Resonance of an object floating within a surface wavefield

TL;DR

This study investigates how floating objects resonate with surface waves, revealing that resonance affects wave emission and diffraction, with implications for natural phenomena like sea ice floes.

Contribution

It provides new experimental insights into the resonance behavior of floating cylinders and their interaction with surface waves, a topic previously underexplored at laboratory scales.

Findings

Resonance frequency depends on cylinder size and density ratio.

Minimal wave generation occurs at resonance frequencies.

Floats diffract and radiate secondary waves affecting incident wavefields.

Abstract

We examine the interaction between floating cylindrical objects and surface waves in the gravity regime. Since the impact of resonance phenomena associated with floating bodies, particularly at laboratory scales, remains underexplored, we focus on the influence of the floats' resonance frequency on wave emission. First, we study the response of floating rigid cylinders to external mechanical perturbations. Using an optical reconstruction technique to measure surface wave fields in both space and time, we study the natural resonance frequency of floats with different sizes. The results indicate that the resonance frequency is influenced by the interplay between the cylinder geometry and the solid-to-fluid density ratio. Second, these floating objects are placed in an incoming wave field. These experiments demonstrate that floats diffract incoming waves, while radiating secondary waves that interfere with the incident wavefield. Minimal wave generation is observed at resonance frequencies. These findings can provide insights for elucidating the behavior of larger structures, such as sea ice floes, in natural wave fields.