The wave-like behavior of matter in quantum physics has spurred insightful analogies between the dynamics of particles and waves in classical systems. In this study, drawing inspiration from synchrotrons that resonate to accelerate ions along a closed path, we introduce a synchrowave: a waveguide designed to generate and sustain traveling water waves within an annular channel. In analogy to unavoidable energy losses in conventional particle accelerators due to electromagnetic radiation and inelastic collisions, the system displays undesired water-wave dampening, which we address through the synchronized action of underwater wavemakers. Our analogies extend the resonance mechanisms of synchrotrons to generate and sustain gravity waves in closed waveguides efficiently. A proof-of-concept experiment at a laboratory scale demonstrates the unique capability of this technique to build up anomalously large traveling waves displaying a flat response in the long-wave limit. Besides quantifying the performance of wave generation, our findings offer a framework for both industrial and computational applications, opening up unexplored possibilities in hydraulics, coastal science, and engineering. In a broader context, our experimental apparatus and methods highlight the versatility of a simple yet powerful concept: a closed-path continuous-energy-pumping scheme to effectively harvest prominent resonant responses within wave-supporting systems displaying weak dissipation.
Keywords: resonance mechanisms; synchrowave; traveling water waves; waveguide.