Localization and far field extrapolation of acoustic sources from wind tunnel experiments for jet engine installation noise

Abstract

The SODIX method for the localization of directive sound sources was used to analyze experimental data from measurements with a model dual jet installed under a wing. The experiments were performed in the framework of the EU project Jeronimo by the French aeronautics, space and defense research lab ONERA in the CEPRA19 aeroacoustic wind tunnel. The dual-jet nozzle was mounted in the free jet that is used to simulate the flight stream in the anechoic chamber. A wing with a high-lift system could be installed above the nozzle. Acoustic data were acquired with a far-field arc of microphones and a microphone array in the near-field of the jet. SODIX was used to compute the source distribution along the jet axis from the microphone array data. The sound field generated by this source distribution was extrapolated to the positions of far-field microphones, showing good agreement between both data sets. This demonstrates that the SODIX method can be applied to wind tunnel tests at model scale in order to estimate the sound power levels of the individual sources of the jet and on the wing and determine the directivity of the sound field at far-field positions