Generation of gravity waves by pedal-wavemakers

TL;DR

This paper introduces a novel pedal-wavemaking method for wave generation in channels, addressing limitations of traditional paddles by effectively producing long waves and mimicking deep water waves, useful for fluid-structure interaction studies.

Contribution

The paper proposes a new underwater multipoint pedal-wavemaking framework that improves wave generation performance and mimics deep water waves, enhancing experimental and simulation capabilities.

Findings

Effectively generates long waves in channels.

Replaces evanescent waves with boundary layers.

Produces deep water wave-like motions through synchronization.

Abstract

Experimental wave generation in channels is usually achieved through wavemakers (moving paddles) acting on the surface of the water. Although practical for engineering purposes, wavemakers have issues: they perform poorly in the generation of long waves and create evanescent waves in their vicinity. In this article, we introduce a framework for wave generation through the action of an underwater multipoint mechanism: the pedal-wavemaking method. Our multipoint action makes each point of the bottom move with a prescribed pedalling-like motion. We analyse the linear response of waves in a uniform channel in terms of the wavelength of the bottom action. The framework naturally solves the problem of the performance for long waves and replaces evanescent waves by thin boundary layer at the bottom of the channel. We also show that a proper synchronisation of orbital motion on the bottom can produce waves that mimic deep water waves. This last feature has been proved to be useful to study fluid-structure interaction in simulations based on smoothed particle hydrodynamics.