Migrational Instability in Shear-Thinning Suspensions
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This work deals with an instability arising from the shear-induced migration of particles in dense suspensions coupled with a dependence of viscosity on particle concentration. As an extension of a recent work by the present author treating the inertialess (Re = 0) linear stability of homogeneous simple shear flow, the current article includes shear-thinning effects. Depending on the importance of shear-induced migration relative to concentration-driven diffusion, the short-wave instability found in the previous work is shown to be enhanced by shear thinning. Such instability would lead ultimately to a two-phase structure, involving particle-rich regions in dynamic equilibrium with particle-depleted regions, which in the case of pipe flow should result in a “core-annular” structure, with viscous core surrounded by a less viscous lubricating layer.
KeywordsPipe Flow Concentrate Suspension Simple Shear Flow Pipeline Transport Isaac Newton Institute
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