Wave flume

Model testing with periodic Stokes waves in the Wave–Tow Tank of the Jere A. Chase Ocean Engineering Laboratory, University of New Hampshire.

A solitary wave in a laboratory wave flume

Breaking wave on a slope in a laboratory wave channel (movie)

File:06golfgootgolven.ogg

Propagating and breaking waves in a wave flume (movie)

In fluid dynamics, a wave flume (or wave channel) is a laboratory facility for the physical modelling of water waves, in order to study their properties and their effects on coastal structures, offshore structures, sediment transport and other transport phenomena.

A wave flume is a special sort of wave tank: the width of the flume is much less than its length. The generated waves are therefore – more or less – two-dimensional in a vertical plane (2DV), meaning that the orbital flow velocity component in the direction perpendicular to the flume side wall is much smaller than the other two components of the three-dimensional velocity vector. This makes a wave flume a well-suited facility to study near-2DV structures, like cross-sections of a breakwater. Also (3D) constructions providing little blockage to the flow may be tested, e.g. measuring wave forces on vertical cylinders with a diameter much less than the flume width.

The waves are most often generated with a mechanical wavemaker, although there are also wind–wave flumes with (additional) wave generation by an air flow over the water – with the flume closed above by a roof above the free surface. The wavemaker frequently consists of a translating or rotating rigid wave board. Modern wavemakers are computer controlled, and can generate besides periodic waves also random waves, solitary waves, wave groups or even tsunami-like wave motion. The wavemaker is at one end of the wave flume, and at the other end is the construction being tested, or a wave absorber (a beach or special wave absorbing constructions).

Often, the side walls contain glass windows, or are completely made of glass, allowing for a clear visual observation of the experiment, and the easy deployment of optical instruments (e.g. by Laser Doppler velocimetry or particle image velocimetry).

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