Evaluation of acoustic frequency methods for the prediction of propeller noise
The accuracy of several computationally inexpensive acoustic frequency methods is evaluated across a range of propeller geometries and operational conditions. The acoustic models considered predict both near-field and far-field harmonic noise. The implemented models approximate or ignore chordwise noncompactness such that they do not require chordwise aerodynamic data, and therefore do not need to be coupled to a panel or grid-based aerodynamic solver. Each implemented method is compared to 14 test cases originating from nine separate published acoustic experiments. The experimental data considered encapsulate a range of propeller geometries, blade numbers, microphone locations, tip speeds, and forward Mach speeds. The implemented acoustic models demonstrate reasonable agreement with the experimental data, particularly for the prediction of the maximum tonal noise for which Hanson’s model showed the greatest overall accuracy with an average error of 5.9 dB. Using different prediction models based on the freestream velocity reduces the error to 4.7 dB. The presented results suggest that the implemented acoustic methods remain a valuable resource for propeller noise prediction, especially for design and optimization studies, in which a low runtime is important.
Kotwicz Herniczek, M.T. (Mark T.), Feszty, D, Meslioui, S.-A. (Sid-Ali), Park, J. (Jong), & Nitzsche, F. (2019). Evaluation of acoustic frequency methods for the prediction of propeller noise. In AIAA Journal (Vol. 57, pp. 2465–2478). doi:10.2514/1.J056658