2007 Volume 73 Issue 734 Pages 2092-2098
We have investigated the negative viscosity of a colloidal dispersion composed of ferromagnetic rod-like particles, which have a magnetic moment normal to the particle axis. We have here treated a simple shear flow problem to clarify the particle orientational distribution and rheological properties of such a semi-dense dispersion, under circumstances of an external magnetic field applied in the direction normal to the shear plane of a simple shear flow. In order to take into account magnetic interactions between particles, the mean field approximation has been adopted. The results obtained here are summarized as follows. Characteristic orientational properties of the particle cause negative viscosity, as in the previous study for a dilute dispersion. However, magnetic particle-particle interactions have a function to make such negative viscosity decrease, since the magnetic moment of the particle tends to align in the magnetic field direction more significantly with magnetic particle-particle interactions increasing.
Transactions of the Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers Series A
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A
Transactions of the Japan Society of Mechanical Engineers Series C
