What is PCORR and why is its residual always 1?


#1

Im doing a multiphase simulation and I’m a little baffled to what PCORR?

and in my solver log I have:

GAMG: Solving for pcorr, Initial residual = 1, Final residual = 0.000997109777294, No Iterations 31
GAMG: Solving for pcorr, Initial residual = 0.414062071895, Final residual = 0.000405436755087, No Iterations 66

yet my residual plot, plots 1? is this odd or just me misunderstanding what PCORR is?

and why does it calculate twice?

Thanks advance,
Darren


#2

@gholami @Ali_Arafat , any ideas on this one?


#3

Hi Darren,

it is not odd. pcorr is only a pressure correction term due to e.g. mesh movement. That is the reason the residual plot is at 1 (initial residual). Monitoring pcorr convergence is not related to overall convergence behavior of the simulation.

It is solved twice, because you have two non-orthogonal corrections in your solver (see properties under numerics).

I hope it helps,
Babak


#4

Hi @gholami, that makes sense. Thank you very much,
Darren Lynch