Riding the Wave: Emergent Metachronal Paddling and Swimming in 3D FSI Model of a Gossamer Worm

Metachrony is often found throughout nature in many locomotory and fluid transport systems. Gossamer worms, also known tomopterids, are a soft-bodied, pelagic polychaete that employ metachronal paddling with their flexible parabodia on both sides of their body to navigate the midwater ecosystem which they inhabit. In the following study, we introduce a three-dimensional, computational, fluid–structure interaction model of a tomopterid, using a stadium (i.e. a rectangle with two half circles) with flexible parapodia appendages. The motion of the flexible parapodia will emerge from from the interplay of passive body elasticity, active tension, and hydro-dynamic forces, and metachrony will result from differences in phase between the parapodia. The body is freely swimming as a result motion of the parapodia and the metachronal waves formed on both sides of the body. The model is used to explore how variations in phase across the body affect the resulting swimming performance and stability.