Abstract:
Aquatic vegetation in the littoral zone plays a crucial role in attenuating wave energy and
protecting coastal communities from hazardous events. This study contributes to the development
of numerical models aimed at designing nature-based coastal defense systems. Specifically, a novel
numerical application for simulating wave–vegetation interactions at the stem scale is presented. The
numerical model employed, DualSPHysics, couples the meshfree Smoothed Particle Hydrodynamics
(SPH) fluid solver with a structural solver to accurately capture the two-way interactions between
waves and flexible vegetation. The proposed numerical model is validated against experimental
data involving a submerged rubber cylinder representing an individual vegetation stem, subjected to
regular waves. The results demonstrate excellent agreement in hydrodynamics, force transfer, and
the swaying motion of the flexible cylinder. Importantly, the approach explicitly captures energy
transfer between the fluid environment and the individual stem. The numerical results indicate
persistent turbulent flow along the vegetation stem, even when its swaying speed matches that of
the surrounding environment. This reveals the presence of vortex shedding and energy dissipation,
which challenges the concept of passive swaying in flexible aquatic vegetation.
