This paper compares two methods for predicting the noise from helicopter rotors in forward flight. Both methods use a computational fluid dynamics (CFD) solver for the Euler equations to predict the aerodynamic and acoustic solutions in the near field. The first method propagates the near-field noise using the acoustic analogy without quadrupole terms. The second method uses a Kirchhoff integration to propagate the near-field rotor noise to the far field. Computed results from both methods are compared with each other and with experimental data for test cases with both high-speed impulsive and blade-vortex interaction noise. Computed results show that both methods give similar results for cases where there is no transonic flow over the rotor blades. For higher-speed cases with transonic flow, the Kirchhoff method gives more accurate results. Both acoustic prediction methods require similar computational resources, but these requirements are small when compared to those of the CFD flow solver.
A comparison of computational aeroacoustic prediction methods
Vergleich von aeroakustischen analytischen Vorhersagemethoden
Journal of the American Helicopter Society ; 42 , 1 ; 54-57
1997
4 Seiten, 2 Bilder, 14 Quellen
Aufsatz (Zeitschrift)
Englisch
A Comparison of Computational Aeroacoustic Prediction Methods
British Library Conference Proceedings | 1995
|A Comparison of Computational Aeroacoustic Prediction Methods
British Library Conference Proceedings | 1995
|A Comparison of Computational Aeroacoustic Prediction Methods
Online Contents | 1997
|Comparison of Computational Aeroacoustic Prediction Methods for Transonic Rotor Noise
Online Contents | 1997
|