Acoustical properties of magnetorheological fluids under applied magnetic field

This work is devoted to the experimental study of acoustical properties of magnetorheological fluids subjected to magnetic field. Evaluation of the change in velocity of ultrasonic waves and attenuation coefficients in magnetorheological fluids based on synthetic oil and carbonyl iron versus magnitude and angle φ between wave vector and intensity direction of applied magnetic field has been carried out by pulse-phase method at 1.52 and 2.5 MHz. It was found that the anisotropy of attenuation coefficient was ~5–6 dB/cm and the velocity of ultrasonic waves was up to ~1%−2% that is much more than in specimens of colloid solutions—magnetic fluids with the same dispersive phase content.