A Model of the Acoustic Intensity Field Generated by a Multi-Engine Turbo-Prop Aircraft
Abstract
High levels of noise within the fuselage of a turbo-prop aircraft cannot be mitigated by traditional acoustic coating techniques, since the primary frequencies are generally less than 500 Hz. Tests of an advanced device, designed to control the relative phase between the engines, identified 10-20 dB reductions in the acoustic noise levels within the fuselage. An analytical framework was developed to model the observed effects independent of airframe design. The Green's function for the three-dimensional non-homogeneous acoustic wave equation was used to obtain the radiation fields for three specific source functions: a harmonic point source, a pulsating non-harmonic distributed source, and a single uniformly rotating paddle. Comparisons were made between the observed data and models for three specific sets of relative engine phases. Although each model exhibited some of the features of the actual data set, no particular source function reproduced all features of the measured data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2002
- Accession Number
- ADA412231
Entities
People
- Brian S. Davis
Organizations
- Air Force Research Laboratory