Meeting Abstract
Long-tailed crustaceans such as krill and mysids use drag-based metachronal swimming for aquatic locomotion. Pleopod pairs are rhythmically paddled starting from the animal tail to head, such that each pleopod pair is delayed in time relative to the neighboring pair. The ratio of inter-pleopod spacing (G) to pleopod length (L) has been observed to lie within a fairly narrow range of 0.2 to 0.7 in a variety of freely-swimming crustaceans (Murphy et al., Mar Biol 158, 2011). In this study, we examined how varying this G/L ratio from 0.4 to 0.6 impacts metachronal swimming performance. A dynamically scaled robotic model capable of self-propulsion was developed for this study. Physical models of idealized paddle-like pleopods were fabricated from acrylic (four pairs) and outfitted onto the robotic platform. The paddles were programmed to oscillate in tail-to-head metachronal motion with 25% inter-limb phase difference. Thrust generated was measured near the leading edge of the robotic model assembly using strain gauges. Our results showed that time-averaged thrust was slightly augmented with decreasing G/L, but peak thrust increased with increasing G/L ratio. The distance advanced by the self-propelling models under varying G/L will be presented.
