A new and very general technique for simulating solid–fluid suspensions is described; its most important feature that the computational cost scales linearly with number of particles. The method combines Newtonian dynamics solid particles a discretized Boltzmann equation fluid phase; many-body hydrodynamic interactions are fully accounted for, both in creeping-flow regime at higher Reynolds numbers. Brownian motion arises spontaneously from stochastic fluctuations stress tensor, rather than...

We present a new method to compute the absolute free energy of arbitrary solid phases by Monte Carlo simulation. The is based on construction reversible path from phase under consideration an Einstein crystal with same crystallographic structure. As application we have recomputed fcc hard-sphere at melting. Our results agree well single occupancy cell Hoover and Ree. major source error nature extrapolation procedure thermodynamic limit. also computed difference between hcp solids densities...

A new and very general technique for simulating solid–fluid suspensions has been described in a previous paper (Part 1); the most important feature of method is that computational cost scales linearly with number particles. In this 2), extensive numerical tests are described; results presented creeping flows, both without Brownian motion, at finite Reynolds numbers. Hydrodynamic interactions, transport coefficients, short-time dynamics random dispersions up to 1024 colloidal particles have simulated.

Recent experiments at strain rates reaching 0.1 GHz suggest a power-law dependence of solid-phase shear stress on rate. Novel nonequilibrium molecular dynamics simulations plastic flow have been carried out. These steady-state isothermal calculations appear to be consistent with the present-day experimental data and that flows metals can described by single physical mechanism over range from 10 kHz 1 THz.

Lattice-Boltzmann simulations are used to examine the effects of fluid inertia, at moderate Reynolds numbers, on flows in simple cubic, face-centred cubic and random arrays spheres. The drag force spheres, hence permeability arrays, is calculated as a function number solid volume fractions up close-packed limits arrays. At numbers O (10 2 ), non-dimensional has more complex dependence fraction than suggested by well-known Ergun correlation, particularly smaller those that can be achieved...

Gauss's principle of least constraint is used to develop nonequilibrium molecular-dynamics algorithms for systems subject constraints. The treatment not only includes "nonholonomic" constraints---those involving velocities---but it also provides a basis simulating steady states. We describe two applications this new use principle. first these examples, the isothermal molecular dynamics three-particle chain, can be treated analytically. second, steady-state diffusion Lennard-Jones liquid,...

The lattice-Boltzmann method has been refined to take account of near-contact interactions between spherical particles. First, we describe a comprehensive solution the technical problems that arise when two discretized surfaces come into contact. Second, how incorporate lubrication forces and torques simulations, test our by calculating particle plane wall. Third, an efficient update velocities, taking possibility some differential equations are stiff.

Theory and lattice-Boltzmann simulations are used to examine the effects of fluid inertia, at small Reynolds numbers, on flows in simple cubic, face-centred cubic random arrays spheres. The drag force spheres, hence permeability arrays, is determined but finite solid volume fractions up close-packed limits arrays. For fraction, compared theory, showing that first inertial contribution force, when scaled with Stokes a single sphere an unbounded fluid, proportional square number. show this...

Accurate values for the hydrodynamic transport properties of random dispersions hard spheres have been determined by numerical simulation. The many-body interactions are calculated from a multipole-moment expansion force density on surface solid particles; singular lubrication forces included exactly pairs particles near contact. It has possible to calculate small periodic systems, at all packing fractions, with uncertainties less than 1%; but larger systems we limited computationally lower...

The thermal conductivity of a monatomic face-centered-cubic lattice has been calculated over range temperatures from one-twentieth to one-half the melting temperature. An inverse-twelfth-power ``soft-sphere'' potential was used represent interatomic forces. We have examined, quantitatively, approximations involved in deriving Peierls phonon-transport expression for and determined temperature which it is useful. This extensive comparisons with formally exact Green-Kubo method, using molecular...

A new Hamiltonian method for deformation simulations is related to the Green-Kubo fluctuation theory through perturbation and linear-response theory. Numerical results bulk shear viscosity coefficients are compared corresponding calculations. Both depend similarly on frequency, in a way consistent with enhanced "long-time tails."

