Analysis of the influence of inflow distortions on turbofan rotor noise

Larisa Grizewski, Maximilian Behn, Stefan Funke, Henri A. Siller
2019 25th AIAA/CEAS Aeroacoustics Conference   unpublished
Acoustic data measured in a fan test facility with and without an inflow control device (ICD) over the inlet were analysed using the cyclostationary analysis technique, which separates the total power into a rotor locked and a fluctuating component. Measurements were taken with an inlet mode ring upstream of the rotor and with far-field microphones for configurations with subsonic and with supersonic fan blade tip speeds. The ICD reduces the fluctuating component and stabilises the rotor locked
more » ... es the rotor locked component of the frequency spectrum at the blade passing frequency and its harmonics. The mode distribution in the inlet and the far-field directivity are also changed when an ICD is installed. The cyclostationary analysis of the mode spectrum in the inlet duct and of the far-field directivity can help to understand the effect of an ICD on the sound field in more detail than a classical spectral analysis.
doi:10.2514/6.2019-2719 fatcat:3ejloit25zbljjqwf7pvwgkov4