An Experimental and Numerical Investigation of Flapping-Wing Propulsion

Flapping-wing propulsion is investigated experimentally and numerically with direct comparisons between experimental and numerical thrust measurements for several geometrically simple con gurations. Numerical simulations are performed using linear theory, and a previously developed, unsteady panel method that models one or two independently moving airfoils with three-degrees of freedom and non-linear deforming wakes. Experiments are carried out in the Naval Postgraduate School 5 5 low-speed tunnel. A apping mechanism that approximates the two-dimensional motions modeled by the panel code is suspended with cables in the wind tunnel, and thrust measurements are made by measuring the streamwise displacement of the model using a laser rangender. The experimental apping mechanism utilizes variable aspectratio wings and optional tip plates to investigate the e ect of three-dimensionality. The device aps two airfoils, each with two degrees of freedom and adjustable pitch and plunge amplitudes, and additional stationary wings may be attached up and/or downstream of the apping wings to investigate interference e ects.

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