Inertial migration of neutrally buoyant particles in a square duct has been investigated by numerical simulation the range Reynolds numbers from 100 to 1000. Particles migrate one small number equilibrium positions cross-sectional plane, located near corner or at center an edge. In dilute suspensions, trains are formed along axis flow, planar single particles. At high (Re⩾750), we observe inner region duct. We present evidence that closely spaced pairs can number.

The effects of fluid inertia on the pressure drop required to drive flow through periodic and random arrays aligned cylinders is investigated. Numerical simulations using a lattice-Boltzmann formulation are performed for Reynolds numbers up about 180. magnitude drag per unit length in square array at moderate number strongly dependent orientation (or gradient) with respect axes array; this contrasts Stokes array, which characterized by an isotropic permeability. Transitions time-oscillatory...

A new and general technique for simulating solid-fluid suspensions, which combines molecular dynamics the solid particles with a lattice-Boltzmann model fluid, is described. The many-body hydrodynamic interactions are fully accounted for, both small particle velocities at higher Reynolds numbers. Brownian motion of included by adding fluctuating component to fluid stress tensor. Simulations colloidal short times compare favorably recent diffusing-wave spectroscopy experiments.

Dynamical simulations of bulk sedimentation have been carried out, using up to 32 000 solid particles. There is no evidence that the long-range hydrodynamic interactions are screened by changes in pair correlation function at large distances. Instead velocity fluctuations and diffusion coefficients diverge linearly with width container, consistent random microstructures observed simulations. Our data suggest other mechanisms must be uncovered account for experimental observations.

A molecular dynamics simulation of the three phases Lennard-Jones system in co-existence is reported. The triple-point properties are compared with bulk-phase Monte-Carlo results, experimental data on argon, and results a preliminary this system. Thermodynamic crystal-liquid liquid-vapour interfaces reported difficulties calculating interfacial excess discussed. tensions accord previous predictions. It suggested that direct co-existing potentially practical route to phase diagram if...

We propose a derivation of the fluctuating lattice Boltzmann equation that is consistent with both equilibrium statistical mechanics and hydrodynamics. The formalism based on generalized lattice-gas model, each velocity direction occupied by many particles. show most probable state this model corresponds to usual distribution equation. Thermal fluctuations about are controlled mean number particles at site. Stochastic collision rules described Monte Carlo process satisfying detailed balance....

A long standing problem in numerical statistical mechanics has been the incorporation of range, many-body hydrodynamic forces between particles suspension. In this paper I describe a general computational method for calculating and torques exerted by slowly moving spheres suspended an incompressible fluid. particular, correctly incorporates effect periodic boundary conditions on flow field. Results are presented friction mobility matrices small clusters as function size unit cell. An...

We investigate the dissolution of artificial fractures with three-dimensional, pore-scale numerical simulations. The fluid velocity in fracture space was determined from a lattice-Boltzmann method, and stochastic solver used for transport dissolved species. Numerical simulations were to study conditions under which long conduits (wormholes) form an initially rough but spatially homogeneous fracture. effects flow rate, mineral rate geometrical properties investigated, optimal wormhole...

Several different interpolation schemes have been proposed for improving the accuracy of lattice Boltzmann simulations in vicinity a solid boundary. However, these methods require at least two or three fluid nodes between nearby surfaces, condition that may not be fulfilled dense suspensions porous media example. Here we propose an equilibrium distribution, which leads to velocity field is both second-order accurate space and independent viscosity. The rule infers population densities on...

Abstract This manuscript presents a benchmark problem for the simulation of single-phase flow, reactive transport, and solid geometry evolution at pore scale. The is organized in three parts that focus on specific aspects: flow transport (part I), dissolution-driven two dimensions II), an experimental validation three-dimensional III). Five codes are used to obtain solution this problem, including Chombo-Crunch, OpenFOAM-DBS, lattice Boltzman code, Vortex, dissolFoam. These cover good...