On the nature of boundary conditions for flows with moving free surfaces (Q5905380)

The authors have considered small perturbations of plane parallel flow between a wall and a moving free surface. The problem is posed on a rectangle with inflow and outflow boundaries. The usual boundary conditions are posed at the wall and the free surface, and the fluid satisfies the Navier-Stokes equations. Nature of boundary conditions, which can be imposed at the inflow and outflow boundaries in order to yield a well-posed problem are examined. Numerical simulations with the FIDAP package are used to illustrate the analytical results.