Heating of Magnetorheological Fluid Dampers

This paper presents experimental and theoretical studies on heat generation and dissipation of fieldcontrollable, magneto-rheological (MR) fluid shock absorbers. Since MR fluid dampers are energy-dissipating devices, the issues of heat generation and dissipation are important. In this study, experiments are conducted on a variety of MR fluid dampers that have been designed, developed, and tested at the University of Nevada, Reno (UNR), for specific applications. Each MR fluid damper is experimentally evaluated for temperature changes that result from various types of sinusoidal input motions. In addition a theoretical model is developed which predicts the temperature increase of the MR fluid dampers. This model is solved numerically, and is compared with experimental results. Also, a non-dimensional form of the governing equations is developed to assess the effect of physical parameters on the heat dissipation as well as heat generation within the MR fluid damper. Moreover, the theoretical results for temperature rise of a MR fluid damper under a seismic force are presented. In all cases, the temperature effect on the damping force is significant.