Visualization;   

DOI  :  10.1252/jcej.37.338

来源: Maruzen Company Ltd

【 摘 要 】

References(20)Cited-By(2)Recent development of super-conducting materials at high temperature has got enabled to use a super-conducting magnet of 5–10 Tesla and various new phenomena have been reported. In the present report, convection is considered for air containing oxygen whose magnetic susceptibility is exceptionally large among gases. Air is filled in a cubic enclosure whose one vertical wall is kept at a higher temperature and an opposing wall is cooled at a lower temperature and other four walls are thermally insulated in the presence of a gradient magnetic field produced by a one-turn coil located above the enclosure. A numerical model including the magnetizing force and the gravitational force was developed and numerical computations were carried out for the parameters, Pr = 0.71, Ra = 105–106, γ = 0–10 to represent the strength of magnetic field versus the gravitational potential. For example, at Ra = 105 the average Nusselt number 4.476 at γ = 0 (with no magnetic field) increased to 5.160 at γ = 10. This system was further studied on the effect of inclination with respect to a horizontal axis at the bottom of the hot wall. With an application of a magnetic field, the conduction state heated from above at an inclination angle of 1.5π radians was found to change to a convection state. Flow visualization experiments were further carried out for the same size of a cubic box attached at an outlet of a bore of a super-conducting magnet of 10T with 100 mm diameter. The magnetic field induced the convection for the system heated from above and cooled from below. The computed flow mode agreed well with the experimental one to support the computed results favorably.

【 授权许可】

Unknown