title: Field induced rotational viscosity of ferrofluid: effect of capillary size and magnetic field direction.
abstract: In the present investigation we report the effect of capillary diameter and the direction of applied magnetic field on the rotational viscosity of water and kerosene based ferrofluids. We found that changes in the field induced rotational viscosity are larger in the case of water based magnetic fluid than that of kerosene based fluid. The field induced rotational viscosity is found to be inversely proportional to the capillary diameter and it falls exponentially as a function of the angle between the direction of field and vorticity of flow. Magnetophoretic mobility and hydrodynamic volume fraction of nanomagnetic particles are determined for above cases.
authors.affiliation: Department of Physics, Bhavnagar University, Bhavnagar 364 02, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Andhariya
authors.forename: Bhupendra
authors.initials: B
authors.lastname: Chudasama
authors.forename: Rajesh
authors.initials: R
authors.lastname: Patel
authors.forename: R V
authors.initials: RV
authors.lastname: Upadhyay
authors.forename: R V
authors.initials: RV
authors.lastname: Mehta