We use shear-reversal simulations to explore the rheology of dense, non-Brownian, noninertial, suspensions, resolving lubrication forces between neighboring particles and modeling particle surface contacts. The transient stress response to an abrupt reversal of the direction of shear shows rate-independent, nonmonotonic behavior, capturing the salient features of the corresponding classical exp...

We calculate the short time and the long time diffusion coefficients of a spherical tracer particle in a polymer solution in the low density limit by solving the Smoluchowski equation for a two-particle system and applying a generalized Einstein relation (fluctuation dissipation theorem). The tracer particle as well as the polymer coils are idealized as hard spheres with a no-slip boundary cond...

We consider many-particle diffusion in 2D colloidal suspensions with hydrodynamic interactions within a mode-coupling approach. We focus on the behaviour of the effective scaled collective diffusion coefficient DC(ρ)/D0 as a function of the density of the colloids ρ, where D0 is the single-particle diffusion coefficient. We find that DC(ρ) is strongly coupled to hydrodynamical conservation laws...

Colloidal shear thickening presents a significant challenge because the macroscopic rheology becomes increasingly controlled by the microscopic details of short ranged particle interactions in the shear thickening regime. Our measurements here of the first normal stress difference over a wide range of particle volume fractions elucidate the relative contributions from hydrodynamic lubrication a...

We show that a phenomenological hydrodynamic lattice-gas model of two-phase flow, developed by Rothman and Keller in 1988 and used extensively for numerical simulations since then, can be derived from an underlying model of particle interactions. From this result, we elucidate the nature of the hydrodynamic limit of the Rothman-Keller model.

Trapping and manipulation of microscale and nanoscale particles is demonstrated using the sole action of hydrodynamic forces. We developed an automated particle trap based on a stagnation point flow generated in a microfluidic device. The hydrodynamic trap enables confinement and manipulation of single particles in low viscosity (1-10 cP) aqueous solution. Using this method, we trapped microsca...

We use a combination of numerical simulations and laboratory experiments to study the timedependent collective diffusion coefficient Dsq, td in concentrated colloidal suspensions. At short times, the particle configuration is frozen, and Dsq, td probes the temporal and spatial evolution of hydrodynamic interactions, via their effects on the particle velocities. We find that Dsq, td exhibits a s...

What is the influence of hydrodynamic interactions on the equations of motion of a suspension of deformable particles ? We propose here a qualitative answer for a neutrally-buoyant suspension with weak particle deformations. We show that the influence of the neighbouring particles can be pictured by only two functions of the particle volume fraction when quadratic deformation terms are neglecte...

We investigate the evolution of angular momentum in Smoothed Particle Hydrodynamic (SPH) simulations of galaxy formation, paying particular attention to artificial numerical effects. We find that a cold gas disc forming in an ambient hot gas halo receives a strong hydrodynamic torque from the hot gas. By splitting the hydrodynamic force into artificial viscosity and pressure gradients, we find ...

In this paper, we extend the method in [5] to derive a class of quantum hydrodynamic models for the density-functional theory (DFT). The most popular implement of DFT is the Kohn-Sham equation, which transforms a many-particle interacting system into a fictitious non-interacting one-particle system. The Kohn-Sham equation is a non-linear Schrödinger equation, and the corresponding Wigner equati...