A feature added in Siemens Simcenter STAR CCM+ 2021.2 allows the fluid film to be used in combination with the Automatic Mesh Refinement (AMR) physics model.
For the simulation of the waterslide, we did just that. On the top of the waterslide water enters the domain with a mass flow rate of 40kg/s. This initially creates a thin fluid film on the bottom of the top basin, after which it flows into the waterslide itself. As the fluid film exceeds a volume fraction of water of more than 0.8 in the first cell on the surface of the waterslide, the fluid film phase is converted to a Volume of Fluid (VOF) water phase.