Tentative Analysis of Electrorheological Fluids by Energy Method

With the aid of microphotography, a novel phenomenon has been detected by the authors that the microstructure of electrorheological fluids (ERF) may emerge in the form of relatively single branched chain columns when the electric field intensity reaches to a certain amount. The central part of columns may easily be broken into fluid state with the increasing of pressure difference of the fluid flow. The central flowing region increases as the pressure difference further increases, and finally it may extend to the boundary areas of the electric plates. To elucidate the above-mentioned phenomenon, a tentative method of energy analysis has been presented. Staring from the energy possessed by a single particle in the electric field, an energy expression was thus derived, covering the parameters such as dielectric constant, total volume of the particles, the distribution of the electric field, and the interface characteristics of ERF control valves, etc. their influences on the performance of ERF are discussed. The paper offers a theoretical basis for the proper preparation of ERF and the design considerations of ER control valves.