scholarly journals Evaluation of energy dissipation on stepped spillway using evolutionary computing

2019 ◽  
Vol 9 (6) ◽  
Author(s):  
Abbas Parsaie ◽  
Amir Hamzeh Haghiabi
Keyword(s):  
Energy Dissipation ◽  
Evolutionary Computing ◽  
Stepped Spillway

scholarly journals Energy Dissipation in Solid Roller Bucket and Controlled Stilling Basin for Ogee Stepped Spillway

2019 ◽  
Vol 8 (4) ◽  
pp. 2109-2112
Keyword(s):  
Energy Dissipation ◽  
Laboratory Experiments ◽  
Ideal Condition ◽  
Stepped Spillway ◽  
Type Ii ◽  
Dimensional Parameter ◽  
Stilling Basin ◽  
Sequent Depth ◽  
Tail Water ◽  
The Ideal

Hydraulic jump type II stilling basin is generally preferred as an energy dissipator for ogee spillway but it is uneconomical due to longer structure. On the other hand, roller bucket uses relatively shorter structure over a sloping apron or horizontal stilling basin. In this study, an attempt has been made to evaluate the performance of an ogee profile stepped spillway in combination with solid roller bucket and stilling basin type II for energy dissipation. Laboratory experiments are performed on a physical working model of ogee profile stepped spillway at discharge ranging from 0.0032 to 0.0069 m3 /s for a head of 1.5m, 4m & 7m and the results compared for energy dissipation (non-dimensional parameter (y c / h) = 0.69). The model results show that stepped spillway model without v-notch achieves 92.40 % energy dissipation. Thus this model is found to be more suitable to acquire the ideal condition of sequent depth and tail water depth in stilling basin for all the discharges.

scholarly journals Uniform flow and energy dissipation of hydraulic-jump-stepped spillways

2020 ◽  
Vol 20 (4) ◽  
pp. 1546-1553
Author(s):  
Yu Zhou ◽  
Jianhua Wu ◽  
Fei Ma ◽  
Jianyong Hu
Keyword(s):  
Energy Dissipation ◽  
Water Flow ◽  
Hydraulic Jump ◽  
Flow Region ◽  
Uniform Flow ◽  
Stepped Spillway ◽  
Flow Depth ◽  
Clear Water ◽  
Air Concentration ◽  
Stepped Spillways

Abstract In skimming flow, a uniform flow can be achieved and the flow depth, velocity and air concentration remain constant if a stepped spillway is sufficiently long. In this study, physical model experiments were performed to investigate the uniform characteristics and energy dissipation of a hydraulic-jump-stepped spillway, which is a new type of stepped spillway for increasing the unit discharge capacity and energy dissipation. Based on the redefinition of uniform flow, experimental results show that at a given stepped spillway slope, a smaller height for the beginning of the uniform flow region, a greater uniform aerated flow depth and a greater uniform equivalent clear water flow depth can be obtained as compared with the traditional stepped spillway due to strong aeration in the aeration basin. Under the condition of uniform flow, the energy dissipation rate of stepped spillways can be estimated by the equivalent clear water flow depth with given inflow conditions. Compared with the traditional stepped spillway, the uniform flow over the hydraulic-jump-stepped spillway has a smaller specific energy, revealing that the hydraulic-jump-stepped spillway is more advantageous for dissipating energy, especially at large unit discharges.

Energy dissipation on a stepped spillway downstream of aPiano KeyWeir – Experimental study

2011 ◽  
pp. 105-111 ◽  
Author(s):  
S Erpicum ◽  
O Machiels ◽  
P Archambeau ◽  
B Dewals ◽  
M Pirotton ◽  
...  
Keyword(s):  
Experimental Study ◽  
Energy Dissipation ◽  
Stepped Spillway

scholarly journals Numerical evaluation of discharge coefficient and energy dissipation of flow over a stepped morning glory spillway

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Mohammad Alkhamis ◽  
◽  
Saeed Reza Sabbagh-Yazdi ◽  
Mohsen Ranjbar-Malekshah ◽  
◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Water Flow ◽  
Unit Length ◽  
Morning Glory ◽  
Design Parameters ◽  
Stepped Spillway ◽  
Reservoir Water ◽  
Flow Solver ◽  
Hydraulic Design ◽  
Coefficient Of Discharge

