Hydraulic jump in a sloped triangular channel

2009 ◽  
Vol 36 (4) ◽  
pp. 655-658 ◽  
Author(s):  
Mahmoud Debabeche ◽  
Sonia Cherhabil ◽  
Amin Hafnaoui ◽  
Bachir Achour
Keyword(s):  
Froude Number ◽  
Experimental Analysis ◽  
Hydraulic Jump ◽  
Central Angle ◽  
Theoretical Relation ◽  
Triangular Channel ◽  
Depth Ratio ◽  
Channel Slope ◽  
Sequent Depth

The hydraulic jump in a sloped triangular channel of 90° central angle is theoretically and experimentally examined. The study aims to determine the effect of the channel's slope on the sequent depth ratio of the jump. A theoretical relation is proposed for the inflow Froude number as function of the sequent depth ratio and the channel slope. An experimental analysis is also proposed to find a better formulation of the obtained relation. For this motive, six positive slopes are tested. The relations obtained are recommended for designing irrigation ditches.

scholarly journals Experimental study and modeling of hydraulic jump for a suddenly expanding stilling basin using different hybrid algorithms

2021 ◽  
Author(s):  
Enes Gul ◽  
O. Faruk Dursun ◽  
Abdolmajid Mohammadian
Keyword(s):  
Experimental Study ◽  
Hydraulic Jump ◽  
Imperialist Competitive Algorithm ◽  
Expansion Ratio ◽  
Stilling Basin ◽  
Jump Length ◽  
Depth Ratio ◽  
Input Variables ◽  
Sequent Depth ◽  
Learning Machine

Abstract Hydraulic jump is a highly important phenomenon for dissipation of energy. This event, which involves flow regime change, can occur in many different types of stilling basins. In this study, hydraulic jump characteristics such as relative jump length and sequent depth ratio occurring in a suddenly expanding stilling basin were estimated using hybrid Extreme Learning Machine (ELM). To hybridize ELM, Imperialist Competitive Algorithm (ICA), Firefly Algorithm (FA) and Particle Swarm Optimization (PSO) metaheuristic algorithms were implemented. In addition, six different models were established to determine effective dimensionless (relative) input variables. A new dataset was constructed by adding the data obtained from the experimental study in the present research to the data obtained from the literature. The performance of each model was evaluated using k-fold cross validation. Results showed that ICA hybridization slightly outperformed FA and PSO methods. Considering relative input parameters, Froude number (Fr), expansion ratio (B) and relative sill height (S), and effective input combinations were Fr – B– S and Fr – B for the prediction of the sequent depth ratio (Y) and relative hydraulic jump length (Lj/h1), respectively.

scholarly journals Uncertainty analyses regarding evaluating effective parameters on the hydraulic jump characteristics of different shape channels

2021 ◽  
Author(s):  
Kiyoumars Roushangar ◽  
Farzin Homayounfar ◽  
Roghayeh Ghasempour
Keyword(s):  
Hydraulic Jump ◽  
Gaussian Process Regression ◽  
Support Vector ◽  
Hydraulic Jumps ◽  
Empirical Equations ◽  
Effective Parameters ◽  
Jump Length ◽  
Depth Ratio ◽  
Sequent Depth ◽  
Semi Empirical

Abstract The hydraulic jump phenomenon is a beneficial tool in open channels for dissipating the extra energy of the flow. The sequent depth ratio and hydraulic jump length critically contribute to designing hydraulic structures. In this research, the capability of Support Vector Machine (SVM) and Gaussian Process Regression (GPR) as kernel-based approaches was evaluated to estimate the features of submerged and free hydraulic jumps in channels with rough elements and various shapes, followed by comparing the findings of GPR and SVM models and the semi-empirical equations. The results represented the effect of the geometry (i.e., steps and roughness elements) of the applied appurtenances on hydraulic jump features in channels with appurtenances. Moreover, the findings confirmed the significance of the upstream Froude number in the sequent depth ratio estimating in submerged and free hydraulic jumps. In addition, the immersion was the highest contributing variable regarding the submerged jump length on sloped smooth bed and horizontal channels. Based on the comparisons among kernel-based approaches and the semi-empirical equations, kernel-based models showed better performance than these equations. Finally, an uncertainty analysis was conducted to assess the dependability of the best applied model. The results revealed that the GRP model possesses an acceptable level of uncertainty in the modeling process.

scholarly journals Estimation of hydraulic jump characteristics of channels with sudden diverging side walls via SVM

