斜边界反弹格式？

zqb138

看文献上边界都是平直的，如果是斜边界怎么做反弹格式呢？

tsfed

可以试试 插值反弹法. 文献见Lattice Boltzmann method for moving boundaries，JCP 2003。   把斜边作为曲边来处理，这样的方法很有一些。详见何老师和郭老师的书中边界处理。

luo@odu.edu

The whole point of the bounce-back boundary condition (BB-BC) is that it is purely local. Thus, a particle with velocity c_i hit a wall can only reverse its velocity to -c_i, and this has absolutely NOTHING with the geometry of the boundary -- it's local or point-wise implementation.

A problem arise when the boundary is office-lattice, so to speak. Then you have no choice but to use interpolations, which can be based on lattice lines (link wise). The paper describes the interpolation process very clearly:

Bouzidi M, Firdaouss M, Lallemand P. Momentum transfer of a
Boltzmann-lattice fluid with boundaries. Phys Fluids 2001;13(11):
3452–9.

Bear in mind that the LBE with multiple-relaxation-time collision model is imperative to achieve accurate boundary conditions. See, example the following paper and references therein (by I. Ginzburg in particular):

C. Pan, L.-S. Luo, and C.T. Miller.
An evaluation of lattice Boltzmann schemes for porous medium flow simulation.
Computers & Fluids 35(8/9):898-909 (2006).

[ 本帖最后由 luo@odu.edu 于 2012-8-22 04:27 编辑 ]