Related Experiment Video
Updated: Aug 25, 2026

Measurements of Waves in a Wind-wave Tank Under Steady and Time-varying Wind Forcing
Published on: February 13, 2018
Long-time behavior of sand ripples induced by water shear flow
A Betat1, C A Kruelle, V Frette
1Experimentalphysik V, Universität Bayreuth, D-95440 Bayreuth, Germany.
Abstract:
The formation of sand ripples under water shear flow in a narrow annular channel and the approach of the ripple pattern towards a steady state were studied experimentally. Four results are obtained: i) The mean amplitude, the average drift velocity and the mean sediment transport rate of the evolving bed shape are strongly related. A quantitative characterization of this relation is given. ii) The ripple pattern reaches a stationary state with a finite ripple amplitude and wavelength. The time needed to reach the state depends on the shear stress and may be several days. iii) The onset of ripple formation is determined by the bed shear stress, but it seems neither to depend on the grain diameter nor on the depth of the water layer. iv) The ripple amplitude, drift velocity and sediment transport in this stationary state depend on the grain size. This dependency is neither captured by the particle Reynolds number nor by the Shields parameter: an empirical scaling law is presented instead.
Related Concept Videos
Rapidly Varying Flow
Damped Oscillations
Although friction and other non-conservative...
Travelling Waves
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is water;...
Partial Differential Equations
Wave Parameters
Typical Model Studies

