Shear-induced migration

D. Leighton and A. Acrivos, The shear-induced migration of particles in concentrated suspensions.. Fluid Mech., 181 (1987) 415-439. 

A particle migration model was proposed by Gadala-Maria and Acrivos to describe experimental shear-induced migration observations. This model allows for a better understanding of the shear effects on particle diffusion for concentrated suspensions. Based on these studies, a conservation equation for the solid phase was established by Phillips, Amstrong, and Brown, which takes into account convective transport, diffusion due to particle-particle interactions, and the variation of viscosity within the suspension, namely ... 

Leighton, D. Acrivos, A. Viscous resuspension. Chem. Eng. Sci. 1986, 41 (6), 1377-1384. Leighton, D. Acrivos, A. Measurement of shear-induced self-diffusion in concentrated suspensions of spheres. J. Fluid Mech. 1987, 177, 109-131. Leighton, D. Acrivos, A. The shear-induced migration of particles in concentrated suspensions. J. Fluid Mech. 1987, 181, 415-439. Altobelli, S.A. Givler, R.C. Fukushima, E. Velocity and concentration measurements of... 

These surface vortices provide an efficient means for microfiuidic mixing, as shown in Fig. 10, where a dye is rapidly mixed within several seconds. The mixing can be enhanced by inducing the vortex instabilities wherein turbulent-like mixing efficiencies are observed [18]. In addition, particles dispersed in the flow are also observed to be drawn into the vortices due to positive dielectrophoresis toward a point on the interface closest to the needle where the field is most intense. Once a sufficient particle concentration is achieved within the vortex, shear-induced migration leads to crossstreamline transport such that the interior of the vortex is populated [18], as shown in Fig. 11a. 

A study using confocal Raman spectrometry was carried out to determine the concentration profile within the extrudate of rubbery particles in a polyethylene matrix during capillary flow (Chartier et al. 2010). Chartier et al. reported that the effect of the concentration of particles on the apparent viscosity of polymer melts measured using capillary flow was the opposite of that based on observations made using linear dynamic viscosity measurements (Fig. 7.41). Shear-induced migration can be detected from the concentration profile of the components of the... 

Jana, S.C. (2003) Loss of surface and volume electrical conductivities in polymer compoimds due to shear induced migration of conductive particles. Polym. Eng. Sci., 43, 570. 

Hong, C.-M., Kim, J., and Jana, S.C. (2003) The effect of shear-induced migration of conductive fillers on conductivity of injection molded articles. Proceedings of the 61st SPE ANTEC, pp. 1625-1629. 

Hong JS et al. Shear-induced migration of nanoclay during morphology evolution of PBT/PS blend. J Appl Polym Sci 2008 108(l) 565-575. 

Particle suspensions Tube/couette flow Shear-induced migration... 

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