With the renewed interest in counter-rotating coaxial rotor (CCR) vehicles, a comprehensive understanding of its performance under out-of-ground effect and in-ground effect (IGE) operating conditions is imperative. The current work reports on an experimental study of a modular three-bladed CCR system during IGE hovering conditions. Thrust and torque produced by the upper and lower rotors were individually measured for two different axial spacings between the rotors with varying rotor heights from the ground. Both fixed-collective (untrimmed) and constant thrust, torque-matched (trimmed) experiments were performed to understand the interdependent effects of rotor-to-rotor interactions and ground effect on the performance of the CCR and its individual rotors. The CCR performance increased monotonically with decreasing rotor height with performance qualitatively similar for the two rotor spacing cases. At the same time, individual rotor performance variation with rotor height showed nonmonotonic behavior due to complementary or opposing effects of the rotor-to-rotor interactions to the ground effect. In general, the lower rotor in CCR experienced the most relative improvement in performance during IGE operations and was also observed to degrade the upper rotor performance.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Aerodynamic Interactions of Counter-Rotating Coaxial Rotors Hovering in Ground Effect


    Contributors:

    Published in:

    Journal of Aircraft ; 59 , 6 ; 1416-1425


    Publication date :

    2022-11-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





    Helicopter with coaxial counter-rotating roller driven rotors

    POPE CHARLES DOUGLAS | European Patent Office | 2024

    Free access

    CFD-based aerodynamic shape optimization of hovering rotors

    Allen, C.B. / Morris, A.M. / Rendall, T.C.S. | Tema Archive | 2009


    CFD-Based Aerodynamic Shape Optimization of Hovering Rotors

    Allen, Christian / Morris, Asa / Rendall, Thomas | AIAA | 2009