Meeting Abstract
The performance space of fish-like robotic swimmers is largely confined to tail beat frequencies measuring less than 2 Hz. However, tuna and scombrid fishes are capable of frequencies in excess of 20 Hz. We design a new tuna-like robotic experimental platform that addresses this disparity in frequency and enables testing over a frequency range comparable to biology. The new platform’s morphology is closely modeled after yellowfin tuna (Thunnus albacares) by incorporating data from computed tomographic (CT) scans and reference images of yellowfin tuna. Propulsion is provided by a 12V DC motor in a waterproof housing of Nylon PA12 plastic 3D printed using 60µ selective laser sintering (SLS). The motor shaft is waterproofed with a stuffing tube design. Measuring 255 mm in total length, this tuna-like system includes first and second dorsal fins and an anal fin. All fins are removable for testing with a snap-in magnetic design to assess fin-fin interactions between the dorsal/anal fins and the caudal fin. The body is 3D printed with flexible joints that can be varied in number and the extent to which they permit lateral motion to explore the impact of body flexibility on swimming performance. For each joint configuration, the performance metrics measured include swimming speed, power, and thrust. Midline kinematics and flow field analysis from particle image velocimetry (PIV) visualization are also analyzed. These results are compared against biological data to understand the role of body flexibility during high-frequency swimming.
