Effect of a static magnetic field on the ultrasonic propagation in magnetic fluids

I. E. Ovchinnikov

Moscow State University of Instrument Engineering and Computer Sciences

Received January 15, 2013

 

Abstract: The propagation of hydrodynamic waves of small amplitude in magnetic fluid was considered with taking into account the process of relaxation of the magnetic field to its equilibrium value. The expressions for phase velocities and absorption coefficients were obtained for the fast magnetohydrodinamic wave and the Alfven type wave under propagation in parallel to magnetic field. It was shown by the theoretical analysis of the experimental data on the ultrasonic velocity in magnetic nanofluids based on water and kerosene should: absorption coefficients of these types of waves almost vanish by prolonged exposure of the homogeneous static magnetic field.

Key words: magnetic fluid, magnetic field, ultrasonics, nanoparticles, magnetite.