The Effect of Nonuniform Magnetic Field on Natural Convection in an Enclosure

Abstract

Numerical two-dimensional study is carried out on the laminar and turbulent natural convection of molten sodium in a square enclosure heated from one vertical wall and cooled from an opposing vertical wall. A nonuniform magnetic field is described by a mathematical equation, which describes the distribution of different values of magnetic induction strength along the magnetic pole faces. The external magnetic field is applied in the x direction, for laminar flow with Ra = 10⁶ and for turbulent flow with Ra = 10¹⁰. The magnetic field intensity required for suppressing the turbulent natural convection is more than that required for laminar natural convection. The effect of a nonuniform magnetic field differs from that of a uniform magnetic field. The flow profile changes dramatically with external magnetic strength and direction, but this change in flow region depends on the distribution of magnetic field strength along magnetic pole faces. The flow of liquid metal in an enclosure occurs in the low-magnetic-strength region far from the high-magnetic-strength region. This affects the temperature distribution in the enclosure and the values of the Nusselt number.