scholarly journals The impact of deepening the stilling basin on the characteristics of hydraulic jump

2018 ◽  
Keyword(s):  
Hydraulic Jump ◽  
Stilling Basin ◽  
The Impact

scholarly journals Longitudinal distribution of extreme pressures in a hydraulic jump downstream of a stepped spillway

RBRH ◽  
2017 ◽  
Vol 22 (0) ◽  
Author(s):  
Carolina Kuhn Novakoski ◽  
Roberta Ferrão Hampe ◽  
Eliane Conterato ◽  
Marcelo Giulian Marques ◽  
Eder Daniel Teixeira
Keyword(s):  
High Pressure ◽  
Hydraulic Jump ◽  
Pressure Fluctuations ◽  
Longitudinal Distribution ◽  
Stepped Spillway ◽  
Pressure Data ◽  
Stilling Basin ◽  
Considerable Portion ◽  
Dissipation Structure ◽  
The Impact

ABSTRACT The overflow system of a dam safely controls the water level of a reservoir. The design of these structures should predict the damage caused by the action of the turbulent flow to which they are subject to. The combination formed by a stepped spillway followed by a stilling basin promotes a considerable portion of the energy dissipation in the actual chute of the stepped spillway but it is not sufficient to completely avoid the risk of damaging the basin. In this paper, we analyze the longitudinal distribution of extreme pressures in a stilling basin downstream of a stepped spillway. The study was based on the instant pressure data from the tests carried out in a physical model in the Laboratório de Obras Hidráulicas in IPH/UFRGS. Thus, it was found that the pressure behavior is similar to that observed in studies involving smooth chute spillways, except in the area surrounding the base of the stepped spillway, where high pressure fluctuations may occur. This happens as a result of the impact caused by the flow in the dissipation structure, which is not observed downstream of smooth chute spillways due to the existence of a vertical concordance curve between the spillway and the stilling basin.

ESTIMATION OF HYDRAULIC JUMP CHARACTERISTICS IN STILLING BASIN WITH GUIDE WALLS

2012 ◽  
Vol 40 (6) ◽  
pp. 1599-1609
Author(s):  
Habib A.A. ◽  
Abdel-Azim M. Ali ◽  
Abd-Allh Y.M ◽  
Saleh y.k.
Keyword(s):  
Hydraulic Jump ◽  
Stilling Basin

APPROACH TO THE VOID FRACTION DISTRIBUTION WITHIN A HYDRAULIC JUMP IN A TYPIFIED USBR II STILLING BASIN

2019 ◽  
Author(s):  
JUAN FRANCISCO MACIÁN-PÉREZ ◽  
RAFAEL GARCÍA-BARTUAL ◽  
BORIS HUBER ◽  
ARNAU BAYÓN ◽  
FRANCISCO J VALLÉS MORÁN
Keyword(s):  
Void Fraction ◽  
Hydraulic Jump ◽  
Stilling Basin ◽  
Void Fraction Distribution ◽  
Fraction Distribution

scholarly journals Experimental Characterization of the Hydraulic Jump Profile and Velocity Distribution in a Stilling Basin Physical Model

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1758
Author(s):  
Juan Macián-Pérez ◽  
Francisco Vallés-Morán ◽  
Santiago Sánchez-Gómez ◽  
Marco De-Rossi-Estrada ◽  
Rafael García-Bartual
Keyword(s):  
Free Surface ◽  
Energy Dissipation ◽  
Velocity Distribution ◽  
Physical Model ◽  
Hydraulic Jump ◽  
Surface Profile ◽  
Air Entrainment ◽  
Stilling Basin ◽  
Free Surface Profile ◽  
Stilling Basins

