The aerodynamic noise characteristics of propellers in turbulent flow have been investigated experimentally. In this work, the effect of turbulence interactions on the noise signatures and aerodynamic loading of propellers were investigated using a turbulence-generating passive grid with a solidity ratio of 0.35 and a 3D printed NACA 0012 airfoil wing wake. These turbulence generating methods aim to simulate the fluctuating gusty wind in flight and airframe installation effect, respectively. The experiments were conducted at forwarding flight configuration with freestream inflow velocity ranging from 8 m/s to 24 m/s. Six-axis aerodynamic load measurements and far-field acoustic pressure measurements were performed simultaneously. The results show an increasing trend of thrust energy spectra for propeller operating with turbulence interactions in relative to clean laminar inflow. The acoustic spectrum of the propeller is rich in discrete tones and broadband noise. The results indicate that at a frequency band above 1000 Hz, an increase of noise spectra by about 2 dB/Hz for grid turbulence and around 5 dB/Hz to 15 dB/Hz for wing wake cases were recorded. The overall sound pressure level directivity appears to be less affected by the turbulence ingestion at a low rotational speed. However, at higher RPM, the results demonstrate enhanced radiation downstream.
|Publication status||Published - 28 Jul 2021|
|Event||AIAA Aviation Forum 2021 - Virtual, United States|
Duration: 2 Aug 2021 → 6 Aug 2021
|Conference||AIAA Aviation Forum 2021|
|Period||2/08/21 → 6/08/21|
- Propeller Noise
- Turbulence inflow