EXPERIMENTAL STUDY OF AIRFOIL-PROPELLER INTERACTION NOISE

摘要

This work experimentally studies the interaction noise between an airfoil-propeller set-up at low Mach numbers to reveal the corresponding aerodynamic mechanisms. In this interaction set-up, the upstream airfoil modifies local downstream wakes, which further impinge the downstream propeller, leading to an increased noise levels compared to the clean set-up with an isolated propeller. A two-component particle image velocimetry (PIV) measurements and far-field acoustic pressure measurements are performed simultaneously. In particular, the velocity field between the stator and the blade of a propeller was measured using PIV. Then, the conventional beamforming technique in aeroacoustics is slightly adapted to locate the sources of the corresponding aerodynamic sound. An increase in the overall propeller noise of about 3 dB was observed, along with the increase of high harmonics of the blade pass frequency tonal noise, when the airfoil is installed. The current work could help deepen physical insight and enlighten aeroacoustic control strategies accordingly.