A new finite volume method for solving the incompressible Navier Stokes equ
ations is presented. The main features of this method are the location of t
he velocity components and pressure on different staggered grids and a semi
-Lagrangian method for the treatment of convection. An interpolation proced
ure based on area-weighting is used for the convection part of the computat
ion. The method is applied to ow through a constricted channel, and results
are obtained for Reynolds umbers, based on half the ow rate, up to 1000. T
he behavior of the vortex in the salient corner is investigated qualitative
ly and quantitatively, and excellent agreement is found with the numerical
results of Dennis and Smith [Proc. Roy. Soc. London A, 372 ( 1980), pp. 393
-414] and the asymptotic theory of Smith.