Lattice Boltzmann Method Of Navier-Stokes/Darcy Coupled Model

The lattice Boltzmann method is a mathematical computional method that has developed rapidly in recent years,and is widely used in hydromechanics.Compared with traditional macro-continuous methods and micro-molecular dynamics methods,the lattice Boltzmann method has many advantages: simple calculations,natural parallel characteristics,and easy implementation of programs.The coupling of free flow and porous media has been a research hotspot in computational mathematics and fluid mechanics in recent years.The coupled Naiver-Stokes/Darcy model is a model with Beavers-JosephSaffman(BJS)interface conditions.This thesis attempts to use the lattice Boltzmann method to construct a decoupling algorithm for the coupled Naiver-Stokes/Darcy model.Aiming at the interface conditions of the coupled Naiver-Stokes/Darcy model,this thesis proposes a new way of handling it.Using the D2Q9 model in Naiver-Stokes and Darcy area,the macroscopic moments are used in the form of u=1/?~?f e+F dt/(2?) and ? =?f.In each step iteration,we add an iterative processing of the interface,the format is simple and easy to apply.In this thesis,the specific numerical examples are simulated,and the corresponding coupling grid boltzmann method is established.And Chapman-Enskog multi-scale expansion analysis was performed.The lattice boltzmann decoupling algorithm given herein is tested.A stable simulation of specific examples is achieved,and the convergence order is similar to the first order.Next,this thesis simulates the flow of the steady plane Poiseuille flow and the lid-driven cavity flow in the Navier-Stokes/Darcy coupled model.The thesis finally made rational analysis.