Abstract
The energy extraction performance of a flapping foil generator is studied through experiment and numerical simulation. A practical flapping foil generator has been proposed. The heave motion and the pitch motion of the foil are adjusted through a crankshaft-like structure. The heave and pitch motions of the foil are transferred to the rotational motion of the main shaft. A pair of gears is adopted to increase the pitch angle. A prototype with pitch amplitude θ0 = 60º has been built and the experiment is carried out in a tunnel. The overall performance of the mechanism has been analysed. Good agreement of numerical results and experiment data has been found. Further simulations with larger pitch amplitudes are carried out. It is found that higher efficiency can be achieved with larger pitch amplitude at medium frequency.
Highlights:
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A new version of energy extraction mechanism through flapping foil has been proposed;
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The performance of the generator with pitch amplitude θ0 = 60° has been studied numerically and experimentally;
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The peak efficiency appears with larger effective attack angle when there is no severe leading edge vortex shedding.