An improved air entrainment model for stepped spillways

• A CFD model to predict aeration of spillway flow. Highly economical approach combining VOF with explicit modelling air entrainment. Tested at four different step Froude numbers and validated by experimental data. Model implemented within the framework OpenFOAM. This work considers application entrainment developed in [P. Lopes et al. Int. J. Nonlin. Sci. Num., vol. 18, pp. 559-574, 2017] simulation flows stepped spillways. Four are considered for flow, parameters selected match available An extensive campaign led identification several deficiencies model, most importantly, its strong grid dependence. improvement interface detection algorithm used is proposed, simulations reveal improved robustness respect density. Furthermore, two criteria predicting inception point tested, based on energy balance boundary layer state, respectively. The layer-based recommended due superior accuracy turbulence selection.