The study of the hydraulic jump developed in stilling basins is complex to a high degree due to the intense velocity and pressure fluctuations and the significant air entrainment. It is this complexity, bound to the practical interest in stilling basins for energy dissipation purposes, which brings the importance of physical modeling into the spotlight. However, despite the importance of stilling basins in engineering, bibliographic studies have traditionally focused on the classical hydraulic jump. Therefore, the objective of this research was to study the characteristics of the hydraulic jump in a typified USBR II stilling basin, through a physical model. The free surface profile and the velocity distribution of the hydraulic jump developed within this structure were analyzed in the model. To this end, an experimental campaign was carried out, assessing the performance of both, innovative techniques such as the time-of-flight camera and traditional instrumentation like the Pitot tube. The results showed a satisfactory representation of the free surface profile and the velocity distribution, despite some discussed limitations. Furthermore, the instrumentation employed revealed the important influence of the energy dissipation devices on the flow properties. In particular, relevant differences were found for the hydraulic jump shape and the maximum velocity positions within the measured vertical profiles, when compared to classical hydraulic jumps.

scholarly journals Hydraulic optimization of corrugated stilling basin with adverse slope

2018 ◽  
Vol 19 (1) ◽  
pp. 313-322 ◽  
Author(s):  
Tooraj Honar ◽  
Nafiseh Khoramshokooh ◽  
Mohammad Reza Nikoo
Keyword(s):  
Optimization Model ◽  
Hydraulic Jump ◽  
Experimental Results ◽  
Data Driven ◽  
Design Parameters ◽  
Algorithm Optimization ◽  
Stilling Basin ◽  
Design Variables ◽  
Bed Slope ◽  
Mlp Model

Abstract In this paper, perhaps for the first time, a data-driven simulation–optimization model is developed based on experimental results to find the effects of state and decision variables on the optimum characteristics of a stilling basin with adverse slope and corrugated bed. The optimal design parameters of the stilling basin are investigated to minimize the length of the hydraulic jump and ratio of the sequent depths of the jump while the relative amount of energy loss is maximized. In order to model the relationship between design variables of the bed, the experimental results are converted to a data-driven simulation model on the basis of a multilayer perceptron (MLP) neural network. Then, the validated MLP model is used in a genetic algorithm optimization model in order to determine the optimum characteristics of the bed under the hydraulic jump considering the interaction between the bed design variables and the hydraulic parameters of the flow. Results indicate that the optimum values of bed slope and the diameter of the corrugated roughness (2r) can be considered as −0.02 and 20 millimetres, respectively.

scholarly journals Study on the Best Depth of Stilling Basin with Shallow-Water Cushion

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1801
Author(s):  
Qiulin Li ◽  
Lianxia Li ◽  
Huasheng Liao
Keyword(s):  
Energy Dissipation ◽  
Shallow Water ◽  
Froude Number ◽  
Flow Regime ◽  
Dissipation Rate ◽  
Hydraulic Jump ◽  
Energy Dissipation Rate ◽  
Main Stream ◽  
Stilling Basin ◽  
Key Factor

The depth of the stilling basin with shallow-water cushion (SBSWC) is a key factor that affects the flow regime of hydraulic jump in the basin. However, the specific depth at which the water cushion is considered as ‘shallow’ has not been stated clearly by far, and only conceptual description is provided. Therefore, in order to define the best depth of SBSWC and its relationship between the Froude number at the inlet of the stilling basin, a large number of experiments were carried out to investigate SBSWC. First of all, 30 cases including five different Froude numbers and six depths were selected for which large eddy simulation (LES) was firstly verified by the experiments and then adopted to calculate the hydraulic characteristics in the stilling basin. Finally, three standards, based on the flow regime of hydraulic jump, the location of the main stream and the energy dissipation rate, were proposed to define the best depth of SBSWC. The three criteria are as follows: (1) a complete hydraulic jump occurs in the basin (2) the water cushion is about 1/10–1/3 deep of the stilling basin, and (3) the energy dissipation rate is more than 70% and the unit volume energy dissipation rate is as high as possible. It showed that the best depth ratio of SBSWC (depth to length ratio) was between 0.1 and 0.3 and it also indicated the best depth increased with the increase in Froude number. The results of the work are of significance to the design and optimizing of SBSWC.

