Three-Bladed Horizontal Axis Water Turbine Simulations with Free Surface Effects

Abstract The water level above a hydrokinetic turbine is likely to vary throughout the season and even along day. In this work, influence of free surface on performance three bladed horizontal-axis explored by means three-dimensional, transient, two-phase flow computational model implemented in commercial CFD software ANSYS Fluent 19.0. k – ω SST Transition turbulence coupled with Volume Fluid (VOF) method used track air-water interface. rotor diameter D = 0 8m . Two operating conditions are analyzed: deep tip immersion ( 0.55D ) shallow 0.19D ). Three speed ratios evaluated for each immersion. Simulation results show good agreement experimental data reported literature, although computed torque thrust coefficients slightly underestimated. Details dynamics, past wake near also discussed.