Direct Numerical Simulation of Electrorheological Fluids*

An electrorheological (ER) fluid is mixture of dielectric particles suspended in a dielectric fluid. When subjected to an electric field, the particles of ER fluids become polarized and interact with each other to form chains and columns. We analyze the behavior of suspended dielectric particles subject to an electric field using direct numerical simulations. Our simulation results show that the particle chains attract each other only when they are staggered in the field direction and the distance between the chains is less than 2.48 times the particle radius. Otherwise, they repel. This causes overall structure to fragment into chains and columns. To diminish this fragmentation of particle distribution in an electric field, we consider ER fluids consisting of particle mixtures. The numerical simulations are corroborated with experimental data.