B. Vernescu
WPI
MULTIPLE-SCALE ANALYSIS OF ELECTRORHEOLOGICAL FLUIDS
Electrorheological fluids are colloidal suspensions that can considerably
change their mechanical properties in an electric field.
We construct a microscale model for an ER fluid that enables us, via
homogenization, to characterize the properties the material exhibits at
the macroscopic scale. The homogenized constitutive equations change due to
the highly oscillating electrostatic forces. It is confimed that in some
rheological experiments their behavior is similar to the Bingham materials.
The material properties are determined by both hydrodynamic and electrostatic
interparticle interactions. Interfacial effects due to hydration are also
considered.
The understanding of the underlying physics governing the electrorheological
response can contribute to the engineering of better ER fluids and can be
useful in building controllable systems.
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