Aaron Dörr, Amsini Sadiki, Amirfarhang Mehdizadeh
Based on the notion of a construction process consisting of the stepwise
addition of particles to the pure fluid, a discrete model for the apparent
viscosity as well as for the maximum packing fraction of polydisperse
suspensions of spherical, non-colloidal particles is derived. The model
connects the approaches by Bruggeman and Farris and is valid for large size
ratios of consecutive particle classes during the construction process.
Furthermore, a new general form of the well-known Krieger equation allowing for
the choice of a second-order Taylor coefficient for the volume fraction is
proposed and then applied as a monodisperse reference equation in the course of
polydisperse modeling. By applying the polydisperse viscosity model to two
different particle size distributions (Rosin-Rammler and uniform distribution),
the influence of polydispersity on the apparent viscosity is examined. The
extension of the model to the case of small size ratios as well as to the
inclusion of shear rate effects is left for future work.
View original:
http://arxiv.org/abs/1202.3804
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