A flow resistance in a river changes with development or attenuation of sand waves. Therefore, it is necessary to know how the flow resistance varies with transformation of sand bed, in order to predict the water surface variations. In this study, the numerical model to reproduce the formation processes of dunes was developed. A depth averaged flow model considering the effects of vertical acceleration and a nonequilibrium sediment transport model is combined. Calculated results on the temporal development processes, the shape characteristics of dunes and flow resistance are compared with previous experimental studies.
In curved channels, velocity distribution in the main flow direction is transformed by the secondary currents and the strength of secondary circulation is varied with the transformation of downstream velocity. Therefore, it is necessary to consider the interaction between main and secondary flows. In this study, a depth averaged flow model in curved channels in generalized curvilinear coordinate system is refined, by including this interaction. The model is applied to the experiments by Rozovskii for uniformly curved channel flow and compared with both the experimental and 3-D results.
In the recent flood disaster, the remarkable water level rise in river flows over a short period led to the levee breaching, which caused severe damage in the landside region. Therefore, numerical methods that can predict flood flows and bed deformation around a levee are of great significance for flood mitigation. In this study, a three-dimensional (3D) numerical model of open channel flows in a boundary fitted coordinate system with the density function method is used, and by comparing the hydraulic characteristics of simulation, such as water level and velocity distributions, to the previous experiments of lateral overtopping flows around a side weir in the curved channel, the reliability of the numerical model is validated and threedimensional flow structures around side weir have also been investigated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.