scholarly journals Experimental Study of Submerged Vanes in Intakes under Sediment Feeding Conditions

2018 ◽  
Vol 40 ◽  
pp. 03016
Author(s):  
Aslı Bor Türkben
Keyword(s):  
Water Intake ◽  
River Flow ◽  
Flow Direction ◽  
Main Channel ◽  
Bed Topography ◽  
Before And After ◽  
Submerged Vane ◽  
Solid Discharge ◽  
Submerged Vanes ◽  
Intake Structure

Sediment is transported along the river flow and deposited in the mouth of the intake structure over time and reducing the water intake capacity. Nowadays, many water intake structures lose their function and are closed to operation. To deal with this problem, recently, submerged vane application has offered a practical and economical solution. The aim of this study was to evaluate the efficiency of three vane installations under sediment feeding conditions by comparing the bed topography before and after vanes were installed. For that purpose, experiments were carried out in a laboratory channel running for 90-degree intake angle. Three vanes were installed in one column at near the intake entrance. The vanes dimensions were equal to; 3cm height, 12cm long, 10 mm thick, and aligned with α = 20° angle to flow direction. The tests were run until equilibrium was reached, i.e. when the outgoing solid discharge was equal or larger than 90% of the incoming. Once the bed topography remained stable, bed and water level surfaces were measured. tests were carried out by feeding sediment from upstream of the main channel.

Test Studyed of Yangjiawan Grand Bridge in the Project of Lanyu Railway by Movable Bed Model

2012 ◽  
Vol 204-208 ◽  
pp. 2070-2073
Author(s):  
Wen She He ◽  
Long Yuan ◽  
Shuang Mei Chang ◽  
Jing Jing Feng ◽  
Liang Ming Wang
Keyword(s):  
Flood Control ◽  
Yellow River ◽  
Flow Direction ◽  
Bridge Site ◽  
Design Data ◽  
Lanzhou City ◽  
Bed Topography ◽  
River Bed ◽  
Before And After ◽  
Movable Bed

Yangjiawan grand bridge is located in Lanzhou section of the Yellow River. In order to study the change laws near the bridge site of flow direction, velocity distribution, water surface slope, backwater area, river bed topography change and the effect of flood control on Lanzhou city after the bridge-built when the river gets through the average discharge, 20-year discharge, and 100-year discharge before and after the bridge-built. Based on the similar principle of model, the river near the bridge site was simulated by the hydraulic model experiment of movable bed. The result of experiment showed that the design data adopted in bridge project of Yangjiawan grand bridge were reasonable and fulfilled the requirements of city flood control. It was also suggested to excavate and dredge river near the piers of 6# ~11# and strengthen embankment near the riverbank and protection of constructions after the bridge-built.

Model testing of submerged vanes in strongly curved narrow channel bends

2002 ◽  
Vol 29 (1) ◽  
pp. 37-49 ◽  
Author(s):  
A Voisin ◽  
R D Townsend
Keyword(s):  
Flow Direction ◽  
Narrow Channel ◽  
Model Testing ◽  
Bend Angle ◽  
Secondary Current ◽  
Channel Bend ◽  
Outer Bank ◽  
Submerged Vane ◽  
Bank Stabilization ◽  
Submerged Vanes

This paper reports on a laboratory study that examines the effectiveness of submerged vanes for the control of erosion in strongly curved narrow channel bends. All previous researches on submerged vanes were performed in either straight or weakly curved channels that were hydraulically "wide". Submerged vanes are thin rectangular-shaped low-profile foils, typically set at small angles to the main current and arranged in either single or multiple parallel arrays in the longitudinal direction. When installed in a channel bend they induce a helicoidal vortex that interacts with and weakens the centrifugally induced secondary current. The latter effect leads to reduced local erosion near the bend's outer bank. Physical model testing was performed to determine the effects of several parameters affecting submerged vane performance, including submerged vane height H, length L, angle to main flow direction α, vane streamwise spacing δs, vane transverse spacing from outer bank δn, and bend angle φ. Submerged vanes effectively stabilize channel bend erosion by reducing the scour depth at the outer bank, generating positive transverse bed slope at the outer bank, and by reducing the net sediment loss through the channel. In general, an increase in vane height tends to shift the thalweg away from the outer bank; an increase in vane length tends to reduce the general erosion through the channel.Key words: submerged vanes, riverbank stabilization, bottom vanes, narrow channels, bank protection, bank stabilization, channel bends.

