Experimental noise source identification in a fuselage test environment based on nearfield acoustical holography
Publication date
2021-11
Document type
Research article
Author
Organisational unit
Scopus ID
Project
Series or journal
CEAS Aeronautical Journal
Periodical volume
12
First page
793
Last page
802
Peer-reviewed
✅
Part of the university bibliography
✅
Keyword
Nearfield acoustical holography
Inverse acoustics
Microphone
Sound intensity
Abstract
A major challenge in the subject of noise exposure in airplanes is to achieve a desired transmission loss of lightweight structures in the low-frequency range. To make use of appropriate noise reduction methods, identification of dominant acoustic sources is required. It is possible to determine noise sources by measuring the sound field quantity, sound pressure, as well as its gradient and calculating sound intensity by post-processing. Since such a measurement procedure entails a large amount of resources, alternatives need to be established. With nearfield acoustical holography in the 1980s, a method came into play which enabled engineers to inversely determine sources of sound by just measuring sound pressures at easily accessible locations in the hydrodynamic nearfield of sound-emitting structures. This article presents an application of nearfield acoustical holography in the aircraft fuselage model Acoustic Flight-Lab at the Center of Applied Aeronautical Research in Hamburg, Germany. The necessary sound pressure measurement takes one hour approximately and is carried out by a self-moving microphone frame. In result, one gets a complete picture of active sound intensity at cavity boundaries up to a frequency of 300 Hz. Results are compared to measurement data.
Version
Not applicable (or unknown)
Access right on openHSU
Metadata only access
Open Access Funding
Springer Nature (DEAL)