Abstract
This study describes experimental investigation on particle-fluid interaction and turbulence modulation in suspended sediment-laden open-channel flow over sand dunes by using a discriminator particle tracking velocimetory (D-PTV), which was developed by Nezu and Azuma (JHE, ASCE, 2004). In this D-PTV system, sediment particles and fluid tracers are discriminated accurately by their occupied particle size, and thus, the particle velocity Up and fluid velocity Uf can be measured simultaneously.
As the results, significant interactions between sediment particles and water were observed in the separation bubble (a reverse flow occurs) and near the rettachment point behind dune. Furthermore, it was revealed that the turbulence intensity of fluid became smaller in sediment-laden flow than in clear water flow without sediment.
