As airlines switch from turbofan engines to turboprop engines on short-haul flights and noise pollution limits around airports become more limited, the acoustical characteristics of commercial propeller aircraft are becoming a key design parameter. In order to study the aerodynamic performance and acoustic characteristics of the propeller, a turboprop aircraft six-blade propeller was studied in the D5 aerodynamic acoustics wind tunnel of Shahe campus, Beijing University of Aeronautics and Astronautics. In the experiment, the combined working conditions of different incoming flow wind speeds were measured under the conditions of fixed blade Angle and rotating speed, so as to obtain the balance force measurement data and far-field sound pressure signal of the propeller under different working conditions. The influence law of incoming flow speed on the far-field noise of the propeller was obtained through the fast Fourier transform. The experimental results show that the discrete part noise can excite higher order harmonic noise under the condition of large incoming flow, and the amplitude of each order harmonic noise decreases gradually with the increase of harmonic number. When the wind speed is low, the sound pressure level of broadband noise increases. This is because the blade is in the stall state and the tension coefficient is in the nonlinear section under the condition of low forward ratio, which is related to the increase of turbulent noise caused by the complex flow field on the blade surface. According to the directivity analysis, the total SPL level at the upstream of the propeller disc is greater than that at the downstream of the propeller disc, mainly because the relative velocity of the propeller disc before and after the change, resulting in the delay of sound propagation distance and acceleration phenomenon.
耿欣,胡天翔,周若君,等.涡桨飞机螺旋桨气动噪声特性试验研究[J].民用飞机设计与研 究,2022(1):64-69GENG Xin, HU Tianxiang, ZHOU Ruojun, et al. Investigation on the aeroacoustic characteristics of the turboprop propeller[J]. Civil Aircraft Design and Research,2022,(1):64-69. ( in Chinese)复制