Author(s): Takahisa Gotoh

Linked Author(s):

Keywords: Non-equilibrium flow and sediment movement; Quasi-3D flow analysis; Turbulent intensity; Bed load layer; Suspended sediment;

Abstract: Large amounts of suspended sediments are transported by flood flows in sandy rivers. The suspended sediment concentration is generally calculated by the three-dimensional advection diffusion equation assuming that the flow and sediment transport near the bed are in equilibrium conditions. In this study, the quasi-3D flood flow and bed variation calculation model is developed by considering non-equilibrium two-phase motion of flow and sediment near beds. The developed model is applied to the experiment of local scouring around a cylinder by Fukuoka et.al. (1997). The calculation model is able to explain the bed scouring in front and side of the cylinder compared with the conventional model which the flow and sediment transport is in equilibrium conditions. It is examined that how the thickness of the bed load layer influences the estimation of flow and bed variation.

DOI: https://doi.org/10.3850/38WC092019-0706

Year: 2019