A novel model is proposed to estimate the optimal propulsive efficiency and the optimal dimensionless heaving velocity of a flapping foil based on a lift–drag ratio under the assumption of negligible pitching power. The optimal efficiency increases with the lift–drag ratio. The optimal Strouhal number of sinusoidal heaving motion approaches 0.318, within the range of 0.25–0.35 for optimal efficiency. In addition, the thrust generation of a foil requires that the product of the lift–drag ratio and the dimensionless heaving velocity must be greater than unity. To demonstrate how to use the new model to estimate the optimal propulsive efficiency and the optimal dimensionless heaving velocity, the lift–drag ratio is estimated using static tests of an impulsively started uniform flow over an infinitely thin flat plate for a range of angle of attack. To illustrate how to design kinematics to achieve the estimated optimal efficiency, two examples of flapping motions of a flat plate at a Reynolds number of 2000 are considered: sinusoidal and nonsinusoidal. Results show that the efficiency of nonsinusoidal flapping motion approaches the optimal efficiency using the lift–drag ratio estimated from static tests over the effective angle of attack of 6–30°.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Optimal Efficiency and Heaving Velocity in Flapping Foil Propulsion


    Contributors:

    Published in:

    AIAA Journal ; 59 , 6 ; 2143-2154


    Publication date :

    2021-06-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Performance of flapping foil propulsion

    Schouveiler, L. / Hover, F.S. / Triantafyllou, M.S. | Tema Archive | 2005



    Comparison of bio-inspired flapping foil propulsion systems with rotary propulsion

    Dharwada, Srikanth / Agarwal, Aman / Rajagopal, Prabhu | SPIE | 2018


    Simulation of the Propulsion Characteristics of a Flapping Foil AUV

    Smith, R. W. / Wright, J. A. / American Institute of Aeronautics and Astronautics | British Library Conference Proceedings | 2005


    Simulation of the Propulsion Characteristics of a Flapping Foil AUV

    Smith, Richard / Wright, Jeffrey | AIAA | 2005