DESIGN OF VISCOUS DYNAMIC VIBRATION ABSORBER FOR A VERTICAL-AXIS WIND TURBINE

This paper presents the investigations brought to fruition for the design of a dynamic vibration absorber (DVA) for vertical-axis wind turbine. A first step is devoted to the experimental analysis of the structure, by seeking its modal behaviour in low frequency range. A numerical model of the turbine system consisting of finite elements is developed. Their dynamics and geometrical characteristics are updated, by fitting the first three bending numerical mode shapes with the experimental ones. Finally, a mathematical model of DVA is implemented and the vibration reduction is evaluated with the help of the updated finite element model, considering the modal decomposition of the structure. The results exhibit significant vibration reduction performance evidencing this kind of device. A tuneable anti-vibration device is then designed, with a purpose of simplicity and low-cost production. The possible non-linearity of the DVA is also studied, by comparing behaviours of linear and quadratic selected dampers.