The computation of compressible and incompressible recirculating flows by a non-iterative implicit scheme

Abstract

The PISO algorithm, which is presented in a companion paper, is a non-iterative method for solving the implicity discretised, time-dependent, fluid flow equations. The algorithm is here applied in conjunction with a finite-volume technique employing a backward temporal difference scheme to the computation of compressible and incompressible flow cases. The results of calculations are compared with similar ones obtained with an existing iterative method. It is shown that for time-evolving flows the splitting error of PISO is negligibly small at the level of time-step required to eliminate the temporal truncation error, while the avoidance of iteration results in a substantial reduction in computing effort over that required by iterative methods. It is also demonstrated that PISO is stable for fairly large time steps, which renders it useful for steady-state calculations as well. © 1986.