Identifying Three-Dimensional Swimming Corridors for Fish to Match Their Swimming Characteristics Under Different Hydropower Plant Operations: Optimization of Entrance Location for Fish-Passing Facilities

2021 ◽  
Author(s):  
Lei Liao ◽  
Min Chen ◽  
Ruidong An ◽  
Jia Li ◽  
Xiliang Tang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hydropower Plant ◽  
Plant Operations ◽  
Operations Optimization

Two Case Studies in 3-D Residual Stress Prediction for Nuclear Power Applications

2016 ◽  
Author(s):  
Michael L. Benson ◽  
Patrick A. C. Raynaud ◽  
Frederick W. Brust
Keyword(s):  
Residual Stress ◽  
Nuclear Power ◽  
Three Dimensional ◽  
Repair Process ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Weld Residual Stress ◽  
Plant Operations ◽  
Stress Prediction ◽  
Residual Stress Modeling

Residual stress prediction contributes to nuclear safety by enabling engineering estimates of component service lifetimes. Subcritical crack growth mechanisms, in particular, require residual stress assumptions in order to accurately model the degradation phenomena. In many cases encountered in nuclear power plant operations, the component geometry permits two-dimensional (i.e., axisymmetric) modeling. Two recent examples, however, required three-dimensional modeling for a complete understanding of the weld residual stress distribution in the component. This paper describes three-dimensional weld residual stress modeling for two cases: (1) branch connection welds off reactor coolant loop piping and (2) a mockup to demonstrate the effectiveness of the excavate and weld repair process.

scholarly journals Mapping the summer 2017 surface water circulation of Picton Bay, ON

2018 ◽  
Vol 54 (2) ◽  
pp. 115-126
Author(s):  
J. A. Shore ◽  
P. Snell
Keyword(s):  
Water Intake ◽  
Three Dimensional ◽  
Small Scale ◽  
Boundary Current ◽  
Circulation Patterns ◽  
Management Perspective ◽  
Plant Operations ◽  
Modelling Studies ◽  
Spill Site ◽  
Surface Drifters

Abstract On March 24, 2017, a fuel spill from a partially submerged barge in Picton Bay contaminated the source water for the drinking water supply of the local township. Immediately after the spill, management decisions regarding the water intake plant operations were made based on contaminant observations and projected wind conditions. From a management perspective, it is essential to understand all the dynamical forcing for a system to direct the best decision-making but, unfortunately, there are no historical observations of currents in Picton Bay or any in-depth numerical modelling studies that have established the circulation patterns or hydrodynamics of the bay. This paper presents observations of surface speeds and drifter pathways collected using Lagrangian drifters and compares the observations to the velocity field estimates from a wind forced three-dimensional hydrodynamic model. Surface drifters were deployed from July to September and moved southwest into the bay during each deployment with almost no tendency to turn and drift out of the bay. Model simulations indicated that currents in the bay are sensitive to small-scale local winds and that a boundary current exists that connects the spill site to the area of the water intake pipes in wind conditions that are to the southwest or southeast.

scholarly journals Investigations of Rake and Rib Structures in Sand Traps to Prevent Sediment Transport in Hydropower Plants

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3882
Author(s):  
Mads Mehus Ivarson ◽  
Chirag Trivedi ◽  
Kaspar Vereide
Keyword(s):  
Three Dimensional ◽  
Flow Distribution ◽  
Head Loss ◽  
Total Weight ◽  
Hydropower Plant ◽  
Trap Efficiency ◽  
Hydropower Plants ◽  
Sand Trap ◽  
Sst Turbulence Model ◽  
Three Dimensional Models

