Direct Numerical Simulation of a Thin Shear-Driven Water Film under Turbomachinery Relevant Conditions

The aim of this study is to present a time and space resolved direct numerical simulation (DNS) of a thin liquid film in a turbulent gas flow. In future work, the results will be used to improve the coupling conditions of film models. Therefore, a film model from the literature is presented and its coupling conditions between the gas flow and the film flow are discussed. Then, the numerical setup and boundary conditions are explained, which are used to investigate the coupling conditions. A simulation with a film Reynolds number of 50 and a gas Reynolds number (defined with the boundary layer thickness) of 54,000 is performed. The numerical prediction is accomplished with the in-house program Free Surface 3D (FS3D), which uses the Volume of Fluid (VOF) method for the interface tracking and the Piecewise Linear Interface Calculation (PLIC) for the surface reconstruction. Instantaneous and time averaged results of the volume fraction, velocity field and shear stress are presented.