Developing Propellers with a Fringed Trailing-Edge Inspired by Owl Flight to Reduce Noise

Overview

Of the many origins of noise, aerodynamic fans and propellers are significant contributors, such as the ones used in ventilation, aircraft, and electrical generation. Fans and propellers produce noise in many spots throughout blade, but a considerable amount is produced at the trailing edge. Owl wings are well-known for their ability to minimize the turbulence all while preserving aerodynamic efficiency through unique features, one of which are fringes at its trailing edge. The use of this feature was tested to predict the reduction of noise in man-made propellers. Two 17.5 cm propellers were designed by the author in a modeling software (Blender) and 3D printed. Each blade was experimented on a 3V DC motor with two 1.5V AA batteries providing 3V at 900 RPM. Data was acquired using MacBook Pro microphones and Sound Meter, a decibel meter application. Each sample was 60 seconds, and data was recorded every 1 second. An independent sample t-test was performed to compare the decibel between the control propeller and the modified propeller. There was a significant difference in decibels between the control propeller (ẋ = 27.00, SD = 0.527) and the modified propeller (ẋ = 26.19, SD = 0.707); t(118) = 7.0514, p = <0.0001). This study showed that fringed propellers using fringed trailing edges inspired by owl wings are quieter than non-fringed propellers. The noise reduction was approximately 0.81 dB. Further testing will allow its use in practical applications such as drones, ventilation, and similar small-scale uses.

Competition history

• JSHS 2022 Category not listed

Resources

• National JSHS abstract book ↗

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