Acoustic and turbulent wavenumbers separation in wall pressure array signals using EMD in spatial domain

Vincent Grulier (1, 2) , Sebastien Debert (1) , Jerome I. Mars (3) , Marc Pachebat (1)

1 PSA Peugeot-Citroen
2 GIPSA-lab - Grenoble Images Parole Signal Automatique
3 GIPSA-SIGMAPHY - GIPSA - Signal Images Physique

Empirical Mode Decomposition (EMD) is a powerful "timefrequency" tool that is used here in the spatial domain to filter out at each instant, short scale wall pressure fluctuations measured by a linear microphone array beneath a boundary layer. A frequency over streamwise wavenumber representation is used to separate acoustic and turbulent energy: it is obtained by a classical spatial-correlogram which is performed either on original signals or on spatial EMD-filtered signals. It is shown how spatial EMD filtering reduces the spread of the convective energy due to the truncation effects and is tuned to improve the separation of the acoustical energy out of the turbulent energy.

Mots clés: Wavenumber filtering; Spatial EMD; Turbulent boundary layer; Acoustics

Domaines: Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Vincent Grulier, Sebastien Debert, Jerome I. Mars, Marc Pachebat. Acoustic and turbulent wavenumbers separation in wall pressure array signals using EMD in spatial domain. ICASSP 2008 - IEEE International Conference on Acoustics, Speech and Signal Processing, Mar 2008, Las Vegas, Nevada, United States. pp.AE-P6.3. ⟨hal-00348772⟩