Downstream Migration of Recently Transformed Sea Lampreys Before and After Treatment of a Lake Michigan Tributary with a Lampricide

1972 ◽  
Vol 29 (8) ◽  
pp. 1237-1240 ◽  
Author(s):  
John W. Hodges
Keyword(s):  
Water Intake ◽  
Lake Michigan ◽  
Average Length ◽  
Petromyzon Marinus ◽  
Downstream Migration ◽  
Chemical Plant ◽  
Sea Lampreys ◽  
Before And After ◽  
Intake Structure

After the Pere Marquette River was treated with a lampricide in May 1964, the number of recently transformed sea lampreys (Petromyzon marinus) collected in the water-intake structure of a chemical plant near the mouth of the stream dropped 99.5%, from 13,913 (average for 1962–63 and 1963–64) to 76 (average for the next four migration seasons). Average length of the lampreys caught increased markedly after the treatment. In five of the six migration seasons, the catch of downstream migrants was higher in the fall than in the spring.

scholarly journals Sediment Control At The Lateral Channel Inlet

2022 ◽  
Vol 961 (1) ◽  
pp. 012096
Author(s):  
Rana A. Al-Zubaidy ◽  
Rawaa H. Ismaeil
Keyword(s):  
Research Work ◽  
Sediment Delivery ◽  
Sediment Control ◽  
Flow Discharge ◽  
Lateral Channel ◽  
Submerged Vane ◽  
Submerged Vanes ◽  
Intake Structure ◽  
Work Done ◽  
Engineering Projects

Abstract Environmental and civil engineering projects frequently employ the open channel side intake structure. However, the commonest among the issues faced in most of the lateral intakes include sedimentation and sediment delivery. This involves several problems namely, decreased flow discharge capacity in the irrigation canals and the threat of water blockage during times of low water flow. Besides, this problem with the sediment either lowers the performance levels or causes failure of the facilities that this sub-channel serves. Hence, the engineers focused on designing an intake with the features of high flow discharge and low sediment delivery. This paper attempts to review and summarize the literature relevant to the branching channel flow and submerged vane technique to minimize the sediment-related issues. The present review highlights that most of the earlier research work done dealt with the characteristics of the flow in a right-angle branch channel possessing rigid confines. Also, more investigations are required regarding the implications of the submerged vanes. Besides, no comprehensive studies are available on the saddle point itself, and a high percentage of the studies have been part of earlier investigations that had focused on only briefly outlining this subject.

scholarly journals Hydraulic Evaluation of the Levee System Evolution on the Kurobe Alluvial Fan in the 18th and 19th Centuries

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4406
Author(s):  
Tadaharu Ishikawa ◽  
Hiroshi Senoo
Keyword(s):  
Channel Capacity ◽  
Flood Control ◽  
River Flow ◽  
Global Climate ◽  
Flow Simulation ◽  
Japan Sea ◽  
Main Channel ◽  
Alluvial Fan ◽  
Flood Peak ◽  
Levee System

The development process and flood control effects of the open-levee system, which was constructed from the mid-18th to the mid-19th centuries, on the Kurobe Alluvial Fan—a large alluvial fan located on the Japan Sea Coast of Japan’s main island—was evaluated using numerical flow simulation. The topography for the numerical simulation was determined from an old pictorial map in the 18th century and various maps after the 19th century, and the return period of the flood hydrograph was determined to be 10 years judging from the level of civil engineering of those days. The numerical results suggested the followings: The levees at the first stage were made to block the dominant divergent streams to gather the river flows together efficiently; by the completed open-levee system, excess river flow over the main channel capacity was discharged through upstream levee openings to old stream courses which were used as temporary floodways, and after the flood peak, a part of the flooded water returned to the main channel through the downstream levee openings. It is considered that the ideas of civil engineers of those days to control the floods exceeding river channel capacity, embodied in their levee arrangement, will give us hints on how to control the extraordinary floods that we should face in the near future when the scale of storms will increase due to the global climate change.

