title: Dynamical models for sand ripples beneath surface waves.
abstract: We introduce order parameter models for describing the dynamics of sand ripple patterns under oscillatory flow. A crucial ingredient of these models is the mass transport between adjacent ripples, which we obtain from detailed numerical simulations for a range of ripple sizes. Using this mass transport function, our models predict the existence of a stable band of wave numbers limited by secondary instabilities. Small ripples coarsen in our models and this process leads to a sharply selected final wave number, in agreement with experimental observations.
authors: Center for Chaos and Turbulence Studies, Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen Ø, Denmark.
authors: K H
authors: KH
authors: Andersen
authors: M L
authors: ML
authors: Chabanol
authors: M
authors: M
authors: van Hecke