Could feather-like flaps improve flight performance and reduce drag?

Bird-inspired wing flaps might be the future of aviation, providing a boost to flight performance by improving lift and reducing drag. In a recent study, engineers investigated how “covert feathers” – the layered, overlapping feathers on bird wings – could be mimicked on aircraft wings to improve manoeuvrability and stability. According to a study, installing lightweight, passive flaps across an aircraft’s wing surfaces could provide significant aerodynamic advantages, enabling planes to achieve enhanced lift and reduced drag.

A New Approach to Aircraft Flap Design

As per to research published on October 28 in Proceedings of the National Academy of Sciences, the Traditional aircraft wings typically use flaps and spoilers, controlled by mechanical systems to manage airflow during flight. However, this bio-inspired approach aims to replace complex controls with a passive design that activates solely through air pressure changes at high angles of attack – the position where wings meet incoming airflow head-on. Engineer Aimy Wissa, from Princeton University, explained that unlike conventional components, these flaps “are not controlled by motors or actuators” but respond naturally to airflow, offering simplicity and coverage across the entire wing surface.

Wind Tunnel Tests Reveal Enhanced Stability and Lift

In wind tunnel tests, researchers examined the impact of these feather-like flaps on airfoil models. Flaps positioned at the front of the wing guided airflow more effectively, improving lift and reducing drag. Additional rows of flaps intensified this effect, while rear-positioned flaps stabilised air pressure by preventing it from flowing forward, a crucial aspect of maintaining lift. The study found that a design with five rows of flaps increased lift by 45% and reduced drag by 31%, highlighting the potential of these flaps to optimise aerodynamics without complex machinery.

Potential Benefits for Modern Aviation

When tested on remote-controlled aircraft, the feather-like flaps also helped expand the range of safe flight angles by nine percent, reducing the likelihood of stall – a sudden loss of lift often encountered during steep climbs or sharp turns. This increased angle-of-attack range could make flights safer, particularly in turbulent conditions or during short runway landings. As Wissa observed, the passive flaps could support a broader range of manoeuvres, offering advantages for various aviation applications from commercial aircraft to drones.