The role of nonlinear effects in the propagation of noise from high-power jet aircraft.
To address the question of the role of nonlinear effects in the propagation of noise radiated by high-power jet aircraft, extensive measurements were made of the F-22A Raptor during static engine run-ups. Data were acquired at low-, intermediate-, and high-thrust engine settings with microphones located 23-305 m from the aircraft along several angles. Comparisons between the results of a generalized-Burgers-equation-based nonlinear propagation model and the measurements yield favorable agreement, whereas application of a linear propagation model results in spectral predictions that are much too low at high frequencies. The results and analysis show that significant nonlinear propagation effects occur for even intermediate-thrust engine conditions and at angles well away from the peak radiation angle. This suggests that these effects are likely to be common in the propagation of noise radiated by high-power aircraft.
Gee
Kent L
KL
Graduate Program in Acoustics, 201 Applied Science Building, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. kentgee@byu.edu
Sparrow
Victor W
VW
James
Michael M
MM
Downing
J Micah
JM
Hobbs
Christopher M
CM
Gabrielson
Thomas B
TB
Atchley
Anthony A
AA
D000401:Aircraft; D000465:Algorithms; D001359:Aviation; D006838:Hydrocarbons; D008144:Loudness Perception; D008962:Models, Theoretical; D009623:Noise, Occupational; D009624:Noise, Transportation; D011846:Radio Waves; D014919:Wind
D006838:Hydrocarbons; C029662:JP5 jet fuel