RHEOLOGICAL PROPERTIES OF ER-FLUIDS IN TERM OF MULTIPARTICLE PHYSICAL MODEL AND MONTE-CARLO COMPUTER SIMULATION

Abstract

An electrorheological fluids (ERF) are the suspensions consisting of dielectric rigid particles in the viscous (or viscoelastic) media. Based on the three-dimensional well-ordered multi-particle model (the crystal model) we describe rheological properties of ERF. We use the model of cubic body-centered lattice. We also assume that the electric field is orthogonal to the velocity of shear of fluid's layers. The displacement gradients are assumed to be different (from small to finite values). For small deformations in the framework of the approach proposed and under assumptions made it was stated that the ERF can be treated as a viscoelastic body and it is consequently described on the basis of the linear theory of viscoelasticity. We obtain a complex dynamic shear modulus as a function of the electric field strength, volume fraction of filler, electric properties of components of ERF and viscosity of the fluid phase. For finite deformation the relation between stresses and shear rate gradients has also been made. The relation does not keeps whatever phenomenological or arbitrary parameters and takes into account contribution an electrostatic interaction painted by external field dipoles. From other side a bunch of computational experiments by Monte-Carlo approximation to model both the structure and the peculiarities of ERF were made. We use a procedure by Metropolis for canonic NVT ensemble and parallel computational technologies. The structural characteristics, density, energetic parameter and others for system under consideration have been estimated. In order to verify a theoretical predictions we compare both approaches and some experimental data.