Mechanical capability and timing of a fish to maneuver from a steady straight-line swimming state

We numerically investigated a fish's mechanical capability and timing to execute maneuvers from a steady straight-line swimming state. The longitudinal forces and yaw moment acting on a fish were evaluated for varied slip number (i.e. ratio of swimming velocity and body-wave velocity). A decreased slip number produces an enhanced mechanical capability for a fish to execute both longitudinal and sideway maneuvers. There are four time instants preferable for a fish to execute the longitudinal maneuvers, whereas only two time instants for the sideway maneuvers. These findings serve as guidance for the design and improvement of the maneuverability of a fish robot.