An Aeroacoustic Investigation of Propeller Installation Effects in the Vicinity of an Airfoil

The present paper investigates the aerodynamic and aeroacoustic parameters of a wake interaction setup comprising a NACA0024 and a propeller in edgewise flight using both experiments and computations. The experiments conducted in an anechoic chamber provide far-field noise measurements to evaluate the azimuthal and polar directivities. This data, along with the aerodynamic performance, is assessed and will also be used to validate the simulation results performed using the SIMULIA PowerFLOW® solver, coupled with the Ffowcs-Williams and Hawkings acoustic analogy. Initial analysis of the noise characteristics experimental data identified the noise sources by evaluating the spectral differences between the isolated and airfoil wake propeller. Haystacking appears in the harmonics of the blade passing frequency and an overall sound pressure level increase over the full frequency range. Coarse numerical simulation results are presented, whilst a high-resolution simulation is currently running and will enable validation of far-field acoustics as well as provide insight into the noise generation mechanisms by analyzing the flow field and blade level data.