In order to increase the lifespan of hydraulic turbines in hydropower plants, it is necessary to minimize damages caused by sediment erosion. One solution is to reduce the amount of sediments by improving the design of sand trap. In the present work, the effects on sand trap efficiency by installing v-shaped rake structures for flow distribution and rib structures for sediment trapping is investigated numerically using the SAS–SST turbulence model. The v-shaped rake structures are located in the diffuser near the inlet of the sand trap, while the ribs cover a section of the bed in the downstream end. Three-dimensional models of the sand trap in Tonstad hydropower plant are created. The present study showed that integrating rib type structure can reduce the total weight of sediments escaping the sand trap by 24.5%, which leads to an improved sand trap efficiency. Consequently, the head loss in the sand trap is increased by 1.8%. By additionally including the v-shaped rakes, the total weight of sediments escaping the sand trap is instead increased by 48.5%, thus worsening the sand trap efficiency. This increases head loss by 12.7%. The results also show that turbulent flow commencing at the sand trap diffuser prevents the downstream settling of sediments with a diameter of less than one millimeter. The hydraulic representation of the numerical model is validated by comparison with particle image velocimetry measurements of the flow field from scale experiments and ADCP measurements from the prototype. The tested rib design has not previously been installed in a hydropower plant, and can be recommended. The tested v-shaped rakes have been installed in existing hydropower plants, but this practice should be reconsidered.

scholarly journals Flow control in a multichamber settling basin by sluice gates driven by a CFD and an ancillary analytical model

2021 ◽  
Author(s):  
Miloš V. Nikolić ◽  
Rade M. Karamarković
Keyword(s):  
Analytical Model ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Hydropower Plant ◽  
Cfd Model ◽  
Three Solutions ◽  
Small Hydropower ◽  
Local Flow ◽  
Settling Basin ◽  
Dimensional Flow

Abstract Unequal flow distribution between the chambers of a three-chamber settling basin causes its malfunction and endangers the turbines of a small hydropower plant. To equalize the flows, sluice gates are used. To find their positions, the following methodologies are considered: (1) measurements combined with trial-and-error method (TAE), (2) measurements with regression analysis (RA), (3) CFD model combined with TAE, (4) CFD model with RA, (5) CFD model supported by a one-dimensional flow model, and (6) CFD model with an analytical model. The additional models and RA are intended to speed up the solution finding. From the previous list, only the sixth methodology is applicable. The first four are not because of the weir design, and the fifth because of the three-dimensional flow character. Initially, the CFD model of the side-weir intake was developed and validated. Afterward, the analytical model, which consists of a system of three pressure drop equations for three parallel and partly imaginary streams, is formed. The local flow resistances in the analytical model are determined by the CFD model combined with RA. To equalize the flows, three solutions with (i) fix, (ii) fix in a range of flows, and (iii) variable positions of the sluice gates are analyzed.

Effect of Abutment Load of Arch Dam on Stability of Underground Caverns Complex

2014 ◽  
Vol 501-504 ◽  
pp. 2045-2048
Author(s):  
Cun Hui Zhang ◽  
Shu Da Zhou ◽  
Xiu Li Ding ◽  
Shu Ling Huang ◽  
Yu Ting Zhang
Keyword(s):  
Three Dimensional ◽  
Simulation Models ◽  
Arch Dam ◽  
Hydropower Plant ◽  
Underground Powerhouse ◽  
Reservoir Storage ◽  
Underground Caverns ◽  
Operation Period ◽  
Calculation Results ◽  
Key Issues

Considering topographic and geologic conditions, project layout and investments, concret arch dam is adopted in a hydropower plant and underground powerhouses are arranged in mountains on left and right banks. However, the minimum distance between the excavation boundary of abutment of arch dam on elevation 850m and underground powerhouse is only 110m. Abutment load created by reservoir storage, permeability and earthquake may affect general stability of underground caverns in operation period. Thus, using elasto-plastic finite difference method, three dimensional numerical simulation models of underground caverns and slope of abutment of arch dam is establised and proposed key issues are systemly studied. The calculation results show that, under reservoir storage and dam vibration subject to earthquke, abutment load has small effect on plastic zone, displacement and stress around opennings and the caverns would be stable in operation period.

