Author(s): M. W. Gallagher
Keywords: No Keywords
Abstract: Research on the structure of turbulent boundary layers over smooth surfaces has revealed the existence of a number of organised motions such as the hairpin vortex. The formation of such structures is thought to be dependent on the existence of a viscous sublayer, which exists on a smooth surface, but is absent in natural rivers due to bed roughness. A series of flume experiments have therefore been conducted to investigate whether similar vortical structures occur over mixed grain sized sediment surface, and evidence is presented which supports the existence of hairpin vortices over beds which display grain roughness and particle movement.