Four-Winged Flapping Flyer in Forward Flight
We study experimentally a four-winged flapping flyer with chord-wise flexible wings in a self-propelled setup. For a given physical configuration of the flyer (i.e. fixed distance between the forewing and hindwing pairs and fixed wing flexibility), we explore the kinematic parameter space constituted by the flapping frequency and the forewing-hindwing phase lag. Cruising speed and consumed electric power measurements are performed for each point in the \((f,\varphi )\) parameter space and allow us to discuss the problem of performance and efficiency in four-winged flapping flight. We show that different phase-lags are needed for the system to be optimised for fastest flight or lowest energy consumption. A conjecture of the underlying mechanism is proposed in terms of the coupled dynamics of the forewing-hindwing phase lag and the deformation kinematics of the flexible wings.
KeywordsThrust Force Flexible Wing Wing Kinematic Aerodynamic Power Wing Deformation
We thank all people at the PMMH workshop for their help with the experimental setup, in particular D. Pradal, who conceived and built most of its parts. We thank also X. Benoit-Gonin, M. Vilmay and G. Lemoult for the LabView interfacing, and S. Ramananarivo, V. Raspa, D. Kolomenskiy and G. Spedding for useful discussions. This work was supported by the French National Research Agency through project No. ANR-08-BLAN-0099 and by EADS Foundation through project “Fluids and elasticity in biomimetic propulsion”. M. C. acknowledges financial support from CONACyT and UNAM, México. P. J. acknowledges support from the Charpak Internship Program.
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