蓝鳃太阳鱼背臀鳍功能:稳定游动过程中流向涡结构
Fishes have an enormous diversity of body shapes andfin morphologies. From a hydrodynamic standpoint, thefunctional significance of this diversity is poorlyunderstood, largely because the three-dimensional flowaround swimming fish is almost completely unknown.Fully three-dimensional volumetric flow measurementsare not currently feasible, but measurements in multipletransverse planes along the body can illuminate many ofthe important flow features. In this study, I analyze flow inthe transverse plane at a range of positions around bluegillsunfish Lepomis macrochirus, from the trailing edges ofthe dorsal and anal fins to the near wake. Simultaneousparticle image velocimetry (PIV) and kinematic measurementswere performed during swimming at 1.2bodylengthss–1to describe the streamwise vortex structure, to quantifythe contributions of each fin to the vortex wake, and toassess the importance of three-dimensional flow effects inswimming.