Output details

Estimation of the far-field directivity of broadband aeroengine fan noise using an in-duct axial microphone array

Significance of output:

The measurement of the noise radiation from aero engines requires the engine to be located within an anechoic chamber and the noise radiation measured using arrays of microphones. Such a facility can be found at the National Test Facility in Farnborough, whose daily charge out rate of £30,000 per day. This paper describes a measurement technique by which the noise radiation in all directions can be estimated from simple measurements of the acoustic pressure at the wall of the engine duct. The need for such costly facilities is therefore circumvented. This technique is now being applied to the test facility at ANECOM in Germany.