A new acoustic three dimensional intensity and energy density probe

Fabien Ayme , Charles Cariou , Mohamed Ichchou (1) , Daniel Juvé (2)

1 LTDS - Laboratoire de Tribologie et Dynamique des Systèmes
2 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique

The acoustic field inside aircraft cavities is very complex. Indeed, there is often a combination of direct, diffuse and modal fields depending on the measurement point and on the frequency band considered. This is directly linked to the fact that different types of sources are present. In such cavities, like a cockpit, sources can be panels radiating not necessary in a normal way, avionics systems, air vents, etc… To find efficient solutions to reduce the noise inside aircraft cavities, a good knowledge of the directivity of the acoustic field in the three dimensions is a great advantage. In this frame, a new intensity acoustic probe has been developed to compute acoustic intensity vector and, acoustic density of energy based on four 1/4" microphones measurements around a small sphere. Its originality consists in the possibility to arrange such probes in an antenna. Several calculation methods have been studied to compute those quantities. Results are compared with three uni-dimensional intensity measurements, considered as the reference, in different environments. The probe provides acoustic quantities which can be input data for energetic identification methods. Finally, acoustic tests are in progress in a cockpit mock-up, coupling both probe measurements and energetic identification method.

Mots clés: intensity; acoustic; density; probe

Domaines: Acoustique [physics.class-ph]

Fabien Ayme, Charles Cariou, Mohamed Ichchou, Daniel Juvé. A new acoustic three dimensional intensity and energy density probe. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811180⟩