Rheology of ERF on various flow fields

This paper is concerned with the experimental investigation of electrorheol ogical effect (ER effect) oil apparent viscosity and yield stress obtained from hydrodynamic characteristics of electrorheological fluid (ERF) in vari ous flow fields. Our conducting flow fields are made by using rectangular d uct, concentric cylindrical pipe, rotating disk and rotating concentric cyl inder. The measured parameters of the former two cases are pressure differe nce at a given volumetric flow rate, and the latters are torque at a given angular velocity. Our using ERF is suspension type. We arrange these data t o obtain increment of apparent viscosity aid yield stress with and without a supplying D. C. electric field by using integral method of rheology. It i s clarified that qualitative:values of increment of apparent viscosity and yield stress are different at each flow field. In addition, the quantitativ e ER effects of shear rate and electric field strength on the increment of apparent viscosity and yield stress are clarified.