scholarly journals Using side flow jets as a scour countermeasure downstream of a sluice gate

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohamed S. Abdelmoaty ◽  
Mahmoud Zayed
Keyword(s):  
Energy Dissipation ◽  
Local Scour ◽  
Sluice Gate ◽  
Remarkable Effect ◽  
Scour Hole ◽  
A New Technique ◽  
Scour Hole Dimensions ◽  
The Stability ◽  
Hole Dimensions ◽  
Side Flow

Abstract Background Local scour is one of the main problems affecting the stability and operation of control hydraulic structures. Many techniques were used to control the resulting scour. In the recent study, a new technique was used to control local scour downstream single-gate hydraulic regulator by using side flow jets. This study aimed to demonstrate the effect of side jets at different angles on the local scour parameters (depth, length, and volume) and energy dissipation in the downstream hydraulic regulator. Results A physical model was used to represent the open channel, regulator, and the side jets with different angles. Five flow discharges, four jet angles, and three gate openings were applied through the experiment. The experiment results showed that the presence of side jets had a remarkable effect on the parameters of the local scour hole and energy dissipation. They dissipated more energy of hydraulic jump than in the absence of jets, and consequently, scour hole dimensions were significantly reduced. Regression analysis was used to deduce equations that can predict the development of local scour downstream sluice gate considering the inclination angle of side flow jets under different flow conditions. Conclusions Side flow jets can be used as scour reducer techniques with the advantages of eliminating the jet clog produced from sediments and suspended solids.

scholarly journals The effects of splitters on the downstream scour hole of overflow spillways: application of support vector regression

2021 ◽  
Author(s):  
Mohammad Ehsan Asadi ◽  
Seyed Taghi Omid Naeeni ◽  
Reza Kerachian
Keyword(s):  
Support Vector Regression ◽  
Experimental Models ◽  
Data Driven ◽  
Support Vector ◽  
Method Performance ◽  
Statistical Measures ◽  
Proposed Model ◽  
Scour Hole ◽  
Scour Hole Dimensions ◽  
Hole Dimensions

Abstract One of the most effective ways to reduce the water jet erosion power during dam overflow is to use splitters on the lower side of spillway. The dimensions of scouring holes and their location in the dam basin should be accurately determined. Experimental models and data driven techniques can be effectively used for estimating the dimensions of scouring holes. The focus of this paper is evaluating the effects of splitters on the downstream scour hole of overflow spillways and providing an optimized splitter configuration. The Support Vector Regression (SVR) method performance in predicting the scour hole dimensions and its location downstream of the dam has been examined using 116 experimental data. In order to evaluate the efficiency of the proposed model, we used different statistical measures. The results show that the presence of splitters decreases the slope of downstream scouring in all situations. It is also shown that the SVR method can accurately estimate the dimensions of the scour hole and its location.

scholarly journals The relationship between the coefficient of discharge and the scour hole depth generated due to the combined flow over weir and below gates

2018 ◽  
Vol 162 ◽  
pp. 03010
Author(s):  
Saleh Khassaf ◽  
Hassan Omran ◽  
Fadhel Abdulabbas
Keyword(s):  
Median Size ◽  
Two Samples ◽  
Scour Hole ◽  
Combined Structure ◽  
Scour Hole Dimensions ◽  
Coefficient Of Discharge ◽  
Size Of Particles ◽  
Hole Dimensions ◽  
The Relationship ◽  
Laboratory Models

In this research, a study was conducted experimentally to investigate the scour hole dimensions downstream the combined structures which consist of weir and gate due to the effect of the coefficient of discharge (Cd) due to flow above the compound weir to the flow under the gate. Fifteen models have been designed, and every model is formed from composite weir consisting of two geometric shapes with rectangular gate of constant dimensions. In this study, the experiment was conducted in a laboratory channel was constructed from blocks and concrete with length of 18 m, 1 m width and depth of 1 m, where the laboratory models were installed after 7 m from the main gate which controlled the passage of water from the main reservoir into the flume. At the beginning, the calibration process was conducted to identify the actual discharge values that pass in the flume, and then seventy-five experiments were conducted in order to derive the formulae for investigating the non-dimensional depth (SD/d50) and non-dimensional length (SL/d50) of the scour hole due to the effect of (Cd). The bed of the flume was spread with sand layer of 30 cm thick for a distance of 4 m downstream combined structure. Two samples of sand were used in the experiments with different median size of particles (d50), the first of 0.7 mm and the second of 1 mm. Using the Excel program 2017, Six polynomial relationships were derived to calculate the dimensionless scour depth (SD/d50) in terms of the coefficient of discharge (Cd), where the resultant coefficients of determinations (R2) from these relationships were high.

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