Application of acoustically tuned resonators for the improvement of sound insulation in aircraft.

M.H.C. Hannink, J.P. Vlasma, Ysbrand H. Wijnant, Andries de Boer

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

2 Citations (Scopus)
28 Downloads (Pure)

Abstract

One of the aims of the EU project FACE (Friendly Aircraft Cabin Environment) is to reduce aircraft interior noise. For modern aircraft flying at cruise conditions, the turbulent boundary layer is the main source for cabin noise. Normally, the turbulent boundary layer causes the trim panels to vibrate, and hence to radiate sound into the aircraft cabin. The purpose of the present work is to reduce this kind of noise by means of sound insulating trim panels with tuned acoustic resonators1. The length and the radius of these resonators are tuned in such a way that the volume velocities at the vibrating panel surface and at the entrance of the resonators are equal in magnitude but opposite in phase. In this way, maximum reduction of the radiated sound can be achieved for a specified frequency range. Because of the repetitive pattern of the resonators in the panel, the influence of the resonators on the sound radiated in normal direction by the panel is studied with a one-dimensional model. The so-called low reduced frequency model is extended to describe the viscothermal wave propagation in the vibrating resonators. An advantage of the viscothermal effects is that, in the low frequency range, more sound reduction is obtained than if these effects are not present or very small. Calculations show that a large reduction of the radiated sound can be achieved. The model is also validated by experiments in an impedance tube. Good agreement is found between theory and measurements.
Original languageUndefined
Title of host publicationInternational Institute of Noise Control Engineering
Place of PublicationRio de Janiero
Pages-
Number of pages10
Publication statusPublished - 7 Aug 2005
Event34th International Congress and Exposition on Noise Control Engineering, InterNoise 2005 - Rio de Janeiro, Brazil
Duration: 7 Aug 200510 Aug 2005
Conference number: 34

Conference

Conference34th International Congress and Exposition on Noise Control Engineering, InterNoise 2005
Abbreviated titleINTERNOISE 2005
CountryBrazil
CityRio de Janeiro
Period7/08/0510/08/05

Keywords

  • IR-58877
  • METIS-230677

Cite this

Hannink, M. H. C., Vlasma, J. P., Wijnant, Y. H., & de Boer, A. (2005). Application of acoustically tuned resonators for the improvement of sound insulation in aircraft. In International Institute of Noise Control Engineering (pp. -). Rio de Janiero.