Microfiber coating for a blade-noise reduction

Microfiber coating has been proven as a drag reduction device for a blunt body. This study investigates the microfiber coating as a device for aeroacoustic noise reduction over a propeller blade in small aerial vehicles. The microfiber coating forms an array of hair-like surfaces that can be taped on a blade. To determine the optimal microfiber locations for a blade-noise reduction, the strips of microfiber coating are placed at different spanwise and chordwise locations on the blade. Sound level is captured to evaluate the aeroacoustic noise from the blade. Microfiber strips reduce the sound level compared to the baseline, which is a bare surface, with a more significant noise reduction effect at the trailing edge rather than the leading edge. The spanwise location of the microfiber coating is important to maximize noise reduction. The current progress of this study and future directions will also be discussed.