A parallel pressure implicit splitting of operators algorithm applied to flows at all speeds

A parallel implementation of the pressure-based implicit splitting of opera tors (PISO) method is described and applied to both compressible and incomp ressible flows. The treatment of variables at the interfaces between adjace nt blocks is highlighted, and, for compressible flow, a straightforward met hod for the implicit handling of density is described. Steady state and osc illatory flow through a sudden expansion are considered at low speeds for b oth two- and three-dimensional geometries. Extension of the incompressible method to compressible flow is assessed for subsonic, transonic and superso nic flow through a two-dimensional bump. Although good accuracy is achieved in these high-speed flows, including the automatic capturing of shock wave s, the method is deemed unsuitable for simulating steady state high-speed f lows on fine grids due to the requirement of very small time steps. Copyrig ht (C) 2001 John Wiley & Sons, Ltd.