Abstract
The necessity to understand and predict flows that carry large suspended sediment and wash loads has become acute in the Shirakawa River Basin where significant erosion and siltation associated with hyperconcentrated flood give rise to many river problems. Mud flows, debris flows or slurries, made up of a large amount of clay and/or silt particles suspended in water, often show non-Newtonian properties but remain poorly understood concerning the impacts of their rheological properties on fully developed turbulent structure.
In this paper, we experimentally investigated resistance and energy budget of hyper-concentrated sediment laden-flow in an open channel with two-dimensional square ribs by using Particle Image Velocimetry(PIV). The results showed that rheological properties significantly diminished energy transfer between mean flow andturbulence by flow fluctuations in cases where the volumetric sediment concentration CV is lower than 8.5%and augmented distinctly the dissipation of mean flow energy by viscosity when CVis higher than 8.5%. incomparison with the clear water flow.
