We study the form factor of thermoresponsive microgels based on poly(N-isopropylacrylamide) at high generalized volume fractions, ζ, where the particles must shrink or interpenetrate to fit into the available space. Small-angle neutron scattering with contrast matching techniques is used to determine the particle form factor. We find that the particle size is constant up to a volume fraction ro...

Three-dimensional numerical simulations are performed to study the stability of a sedimenting suspension of weakly flexible fibers. It is well known that a suspension of rigid rods sedimenting under gravity at low Reynolds number is unstable to concentration fluctuations owing to hydrodynamic interactions. Flexible fibers, however, reorient while settling and even weak flexibility can alter the...

Hard spheres in Newtonian fluids serve as paradigms for nonNewtonian materials phenomena exhibited by colloidal suspensions. A recent experimental study (Cheng et al. Science 2011, 333, 1276) showed that upon application of shear to such a system the particles form string-like structures aligned in the vorticity direction. We explore the mechanism underlying this outof-equilibrium organization ...

‎The problem of two-phase MHD boundary layer flow, heat and mass transfer over a stretching sheet with fluid-particle suspension and thermal radiation has been studied. The effect of mass transfer in dusty fluid over a stretching sheet is considered for the first time. The governing equations are reduced to a set of non-linear ordinary differential equations under suitable similarity transforma...

The beneficiation of coal through gravity separation plays a key role in industry, allowing for particle size distribution determination and separation of coal in to various sizes for future combustion in boilers, and separation of impurities. For a complete combustion an industrial suspension boiler using bituminous coal requires an average particle size of 45μm and 80 to 85% of particles to b...

Having sufficient and accurate understanding about kinetics of phenomena, could be an important reason for further technological progresses. Finding a white-box mathematical model for weight vs. time curves of Electrophoretic Deposition (EPD) using large and small signal analysis has been studied thoroughly in the present investigation. Weight-Time curves of nano-Mullite suspension have been tr...

The aggregation and breakup of particle flocs were investigated by monitoring the size distribution of a suspension of aggregates, with diameter d(o), under shear flow created by two mixing systems. The aggregation behavior was studied in 63 experiments under various conditions of induced shear rate and particle volume concentration for particle aggregates smaller than the Kolmogorov scale. Des...

A simple kinetic model is presented for the shear rheology of a dilute suspension of particles swimming at low Reynolds number. If interparticle hydrodynamic interactions are neglected, the configuration of the suspension is characterized by the particle orientation distribution, which satisfies a Fokker-Planck equation including the effects of the external shear flow, rotary diffusion, and par...

Submitted for the DFD10 Meeting of The American Physical Society Normal stresses in non-Brownian suspensions: bulk rheology and particle migration FRANCOIS BOYER, OLIVIER POULIQUEN, ELISABETH GUAZZELLI, IUSTI, CNRS Aix-Marseille Universite — Concentrated suspensions are known to exhibit non-Newtonian effects and classical rheology often fails to give a consistent description of actual flows. Pa...