PISO Algorithm
 

I have two questions about PISO algorithm: 1. Is underrelaxation for the secons Pressure Correction in PISO never necesseray? 2. Have I also to correct the massfluxes with a expression of the second corrections? (I think, mass conservation should already be fullfilled after the first correction?!)

Thank you for your Help!!

Re: PISO Algorithm
 

1) Provided you solve for the pressure properly, no (beware of non-orthogonal correctors)

2) Yes, you should correct the mass fluxes after every pressure solution - the fluxes are conservative after the first corrector as well but are no longer consistent with the velocity field (which is kind of important) :)

Enjoy,

Hrv