大家对Peclet数于Courant数有什么评论？

sillybear

Peclet number is used to help guide space discretization
where
Pe = Peclet number,
v = average linear flow velocity,
x = maximum grid spacing, and
D = coefficient of dispersion
If Pe is less than 2, it has been shown that numerical dispersion is minimized.
For some models, a value of 10 may not cause significant numerical oscillation.

sillybear

Use the Courant number for time discretization.
where
Cr = Courant number,
v = average linear flow velocity,
t = maximum time step, and
x = maximum grid spacing.
It has been shown that numerical dispersion can be minimized if a time step is selected
such that the Courant number is less than 1.
根据离散的不同，有的在方程的右边乘密度(Peclet number也一样)。

sillybear

大家看看如下评论，如何深入理解？
It is well known that the advective-dispersive transport equation is more difficult to solve numerically. The problems are particularly severe when advection dominates over dispersion. In this situation, the Galerkin finite element solution usually exhibits numerical spatial oscillations - overshoot and undershoot - near the concentration (temperature) front.