翼型在风或水流中扑动既可以作为一种推进方式也可以在改变运动参数后从中获取能量. 通过控制波形参数得到扑翼的升沉和俯仰运动波形, 并利用非定常数值模拟来研究St数、俯仰幅值和升沉俯仰运动的波形对其获能效率的影响. 同时, 还研究了不同的扑动俯仰轴位置对扑翼获能效率的影响. 研究结果表明, 在获能参数域内俯仰运动的波形和俯仰轴位置会对扑翼获能产生较大的影响, 而升沉运动的波形对扑翼获能的影响有限, 且当St=1.332,θ0=76.3, βt和βr分别为1.13 (此时的俯仰波形为接近正弦波)和0.67时, 翼型扑动获能的效率最高, 为41%.
Airfoil flapping in wind or water flow can be either propulsion or power extraction. This study uses waveform parameters to control the flapping motion. Unsteady
numerical simulation is performed to study the effect of St number, amplitude and waveform of heave pitch motion on its energy extraction efficiency. The influence of different positions of pitching axis on the power extraction efficiency is also studied. The results show that the waveform-parameter and pitching axis location have a great influence on the flapping wing for power extraction in the parameter domain. Contrarily, the influence of waveform of heave motion is limited. When St is 1.332,θ0 is 76.3, and both βt and βrare 1.13 (making the pitch waveform close to a sine wave) and 0.67 respectively, the flapping airfoil can extract power at the highest efficiency, which is 41%.
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