A phenomenological treatment is given for the steady ferrofiuid flows in annular pipes in the presence of uniform external magnetic fields. It is found that the apparent viscosity of a dilute colloidal suspension of ferromagnetic particles is a marked function of both the magnitude and direction of an externally applied magnetic field. The experimental fact shown by McTague (1969) that the additional viscosity is greater by a factor of 2 for the field parallel to the flow than with it perpendicular is theoretically explained. Analytical expressions of the distributions of velocity and angular velocity of the ferrofiuid in annular pipes are derived under the influence of the external field. The induced magnetization calculated here to first order is skewsymmetric with respect to the plane through the center line of the pipe and perpendicular to the applied magnetic field.
|ジャーナル||Transactions of the Japan Society of Mechanical Engineers Series B|
|出版ステータス||Published - 1983 1|
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