Experimental investigation into the electrical modeling of electrorheological fluids in the shear mode

An understanding of the mechanical, thermal and electrical response characteristics of electrorheological (ER) fluids is vital to the design of any machine based on them. If the full potential of this original mechatronic medium is to be utilised, all will be included in steady and time domain-interactive optimisations of the particular application/process aim. The paper deals with the electrical modelling of ER fluids in the shear mode and presents the results of experimental tests conducted under true engineering conditions. In particular, the effects of the electrode separation and surface area are investigated for a range of shear rates and field magnitudes and a study of the effect of fluid temperature is reported. It is shown that controller capacitance typically does not vary significantly with the field strength, the shear rate or the temperature applied, but increases with increasing electrode surface area and reduces with increasing interelectrode spacing. The electrical resistance of a controller, however, although showing no reliable dependency on shear rate, reduces with increasing field strength, temperature and electrode surface area and increases with increasing interelectrode gap