As is known, the maximum thickness position plays a key role in determining the energy extraction properties for flapping wing airfoils. Previous work demonstrated that the energy extraction efficiency might increase when we move the maximum thickness position towards the leading-edge direction. Inspired from this phenomenon, we propose in this work the addition of a flat plate at the tail of the flapping wings. Under two different Reynolds numbers (Re = 1100 and Re = 5×10⁵), the effect of adding a rigid flat plate or a flexible flat plate to the trailing edge of the flapping wing on the flapping wing’s energy efficiency was investigated. The corresponding results were also compared with that of the original flapping wing. Results show that the addition of a rigid flat plate is sufficient for the amelioration of the flapping wing’s energy extraction efficiency in low Reynolds number cases. At high Reynolds number cases, the flapping wing with flexible flat plate trailing edge can maintain a relatively high energy extraction efficiency over a wide range of frequency, while the flapping wing with rigid flat plate trailing edge can only improve the energy extraction efficiency in the low frequency region. Therefore, we propose the application of flapping wings with flexible flat plate trailing edge for increasing the energy extraction efficiency under high Reynolds number conditions.

众所周知，最大厚度位置在确定扑翼翼型的能量提取特性中起关键作用。先前的工作表明，当我们将最大厚度位置移向前沿方向时，能量提取效率可能会提高。受此现象的启发，我们建议在这项工作中在拍打机翼的尾部增加一块平板。在两个不同的雷诺数下（Re = 1100和Re = 5×10 ⁵），研究了在襟翼的后缘添加刚性平板或柔性平板对襟翼能量效率的影响。相应的结果也与原始的襟翼进行了比较。结果表明，在低雷诺数情况下，增加刚性平板足以改善襟翼的能量提取效率。在高雷诺数的情况下，具有柔性平板后缘的襟翼可以在较宽的频率范围内保持较高的能量提取效率，而具有刚性平板后缘的襟翼只能在较低的频率下提高能量提取效率频率区域。因此，