Dynamic responses of electrorheological fluid in steady pressure flow

• Published in: Experiments in fluids Vol. 44; no. 6; pp. 915 - 926
• Main Authors: Nam, Y. J., Park, M. K., Yamane, R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2008; Springer
• Subjects: Clusters; Cross-disciplinary physics: materials science; rheology; Dynamic tests; Dynamics; Electric field strength; Electro- and magnetorheological fluids; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Exact sciences and technology; Flow velocity; Fluid dynamics; Fluid flow; Fluid- and Aerodynamics; Fluids; Fundamental areas of phenomenology (including applications); Heat and Mass Transfer; Instrumentation for fluid dynamics; Material types; Physics; Research Article; Rheology; Hydrodynamic Force; Shear Mode; Pressure Response; Electric Field Strength; Flow Channel; Dynamic response; Test facilities; Particle cluster; Electric field effects; Electrorheological fluid; Flow visualization; Experimental study; Step response
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-007-0449-1

The dynamic responses of the electrorheological fluid in steady pressure flow to stepwise electric fields are investigated experimentally. First of all, the transient responses of the ER fluid under various electric field strengths and flow velocities are obtained from the pressure behaviors in the flow channel with two parallel-plate electrodes. The response times are exponentially decreased with the increase of the flow velocity and the decrease of the electric field strength. Next, the relationship between the dynamic pressure behaviors of the ER fluid and the cluster structure formation processes of the ER particles is investigated using the flow visualization technique. Through the comparison study, it is verified that the dynamic responses of the ER fluid in the flow mode are mainly caused by the cluster densification process in the competition of the electric field-induced particle attraction and the hydrodynamic force, unlike those in the shear mode determined by the particle aggregation process.