initial residuals in icoFoam
 

Hi,
My question is about the icoFoam solver (used for transient incompressible Newtonian fluids). Does someone know how the initial residual is evaluated ? I mean the equation.
Thank you in advance.
Mhrz

Have a look at the following post, where you will find that L1 norm is used.

http://www.cfd-online.com/Forums/ope...tml#post299291

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Best Regards!

Hi,
Thank you for this answer.
It is mentioned on the OpenFoam doc that "the residual is evaluated by substituting the current solution into the equation and taking the magnitude of the difference between the left and right hand sides".
So if I understand well, from the PCG.C file where
solverPerf.initialResidual() = gSumMag(rA)/normFactor
The (rA) is the difference between the left and right hand sides of the equation to solve ?
If we consider the IcoFoam solver. At which step of the PISO algorithm the residual is computed ?
You can see here the numbered equations :
https://www.dropbox.com/s/m848engmee4qawy/Algo.pdf?dl=0
Can you please based on the this file tell me the complete formula of the residual ?

Thanks in advance !

Mhrz