求助一个关于格子声速的问题

tenitsu

最近在看一些格子Boltzmann方法的书，包括郭照立老师和一本国外老师写的书，发现上面在介绍到D2Q9模型的时候都说格子声速Cs的平方等于1/3，我只是比较好奇为什么这里格子声速的平方要等于1/3呢，其他速度离散模型又是另外的值呢？
如果有相关的参考资料最好啦，谢谢~

luo@odu.edu

The speed of sound is defined as the propagation speed of density fluctuations. Thus, one can DERIVE this speed based on a model. More specifically, one can derive linearized hydrodynamic equations to figure out the speeds of all waves and dissipation. For D2Q9 model, you can see how this is done in the following paper:

P. Lallemand and L.-S. Luo.
Theory of the lattice Boltzmann method: Dispersion, dissipation, isotropy, Galilean invariance, and stability.
Physical Review E 61:6546-6562 (June 2000).

You can download this paper from my website in case you cannot get it else where.

-- LSL

tenitsu

谢谢！