Experimental and numerical investigation on a Troposkein Vertical Axis Wind Turbine

The Vertical Axis Wind Turbine (VAWT) is a promising technology for energy harvesting in complex environments, as urban sites and floating offshore installations, which experience aerodynamic complexity due to the platform motion. In this paper, we present a numerical investigation into the aerodynamics and performance of a troposkein VAWT, supported by a systematic experimental assessment on the wind-tunnel model of a suitable rotor. The flow in the rotor equatorial plane is first investigated over the entire operational curve of the turbine, applying a validated computational model. A fully three-dimensional analysis is then carried out for one specific tip speed ratio, in order to investigate the spanwise evolution of the rotor aerodynamics and the system of vortices generated by the peculiar shape of the rotor. It is shown that these three-dimensional motions influence the flow and the evolution of the wake also in the midspan section. The observed flow features are also discussed in the perspective of a comparison with the aerodynamics of a H shape turbine featuring the same swept area, blade number, and blade profile.