secondary flow investigation could be regarded as an important issue in open channel flow, in spite of its lower quantity compared to the base flow in the water course. it should be given special consideration because of the influence on some hydraulic factors in open channel, specifically in compound channels. in compound channels' due to the difference in the flow velocity of the main ch...

the developing turbulent flow in an open channel is a complex three-dimensional flow influenced by the secondary currents and free surface effects and is, therefore, not amenable to analytical solution. this paper aims to study the impact of three key hydraulic parameters (relative roughness, the froude number and the reynolds number) on the establishment length using computational fluid dynami...

Several rigorous turbulent models have been developed in the past years and it can be seen that more research is needed to reach a better understanding of their generality and precision by verifying their applications for distinct hydraulic phenomena; under certain assumptions. This survey evaluates the performance of Standard k-ε, Realizable k-ε, RNG k-ε, k-ω and RSM models in predicting flow ...

open-channel junctions have a broad application in civil and environmental engineering. formation of a low-pressure zone with recirculating flow (high sedimentation) accompanied by a high-velocity zone (high erosion) is the most characteristic feature of flow in junctions. a large number of researches have been performed to study the complexity of the flow in junctions in open-channel flows. in...

water distribution method based on the type of water conduits can be divided into two groups, namely, open and closed systems, while on the basis of the energy of the water flow, the two groups are gravity flow and pressurized flow. open channel type conveyance and distribution is achieved by gravity and includes channels made by embankment construction, excavation, or construction of prefabric...

This paper applies an evolutionary algorithm, the particle swarm optimization (PSO), to design the optimum open channel section. Depth, channel side slope and bottom width are considered as the variables for rectangular, triangular and trapezoidal channels, respectively. The objective function is minimizing the construction cost of the channel section. MATLAB software is used for programming an...

Water flow in open channels is always subject to the resistance to flow and energy dissipation. For design purposes, one of the needed variables is the hydraulic resistance coefficient. For this mean, the influence of cross-sectional shape together with secondary flow cells and lateral distribution of true boundary shear stress have not yet been fully explored. This paper surveys the number of ...

In the Manning equation the hydraulic radius can be defined as the cross-section dimension of the shape. In pipe flow the bed shear stress is assumed to be uniformly distributed along the wetted perimeter which cannot be true in open channel flow. Hence, three approximation of the true boundary shear-stress distribution are examined and more practical conveyance depth or resistance radius formu...