landing flap
1.Abstract: A large planar microphone array,which consists of 111 microphones,was successfully applied to obtain a two-dimensional mapping of the sound sources on a landing aircraft.The focus of study in this paper is on the landing gear noise source.The spectra,directivities and sound pressure levels of flap side-edge noise of 7 narrow-board commercial aircraft and 7 wide-board commercial aircraft are presented.It is found that the landing gear noise spectrum is broadband with some single tones in some cases.The directivity of the total sound pressure level of a landing gear noise resembles that of a horizontal dipole.The level differences between the various aircraft landing gears are larger than those expected from the airspeed differences.It is thus expected that the louder noise emission of the landing gears can be reduced by redesigning.
2.A large planar microphone array,which consists of 111 microphones,was successfully applied to obtain a two-dimensional mapping of the sound sources on a landing aircraft.The focus of study in this paper is on the landing gear noise source.The spectra,directivities and sound pressure levels of flap side-edge noise of 7 narrow-board commercial aircraft and 7 wide-board commercial aircraft are presented.It is found that the landing gear noise spectrum is broadband with some single tones in some cases.The directivity of the total sound pressure level of a landing gear noise resembles that of a horizontal dipole.The level differences between the various aircraft landing gears are larger than those expected from the airspeed differences.It is thus expected that the louder noise emission of the landing gears can be reduced by redesigning.
