Residual criteria (relative or absolute norm)

[Sudharsan Madhavan]

Hello,

Does anyone know the mathematical form of the residual norm we try to bound by the following lines of code in solver.inp

"Residual Control: True
Residual Criteria: 0.01"

1. In particular, what does the parameter 'residual criteria' imply ? Would this monitor error norms on velocities or pressure or both ?
2. Are we iterating to get the absolute or the relative norm of the quantities converge ? If we are working with relative norms, is it with respect to the quantities from the last iteration ?

Thanks in advance for your time!

Sincerely,
Sudharsan

[Hongzhi Lan]

Hi,

The Residual Criteria monitors the average residual norm over all finite elements. The residual includes four components, one form continuity equation, three from momentum. It's absolute residual.

Thanks,
Hongzhi

[Sudharsan Madhavan]

Hi Hongzhi,

Thanks a lot for explaining.

Have a nice day!
-Sudharsan