NUMERICAL STUDY OF SUSPENSIONS OF PARTICLES IN ELECTRORHEOLOGICAL FLUIDS
Speaker: Xianjin Jiang
Advisor: Dr. N. Aubry
Abstract
A molecular-dynamics-like method is used to simulate numerically the suspension of polarizable particles in nonconductive solvent subjected to external electric fields. The particles experience both hydrodynamic and electrostatic interactions. In this paper, the former is determined with the Stokesian dynamics methods with assumption that the Reynolds number Re is less than 1.0. While electrostatic interactions are modeled from the electrostatic energy of the suspension. The energy of the suspension is computed from the induced particles dipoles with a method that was first developed by Bonnecaze et al. [1]. This method was expanded here and can be used to calculate the electrostatic forces on particles where ER fluids are subjected to nonuniform electric fields. First, the suspensions are modeled as monodisperse suspensions of hard, dielectric spheres in Newtonian fluids sandwiched between parallel plate electrodes. Then, spatially nonuniform electric fields will be applied to study the time evolution of the particle movement in Newtonian fluids with or without imposed pressure-driven flow. The results show that the particles will move towards high field or low field, depending on whether the particle is more or less polarizable than the surrounding medium (the sign of b).