Main effects of volume magnetic couples in a uniform field

For a magnetic fluid moving in a uniform external field, the volume magnetic force in a noninductive approximation should be set zero for any flow geometry. However, in the equation of motion, a part of the magnetic source due to the action of couples is other than zero. Their findings, taking account of the continuity equation are described in this paper. Their resultant equation of motion is applicable both to the stationary and arbitrary time-dependent uniform magnetic field. In order to formulate particular problems, they use expressions for the operators in this equation in curvilinear orthogonal coordinate systems. They discuss how one component of the space-constant specifying their equation is prescribed