A hybrid Eulerian-Lagrangian algorithm for soft slender structures immersed in viscous flows*

Structures encountered in ­biolog­ical and robotic domains are often con­stituted of slender elastic elements that are distributed, heterogeneous, and hierarchically ­organized. Their interaction with surrounding fluids is often tedious and computationally expensive to resolve. Here we mitigate these issues via a hybrid Eulerian-Lagrangian algorithm that combines Cosserat rod theory and remeshed vortex methods. The resulting elastohydrodynamic solver is tested against a battery of benchmarks, and further extended to the context of active swimmers, multi-body contact, magnetic actuation, and viscous streaming.