Wind energy is generated by efficient wind turbine blades that act as airfoils, similar to aviation wings. Airflow control accessories, which are similar to those seen in airplanes, improve the aerodynamic performance of turbine blades.
Scientists from China report in the AIP Publishing Journal of Renewable and Sustainable Energy that a bionic technique combining aspects of the seagull’s wing featuring an engineering flow control attachment referred as a Gurney flap can considerably enhance performance of the wind turbine.
A Gurney flap is usually a tiny tab that projects from the narrow end of a wing at a right angle. Its presence disrupts wind flow patterns and improves effectiveness at the low angles of attack in particular. The angle of attack in aerodynamics is the angle formed by a line passing through the middle of an aircraft wing as well as the oncoming airflow.
Gurney flaps increase airfoil performance at low attack angles, but they aren’t optimal for large attack angles. Gurney flaps can considerably enhance the efficiency of wind turbines in particular scenarios, but the turbine speed is going to be reduced, according to research.
Bionic flow control is a new technique that mimics biological flight control systems, such as wings and feathers. The concept is based on the observation which the feathers that are found on the tip of a bird’s wings flare out when landing or during a gust of wind, generating a natural flap.
Bionic feather-inspired flaps can improve lift and slow the progression of derailing at high angles of attack, according to computational and experimental investigations. Despite their benefits, bionic flaps can restrict lift, especially before a stall develops. As a result, the researchers investigated merging Gurney flaps with bionic elements.
The scientists simulated the employment of the integrated flow control accessory in a range of settings, encompassing lower and higher angle of attack plus pre-and post-stall scenarios, to get the optimal aerodynamic performance. They compared the findings of their computational simulations to test findings for a dynamic stalling aircraft wing.
“The computed lift curve’s overall trend agrees well with the experimental measurement data. Because dynamic stalls and their control are famously difficult to predict, our simulation accuracy is judged satisfactory “Xiaomin Liu is the author of the book.
According to Liu, the integrated flow control accessory efficiently enhances the airfoil’s lift coefficient. “When a mix of Gurney flap and the bionic flap is employed at angles of attack between 16 and 24 degrees, the peak lift coefficient of the airfoil is enhanced by 15%.”