LBM BGK 稳定性图

由物理尺度和 lattice 速度计算 BGK tau、omega 与 lattice Mach，并可视化安全工作区间。

visual calculator数值与稳定性

先看流动形态，再相信数字。

该工具把 CFD 设置转换为工况、尺度和主导效应提示。调节下方计算器，观察动态图与计算结果如何一起变化。

输入尺度

模型

判断

LBMBGKlattice Machstability

公式

KaTeX rendered

\begin{aligned}\text{nu\_lu = nu\_phys dt/dx\^{}2}\\[0.35em]\text{tau = 0.5 + nu\_lu / c\_s\^{}2}\\[0.35em]\text{Ma\_lu = U\_lu / c\_s}\end{aligned}

ASCII source

nu_lu = nu_phys dt/dx^2, tau = 0.5 + nu_lu / c_s^2, Ma_lu = U_lu / c_s

U physical (m/s)L physical (m)nu physical (m^2/s)cells across LU lattice

tau

0.5004

omega

1.9985

lattice Mach

0.1386

nu lattice

0.0001

dx (m)

0.0006

dt (s)

5.000e-5

Re physical

1.000e+5

status

tau near unstable range

For weakly compressible LBM, keep lattice Mach small and tau safely above 0.5. Practical limits depend on collision model and boundary treatment.