Towards perfectly matching layers for lattice Boltzmann equation

Theory of the lattice Boltzmann method: From the Boltzmann equation to the lattice Boltzmann equation

Xiaoyi He1,2,* and Li-Shi Luo Center for Nonlinear Studies, MS-B258, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Complex Systems Group T-13, MS-B213, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 ICASE, MS 403, NASA Langley Research Center, 6 North Dryden Street, Building 1298, Hampton, Virginia 23681-0001 ~Received 29 April 1997; revised ma...

Implicit Schemes for the Lattice Boltzmann Equation

Lattice Boltzmann Equation for Laminar Boundary Flow

A simple method based on the lattice Boltzmann equatio n is presented for the evaluati on of the velocity profile of fluid flows near walls or in the vicinity of the interface between two fluids. The met hod is applied to fluid flow near a wall, to channel flow, and to the transition zone between two fluids flowing parallel to each other in opposite direct ions. The results show good agreement ...

Sweeping Preconditioner for the Helmholtz Equation: Moving Perfectly Matched Layers

This paper introduces a new sweeping preconditioner for the iterative solution of the variable coefficient Helmholtz equation in two and three dimensions. The algorithms follow the general structure of constructing an approximate LDLt factorization by eliminating the unknowns layer by layer starting from an absorbing layer or boundary condition. The central idea of this paper is to approximate ...

Adjoint Lattice Boltzmann Equation for Parameter Identification

The Lattice Boltzmann Equation is briefly introduced using moments to clearly separate the propagation and collision steps in the dynamics. In order to identify unknown parameters we introduce a cost function and adapt control theory to the Lattice Boltzmann Equation to get expressions for the derivatives of the cost function vs. parameters. This leads to an equivalent of the adjoint method wit...