For many complex dynamical systems, a separation of scales prevails between the (microscopic) level of description of the available model, and the (macroscopic) level at which one would like to observe and analyze the system. For this type of problems, an “equation-free” framework has recently been proposed. Using appropriately initialized microscopic simulations, one can build a coarsegrained ...

because of its kinetic nature and computational advantages, the lattice boltzmann method (lbm) has been well accepted as a useful tool to simulate micro-scale flows. the slip boundary model plays a crucial role in the accuracy of solutions for micro-channel flow simulations. the most used slip boundary condition is the maxwell slip model. the results of maxwell slip model are affected by the ac...

micro scale gas flows has attracted significant research interest in the last two decades. in this research, the fluid flow of gases in the stepped micro-channel at a wide range of knudsen number has been analyzed with using the lattice boltzmann (mrt) method. in the model, a modified second-order slip boundary condition and a bosanquet-type effective viscosity are used to consider the velocity...

For many complex dynamical systems, a separation of scales prevails between the (microscopic) level of description of the available model, and the (macroscopic) level at which one would like to observe and analyze the system. For this type of problems, an “equation-free” framework has recently been proposed. Using appropriately initialized microscopic simulations, one can build a coarse-grained...

This paper presents the numerical results of electro-osmotic flows in micro- and nanofluidics using a lattice Poisson-Boltzmann method (LPBM) which combines a potential evolution method on discrete lattices to solve the nonlinear Poisson equation (lattice Poisson method) with a density evolution method on discrete lattices to solve the Boltzmann-BGK equation (lattice Boltzmann method). In an el...

This document reports investigations of models of multiphase flows using Lattice Boltzmann methods. The emphasis is on deriving by ChapmanEnskog techniques the corresponding macroscopic equations. The singular interface (Young-Laplace-Gauss) model is described briefly, with a discussion of its limitations. The diffuse interface theory is discussed in more detail, and shown to lead to the singul...

We present a new approach to find accurate solutions to the Poisson equation, as obtained from the steady-state limit of a diffusion equation with strong source terms. For this purpose, we start from Boltzmann’s kinetic theory and investigate the influence of higher order terms on the resulting macroscopic equations. By performing an appropriate expansion of the equilibrium distribution, we pro...

An unconditionally stable thermal lattice Boltzmann method (USTLBM) is proposed in this paper for simulating incompressible thermal flows. In USTLBM, solutions to the macroscopic governing equations that are recovered from lattice Boltzmann equation (LBE) through Chapman–Enskog (C-E) expansion analysis are resolved in a predictor–corrector scheme and reconstructed within lattice Boltzmann frame...

A new derivation of the quantum Boltzmann transport equation for the Fermion system from the quantum time evolution equation for the wigner distribution function is presented. The method exhibits the origin of the time - irreversibility of the Boltzmann equation. In the present work, the spin dependent and indistinguishibility of particles are also considered.