In all rotorcraft, the main rotor is the primary source of helicopter vibration, transmitting aerodynamic and inertial loads to the fuselage at a frequency proportional to the rotor speed. However, simulation of progressive immersion into an idealised sharp-edged gust induces a split around this frequency proportional to the relative velocity between gust and aircraft. To test for this effect in more complicated gust patterns, a realistic operational flowfield was generated using a computational fluid dynamics package. Numerical experiments suggest that a realistic atmospheric environment can be found which induces this split about the fundamental forcing frequency. A simple mathematical expression is derived which also predicts changes in frequency as a function of flight condition. The sensitivity of a class of optimal frequency-tuned active vibration control algorithms (higher harmonic control), to this type of disturbance is found to be poor. Enhancements to the algorithm through the inclusion of a Kalman state estimator and multi-harmonic inputs fail to yield any performance improvement. A novel modification to the algorithm allowing for direct feed forward of a Fourier estimate of the gust is shown to significantly improve controller performance. However accurately estimating the disturbance vector significantly complicates implementation of the technique.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Helicopter vibration induced by highly structured turbulence


    Weitere Titelangaben:

    Anregung mechanischer Schwingungen eines Helikopters durch hochgradig strukturierte Turbulenz


    Beteiligte:
    Anderson, D. (Autor:in)

    Erschienen in:

    Erscheinungsdatum :

    2003


    Format / Umfang :

    9 Seiten, 12 Bilder, 1 Tabelle, 22 Quellen



    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Print


    Sprache :

    Englisch





    Helicopter vibration

    Prouty, W.R. | Tema Archiv | 1988


    Helicopter vibration investigations

    Howe, D. | Engineering Index Backfile | 1959


    Helicopter Vibration Isolation

    KELLEY, BARTRAM | SAE Technical Papers | 1948


    Unmanned helicopter vibration isolation device and unmanned helicopter

    HAI RIHAN / WANG XIANYU / LI JINGYANG et al. | Europäisches Patentamt | 2023

    Freier Zugriff