Experimental observation of periodic Korteweg-de Vries solitons along a torus of fluid

TL;DR

This study experimentally observes and characterizes periodic Korteweg-de Vries solitons along a fluid torus, highlighting differences from classical geometries and validating theoretical models through high-resolution measurements and spectral analysis.

Contribution

It provides the first experimental validation of periodic KdV solitons in a fluid torus, demonstrating unique behaviors and confirming theoretical predictions with spectral analysis.

Findings

Observation of subsonic elevation solitons

Nonlinear velocity-amplitude relationship

Validation of periodic inverse scattering transform

Abstract

We report on the experimental observation of solitons propagating along a torus of fluid. We show that such a periodic system leads to significant differences compared to the classical plane geometry. In particular, we highlight the observation of subsonic elevation solitons, and a nonlinear dependence of the soliton velocity on its amplitude. The soliton profile, velocity, collision, and dissipation are characterized using high resolution space-time measurements. By imposing periodic boundary conditions onto Korteweg-de Vries (KdV) equation, we recover these observations. A nonlinear spectral analysis of solitons (periodic inverse scattering transform) is also implemented and experimentally validated in this periodic geometry. Our work thus reveals the importance of periodicity for studying solitons and could be applied to other fields involving periodic systems governed by a KdV equation.