Predicting far-field broadband noise levels from in-duct phased array measurements


Tester B. J. , ÖZYÖRÜK Y.

20th AIAA/CEAS Aeroacoustics Conference 2014, Atlanta, GA, United States Of America, 16 - 20 June 2014 identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • Doi Number: 10.2514/6.2014-2913
  • City: Atlanta, GA
  • Country: United States Of America

Abstract

Far-field inlet fan noise can be measured in the AneCom test facility under anechoic conditions but far-field aft fan measurements are not possible because the bypass flow is ducted away through a throttle valve into an exhaust stack. A beamformer-based technique has been developed for processing measurements taken with an in-duct axial ('phased') array, which with certain modelling assumptions, enables the fan broadband noise level and directivity to be predicted in the far-field. The status of this 'in-duct to far-field' method is reviewed, in terms of validation with experimental data and its further development to include realistic bypass nozzle geometry and duct/nozzle flow Mach numbers.