[s.m]

Originally Posted by yhaomin2007

the simulation will blows up, produce some extreme large number(NAN), if the simulation is not stable.~~
You can just try some lower URF to see it the simulation do not stop in the middle.

you mean if we do not have good stability, our residual don't reduce well, like the first and second pictures in the attachment, is it true?
and when our stability is good the residual reduce well, like the third picture in the attachment.yes?

[yhaomin2007]

yes, pretty much.

[s.m]

Originally Posted by yhaomin2007

yes, pretty much.

Thank you very much, i understand it well
The URF multiple to the obtained p and u after solving their equations, the URF make our solution more stable, because they reduce the error that is between the obtained p and u and the exact one, is it right?
i want to know why these relaxation factors, apply to the equations? and how they do their work?

[yhaomin2007]

when relaxation factor apply to equations, it increase the central coefficient of the matrix, and make simulation stable.