scholarly journals Effects of Water Surface oscillation on Flow Characteristics in Open-channel Flow with Spur Dikes

2001 ◽  
Vol 4 ◽  
pp. 533-540 ◽  
Author(s):  
Terunori Ohmoto ◽  
Ryuichi Hirakawa
Keyword(s):  
Channel Flow ◽  
Water Surface ◽  
Open Channel ◽  
Flow Characteristics ◽  
Open Channel Flow ◽  
Surface Oscillation ◽  
Spur Dikes

Transverse Distribution of the Streamwise Velocity for the Open-channel Flow With Floating Vegetated Islands

2021 ◽  
Author(s):  
Xuecheng Fu ◽  
Feifei Wang ◽  
Mengyang Liu ◽  
Wenxin Huai
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Flow Characteristics ◽  
Open Channel Flow ◽  
Streamwise Velocity ◽  
Transport Efficiency ◽  
Transverse Distribution ◽  
Floating Vegetation ◽  
Shear Turbulence ◽  
Field Disturbance

Abstract Floating vegetation islands (FVIs) have been widely utilized in various river ecological restoration projects due to their ability to purify pollutants. FVIs float at the surface of shallow pools with their roots unanchored in the sediment. Biofilm formed by roots under islands filters nutrients and particles in the water flowing through it. Flow field disturbance will occur and transverse distribution of flow velocity will change due to the existence of FVIs. Transport efficiency of suspended solids, nutrients, and pollutants will also be altered. A modified analytical model that considers effects of boundary friction, drag force of vegetation, transverse shear turbulence, and secondary flow is established to predict transverse variation of depth-averaged streamwise velocity for the open-channel flow with FVIs using Shiono and Knight method. The simulation results with suitable boundary conditions successfully predicted lateral profile of the depth-averaged streamwise velocity compared with the experimental results of symmetrical and unsymmetrical arrangements of FVIs. Hence, the presented model can provide guidance for investigating flow characteristics of rivers with FVIs.

scholarly journals Experimental dataset and numerical simulation of floating bodies transport in open-channel flow

2020 ◽  
Vol 22 (5) ◽  
pp. 1161-1181
Author(s):  
Elisabetta Persi ◽  
Gabriella Petaccia ◽  
Stefano Sibilla ◽  
Pilar Brufau ◽  
José Ignacio García-Palacin
Keyword(s):  
Channel Flow ◽  
Water Surface ◽  
Open Channel ◽  
Numerical Models ◽  
Rectangular Channel ◽  
Open Channel Flow ◽  
Body Motion ◽  
Lagrangian Model ◽  
Floating Body ◽  
Floating Bodies

Abstract Numerical models trying to faithfully represent the movement of floating bodies transport in open-channel flow require experimental data for validation. In order to provide an adequate dataset, flume experiments were carried out to analyse the transport of singular and grouped rigid bodies floating on the water surface. Both cylindrical and spherical samples were employed: they were released in a rectangular channel under steady conditions in one-dimensional (plain channel) and two-dimensional (2D) configurations using one rectangular side obstacle, one smooth side obstacle or two rectangular alternate obstacles. The outcomes of the experiments are the planar displacement and the rotation of the samples, which are related to the flow field in the different configurations. The detailed experimental analysis of the floating body motion provides information for the calibration of numerical models simulating floating bodies transport. This dataset is thus employed for the validation of the Eulerian–Lagrangian model ORSA2D_WT, highlighting its strengths and improvable aspects. Similar applications could be carried out with any 2D model which performs the simulation of discrete elements moving on the water surface.

scholarly journals ON A COEXISTENCE SYSTEM OF FLOW AMD WAVES

1966 ◽  
Vol 1 (10) ◽  
pp. 25
Author(s):  
Junzaburo Matsunashi
Keyword(s):  
Channel Flow ◽  
Periodic Motion ◽  
Water Surface ◽  
Open Channel ◽  
Forced Oscillation ◽  
Fixed Bed ◽  
Open Channel Flow ◽  
Experimental Fact ◽  
Incoming Wave ◽  
Mechanical Effects

It is a well known experimental fact that the undulation such as sand-ripples or antidunes are formed on the bed surface composed of fine sand, corresponding to the flow characteristics of open channel flow.O In this case, as the mechanical effects of the bed undulationes stated above, a kind of periodic motion is superposed on the flow, and accordingly the water surface undulates periodically. On the other hand, the mechanical effects of this surface undulationes are surperposed on these undulating bed surfaces as another kind of periodic motion. The wave generated in open sea propagates upstream through an estuary. Accordingly the incoming wave is superposed on the flow stated above as a forced oscillation. Both of these phenomena are in the coexistence system of flow and waves in the open channel flow. In this paper, as the first step to study the subjects stated above, the author treats the problem of the coexistence system in the case when the forced oscillation of water surface is superposed on the open channel flow with fixed bed, and analyzes theoretically and experimentally the mechanical properties of the reciprocal action between flow and waves.

ANALYSIS OF OPEN-CHANNEL FLOW WITH A SIDE CAVITY ZONE BY LES TAKING INTO ACCOUNT OF WATER SURFACE VARIATION

2007 ◽  
Vol 51 ◽  
pp. 655-660
Author(s):  
Ken KADOTANI ◽  
Ichiro FUJITA ◽  
Ryota TSUBAKI ◽  
Takayuki MATSUBARA
Keyword(s):  
Channel Flow ◽  
Water Surface ◽  
Open Channel ◽  
Open Channel Flow ◽  
Surface Variation
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