The prediction of STOVL noise - Current semiempirical methods and comparisons with jet noise dataThe prediction of conventional or STOVL turbojet propulsion system-using aircraft noise is presently undertaken by means of a method incorporating empirical models for jet-mixing noise, engine core noise, and broadband shock noise. The free-jet noise is coupled with a novel empirical equation for ground-interaction noise generated by a vertically impinging jet, and supplemented with the out-of-ground-effect free-jet acoustic directivity pattern of a Harrier-type vectoring nozzle installation. This acoustic-prediction method yielded reasonable agreement with measured far-field Harrier noise during hover in and out of ground effect. Unlike small-scale studies of jet impingement on a hard surface, no tones were found in the present Harrier nozzle spectra.
Document ID
19910036632
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Soderman, Paul T. (NASA Ames Research Center Moffett Field, CA, United States)