Aero-Acoustic assessment of installed propellers

Abstract

The volume of general aviation transport is increasing and consequently this gives rise to the need for reducing noise levels while improving or at least maintaining the same level of aerodynamic performance. This can be achieved through the use of modern propellers and engines. In this paper we present a methodology to study and predict the installed propeller noise at the same time with the aerodynamic characterization, through the use of unsteady CFD and Acoustic-Analogies analysis. The analysis shows the influence of different acoustic sources generated by the installed propeller on the far field noise by monitoring the monopoles and dipoles with and without taking into account the quadrupoles. In this way we can observe the influence of the distance from the propeller to the engine intake on the overall sound. Time averaged aerodynamic performances are presented along with instantaneous results.

Keywords

• Aeroacoustic
• CFD
• Propeller
• Ffowcs-Williams Hawkings
• Direct Sound Computation