Solution of the incompressible Navier-Stokes equations on domains with one or several open boundaries

The aim of this paper is to develop a methodology for solving the incompressible Navier-Stokes equations in the presence of one or several open boundaries. A new set of open boundary conditions is first proposed. This has been developed in the context of the velocity-vorticity formulation, but it is also emphasized how it can be formally extended to the equations in primitive variables. The case of a domain involving several independent open boundaries is considered next. An influence matrix technique is applied such that the inlet mass flux is split onto the several outlets in order to enforce the prescribed mean pressure at each outlet. Both approaches are validated by numerical test cases. Copyright (C) 1999 John Wiley & Sons, Ltd.