Dynamics of suspensions in wall-bounded shear flows
Maxey, Brown University, Applied Math
Suspensions such as corn starch in
liquid or superparamagnetic beads used in biomedical assays
involve particles several microns or larger in size for which
thermal (Brownian) agitation is not significant as the suspensions
are sheared. Viscous shear flows, such as pressure-driven flow in
a channel, drive these into non-equilibrium states, with
nonuniform concentrations and particle stress distributions.
Confinement by rigid walls introduces significant local structure
to the flow. Methods for the numerical simulation of such flows
will be discussed. Results of recent numerical simulations of
fully three-dimensional shear flows will be presented for
suspensions of spherical particles for dense suspensions over the
range of particle volume fractions 20% - 50%. Both the mean
structure and the fluctuation levels will be discussed.