More efficient wind turbine blade design inspired by owl wings and feathers

Wind turbines convert the kinetic energy in wind to clean, renewable electricity. Even environments with low wind speeds can take advantage of wind power with the optimization of blade design. Improvements in the aerodynamic performance of blades will lead to a boost in the power generation efficiency of wind turbines.

Gao et al. demonstrate a bionic design for wind turbine blades based on features of the wings and feathers of a bird. Their nature-inspired blade is based on 50% and 70% cross-section airfoils of an owl’s wing, coupled with a herringbone groove structure of an owl’s feather.

“Without changing the size of the wind turbine blade, the blade has higher working efficiency and higher power generation through structural design,” said author Kun Chen. “[Our study shows that] the extraction of biological structure from birds can be used in wind turbine blades.”

Using modeling software, the researchers modified a prototype blade to fit the cross-section airfoils of the long-eared owl wing to create a bionic airfoil blade. After closely observing owl feathers through a microscope, they added a herringbone groove structure to form a bionic coupling blade, since the microstructure of feathers plays an important role in efficient and high-mobility bird flight.

The scientists evaluated the performance of all three blades – the prototype blade, bionic airfoil blade, and bionic coupling blade – with numerical simulation, finding the pressure difference between the windward and leeward surfaces of the bionic coupling blade is larger than the other two blades. Small vortices appear in each depression of the herringbone groove structure, which increases the local flow velocity of the leeward surface of the bionic coupling blade.

Source: “Investigation on aerodynamic performance of wind turbine blades coupled with airfoil and herringbone groove structure,” by Ruibiao Gao, Kun Chen, Yixiao Li, and Weiwei Yao, Journal of Renewable and Sustainable Energy (2021). The article can be accessed at http://doi.org/10.1063/5.0051729 .