3D Synthetic Aperture PIV of a Swimming Fish

The efficiency and maneuverability of fish swimming has yet to be rivaled by manmade vehicles. Fish owe much of this locomotive success to highly three-dimensional body kinematics and wake interactions. Study of these behaviors is inherently simplified by planar measurement techniques including conventional 2D PIV. Thus, volumetric velocimetry systems are required to provide further insight into swimming hydrodynamics. In this study, Synthetic Aperture PIV (SAPIV), a new three-dimensional PIV method based on light field imaging, is applied to study swimming in 3D with minimal constraints on animal behavior. Results successfully depict all three components of the velocity field and vortex ring structures surrounding a freely swimming Giant danio (Devario aequipinnatus) during steady forward swimming and turning maneuvers