Bruit des avions légers : réduction du rayonnement acoustique d'une hélice

Abstract
This paper deals with an acoustic and aerodynamic parametrical study of a light airplane propeller. The aim of this study is to obtain a decrease of noise level with checking the performances. Flyover sound generation is analysed through an analytical formulation which is a sum of blade passing frequency harmonics. D. B. Hanson's formulation used for sound pressure level calculations is coupled with aerodynamic investigations which are carried out with a model based on lifting line theory. In the first part, the accuracy of the acoustic method is achieved with experimental measurement comparison. Next, propeller geometry parametrical study shows the influence of number of blades and scale blade factor modifications. The most suitable solution to provide the same performances with a reduction of noise is obtained by performing the best compromise between acoustics and aerodynamics.