"Buzz-saw" noise: a comparison of measurement with prediction

McAlpine, A., Fisher, M.J. and Tester, B.J. (2006) "Buzz-saw" noise: a comparison of measurement with prediction. Journal of Sound and Vibration, 290 (3-5), 1202-1233. (doi:10.1016/j.jsv.2005.05.028).

Abstract

Accurate prediction of “buzz-saw” noise in a turbofan inlet duct necessitates consideration of nonlinear acoustics, modelling a complete fan blade set, modelling an acoustic liner, and calculations at high frequencies. A recent series of papers has described new work concerning the application of one-dimensional propagation models to the prediction of buzz-saw noise. A numerical model, termed the frequency domain numerical solution or FDNS, has been developed. It can be used to calculate the nonlinear propagation of the rotor-alone pressure field in either a rigid or acoustically-lined inlet duct. From this the in-duct noise level of the buzz-saw tones can be determined. In previous work, validation of this method by comparison with in-duct noise measurements has been limited to rigid inlet ducts, because of the lack of availability of suitable measurements from lined ducts. In this article new measurements of buzz-saw noise in an acoustically-lined inlet duct are utilized. A comparison of measurements of buzz-saw noise in a lined inlet duct, and noise predictions from numerical simulations by the FDNS is presented. The detailed measurements reveal the effect of an acoustic liner on buzz-saw noise. The suitability of the numerical model to be used to provide realistic noise predictions for supersonic ducted fans is also examined.

This record has no associated files available for download.

Contributors

Author: A. McAlpine

Download statistics