The efficiency of alternative pressure-correction formulations for incompressible turbulent flow problems

Abstract

Two test cases, one two-dimensional and one three-dimensional, were considered to highlight the convergence characteristics and assess the computational efficiency of three alternative formulations for the pressure-velocity coupling (viz SIMPLE, PISO, and AVPI) in the calculation of incompressible turbulent flows. The results from these test cases showed that the use of the more elaborate pressure-velocity algorithm (PISO), requiring more than one pressure-correction equation, did lead to a reduction of the computing time by about 30% after careful optimization of the numerical parameters. This relatively small reduction occured, however, at the expense of an increased memory requirement and the present test cases did not therefore lend strong support to the use of such algorithms. In addition, our results also showed that, in the calculation of at least some turbulent flows, the overall rate of convergence is dominated by the convergence of the turbulence model equations and the influence of the pressure-correction formulation is not then significant.