Numerical Prediction of Aerodynamic Noise for a Propeller-wing Configuration and an Investigation of Pitch Effect

Abstract

Driven by the sustainable and eco-friendly vision of aviation, Distributed Electric Propulsion (DEP) technology has received much attention for its high aerodynamic efficiency. Simultaneously, lower noise emissions from DEP configurations are desired and therefore it is important to investigate the aerodynamic noise features, which include but are not limited to the noise generation mechanism and the effect of propeller-propeller/wing interactions. This paper focuses on a numerical approach, which is suitable for industrial practice, for predicting the aerodynamic noise of propeller-wing configurations. A generic DEP configuration is employed, consisting of a Mejzlik 2-blade propeller installed on the leading edge of a NACA0018 airfoil. A hybrid method of computational aeroacoustics has been performed in the present simulations, where aeroacoustics in the near field is solved by coarse-grid compressible large-eddy simulations and then the acoustic far field is calculated by the Ffowcs-Williams Hawkings analogy. The influence of grid resolution is studied based on Pope's criterion M and satisfactory results are achieved at a moderate mesh count as compared to the experimental measurements. Further simulations are conducted to investigate the effect of propeller pitch on the aerodynamic performance, noise generation and propeller-wing interactions.