Tack Nils B, Du Clos Kevin T, Gemmell Brad J
Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620, USA.
R Soc Open Sci. 2024 Jan 3;11(1):231265. doi: 10.1098/rsos.231265. eCollection 2024 Jan.
During swimming, many fishes use pectoral fins for propulsion and, in the process, move substantial amounts of water rearward. However, the effect that this upstream wake has on the caudal fin remains largely unexplored. By coordinating motions of the caudal fin with the pectoral fins, fishes have the potential to create constructive flow interactions which may act to partially recapture the upstream energy lost in the pectoral fin wake. Using experimentally derived velocity and pressure fields for the silver mojarra (), we show that pectoral-caudal fin (PCF) coordination enables the circulation and interception of pectoral fin wake vortices by the caudal fin. This acts to transfer energy to the caudal fin and enhance its hydrodynamic efficiency at swimming speeds where this behaviour occurs. We also find that mojarras commonly use PCF coordination in nature. The results offer new insights into the evolutionary drivers and behavioural plasticity of fish swimming as well as for developing more capable bioinspired underwater vehicles.
在游泳过程中，许多鱼类利用胸鳍进行推进，在此过程中，大量的水被向后推动。然而，这种上游尾流对尾鳍的影响在很大程度上仍未得到探索。通过协调尾鳍与胸鳍的运动，鱼类有可能创造出建设性的流动相互作用，这可能有助于部分重新捕获在胸鳍尾流中损失的上游能量。利用通过实验得出的银莫拉鱼的速度场和压力场，我们表明胸鳍 - 尾鳍（PCF）协调能够使尾鳍循环和拦截胸鳍尾流涡旋。这有助于将能量传递给尾鳍，并在出现这种行为的游泳速度下提高其水动力效率。我们还发现莫拉鱼在自然环境中通常会使用PCF协调。这些结果为鱼类游泳的进化驱动因素和行为可塑性以及开发更具能力的仿生水下航行器提供了新的见解。
