Hopscotching Jellyfish: combining different duty cycle kinematics can lead to enhanced swimming performance

TL;DR

This study demonstrates that combining different duty cycle kinematics in jellyfish models can significantly improve swimming speed and efficiency, revealing new insights into their propulsion mechanisms.

Contribution

It introduces a fluid-structure interaction model exploring mixed duty cycle kinematics, showing potential performance enhancements in jellyfish propulsion.

Findings

Speed increased by up to 80% with mixed duty cycles

Cost of transport reduced by up to 50%

Lower contraction frequencies benefit more from duty cycle shuffling

Abstract

Jellyfish (Medusozoa) have been deemed the most energy-efficient animals in the world. Their bell morphology and relatively simple nervous systems make them attractive to robotocists. Although, the science community has devoted much attention to understanding their swimming performance, there is still much to be learned about the jet propulsive locomotive gait displayed by prolate jellyfish. Traditionally, computational scientists have assumed uniform duty cycle kinematics when computationally modeling jellyfish locomotion. In this study we used fluid-structure interaction modeling to determine possible enhancements in performance from shuffling different duty cycles together across multiple Reynolds numbers and contraction frequencies. Increases in speed and reductions in cost of transport were observed as high as 80% and 50%, respectively. Generally, the net effects were greater for cases involving lower contraction frequencies. Overall, robust duty cycle combinations were determined that led to enhanced or impeded performance.