PIV experimental study on fish swimming vortex structure

Fish escape and cruise have gradually become a research hotspot in the field of fish bionic propulsion hydrodynamics. Study of fish escape and cruise can provide a good theoretical foundation and guidance for the underwater vehicle propulsion technology. In the present work, planar PIV is used to measure the wake flow field of zebrafish swimming in the water, and different fish wake vortex patterns under different swimming states are further analyzed. Meanwhile, Tomo-PIV is also used to measure the three-dimensional wake flow field of the fish swimming, and the linked ring vortex wake pattern is obtained. All the results indicate that the fish swimming wake presents different flow structures and wake patterns under different swimming conditions, which is helpful to reveal the mechanism of fish swimming.