Experimental Study on Unsteady Aerodynamic Characteristics of Deformed Blades for Vertical Axis Wind Turbines

Abstract Based on the self-deforming blade mosmall-scale long separation vortex structure to the extremely stable appendage flow del and the related wind tunnel test platform, the simultaneous deformation and pitch experiments of the blade were carried out to simulate the operating conditions of the blade on the vertical axis wind turbine(VAWT). Taking NACA0012 as the reference blade, the unsteady aerodynamic characteristics of blade deformation at different deformation frequencies and amplitudes at a fixed angle of attack were investigated at low Reynolds number (2.5×105). It was found that the maximum lift of the blade was increased by nearly 60% compared with that of the rigid blade and amplitude of deformation of 0.06c. Secondly, the same deceleration frequency, the same pitch amplitude and the different initial angle of attack were applied to the blade, where the flow hysteresis phenomenon was obviously different in different amplitudes of synchronous deformation, and the special aerodynamic characteristic curves were obtained. The lift value increases significantly with the increase of deformation amplitude and drag value, but the lift-drag ratio increases in one cycle. The study in this paper proves the applicability of the blade with this deformation law in the VAWT, and provides a reference for the design of the blade with this deformation law in the VAWT.