On the dissipation processes in the oscillating system with a magneto-liquid element

G. V. Karpova - A. N. Kutuev - P. A. Ryapolov - V. M. Polunin - E. K. Zubarev - V. V. Kovarda

Kursk State Technical University, 94, 50 let Octyabrya str., 305040, Kursk, Russia

Abstract
Results of damping coefficient measurements in the oscillation system, in which the inert-viscosity element is a magnetic fluid (MF) filling a glass U-tube, are discussed in the paper. An air cavity formed inside one of the tube bends under the piezoelectric plate attached to the tube face and designed to indicate oscillations performs the role of elasticity. A procedure allowing to measure the oscillation-damping coefficient (attenuation coefficient of oscillations) and to obtain on this base the value of shear viscosity in MF samples under study determined by the magnetic field strength is proposed. The measured results of the field dependence on viscosity in a sample with a volume concentration of solid phase of 5% do not contradict the concept of ``rotational viscosity'' of the diluted disperse system of magnetic nanoparticles. We can interpret the data obtained for a MF sample with the concentration 16.6% by chain-forming aggregates in it. Tables 1, Figs 5, Refs 14.