This is a pioneering paper that deals with the semi-steady-state liquid film thickness on a rotating drum partially submerged in liquid using CFD. The CFD predictions have been compared with both experimental results and analytical solutions. The liquid film thickness and the film rising on a circular curved wall were monitored for various rpm of the rotating drum. The 2D simulations were performed neglecting the end effects (assuming the rotating drum is very long). As the rotating drum speed was increased, the film thickness was found to increase at the film rising side and at the minimum film thickness point (top of the rotating drum). There was never been a steady-state condition reached, the opposite was expected as a wiper is used in the CFD calculation (same as the experimental investigation). The liquid that leaves the domain by the wiper (as outflow boundary condition) is forced to enter to the domain from far end to keep the level of the free surface constant.