A method is presented for the exact numerical integration of acoustic radiation integrals for a disc-shaped source in a mean flow. The technique allows the calculation of a harmonic of the acoustic field around the source and the study of its variation with the parameters relevant to aircraft propeller noise. Results are given for two sources representative of convential and advanced aircraft propellers at zero, takeoff and cruise Mach numbers. The structure of the fields is discussed and in particular the form of the transition from the near to the far field and the circumstances under which the strong beaming pattern of supersonic rotors becomes apparent.
Sound radiation from propellers in forward flight
Die Schallemission von Flugzeugpropellern im Vorwärtsflug
Journal of Sound and Vibration ; 225 , 2 ; 353-374
1999
22 Seiten, 8 Bilder, 18 Quellen
Article (Journal)
English