Analysis of an exact fractional step method

An exact fractional step or projection method for solving the incompressible Navier-Stokes equations is analyzed. The method is applied to both structured and unstructured staggered mesh schemes. There are no splitting errors associated with the method; it satisfies the incompressibility condition to machine precision and reduces the number of unknowns. The exact projection technique is demonstrated on a two-dimensional cavity flow and a multiply connected moving domain with a free surface. Its performance is compared directly to classic fractional step methods and shown to be roughly twice as efficient. Boundary conditions and the relationship of the method to streamfunction-vorticity methods are discussed. (C) 2002 Elsevier Science (USA).