Experimental study of flow in wake robotic bird

F. Gijsman, H.W.M. Hoeijmakers

    Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

    2 Citations (Scopus)


    The Robird is a robotic bird designed and manufactured by the company Clear Flight Solutions. The Robird is inspired by the Peregrine Falcon and mimics the flapping flight of its real-life counterpart. The robotic bird is used to scare off birds by pretending to be a natural enemy. Though this robotic bird proves that flapping flight by a robot is possible, the mechanism behind flapping flight is not fully understood. The goal of the present experimental study is to contribute to a better understanding of flapping wing propulsion of a robotic bird like the Peregrine Falcon based Robird. To that aim a set-up has been designed, realized and utilized for the Silent Wind Tunnel of the University of Twente. The semi span wind tunnel model corresponds to the starboard side of the full-scale robotic bird, capable to operate at realistic conditions of flapping flight in which the wing carries out a combination of a plunge and a pitch motion. In the first part of the study a 21-Pitot-tube wake rake is used to measure profiles of the time-averaged velocity magnitude along traverses downstream of the wind tunnel model for flapping frequencies in the range [2.5-4.0]Hz and free-stream velocities in the range [2.5-7.0]m/s. Utilizing a control-volume analysis then gives an estimate of the time-averaged thrust produced by the robotic bird. The results show that for Strouhal numbers above 0.1 the wake of the flapping wing has, time-averaged, a jet-like streamwise velocity profile, associated with the generation of thrust. For increasing values of the Strouhal number, up to St = 0.45, the maximum value of the jet velocity increases. For Strouhal numbers smaller than 0.27 a jet-like profile is found that is symmetric about the mid position of the flapping wing. For higher values of the Strouhal number the jet-like profile becomes asymmetric.

    Original languageEnglish
    Title of host publication2018 Applied Aerodynamics Conference
    EditorsKeith Bergeron, Mehdi Ghoreyshi, Adam Jirasek
    PublisherAmerican Institute of Aeronautics and Astronautics Inc. (AIAA)
    ISBN (Print)9781624105593
    Publication statusPublished - 1 Jan 2018
    Event36th AIAA Applied Aerodynamics Conference 2018 - Hyatt Regency, Atlanta, United States
    Duration: 25 Jun 201829 Jun 2018
    Conference number: 36


    Conference36th AIAA Applied Aerodynamics Conference 2018
    Abbreviated titleAIAA 2018
    CountryUnited States


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