Effects of Rib Arrangements on Pressure Drop and Heat Transfer in a Rib-Roughened Channel With a Sharp 180 deg Turn

1997 ◽  
Vol 119 (3) ◽  
pp. 610-616 ◽  
Author(s):  
S. Mochizuki ◽  
A. Murata ◽  
M. Fukunaga
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Secondary Flow ◽  
Flow Direction ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Diameter Ratio ◽  
Equivalent Diameter ◽  
Before And After ◽  
Rib Roughened

The objective of this study was to investigate, through experiments, the combined effects of a sharp 180 deg turn and rib patterns on the pressure drop performance and distributions of the local heat transfer coefficient in an entire two-pass rib-roughened channel with a 180 deg turn. The rib pitch-to-equivalent diameter ratio P/de was 1.0, the rib-height-to-equivalent diameter ratio e/de was 0.09, and the rib angle relative to the main flow direction was varied from 30 ∼ 90 deg with an interval of 15 deg. Experiments were conducted for Reynolds numbers in the range 4000 ∼ 30,000. It was disclosed that, due to the interactions between the bend-induced secondary flow and the rib-induced secondary flow, the combination of rib patterns in the channel before and after the turn causes considerable differences in the pressure drop and heat transfer performance of the entire channel.

Effect of Western the Fourth Phase Project on Hydrodynamic Condition for Shijiu Port in Rizhao

2012 ◽  
Vol 204-208 ◽  
pp. 2369-2373
Author(s):  
Jia Rui Li ◽  
Die Shuang Yu
Keyword(s):  
Channel Flow ◽  
Water Area ◽  
Main Channel ◽  
Hydrodynamic Condition ◽  
Port Area ◽  
Before And After ◽  
Project Construction ◽  
Sheltering Effect ◽  
Sea Area ◽  
Flow Velocities

A hydrodynamic model of Shijiu port and its adjacent sea area was built to discuss the effect of western the fourth phase project on the flow condition for Shijiu port area. The results show that with the sheltering effect of breakwaters, flow velocity values are small inside the breakwaters. The water area near the project is affected more by the project construction. The flow velocities there are faster after the project construction than before it. In the main channel, flow velocities outside the breakwaters almost have no difference before and after the project. The project construction doesn’t have significant effect on it.

Assessing the Ensemble Spread–Error Relationship

2014 ◽  
Vol 142 (3) ◽  
pp. 1125-1142 ◽  
Author(s):  
T. M. Hopson
Keyword(s):  
River Flow ◽  
Forecast Error ◽  
Ensemble Prediction ◽  
Ensemble Prediction System ◽  
Before And After ◽  
Variable Dispersion ◽  
Strong Motivation ◽  
Error Correlation ◽  
The Stability ◽  
The Cost

Abstract The potential ability of an ensemble prediction system (EPS) to represent its own varying forecast error provides strong motivation to produce an EPS over a less expensive deterministic forecast. Traditionally, this ability has been assessed by correlating the realized forecast error with the ensemble's dispersion. This paper revisits the limitations of the skill–spread correlation, but uses aspects of the correlation to introduce two metrics to assess an EPS's capacity to provide a reliable likelihood of its own error. Using a perfect EPS, skill–spread correlation is shown to be limited by its dependence on how “skill” and “spread” are defined and, perhaps most fatally, by its inability to distill the skill–spread reliability from the stability properties of the physical system being modeled. Building from this, it is argued there are two aspects of an ensemble's dispersion that should be assessed. First, is there enough variability in the dispersion to justify the expense of the EPS? The factor that controls the theoretical upper limit of the spread–error correlation can be useful in diagnosing this. Second, does the variable dispersion of an ensemble relate to a variable expectation of the forecast error? Representing the spread–error correlation in relation to its theoretical limit can provide a simple diagnostic of this attribute. A context for these concepts is provided by assessing two operational ensembles: western U.S. temperature forecasts and Brahmaputra River flow before and after postprocessing. It is shown that “skill–spread” reliability can be improved by postprocessing to that of a perfect EPS, but at the cost of the potential information content of the EPS's variable dispersion.

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