Migrating Pools in Yangtze River

The severity and location of bank erosion and bed scour changes with the variation of water level. At low flows, the main flow thread tends to follow the concave bank. As the discharge increases, the flow tends to cut across the convex bar, to concentrate against concave bank only downstream the bend apex. This change of flow pattern is...

Ontgrondingen rond pijpleidingen op slibhoudend zand

Het transport en de erosie van mengsels van zand met 10 tot 30% slib is onderzocht. Zowel het transport in de algemene zin als de erosie rond pijpleidingen is in beschouwing genomen. De transport karakteristieken van zand waar zich slib in bevindt verschillen van die van zuiver zand. De critische bodemschuifspanning neemt toe voor een toenemend...

Users manual: DUCT-SUSTRA

Some information is given how to use the scour model DUCT-SUSTRA (Hoffmans, 1991). The scour model predicts the morphological process in scour holes or trenches and consists of two separated sub-models: a flow model DUCT and a morphological model SUSTRA. The flow model is based on the equation of continuity and the momentum equations for...

Concentration and flow velocity measurements in a local scour hole

Flume experiments with small Froude numbers have been carried out to study the concentration field in a local scour hole without supply of sediment load. The measuring results will be used to check the validity of the two dimensional scour model DUCT-SUSTRA. The objective of the experiments was to measure the concentrations at various locations...

Scouring of a sand bed in front of a vertical breakwater

The scouring profile of a bottom consisting of movable material as this is formed in front of a vertical wall under influence of the standing wave against this wall is discussed. The form of this profile is different for coarse and fine material. In the case of fine material this material is moved in suspension by the mass transport currents...