Modeling of Magnetorheological Fluids by the Discrete Element Method

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. Modeling of Magnetorheological Fluids by the Discrete Element MethodMagnetorheological (MR) fluids are fluids whose properties vary in response to an applied magnetic field. Such fluids are typically composed of microscopic iron particles ($ 1 À 20 lm diameter, 20 À 40% by volume) suspended in a carrier fluid such as mineral oil or water. MR fluids are increasingly proposed for use in various mechanical system applications, many of which fall in the domain of tribology, such as smart dampers and clutches, prosthetic articulations, and controllable polishing fluids. The goal of this study is to present an overview of the topic to the tribology audience, and to develop an MR fluid model from the microscopic point of view using the discrete element method (DEM), with a long range objective to better optimize and understand MR fluid behavior in such tribological applications. As in most DEM studies, inter-particle forces are determined by a force-displacement law and trajectories are calculated using Newton's second law. In this study, particle magnetization and magnetic interactions between particles have been added to the discrete element code. The global behavior of the MR fluid can be analyzed by examining the time evolution of the ensemble of particles. Microscopically, the known behavior is observed: particles align themselves with the external magnetic field. Macroscopically, averaging over a number of particles and a significant time interval, effective viscosity increases significantly when an external magnetic field is applied. These preliminary results would appear to establish that the DEM is a promising method to study MR fluids at the microscopic and macroscopic scales as an aid to tribological design.

Influence of Shell Thickness on the Colloidal Stability of Magnetic Core-Shell Particle Suspensions

“…The cores and shells were simulated as made of pure iron and silica respectively (Neville and Moreno-Atanasio, 2012 ; Hyde et al, 2017 ). The magnetization of the particles was set at 1/10 th of the saturation magnetization value of iron 0.228 T/μ 0 (Reitz et al, 2008 ; Kargulewicz et al, 2012 ).…”

“…Lindner et al ( 2013 ) combined DEM with FEM to determine the external magnetic field and the fluid flow around cylindrical wires. Other DEM studies focused on predicting the magnetic particle behavior during compression, shearing and breakage of magnetic chains were published by Kargulewicz et al ( 2012 ); Lagger et al ( 2015a , b ); Soda et al ( 2015 ). Ke et al ( 2017 ) coupled DEM with Lattice Boltzmann Method and Immersed Boundary Method to simulate the settling of two individual magnetic particles.…”

State of the art of control schemes for smart systems featuring magneto-rheological materials

“…In other words, the output control performance of MRF and MRE application systems should be the best with the chosen controller under any environmental conditions. Despite the significance of the choice of an appropriate controller for MRF and MRE application systems, a full review article on the control strategies has not been reported so far, while several review articles on modeling of MR materials and dynamic modeling techniques of MR application systems have been introduced by several researchers [293][294][295][296][297][298][299][300][301][302].…”

Study of Nonlinear MHD Tribological Squeeze Film at Generalized Magnetic Reynolds Numbers Using DTM

“…Kargulewicz et al . [ 18 ] developed a discrete element algorithm to optimize aircraft ejector seat applications. Zueco and Bég [ 19 ] applied the electro-thermal network simulation code to study magneto-elastic hydrodynamic lubrication between rotating disks at generalized magnetic Reynolds numbers, as a model of conceptual spacecraft landing gear systems for Mars NASA missions.…”