The NASA Aeroacoustic Prediction System (NAPS) is used to establish a link between model-scale and full-scale rotor predictions and is partially validated against measured wind tunnel and flight aeroacoustic data. The prediction approach of NAPS couples a comprehensive rotorcraft analysis with acoustic source noise and propagation codes. The comprehensive analysis selected for this study is CAMRAD-II, which provides the performance/trim/wake solution for a given rotor or flight condition. The post-trim capabilities of CAMRAD-II are used to compute high-resolution sectional airloads for the acoustic tone noise analysis, WOPMOD. The tone noise is propagated to observers on the ground with the propagation code, RNM (Rotor Noise Model). Aeroacoustic predictions are made with NAPS for an isolated rotor and compared to results of the second Harmonic Aeroacoustic Rotor Test (HART-II) program, which tested a 40% dynamically and Mach-scaled BO-105 main rotor at the DNW. The NAPS is validated with comparisons for three rotor conditions: a baseline condition and two Higher Harmonic Control (HHC) conditions. To establish a link between model and full-scale rotor predictions, a full-scale BO-105 main rotor input deck for NAPS is created from the 40% scale rotor input deck. The full-scale isolated rotor predictions are then compared to the model predictions. The comparisons include aerodynamic loading, acoustic levels, and acoustic pressure time histories for each of the three conditions. With this link established, full-scale predictions are made for a range of descent flight conditions and compared with measured trends from the recent Rotorcraft Operational Noise Abatement Procedures (RONAP) flight test conducted by DLR and ONERA. Additionally, the effectiveness of two HHC conditions from the HART-II program is demonstrated for the full-scale rotor in flight.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen


    Exportieren, teilen und zitieren



    Titel :

    Full Scale Rotor Aeroacoustic Predictions and the Link to Model Scale Rotor Data


    Beteiligte:

    Kongress:

    American Helicopter Society 4th Decennial Specialists Conference on Aeromechanics ; 2004 ; San Francisco, CA, United States


    Erscheinungsdatum :

    01.01.2004


    Medientyp :

    Preprint


    Format :

    Keine Angabe


    Sprache :

    Englisch


    Schlagwörter :


    Tilt Rotor Aeroacoustic Model Project

    J. L. Johnson / L. A. Young | NTIS | 1999



    ROTOR-ON-ROTOR AEROACOUSTIC INTERACTIONS OF MULTIROTOR IN HOVER

    Alvarez, E. / Schenk, A. / Critchfield, T. et al. | TIBKAT | 2020


    Aeroacoustic simulations of full-scale sedan vehicle towards interior noise predictions

    Brès, Guillaume A. / Ivey, Christopher B. / Philips, David A. et al. | AIAA | 2023


    ATIC Aeroacoustic Model Rotor Test at DNW

    Murashige, A. / Kobiki, N. / Tsuchihashi, A. et al. | British Library Conference Proceedings | 1998