Preliminary Analysis of Nonlinearity in Military Jet Aircraft Noise Propagation

摘要

Analyses of the F/A-18E static engine run-up measurements have indicated that the noise is non-Gaussian and the propagation nonlinear at afterburner and military thrust conditions. Also, calculation of the nonlinearity indicator derived by Howell and Morfey, Q/S, supports the nonlinear propagation hypothesis and calls attention to the indicator itself, which has seen only very limited use since it was derived (see Refs. 2 and 3). Finally, this study has demonstrated that additional and perhaps more extensive investigations in this area are merited. Whereas nonlinear effects do appear to be a factor in the propagation of noise radiated from high-performance jet aircraft, their role has not been defined quantitatively and will likely depend on the propagation environment as well as on source parameters such as jet velocity and temperature.