Acoustic characterization of magnetorheological fluids.

Abstract

Magnetorheological (MR) fluids contain magnetic particles dispersed within a host fluid. These materials are considered a type of “smart” fluid in that their viscoelastic properties can be controlled by varying the magnetic field intensity. MR fluids have found favor in high-end automobile applications such as the General Motors dynamic MR suspension system which has been in Corvettes (and other GM products) since 2005. Recently there has been interest in understanding the acoustic properties of MR fluids. In particular, the ability to control the radial and orthogonal bulk moduli suggests that MR fluids are a potential candidate for acoustic metamaterial applications. This presentation will discuss MR fluids and a method for the acoustic characterization of these fluids as functions of frequency and magnetic drive levels. [Work supported by the Office of Naval Research.]