Far-field boundary conditions in numerical solutions of the Navier-Stokes equations

The purpose of this project was to investigate the artificial boundary conditions which must be imposed at the boundary of a numerical grid. Numerical experiments were performed which evaluated various boundary conditions of this type. Of particular interest was the question of whether linearization around the flow at infinity provides an adequate choice of boundary condition for the fully nonlinear equations. Inflow-outflow conditions as well as several choices of periodic boundary conditions were considered. The inflow-outflow conditions worked reasonably well for two dimensional problems. For the periodic conditions, results were mixed. Concerns about over specification when using pure periodic conditions proved to be groundless. However, the method failed when attempting to use periodicity in the two sideways traveling periodic waves.