In this work, the flow features of coaxial rotors measured in water tunnel are investigated via particle image velocimetry technique. The experiments are conducted using a two-bladed model-scale coaxial rotor and a single rotor with the same geometry. Some noticeable flow features are found. For the coaxial rotor in hover, there is an annular region radially inboard of the lower rotor disk, where there are almost no intrusions from the upper rotor wake. At the same time, upwash occurs at the outboard edge of the lower rotor, while no such phenomenon occurs near the upper rotor blade tip. Sometimes, two upwash phenomena are found both at the blade tip and root in the single-rotor case. For both the single and coaxial rotors in forward flight, there is a sudden velocity change at about 0.7 R on the retreating side. From comparisons with the prior performance experiments, it can also be found that mutual interferences are playing a positive role in the hovering coaxial rotor configuration. The previously prescribed wake models can well describe the tip vortex trajectories of the single rotor and coaxial rotor in hover and forward flight, especially at high advance ratios. However, in this experiment, some special features are also found slightly different with that of the experiment conducted in air. Some valuable results obtained from this experiment would be helpful to reasonable designs of coaxial helicopters in the future.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Scale-model tests of coaxial rotors in water tunnel via particle image velocimetry technique


    Beteiligte:
    Ma, Yimin (Autor:in) / Chen, Ming (Autor:in) / Zhang, Xingwen (Autor:in) / Wang, Qiang (Autor:in)


    Erscheinungsdatum :

    2016-03-01


    Format / Umfang :

    18 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Particle Image Velocimetry Technique: Calibration Tests

    Sanz, A. / Espino, J. L. | British Library Online Contents | 1992




    Hover Performance Correlation for Full-Scale Coaxial Rotors

    Lim, J. W. / McAlister, K. W. / Johnson, W. et al. | British Library Conference Proceedings | 2007


    Particle image velocimetry

    Online Contents | 1995