ABSTRACT
The present study focuses on capturing small-scale parameters by implementing temporally and spatially resolved Laser-Doppler and Particle-Imaging Velocimetry in the presence and absence of coarse sediment transport. An open-channel flow was simulated using a hydraulic flume with a built-in fixed bed roughness (a casting of a gravel bed). Experiments presented were conducted under steady state conditions with and without sediment feeding. The measured data provide information about the shear stress and turbulence intensity distribution in the profile and allow a unique direct comparison between the cases with and without moving sediment as well as to determine the large scale based parameters related to sediment transport. Reduced flow resistance was observed during bed-load transport. Further, a comparison of the PIV and LDA results is inherently provided.
