Response to ``Comment on ``Tangential stresses on the magnetic fluid boundary and rotational effect''''

A. F. Pshenichnikov

Institute of Continuous Media Mechanics, Ural Branch of the Russian Academy of Sciences 1 Korolyov Str., 614013 Perm, Russia

Abstract
In 2000, we published a paper joining experimental and theoretical studies [1] on the rotational effect - a macroscopic flow of a magnetic fluid under the influence of a rotating magnetic field. Following [2], we show that in the case of weak fields the effect is caused by magnetic tangential stresses at the boundary of the magnetic fluid, not by bulk effects as supposed in most of the papers by predecessors. One of the results of the study [1] were the formulae for the torques acting on internal and external coaxial cylinders, the gap between which is filled with a magnetic fluid. Rinaldi and Chaves [3] got analogous expressions, but their formula for the torque acting on the internal cylinder differs by a quantity about (ωτ)² from ours (ω is the frequency of the rotating field and τ is the magnetization relaxation time). Besides, Rinaldi and Chaves point to the discrepancy in the phase shift between the homogeneous and inhomogeneous parts in the expressions for the magnetic field strength in the magnetic fluid. In their opinion, all these discrepancies are explained by mistakes in the integration constants for the magnetic field and magnetization made in our paper. Refs 7.