EFFECTS OF FLUID CONVECTION AND PARTICLE SPIN ON FERROHYDRODYNAMIC PUMPING IN TRAVELING-WAVE MAGNETIC-FIELDS

Ferrofluid pumping in a traveling wave magnetic field without a free s urface is analyzed by finding the time average magnetic force and torq ue and numerically solving the coupled linear and angular momentum con servation equations. It is necessary that the fluid convection and par ticle spin terms be significant in the magnetization constitutive law and that spin viscosity be small in order to predict the experimentall y observed reverse pumping at low magnetic field strengths and forward pumping at high magnetic field strengths.