PISO algorithm for unsteady flow field

PISO algorithm, as one of the pressure-based schemes, was discussed under staggered and non-staggered grid systems. To apply it in non-staggered grid system easily, an improved PISO algorithm was developed. Compared to the SIMPLE algorithm, the improved PISO algorithm is superior in the simulation of unsteady flow. The computation results of the Stokes II problems prove the fact. In addition, the algorithm can be used to calculate unsteady flow field due to rotor/stator interaction in turbomachinery.