Preliminary Noise Emission Analysis of an Elastic Small Scale Propeller

In this study, we conduct a preliminary investigation into the effects of structural deformability on tonal noise emissions from a small propeller operating at low Reynolds numbers, a critical aspect for the advancement of urban air mobility solutions. Given that propeller blades are typically constructed from lightweight materials and feature elongated, slender designs, their inherent vibrations and deformations can significantly influence both aerodynamics and aeroacoustics. To model these effects, a two-way partitioned Fluid-Structure Interaction framework is used. This involves coupling the multi-body dynamics code MBDyn with the high-fidelity aerodynamics solver SU2 via the preCICE coupling library. The work is specifically focused on the low-frequency tonal noise in hover conditions perceived by far-field observers, which are computed solving the Ffowcs Williams-Hawkings equation using as noise source the surface of the blade. The rotor model considered in this study is constructed entirely from wood and designed with low collective angles, resulting in limited tip displacements and modest aeroelastic effects. Therefore, a more deformable rotor made of low-density polyethylene is simulated for comparison.