A systematic study of the dynamics of chain formation in electrorheological fluids

TL;DR

This paper systematically investigates the dynamics of chain formation in electrorheological fluids through Brownian Dynamics simulations, analyzing how various parameters influence chain growth and identifying characteristic time constants.

Contribution

It provides a comprehensive analysis of chain formation dynamics in ER fluids, including the effects of multiple parameters and preliminary insights into particle-particle polarization effects.

Findings

Identification of two distinct time constants for short and long chain formation.

Mapping of system behavior over a wide parameter range.

Preliminary results on particle-particle polarization effects.

Abstract

We report a systematic study of the dynamics of chain formation in electrorheological (ER) fluids using Brownian Dynamics simulations. The parameters of the system such as applied electric field, polarizability, dipole moment, friction coefficient, and number density are expressed in reduced units and changed in a wide range in order to map the system's behavior as a function of them. We define time constants obtained from bi-exponential fits to time dependence of various physical quantities such as dipolar energy, diffusion constant, and average chain length. The smaller time constant is associated with the formation of shorter chains (pairs, triplets, and so on), while the larger time constant is associated with the formation of longer chains in the regime of those that overarch the simulation cell. We use the approximation that the dipole moments are induced by the applied electric field only, as usual in the literature. However, we report preliminary results for the case when particle-particle polarization is also possible.