Dynamics and stability of inline swimming with burst-and-coast swimming behavior

Fish swimming inline may obtain hydrodynamic benefits by interacting with the wake of upstream swimmers. This involves many complex interactions between the downstream swimmer and the vortices generated by the upstream swimmer. However, basic characteristics of this interaction have been observed and can be used to simplify the dynamics. We use these findings to study the configuration of two fish swimming inline. Specifically, the contributions of this work are (1) a simplified dynamic model of a downstream swimmer's position based on experimentally observed behaviors; (2) the introduction of a burst-and-coast dynamics to improve the perception of the downstream swimmer; and (3) an analysis of the systems with continuous and discontinuous swimming behaviors. In particular, we characterize the stability of the system when burst-and-coast gaits are introduced. This work has applications in the propulsion of bio-inspired underwater vehicles.