Consideration of Geometric Imperfections in Three-Dimensional Finite Element Model Analysis of Stiffened Steel Liners Subjected to External Pressure

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
J. L. G. Valdeolivas ◽  
J. C. Mosquera
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Element Model ◽  
External Pressure ◽  
Hydropower Plant ◽  
Geometric Imperfections ◽  
Modeling And Analysis ◽  
Steel Liner ◽  
Three Dimensional Finite Element

The availability of tools for safety evaluation of a pressure liner is a relevant issue in both structural and hydraulic engineering. A suitable design of a steel liner may involve a significant reduction in the investment cost of a hydropower plant and may also ensure its future integrity, avoiding prolonged stoppages in the operation stage. First, a review of the design methods for steel pressure liners is outlined and certain key aspects for the critical buckling load assessment are pointed out. Second, a numerical modeling and analysis procedure of a steel pressure liner is presented. The methodology is based on 3D nonlinear finite element modeling procedures, involving both liner constraining and the effect of stiffeners. In addition, both large displacements and a surrounding elastic medium are assumed in the model. Besides, some types of geometric imperfections such as weld-induced ones, initial gap, ovality, and wall-thickness loss due to corrosion are taken into account in this work. Finally, some conclusions are drawn regarding the role of imperfections in the calculated critical pressure of a steel liner.

3D Simulation Training Systems on Ship Lift of Hydropower Station

2013 ◽  
Vol 871 ◽  
pp. 310-314
Author(s):  
Zhi Huai Xiao ◽  
Yu Fan Chen ◽  
Li Bo Song ◽  
Xin Ying He
Keyword(s):  
Simulation Training ◽  
Three Dimensional ◽  
3D Models ◽  
Single Step ◽  
Training System ◽  
3D Simulation ◽  
Hydropower Plant ◽  
Easy Access ◽  
Ship Lift ◽  
3D Scene

In order to meet the needs of 3D simulation training system, this paper proposed a three-dimensional simulation training system based on Web3D technology. 3Dmax,Balder3D and Silverlight5 are used to build 3D models, construct 3D scene and bear the 3D scene, respectively. Combining with the ASP.NET platform, we constructed a 3D training system platform, which could be applied to the hydropower plant simulation training system. The system includes whole process simulation, single-step simulation and dynamic simulation. Since its built on B/S structure, users have an easy access to the simulation system by using the browser. So the system will surely help the users to get a more intuitive and convenient knowledge of ship lift operation process.

scholarly journals A Systematic Operation Program of a Hydropower Plant Based on Minimizing the Principal Stress: Haditha Dam Case Study

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1270 ◽  
Author(s):  
Jing Li ◽  
Ameen Ameen ◽  
Thamer Mohammad ◽  
Nadhir Al-Ansari ◽  
Zaher Yaseen
Keyword(s):  
Principal Stress ◽  
Hydraulic Structure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Water Levels ◽  
Hydropower Plant ◽  
Fe Model ◽  
Static Modeling ◽  
Earthfill Dams ◽  
Dam Stability

Dam operation and management have become more complex recently because of the need for considering hydraulic structure sustainability and environmental protect on. An Earthfill dam that includes a powerhouse system is considered as a significant multipurpose hydraulic structure. Understanding the effects of running hydropower plant turbines on the dam body is one of the major safety concerns for earthfill dams. In this research, dynamic analysis of earthfill dam, integrated with a hydropower plant system containing six vertical Kaplan turbines (i.e., Haditha dam), is investigated. In the first stage of the study, ANSYS-CFX was used to represent one vertical Kaplan turbine unit by designing a three-dimensional (3-D) finite element (FE) model. This model was used to differentiate between the effect of turbine units’ operation on dam stability in accordance to maximum and minimum reservoir upstream water levels, and the varying flowrates in a fully open gate condition. In the second stage of the analysis, an ANSYS-static modeling approach was used to develop a 3-D FE earthfill dam model. The water pressure pattern determined on the boundary of the running turbine model is transformed into the pressure at the common area of the dam body with turbines. The model is inspected for maximum and minimum upstream water levels. Findings indicate that the water stress fluctuations on the dam body are proportional to the inverse distance from the turbine region. Also, it was found that the cone and outlet of the hydropower turbine system are the most affected regions when turbine is running. Based on the attained results, a systematic operation program was proposed in order to control the running hydropower plant with minimized principal stress at selected nodes on the dam model and the six turbines.

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