Intermittent locomotion is a widely used behavioral strategy for fish and birds to reduce the cost of movement. The intermittent locomotion performance of a self-propelled flapping plate is investigated numerically. Two intermittent swimming modes, namely, the multiple-tail-beat mode (MT mode) and the half-tail-beat mode (HT mode), as well as the continuous swimming mode (CT mode), are considered. Performance is evaluated from propulsive speed, efficiency, and cost of transport. The hydrodynamic performances of the intermittent modes are found to be better than the hydrodynamic performance of the CT mode when the bending stiffness $K$ is moderate [i.e., $K\approx O\left(1\right)]$ and the duty cycle is not too small. For the two intermittent modes, the performance of the HT mode is better than that of the MT mode when $K$ is small or moderate, while the situation is opposite when $K$ is large. It is found that compared to the asymmetric wake of the MT mode, the symmetric wake of the HT mode is favorable to generate more thrust force and therefore achieve better performance. Besides, at moderate $K$, the largest bending deformation of the plate in the HT mode, as well as the large normal force, produces the largest thrust during the flapping. The present results can help us to better understand the intermittent locomotion of animals and may be helpful for bionic design.

中文翻译：

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自行式拍打板间歇运动的水动力优势

间歇运动是鱼类和鸟类减少运动成本的一种广泛使用的行为策略。数值研究了自行式襟翼板的间歇运动性能。考虑了两种间歇游泳模式，即多尾拍模式（MT模式）和半尾拍模式（HT模式）以及连续游泳模式（CT模式）。从推进速度，效率和运输成本中评估性能。弯曲刚度时，间歇模式的水动力性能优于CT模式的水动力性能。$ķ$ 中等[即， $ķ\approx Ø（\mathrm{1个}）]$而且占空比也不会太小。对于两种间歇模式，在以下情况下，HT模式的性能要优于MT模式。$ķ$ 很小或中等，而情况相反 $ķ$大。已发现，与MT模式的非对称唤醒相比，HT模式的对称唤醒有利于产生更大的推力，从而获得更好的性能。此外，适度$ķ$在HT模式下，板的最大弯曲变形以及较大的法向力会在拍打过程中产生最大推力。目前的结果可以帮助我们更好地了解动物的间歇运动，并可能对仿生设计有所帮助。