Influence of Flow-induced Vibration of a D-VAWT With and Without Leading-edge Rod at Various Pitch Angles

Under specific incoming wind speeds, Darrieus- Vertical Axis Wind Turbines (D-VAWT) have been found to display significant amplitude vibrations. Previous studies mainly examined the D-VAWT's aerodynamics, ignoring flow-induced vibration (FIV). A full-scale measurement of the VAWT mast support structure is used to study the impact of the incoming wind speed (V) and pitch angle (α). The D-VAWT's rotor rotates when the incoming wind encounters its blades, causing vibrations to be transmitted to the turbine's shaft and other supporting elements. As a result, tip speed and pitch angle, which aid in the turbine's rotation, also play a significant role in producing the FIV. Based on the rotation law, the D-VAWT's rotational rate and the enforced Pitch are proportionate to the cylinder displacement. In contrast to the prior report, the vibrations are caused by vortex-induced vibration (V.I.V.) and galloping, which depend on the turbine's pitch angle and tip speed. V.I.V. predominates at high-pitch angles, while galloping is more common at high blade tip speeds and low-pitch angles. Lastly, a leading-edge rod (L.R.) with a 4 mm diameter is fastened to the turbine's blades to suppress V.I.V., which yields a reasonable outcome. Henceforth, this was the first experimental investigation to comprehend the galloping instability and V.I.V. in D-VAWT at various pitch angles and tip speeds.