Quantitative Analysis of Air Convection Caused by Magnetic-Fluid Coupling

Abstract

Magnetic attractive forces acting on paramagnetic oxygen have recently been found to induce gas e ow and promote combustion. The study of the interaction between electrically nonconducting gases and magnetic e elds is a new interdisciplinary research area called “ magnetoaerodynamics.” The authors present the magnetic body force acting on the gas and the governing equations for magnetoaerodynamics. The authors used these equations to evaluate the N 2‐air jet numerically to understand the mechanism and physics of this phenomenon. The key results are as follows: 1 ) The magnetic body force becomes nonconservative under gradients of both the O 2 gas concentration and themagneticstrength. 2 )Thenumerical analysesclarifythemechanism of thecoupling between magnetic forces and the convective motion and indicate the existence of air convection and the N 2 jet due to the nonconservative magnetic body force. 3 ) The maximum velocity of the N 2 jet, umax, increases with the magnetic strength at the center of the magnet, B0. For B0 =1:5 T and entrance velocity of the N 2 gas of 7.4 cm/s, umax =44 cm/s. 4) Measured velocities were in good agreement with our simulation. This study suggests the potential use of magnetic e elds to control gas e ows and combustion.