Acoustic Analysis and Geometrical Parametric Study of Propeller Trailing-Edge Serrations for Advanced Air Mobility Applications

Abstract

The social acceptance of Advanced Air Mobility (AAM) vehicles mainly depends on safety aspects and noise emissions. As propellers are widely applied in the propulsion system of those vehicles, geometrical modifications of those blades are considered a promising noise reduction solution. Especially the serration of a blade’s trailing-edge shows great potential in reducing the noise signature for certain frequencies in the broadband region. Experimental and computational results found in literature only focus on propeller diameters lower than 17 inches. Because the examined effects of such geometries are not directly scalable to larger diameters, the objective of this paper is to investigate the aeroacoustics effects of a 24 inches diameter propeller with serrated trailing edges. The design of the serrations is parametrized, and the influence of each parameter is assessed. Furthermore, different operational conditions are investigated and the influence of the advance ratio on the effectiveness of serrations is evaluated.