Wind turbine tip deflection control using bio-inspired tubercle leading edges: Analysis of potential designs

A major challenge to wind turbine design is enlarging their blades to harness more power. However, aerodynamic loads can cause blades to deflect, flutter and possibly fail. Humpback Whales do not have this problem, despite their large size, due to the presence of tubercles on their flippers. This study investigates the design of bio-inspired tubercles on the leading edge of wind turbine blades to minimize deflection and maximize power capture. CFD and fluid-solid interaction models were developed and validated for the WindPACT 1.5-MW baseline blade to simulate the wind flow and deflection before and after adding the tubercles. A first and second law analysis was conducted to investigate the optimum tubercle design. The results showed a stress concentration and maximum tip deflection affecting the baseline blade of 74.57 MPa and 1.51 m, respectively. The applied tubercles of 2.5% height and 50% length of the chord length achieved better characteristics by reducing the blade's deflection by 16.4%. By implementing the tubercles, the blades' length can be increased by 25% to achieve a 65% improvement in captured torque at an equal deflection to the smaller baseline blade. This confirmed the improved blade performance using the bio-inspired tubercle leading edges.