title: A synthesis approach for reproducing the response of aircraft panels to a turbulent boundary layer excitation.
abstract: Random wall-pressure fluctuations due to the turbulent boundary layer (TBL) are a feature of the air flow over an aircraft fuselage under cruise conditions, creating undesirable effects such as cabin noise annoyance. In order to test potential solutions to reduce the TBL-induced noise, a cost-efficient alternative to in-flight or wind-tunnel measurements involves the laboratory simulation of the response of aircraft sidewalls to high-speed subsonic TBL excitation. Previously published work has shown that TBL simulation using a near-field array of loudspeakers is only feasible in the low frequency range due to the rapid decay of the spanwise correlation length with frequency. This paper demonstrates through theoretical criteria how the wavenumber filtering capabilities of the radiating panel reduces the number of sources required, thus dramatically enlarging the frequency range over which the response of the TBL-excited panel is accurately reproduced. Experimental synthesis of the panel response to high-speed TBL excitation is found to be feasible over the hydrodynamic coincidence frequency range using a reduced set of near-field loudspeakers driven by optimal signals. Effective methodologies are proposed for an accurate reproduction of the TBL-induced sound power radiated by the panel into a free-field and when coupled to a cavity.
authors.affiliation: Centro de Acústica Aplicada y Evaluación No Destructiva, CSIC-UPM, Serrano 144, 28006 Madrid, Spain. teresa.bravo@ia.cetef.csic.es
authors.forename: Teresa
authors.initials: T
authors.lastname: Bravo
authors.forename: Cédric
authors.initials: C
authors.lastname: Maury
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000401:Aircraft; D000535:Aluminum; D003198:Computer Simulation; D008962:Models, Theoretical; D009038:Motion; D009624:Noise, Transportation / Q000517:prevention & control*; D009716:Numerical Analysis, Computer-Assisted; D011312:Pressure; D013018:Sound Spectrography; D013997:Time Factors; D014159:Transducers; D014732:Vibration
chemical_list: D000535:Aluminum