Predicted XV-15 exterior surface acoustic pressures are compared with previously published experimental data. Surface acoustic pressure transducers were concentrated near the tip-path-plane of the rotor in airplane mode. The comparison emphasized cruise conditions which are of interest for tiltrotor interior noise-level flight for speeds ranging from 72 m/s to 113 m/s. The predictions were produced by components of the NASA Langley Tiltrotor Aeroacoustic Code (TRAC) system of computer codes. Comparisons between measurements and predictions were made in both the time and frequency domains, as well as overall sound pressure levels. In general, the predictions replicated the measured data well. Discrepancies between measurements and predictions were noted. Some of the discrepancies were due to poor correlation of the measured data with the rotor tach signal. In other cases limitations of the predictive methodology have been indicated.
A comparison of measured and predicted XV-15 tiltrotor surface acoustic pressures
Vergleich von gemessenen und vorhergesagten Oberflächenschalldrücken von XV-15-Schwenkrotoren
Journal of the American Helicopter Society ; 44 , 4 ; 285-292
1999
8 Seiten, 16 Bilder, 2 Quellen
Aufsatz (Zeitschrift)
Englisch
Hubschrauber , Rotor (Drehflügel) , Oberflächenschallwelle , Schalldruck , Schallwandler , Schallmessung , Vorhersage , Theorie-Experiment-Vergleich , Geräuschemission , Innenraum , Fluggeschwindigkeit (Luft) , rechnerunterstützte Simulation , Frequenzbereich , Zeitbereich , Korrelation , Aeroakustik
A Comparison of Measured and Predicted XV-15 Tiltrotor Surface Acoustic Pressurures
Online Contents | 1999
|XV-15 Tiltrotor Aircraft: 1997 Acoustic Testing
NTIS | 2003
|XV-15 Tiltrotor Aircraft: 1997 Acoustic Testing
NTRS | 2003
|