Fluid-Structure Interaction Analysis to Verify Small Power VAWTs

Sergio Segreto, Alessandro Bozzolo

The demanding requirements imposed on wind turbines by current legislations make CAE techniques a reliable instrument to design and verify their structural integrity when coupled to experimental data. 3D multi-body static structural analyses have been conducted on Vertical Axis Wind Turbines (VAWT) of small power (1 kW and 3 kW). Two critical operating conditions have been analyzed according to reference standards, i.e., max wind velocity at steady turbine and max rotational velocity. For each condition, the less favourable angular position (azimuth) and the related pressure distribution acting on the airfoil have been determined by theoretical computations taking into account kinematics, wind conditions and power generation curves and applied to the FE model together with bolts pretension, gravity and rotational inertia. Specific failure criteria (Tsai-Wu and Maximum Stress for composite parts, Von Mises for metallic parts) have been considered to identify critical areas and drive suggestions to reduce stress states.