[LeeTao]

hello guys,

I have been troubled with this question for a long time.

Here is the thing:

When we solve a problem whether use segregated or coupled approach, we need to employ the AMG linear solver as the solver of linear equation system. There are some properties that we can change to optimize the performance of AMG solver, such as the max cycles, convergence tolerance and so on.

What I was wonder about is the convergence tolerance, the default value is 0.1, but is it necessary to decrease this value? In the official tutorials there is only one case that care about this thing and decrease this number of the pressure solver to 0.05. I think there must be some case that we really need to decrease this number, but when? Can somebody give me some advise?

Thanks and apologize for my poor english

Leetao