Antidune
= Antidune
An antidune is a bedform associated with supercritical free-surface flow, in which bed and surface undulations are approximately in phase. In the elementary erodible-bed model with suspended sediment, an unstable branch can migrate upstream. Its growth and migration depend on the hydraulic and sediment-response parameters; the <high-wavenumber antidune dispersion> calculation makes the required supercritical regime explicit.