A SIMPLIFIED MARKER AND CELL METHOD FOR UNSTEADY FLOWS ON NON-STAGGERED GRIDS

The SMAC (simplified marker and cell) time-advancing method for solving the unsteady incompressible Navier-Stokes equations on non-staggered grids is developed in generalized co-ordinate systems. The primitive variable formulation uses Cartesian velocities and pressure, all defined at the centre of the control volume, as the dependent variables. A special elliptic flux correction at the faces of the finite volume is utilized in discretizing the continuity equation to suppress pressure oscillations. The test flows considered are a polar cavity flow starting from rest and the flow around a circular cylinder. The numerical results are compared with experimental results and results obtained by the well-known SIMPLEC and PISO methods. The comparisons show that the elliptic flux correction technique works well in suppressing pressure oscillations and that the SMAC method is more efficient than the SIMPLEC and PISO methods for both steady and unsteady flows.