Simulations of Particle Dynamics in Magnetorheological Fluids

✍ Scribed by H.V Ly; F Reitich; M.R Jolly; H.T Banks; K Ito

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 334 KB
• Volume: 155
• Category: Article
• ISSN: 0021-9991
• DOI: 10.1006/jcph.1999.6335

✦ Synopsis

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.