Investigation into Aeroacoustic Rotor Scaling Effects using Near-Field and Time-Resolved Particle Image Velocimetry Measurement Techniques

Abstract

Over the past couple of years there has been an increase in interest in urban air mobility in both human and package transportation. NASA is one such entity that has begun researching this field. Of the vehicle designs proposed for such an endeavor, many invoke a vertical takeoff and landing configuration. One of the biggest challenges that come with implementing such designs comes from the public acceptance of the noise produced by these aircraft as they travel through urban and suburban environments at low altitudes. Therefore, being able to measure, categorize, and interpret the various noise spectra will prove invaluable in developing techniques and designs for quieter air travel. Previous research has measured that a small quadcopter may produce less noise than a modern car, but the perceived annoyance is higher. If this is the case for small quadcopters, one can only imagine how much worse this could be with larger aircraft. This study will evaluate the velocity field and acoustic effects of several rotors ranging in diameter from 12.5” – 30.5”.