scholarly journals Analysis of the Flow in a Typified USBR II Stilling Basin through a Numerical and Physical Modeling Approach

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 227 ◽  
Author(s):  
Juan Francisco Macián-Pérez ◽  
Rafael García-Bartual ◽  
Boris Huber ◽  
Arnau Bayon ◽  
Francisco José Vallés-Morán
Keyword(s):  
Physical Model ◽  
Hydraulic Jump ◽  
Numerical Approach ◽  
Free Surface Flows ◽  
United States Bureau ◽  
Bureau Of Reclamation ◽  
Stilling Basin ◽  
Modeling Approach ◽  
Stilling Basins ◽  
Energy Dissipation Devices

Adaptation of stilling basins to higher discharges than those considered for their design implies deep knowledge of the flow developed in these structures. To this end, the hydraulic jump occurring in a typified United States Bureau of Reclamation Type II (USBR II) stilling basin was analyzed using a numerical and experimental modeling approach. A reduced-scale physical model to conduct an experimental campaign was built and a numerical computational fluid dynamics (CFD) model was prepared to carry out the corresponding simulations. Both models were able to successfully reproduce the case study in terms of hydraulic jump shape, velocity profiles, and pressure distributions. The analysis revealed not only similarities to the flow in classical hydraulic jumps but also the influence of the energy dissipation devices existing in the stilling basin, all in good agreement with bibliographical information, despite some slight differences. Furthermore, the void fraction distribution was analyzed, showing satisfactory performance of the physical model, although the numerical approach presented some limitations to adequately represent the flow aeration mechanisms, which are discussed herein. Overall, the presented modeling approach can be considered as a useful tool to address the analysis of free surface flows occurring in stilling basins.

Hydraulic Jump Stilling Basin Design over Rough Beds

2021 ◽  
Vol 147 (1) ◽  
pp. 04020087
Author(s):  
Shayan Maleki ◽  
Virgilio Fiorotto
Keyword(s):  
Hydraulic Jump ◽  
Stilling Basin ◽  
Rough Beds

scholarly journals Macro-turbulent characteristcs of pressures in hydraulic jump formed downstream of a stepped spillway

RBRH ◽  
2017 ◽  
Vol 22 (0) ◽  
Author(s):  
Carolina Kuhn Novakoski ◽  
◽  
Eliane Conterato ◽  
Marcelo Marques ◽  
Eder Daniel Teixeira ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Hydraulic Jump ◽  
Pressure Fluctuations ◽  
Longitudinal Distribution ◽  
Stepped Spillway ◽  
Stepped Spillways ◽  
Stilling Basin ◽  
Large Pressure ◽  
Skewness Coefficient ◽  
Mean Pressure

ABSTRACT Stilling basins are structures built at the base of the spillway to dissipate energy, by means of a hydraulic jump. Hydraulic jump is a turbulent phenomenon that causes large pressure fluctuation in the stilling basin bottom, and can damage the sink structure through mechanisms such as fatigue, upflit pressure and cavitation. The use of stepped spillways allows the dissipation of a parcel of the energy while the water falls by the spillway, allowing a reduction in the stilling basin’s dimensions and cost. The present article presents the analysis of the longitudinal distribution of mean pressure, pressure fluctuations, skewness coefficient and kurtosis coefficient, derived from tests on physical hydraulic models. Pressure values measured in a stilling basin downstream of a stepped spillway (for Froude numbers between 5 and 8) were compared with data observed in a stilling basin downstream of a smooth spillway with a radius of concordance between the chute and the basin (for Froude numbers between 4.5 and 10). The results of these studies show that the mean pressures and the pressure fluctuation observed in the stilling basin downstream of stepped spillway present maximum values at the spillway’s closest point, differing, thus, from those at the smooth spillway. The longitudinal distribution of skewness and kurtosis coefficients enabled to define the positions for flow detachment start, roller ending and as well as the ending of the influence of the hydraulic jump over the flow.

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