channel flows have three components of velocity, 1component in flow direction and 2components in spanwise of channel. because of heterogeneity of velocity undulations, in the channel section the vortices are formed that are nominated “secondary current cells”. these cells cause the lateral shear stress in the channel walls and introduce the erosion and scour of the channel walls. heterogeneity ...

The behavior of turbulent open channel flows over permeable surfaces is not well understood. In particular, it is not clear how the surface and the subsurface flow within the permeable bed interact and influence each other. In order to clarify this issue we carried out two sets of experiments, one involving velocity measurements in open channel flows over an impermeable bed composed of a single...

Using lateral intake is a method of floodwater diverting. In arid and semi-arid areas, floodwatercontains a large amount of sediment that will be carried in to the intakes and it causes a reduction inchannel conveyance. Sediment is almost transported into the intake and it is settled in the upstreamside of lateral channel. Sedimentation in this zone reduces the conveyance of lateral channel and...

A numerical model based on the smoothed particle hydrodynamics method is developed to simulate depth-limited turbulent open channel flows over hydraulically rough beds. The 2D Lagrangian form of the Navier-Stokes equations is solved, in which a drag-based formulation is used based on an effective roughness zone near the bed to account for the roughness effect of bed spheres and an improved sub-...

Substantial variations in the particle flux are commonly observed in field measurements on gravel-bed rivers and in laboratory experiments mimicking river behavior on a smaller scale. These fluctuations can be explained by the natural variability of sediment supply and hydraulic conditions. We conducted laboratory experiments of particle transport down a two-dimensional inclined channel, for wh...

Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses ...

In this study, the effect of channel-bed slope and non-prismatic converging channel on discharge coefficient labyrinth weirs is numerically investigated utilizing FLOW-3D model. Numerical simulation results show that modifying weir through both methods improves coefficient. Among selected bed slopes wall, β=4% angle θ=10° yielded highest For a ratio HT/P=0.1, (HT: flow height, P: height) rate f...