Laboratory experiments will be conducted to measure the mean flow and turbulence over fixed concrete low and intermediate-angle estuarine bedforms with the use of an Acoustic-Doppler Velocimeter (ADV). Three sets of experiments are planned with modelled shapes resembling that of the estuarine dunes observed in the Weser Estuary, Germany. Furthermore, measurements with reversed flow direction will also be carried out for each experimental case. Mean flow and turbulence structures will be measured through the two component instantaneous velocity profiles. Specifically, horizontal and vertical velocities will be used to define the (intermittent) flow separation zone, the turbulent kinetic energy will be used to define the turbulent wake structure, and the vertical gradient of the horizontal velocity to define the region of shear layer. The results from this study can be used to characterise in detail the flow dynamics over low-angle estuarine bedforms.
