请教一个关于反弹格式的问题

tenitsu

反弹格式在边界角点的地方怎么处理呢
比如我想做poiseuille流动，上下边界我用反弹格式，那在最左上角那个节点总共有6个未知分布函数，该怎么用反弹格式处理呢？
谢谢大家？

matrixmess

以左下角为例。f0，f3，f4和f7迁移之后就可得到；f1，f2和f5做反弹处理。剩下的f6和f8取碰撞后f6和f8的平均值，从而保证这两个分量大小相等。

大名青年奥巴牛

这图画的真清楚，赞一个

大名青年奥巴牛

f6+f8 =？

还是不明白；f6+f8 = rho - (f0 +f1 +f2+f3+4+f5+f7)?

luo@odu.edu

This question is so tempting that I have been thinking about responding to it. Before that, let's address the following non-technical questions first:

1) Succi's book on LBM has been perhaps the most cited book among Chinese authors. I wonder the book can offer any explanation, elucidation, or insights
about bounce-back boundary conditions (BB-BCs), which are so elementary and elemental in the LBE. If one could not even learn the BB-BCs from that book, why is it still so popular?

2) When discussing Poiseuille flow, it is important to distinguish cases of "constant body-force" vs. "pressure driven" -- the former is rather trivial while the latter is more challenging.

3) It is worthwhile for everyone who would like to learn LBE to understand the Poiseuille flow with a constant body force very well before doing anything else. This issue comes up times and again (you can see my debate with with others on various occasions).

So, my suggestion: go to Mr. Succi's book, if you find it cannot help you, don't cite it next time when you write a paper on LBE. When you come back with question about Poiseuille flow again, make it sure to specify which case (constant body force or pressure driven) you are discussing.

Good luck.

-- LSL

应物贺兴龙

同志！你有没有现成的封闭空腔的气体流动的程序啊我希望的边界也是反弹格式的啊