[FluidKo]

Hello everybody~!
I've written this thread to get a help of simplefoam and pimplefoam.

I've heard there are 2 kinds of residual, one is initial residual and another is final residual.
And what I know is initial residual is related to 'tolerance' in solvers and final residual is related to 'residualControl'.

Words that initial residuan and final residual mean that there is a number of iterations.

But I can't match the meaning of initial residual and final residual with algorithm diagram of simplefoam and pimplefoam.

Diagram of pimplefoam: https://www.researchgate.net/publica...w/figures?lo=1

Diagram of simplefoam: https://doc.cfd.direct/notes/cfd-gen...state-solution

Actually what I can't understand is why there is not only final residual but also initial residual?('rotorDisk' case in tutorial file)
What I know is both initial residual and final residual have to be satisfied for convergence.
But simplefoam is solver for steady state which deals with only 1 time step.
So I think it is impossible to satisfy initial condition unless we write perfect initial value by very high high fortune.
But most of simplefoam cases use tolerance in solvers part of fvSolution for criteria for initial residual.

I'm really confused it. Please help me...
Thank you~!