Bicoherence analysis of model-scale jet noise.
Bicoherence analysis has been used to characterize nonlinear effects in the propagation of noise from a model-scale, Mach-2.0, unheated jet. Nonlinear propagation effects are predominantly limited to regions near the peak directivity angle for this jet source and propagation range. The analysis also examines the practice of identifying nonlinear propagation by comparing spectra measured at two different distances and assuming far-field, linear propagation between them. This spectral comparison method can lead to erroneous conclusions regarding the role of nonlinearity when the observations are made in the geometric near field of an extended, directional radiator, such as a jet.
Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA. kentgee@byu.edu
Kent L
KL
Gee
Anthony A
AA
Atchley
Lauren E
LE
Falco
Micah R
MR
Shepherd
Lawrence S
LS
Ukeiley
Bernard J
BJ
Jansen
John M
JM
Seiner
D000162:Acoustics; D000401:Aircraft; D006801:Humans; D009624:Noise, Transportation; D017711:Nonlinear Dynamics