Mason number modified for magnetorheological fluid dynamic characteristics

A quantitative analysis of characteristics of a magnetorheological fluid (MRF) under dynamic oscillation conditions was conducted using the Mason number method. The expression for the modified dynamic Mason number Mn* under different vibration frequencies, vibration amplitudes, and magnetic field strengths was established through theoretical derivations. The energy storage and loss moduli of the MRF were measured using dynamic sweep-amplitude experiments under different oscillation conditions. The results revealed that the data of the energy storage and loss moduli can be collapsed into the main curve when the dynamic Mason number Mn* is regarded as the abscissa. Furthermore, the function of each modulus and Mn* was obtained by data fitting. Thus, a unified mathematical model for MRF moduli vs. magnetic field strength and oscillatory parameters such as frequency, amplitude, et al. was established. This will provide support for the application of the MRF in vibration control and other fields.