Boundary conditions for Equation 17–1 and Equation 17–2, film mass and momentum equations, are specified only at the wall on which film modeling is enabled. There are two types of conditions: one is the fixed mass and momentum fluxes and the other specified initial film height and velocity. When the fluxes are specified, they are added to the equations as source terms. When the initial film height and velocity are specified, these values are enforced only at the first film time step.