CFD and PIV investigation of unsteady flow through Savonius wind turbine

This paper aims to present the study of flow through a vertical axis wind turbine of Savonius type. The studied turbine is intended to be used within a compact package with multisource of energy. The rotor has height, which is approximately equivalent to the rotor diameter. In this condition, the simulation of flow through the wind turbine needs 3D model. Due to its principle of operation and the continuous variation of flow angle with respect to blades, strong unsteady effects including separation and vortex shedding are observed. In these conditions, the turbulence modeling by means of k-ω and DES permits to obtain good results comparatively to experiments. In this work we are using CFD to study the behaviour of a Savonius wind turbine under flow field conditions and to determine its performance and the evolution of wake geometry. The flow analysis helps to qualify the design of the wind turbine. To validate simulations, experimental investigation in wind tunnel is carried out using PIV. The investigation permits to determine the structure of the real flow and to access the quality of numerical simulations