Aerodynamic robustness in owl-inspired leading-edge serrations: a computational wind-gust model

Area of Science:

• Fluid dynamics
• Aerodynamics
• Biomimetics

Background:

• Owls achieve silent flight through unique wing morphologies.
• Leading-edge serrations are known passive flow control devices for aerodynamic force and sound suppression.
• The gust rejection capabilities of these serrations remain unclear.

Purpose of the Study:

• To investigate the aerodynamic robustness of owl-inspired leading-edge serrations under wind-gust conditions.
• To assess the effectiveness of serrations in rejecting wind-gust fluctuations.
• To understand the trade-off between flow control and force production.

Main Methods:

• Large-eddy simulation (LES) was employed.
• Clean and serrated wing models were used.
• Wind-gusts were mimicked via longitudinal free-stream inflow and lateral pitch angle fluctuations.

Main Results:

• Leading-edge serrations effectively manage laminar-turbulent transition under fluctuating conditions.
• Serrations show potential for gust fluctuation rejection and aerodynamic robustness.
• A trade-off exists between aero-acoustic suppression and force production, with equivalent performance to clean models at higher angles of attack (>15°).

Conclusions:

• Owl-inspired leading-edge serrations are robust micro-devices for aero-acoustic control.
• These serrations can cope with unsteady and complex wind environments.
• They offer potential for biomimetic rotor designs in fluid machinery.