2017 ◽  
Vol 76 (7) ◽  
pp. 1614-1628 ◽  
Author(s):  
Kiyoumars Roushangar ◽  
Reyhaneh Valizadeh ◽  
Roghayeh Ghasempour
Keyword(s):  
Froude Number ◽  
Hydraulic Jump ◽  
Relative Energy ◽  
Expansion Ratio ◽  
Superior Performance ◽  
Support Vector ◽  
Great Performance ◽  
Stilling Basins ◽  
Side Walls ◽  
Sequent Depth

Sudden diverging channels are one of the energy dissipaters which can dissipate most of the kinetic energy of the flow through a hydraulic jump. An accurate prediction of hydraulic jump characteristics is an important step in designing hydraulic structures. This paper focuses on the capability of the support vector machine (SVM) as a meta-model approach for predicting hydraulic jump characteristics in different sudden diverging stilling basins (i.e. basins with and without appurtenances). In this regard, different models were developed and tested using 1,018 experimental data. The obtained results proved the capability of the SVM technique in predicting hydraulic jump characteristics and it was found that the developed models for a channel with a central block performed more successfully than models for channels without appurtenances or with a negative step. The superior performance for the length of hydraulic jump was obtained for the model with parameters F1 (Froude number) and (h2—h1)/h1 (h1 and h2 are sequent depth of upstream and downstream respectively). Concerning the relative energy dissipation and sequent depth ratio, the model with parameters F1 and h1/B (B is expansion ratio) led to the best results. According to the outcome of sensitivity analysis, Froude number had the most significant effect on the modeling. Also comparison between SVM and empirical equations indicated the great performance of the SVM.

scholarly journals The performance of hydraulic jump over rough bed stilling basin consisting of cubic-shape elements

2018 ◽  
Vol 162 ◽  
pp. 03001
Author(s):  
Jaafar Maatooq ◽  
Enass Taleb
Keyword(s):  
Hydraulic Jump ◽  
Relative Energy ◽  
Stilling Basin ◽  
Depth Ratio ◽  
Roughness Elements ◽  
Rough Bed ◽  
Specific Configuration ◽  
Experimental Works ◽  
Sequent Depth ◽  
Group Configuration

Three groups of cubic roughness elements non-protruding to the flow were fixed with a specific configuration at the downstream of a stream lined lib sluice gate. The aim was to test the performance of the hydraulic jump under using such elements as appurtenances of stilling basin. The experimental works has been conducting to test; four different intensities, I=8%, 10%, 12% and 16%; three width to height ratios, We/he=0.75, 1.5 and 2; and three length to height ratios, Le/he=0.75, 2 and 4, of cubic elements made from waterproof stiff rubber. The test was performed under the incoming Froude number; F1 ranged between 2.7 to 9. After analysing the experimental data one from the second group configuration gives a higher reduction of sequent depth ratio, y2/y1 as compared with the depth ratio of the un-forced hydraulic jump which calculated by Belanger equation, this decreases arrived 20%. Also greater relative energy has been dissipated, and the gain in dissipation (%GED) ranged between 10.8-22.3%.

scholarly journals The Effect of Infill Steel Plate Thickness on the Cycle Behavior of Steel Plate Shear Walls

2018 ◽  
Vol 11 (3) ◽  
pp. 7-13 ◽  
Author(s):  
Ali Sadik Abbas
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Steel Plate ◽  
Plate Thickness ◽  
Shear Walls ◽  
Depth Ratio ◽  
Stilling Basins ◽  
Bed Slope ◽  
Sequent Depth ◽  
Energy Dissipation Ratio

The effect of changing in the bed slope of stilling basins produces changing in characteristics of the hydraulic jump such as sequent depth ratio, length of jump ratio, length of the roller and energy dissipation ratio, consequently the dimensions of stilling basin changed. In this study hydraulic jump investigated on smooth bed (without any appurtenances) for three adverse slopes (- 0.03, - 0.045, - 0.06) in addition to horizontal bed slope, the experiments were applied for the range of Froude number (Fr1) between 3.99 and 7.48. The results showed a reduction about10 % in sequent depth ratio, 22.1 % in length of jump ratio, 20.51 % in length of roller ratio and 13.87% in the energy dissipation ratio when the adverse slope (- 0.06) used instead of horizontal bed for the same Froude numbers. Empirical equations for the sequent depth ratio, length of roller ratio and the energy dissipation ratio were obtained from the experimental data

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