Transport of lightweight polystyrene granulates on transverse-sloped beds

Required knowledge: River flow and morphology (HWM30306)

Lightweight polystyrene granulates are often used in laboratories to perform alluvial physical scale-models. The low density of the granulates allows to properly scale sediment mobility, through the Shields parameter, and therefore properly reproduce morphological changes induced by bed-load transport. Despite the proper scaling of the Shield parameter, several other sediment transport processes might be improperly scaled, including transverse bed-slope effects.

Bed levelling experiments are a classic way to study the effect of a transverse sloping bed on the transport of sediment particles in alluvial channels. Due to gravity, transverse slopes will steer sediment transport sidewards, eventually flattening the bed until it becomes horizontal. The rate at which this happens is characteristic for the sediment and the intensity of the transverse slope.

To investigate whether transverse slope effects can be properly reproduced using lightweight polystyrene granulates, you will perform a series of bed-levelling experiments in the Kraijenhoff van de Leur laboratory for water and sediment dynamics. You will collect measurements on the bed level development, water level and flow velocity patterns. Possibly, numerical modelling will aid the experiments.