Unexpected secondary flows in reverse nonequilibrium shear flow simulations

Wormlike micelles under shear flow: A microscopic model studied by nonequilibrium-molecular-dynamics computer simulations.

Aqueous surfactant solutions are known to form elongated micelles under certain thermodynamic conditions characterized by surfactant concentration, salinity or temperature [1,2]. In the semidilute regime these linear and flexible particles, with persistence lengths varying from 15 to 150 nm [3], form an entangled viscoelastic network. Recently observed phenomena such as shear banding structure,...

Stationary Nonequilibrium States in Boundary Driven Hamiltonian Systems: Shear Flow

We investigate stationary nonequilibrium states of systems of particles moving according to Hamiltonian dynamics with specified potentials. The systems are driven away from equilibrium by Maxwell demon “reflection rules” at the walls. These deterministic rules conserve energy but not phase space volume, and the resulting global dynamics may or may not be time reversible (or even invertible). Us...

3D simulations of shear instabilities in magnetized flows

We present results of three-dimensional (3D) simulations of the magnetohydrodynamic Kelvin-Helmholtz instability in a stratified shear layer. The magnetic field is taken to be uniform and parallel to the shear flow. We describe the evolution of the fluid flow and the magnetic field for a range of initial conditions. In particular, we investigate how the mixing rate of the fluid depends on the R...

On the effects of assuming flow profiles in nonequilibrium simulations

Reweighting in nonequilibrium simulations.

A simple reweighting scheme is proposed for Monte Carlo simulations of interacting particle systems, permitting one to study various parameter values in a single study, and improving efficiency by an order of magnitude. Unlike earlier reweighting schemes, the present approach does not require knowledge of the stationary probability distribution, and so is applicable out of equilibrium. The meth...