This article presents the results of a two-dimensional computational study into the effects of rotor blade thickness and camber on the performance of a 5 kW scale vertical axis wind turbine. Validation is provided by reference to experimental data for a pitching aerofoil with dynamic stall phenomenon. The performance of the turbine is mapped out for a variety of different tip speed ratios and detailed investigations are presented to determine how and, most importantly, why the turbine performance varies with thickness and camber as it does. The rotor blades chosen were the NACA0012, NACA0022, NACA5522 and LS0421. The turbine rotor has a diameter of d = 3.1 m with a blade chord length of c = 0.18 m. Over the range of tip speed ratios examined, the NACA0012 profile performed with the highest overall performance of 50% at λ = 3.5. Slightly cambered aerofoils (such as the LS0421) can improve the overall performance of the vertical axis wind turbine, whereas a camber of 5% (NACA5522) results in unfavourable performance. Of the cambered blades tested, the LS0421 performs the best with maximum CP of 0.40 at λ = 3.5. A camber along the blade path causes the blades to generate higher values of torque in both the upwind and the downwind regions. It was also determined that inverted cambered profiles produce power mostly in the upwind region.

Through novel experimental and computational methods, this paper details a study into the performance aerodynamics of a small-scale vertical axis wind turbine (VAWT). A novel experimental method is first developed and validated before the results are compared to those of a computational fluid dynamics (CFD) study. The computational study is further validated by comparing the flow field to PIV data. The CFD simulations are then analyzed to explain the aerodynamics in further detail, including a discussion of the effect of the streamwise induction on the local angle of attack on the blade. The University of Sheffield’s three-bladed NACA0022 small-scale VAWT experimental rig is mounted within the University’s Low-Speed Wind Tunnel. Tests at tip speed ratios up to 5 were carried out, where the blade Reynolds number (based on rotational speed) ranged from 37,500 to 75,000. The same test conditions are simulated using unsteady computational fluid dynamics.