The Prediction of STOVL Noise- Current Semi-Empirical Methods and Comparisons with Jet Noise Data
1990; Linguagem: Inglês
10.4271/901058
ISSN2688-3627
Autores Tópico(s)Wind and Air Flow Studies
ResumoThe 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.
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