Numerical Study of the Hydrodynamic Structure of a Water Savonius Rotor in a Test Section

Turbulent free surface flows are encountered in many hydraulic and water resources engineering problems. Their understanding is thus a critical prerequisite for designing stream and river restoration projects and a broad range of hydraulic structures. For this purpose, a volume of fluid (VOF) advection algorithm, coupled with the Reynolds averaged Navier- Stokes (RANS) equations with a two-equation turbulence closure model, is employed. For efficiently describing and predicting the degree of turbulence in dam-break flows, the computations are carried out with the variation of initial turbulence intensities. From this investigation, it was found that the power performances of a Savonius water turbine were changed with the distance between the rotor and the bottom wall of the tunnel and with a rotation direction of the rotor.