Model for particle migration in bidisperse suspensions by use of effective temperature

Abstract

A model for the particle migration in a bidisperse flowing suspension is proposed and compared to experimental data. A mixture formulation, describing the suspension velocity and pressure and the concentrations of two solid fractions is derived from a multi-fluid model. In the multi-fluid model the liquid phase and both dispersed phases are interpenetrating phases. The closure relations are based on a mean field approach extending closure relations of a monodisperse suspension. The model is used to predict segregation based on particle size in channel flow where the particles are subjected to Brownian motion and shear-induced migration. The comparison of the model results with experimental data shows that particle migration is predicted well by the given formulation.

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].…”

Shear-induced particle migration in three-dimensional bifurcation channel

“…Both the diffusive flux and suspension balance model over predict the wall concentration. Vollebregt et al (2012) in the mixture model proposed the adjustment of the maximum packing close to the wall, which corrects the depletion of particles near the wall. Recently, van Dinther et al (2013) have probed the role of shear induced diffusion phenomena in the fractionation of droplets based on their size.…”

Comparison of first principles model of beer microfiltration to experiments via systematic parameter identification

“…This concept has allowed us to extend the theory to bidisperse suspensions like mixtures of yeast cells and aggregates [39]. In a previous paper we have analyzed the applicability of the bidisperse model for beer microfiltration [36].…”

“…In a parallel research program we have developed the current stateof-the-art first-principles model for shear-induced diffusion [33,38,39,35], which is based on the soft matter concept of the effective temperature [34,35]. This concept has allowed us to extend the theory to bidisperse suspensions like mixtures of yeast cells and aggregates [39].…”

“…The model incorporates the most recent description of shear-induced diffusion [38,35,39], which is the dominant backtransport mechanism in the boundary layer above the cake layer, deposited on top of the membrane. Shear-induced diffusion is caused by hydrodynamic interactions between micron-sized particles, the suspended yeast cells in the case of beer, which are flowing in the boundary layer above the cake layer.…”