论文标题
具有时间周期性灵活性的振荡板的推进性能
Propulsive performance of oscillating plates with time-periodic flexibility
论文作者
论文摘要
我们使用小型振幅无粘性理论来研究具有随时间变化的灵活性的柔性拍打板的游泳性能。板的刚度以运动学频率的两倍振荡，以保持对称运动。比较具有恒定和时间周期性刚度的板，在一系列平均板刚度，振荡刚度振幅和振荡刚度相的范围内进行了比较，用于孤立的隆起，孤立的倾斜和前沿运动学组合。我们发现，振荡刚度对推力有深远的影响，对推进效率的影响较小。相对于恒定板的推力最多可改善高达35％的推力。对于刚度振荡的足够频率和振幅，出现了不稳定性。不稳定的地区可能会提出提高的推进性能；该假设必须通过实验或非线性模拟进行验证。
We use small-amplitude inviscid theory to study the swimming performance of a flexible flapping plate with time-varying flexibility. The stiffness of the plate oscillates at twice the frequency of the kinematics in order to maintain a symmetric motion. Plates with constant and time-periodic stiffness are compared over a range of mean plate stiffness, oscillating stiffness amplitude, and oscillating stiffness phase for isolated heaving, isolated pitching, and combined leading edge kinematics. We find that there is a profound impact of oscillating stiffness on the thrust, with a lesser impact on propulsive efficiency. Thrust improvements of up to 35% relative to a constant-stiffness plate are observed. For large enough frequencies and amplitudes of the stiffness oscillation, instabilities emerge. The unstable regions may confer enhanced propulsive performance; this hypothesis must be verified via experiments or nonlinear simulations.
