Shear-induced particle migration in a polydisperse concentrated suspension

Abstract

The shear-induced particle migration in a polydisperse concentrated suspension is described using migration potentials for the various particle size fractions. The model is applied to solve the flow patterns and the particle concentration distributions in bidisperse suspensions in various viscometric flows. For the case of a continuous particle size distribution a formulation of this model in terms of concentration distribution moments is presented. The model predicts the total migration of the particles in the various flow devices and the size segregation of the various fractions. The calculations capture well the few experimental observations reported so far. It is found that in all calculated cases the total energy dissipation rate and, therefore, the power required to drive the flow were diminished considerably at steady state.

Effects of particle size segregation on crossflow microfiltration performance: Control mechanism for concentration polarisation and particle fractionation

“…Although their calculations may be illustrative for the effects of polydispersity, the predictions of Kramadhati et al have not been validated yet. In earlier work [6], we adapted a shear-induced migration model of Shauly et al [7] for MF of bidisperse suspensions and found that this model gave a good description of the stationary filtration rate for relative volume fractions of large particles between 20 and 80%. The paper is one of the few that include the effects of particle polydispersity on the kinetics of particle deposition, albeit directed at stationary situations.…”

On instabilities and migration phenomena in cone and plate geometry

“…The model proposed by Shauly et al [11] is based on particle migration potentials and incorporates different mechanisms of migration induced by particle concentration, shear rate and streamlines curvature gradients. It predicts well the particles shear-induced migration and the segregation of sizes, which are experimentally reported for polydisperse systems.…”

Modelling Shear Induced Diffusion Based Particle Segregation: A Basis for Novel Separation Technology

“…SID is dominant for particles in the range of 1 to 10 µm, with a particle Reynolds number lower than one and a Péclet number that is higher than one (Figure 1). Considerable effort is put into understanding the principle of shear induced diffusion [12][13][14][15][16][17][18][19][20] that is especially relevant at high volume fractions and it causes particles to interact and move towards a region with low shear (i.e., the center of a channel) [21]. Depending on the size and volume fractions of small and large particles the former or latter will predominantly move towards the center of the channel when using particles of different sizes [19].…”