Improving source localization with SODIX for far-field measurements in static engine noise tests.

Kurzfassung

The source localization method SODIX is able to determine the contributions of individual sound sources of aircraft engines to the overall radiated noise. It has been applied to static engine noise measurements with a short-cowl turbofan engine using a far-field microphone array. The analysis of far-field microphone data is very challenging due to the low number of microphones in this array. SODIX is used to evaluate the effect of an intake liner on the sound field radiated from the engine intake. The source localization results show that SODIX is able to quantify the effect of the intake liner even when the overall sound pressure levels are dominated by other sound sources, e.g. by jet noise. A review of the mathematical formulation of SODIX shows that the point-spread function is relevant for the source localization with SODIX and has to be taken into account in the design of future measurements.