SOLA-SURF, 2-D Plane, Axisymmetric, Incompressible Flow Navier Stokes Equation for Transient

1 - Description of problem or function: SOLA and SOLA-SURF are numerical solution algorithms for transient fluid flows. SOLA is for incompressible fluid flows without free surfaces. SOLA-SURF, an extension of the SOLA code, permits a free surface or curved rigid boundary (free-slip) to be located across the top or bottom of the fluid region. 2 - Method of solution: SOLA uses a finite difference technique, based on the marker-and-cell (MAC) method, to solve the Navier-Stokes equations for an incompressible fluid in two-dimensional plane or axisymmetric coordinates. Boundaries of the rectangular computing region can be chosen as (1) rigid walls with free-slip or no-slip tangential velocities, (2) specified inflow or outflow boundaries, (3) continuative outflow boundaries, or (4) periodic boundaries. Internal walls and obstacles or sources and sinks can be added by inserting additional boundary conditions in a special section of the code reserved for this purpose. 3 - Restrictions on the complexity of the problem: The surfaces used in SOLA-SURF must be definable by single-valued functions, for example, y=h(x,t) for the top surface and y=hb(x,t) for the bottom surface. Also, the slope of the surface must not exceed the cell aspect ratio, δy/δx