A Fluctuating Lattice-Boltzmann Model for Direct Numerical Simulation of Particle's Brownian Motion

【摘要】：正A single-relaxation-time fluctuating lattice-Boltzmann(LB) model for direct numerical simulation(DNS) of particle's Brownian motion is established by adding a fluctuating component to the lattice-Boltzmann equations(LBEs).The fluctuating term is proved to be the random stress tensor in fluctuating hydrodynamics by recovering Navier-Stokes equations from LBEs through a Chapman-Enskog expansion.A three-dimensional implementation of the model is also presented,along with simulations of a single spherical particle and 125 spherical particles at short times.Numerical results including the mean-square displacement,velocity autocorrelation function and self-diffusion coefficient of particles compare favorably with theoretical results and previous numerical results.