A morning glory spillway usually has an ogee shaped crest and conveys spill water flow to its downstream vertical shaft followed by a horizontal tunnel. The ungated morning glory spillways should convey variable discharges, which nonlinearly depends on the reservoir water elevation. The variation of discharge for unit length of the crest may cause challenges on design of downstream crest curve (which affects coefficient of discharge and downstream crest negative pressure). Furthermore, formation of a horizontal vortex flow affects the spillway discharge. In this paper, in order to resolve these problems by energy dissipation and water flow aeration, variable size steps are mapped to downstream of the curved ogee crest of morning glory spillway. A finite volume base numerical flow solver is used to investigate the effects of the considered configurations on the hydraulic design parameters. In this work, having verified the pressure and aeration of the flow over an ordinary stepped spillway, the characteristics of flow over geometry of an ordinary morning glory spillway, as well as stepped spillway, are modelled and compared to the available measurements on laboratory hydraulic models. Finally, an existing ordinary morning glory spillway is computationally modelled by considering an alternative design of variable sized steps at downstream crest (by mapping their edges to the ordinary profile of the morning glory spillway). The stepped morning glory spillway alternatives are numerically simulated for various flow rates, and the computed discharge coefficients and energy dissipations are compared with simulation results for ordinary morning glory spillway of the case.

scholarly journals Genetic algorithms for optimizing stepped spillways to maximize energy dissipation

2021 ◽  
Author(s):  
Farzin Salmasi ◽  
John Abraham
Keyword(s):  
Water Management ◽  
Genetic Algorithm ◽  
Energy Dissipation ◽  
Objective Function ◽  
Relative Energy ◽  
Stepped Spillway ◽  
Construction Time ◽  
Stepped Spillways ◽  
Decision Variables ◽  
West Azerbaijan

Abstract Stepped spillways are important water-management structures that are used for energy dissipation. Use of these spillways has increased in recent decades, they can reduce construction time and they are effective for reducing the flow's downstream kinetic energy. In this study, the width and height of the steps as well as the slope and height of the overflow spillway were considered as variables. Due to the large number of variables, non-linearity of the objective function and constraints, and the lack of an explicit relationship between decision variables, a genetic algorithm (GA) was used. A stepped spillway with optimal dimensions was proposed as a replacement of the smooth spillway of Sarogh Dam located in West Azerbaijan province, Iran. The proposed steps increase energy dissipation; for constant discharge and varying slopes, the changes in the optimal height of the steps were insignificant. Sensitivity analysis using the objective function showed that the relative energy dissipation for a constant discharge is independent of the optimal height of the steps and decreases with increasing spillway slope. In addition, for fixed slopes, increasing the flow rate leads to a decrease in relative energy dissipation and an increase in the optimal height of the steps.

scholarly journals Stepped Spillways and Energy Dissipation: A Non-Uniform Step Length Approach

2019 ◽  
Vol 9 (23) ◽  
pp. 5071
Author(s):  
Abdelwanees Ashoor ◽  
Amin Riazi
Keyword(s):  
Energy Dissipation ◽  
Step Length ◽  
Maximum Energy ◽  
Stepped Spillway ◽  
Constant Number ◽  
Stepped Spillways ◽  
Interference Region ◽  
Different Types ◽  
Stepped Chute

A stepped spillway, which is defined as a spillway with steps on the chute, can be used to improve the energy dissipation of descending water. Although uniform stepped spillways have been studied comprehensively, non-uniform stepped spillways need more attention. In the interest of maximum energy dissipation, in this study, non-uniform stepped spillways were investigated numerically. To this end, within the range of skimming flow, four different types of non-uniform step lengths, including convex, concave, random, and semi-uniform configurations, were tested in InterFOAM. To evaluate the influence of non-uniform step lengths on energy dissipation, the height and number of steps in all models were fixed and equal to a constant number. The results indicated that in semi-uniform stepped spillways, when the ratio between the lengths of the successive steps is 1:3, a vortex interference region occurs within the two adjacent cavities of the entire stepped chute, and as a result, the energy dissipation increases by up to 20%.

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