Paper number 842

DYNAMICAL MODELLING OF THE CHAIN STRUCTURE FORMATION IN ELECTRORHEOLOGICAL FLUIDS

BIAO WANG^*, YULAN LIU^* and ZHONGMIN XIAO

School of Mechanical and Production Engineering
Nanyang Technological University
Nanyang Avenue, Singapore 639798

Summary

An electrorheological fluid consists of a suspension of fine particles in a liquid of low dielectric constant and low viscosity. Its apparent viscosity increases dramatically in the presence of an electric field. Experimental investigations reveal that as the electric field is applied, the depolarized particles form a chain structure along the electric field, and the formation of chains underlies all phenomena of ER fluid. In this paper, the released electromagnetic energy accompanying the growth of the chain was derived first based on a dynamic electromagnetic solution. The released energy, serving as the driving force for the chain formation, should equal to the dissipated energy related with friction resistance of the viscous fluid in the chain formation. In such way, the governing differential equation of the chain growth was established. Based on this energy model, the velocity of the chain forming, and the response time of ER fluid can be predicted.

Keywords

ER fluid, chain formation, mechanism, energy approach, dynamic model.