Atmospheric Propagation Model Validation with the NRC Convair 580 Aircraft

摘要

The ability to predict the propagation of an aircraft acoustic signature over large distances is of great interest for a range of applications. It is for these applications that NRC undertook the characterization and validation of an acoustic atmospheric propagation model of aircraft noise. The NRC Flight Research Laboratory twin-engine Convair 580 aircraft was utilized as the acoustic source and the Smiths Falls Montague aerodrome was selected as the testing environment location. Acoustic data was recorded using five independently time-synchronized acoustic measurement stations located throughout the aerodrome. Low altitude aircraft fly-by acoustic measurements were first performed to characterize the acoustic signature of the aircraft, while high-altitude fly-by acoustic measurements were conducted to validate the performance of the atmospheric propagation model. The atmospheric models accurately and consistently calculated acoustic spectra which were in agreement with the high-altitude fly-by measurements although it was observed that there was a slight degradation in the model performance for the estimation of tones over large distances; the degradation is likely related to ambient background and atmospheric turbulence.