MR Fluids - Dynamics Simulations

by

H.V. Ly,  F. Reitich, M. Jolly, H.T. Banks and K. Ito

submitted to: Journal of Computational Physics

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Introduction

We present particle dynamics simulations for the response of magnetorheological (MR) fluids upon application of a magnetic field. The particles motion is considered to be governed by magnetic, hydrodynamic and repulsive interactions. Fluid-particle interactions are accounted for via Stokes' drag while inter-particle repulsions are modeled through approximate hard-sphere rejections. In accordance with their greater significance, on the other hand, (linear) magnetic interactions are fully simulated. The time evolution is considered to be magnetically quasi-static and magnetostatic forces are derived from the solution of (steady) Maxwell's equations, recomputed at each instant in time. For this we use a potential theoretic formulation where the boundary integral equations are solved with a fast multipole approach. We
show that the  resulting numerical codes can be effectively used to study a number of experimental observables such as effective magnetic permeabilities and response time-scales which are of crucial importance in the design of MR fluids.

 

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Numerical Results (Click on volume fractions)

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The research in this project was done when Hung V. Ly was a National Science Foundation
Industrial Post-Doctoral Fellow at the Center for Research in Scientific Computation-
North Carolina State University. This work was supported jointly by the National Science Foundation under Grant No. DMS-9704963 and by the Lord Corporation through funds to the Center for Research in Scientific Computation at the North Carolina State University.