Energy is one of the most major fields in the development of a society and its economy. Its consummations rate could by the way be an indicator of the level of prosperity that a nation could achieve. Among renewable sources of energies, hydro power is an important source of environmental-friendly energy and has become more and more important in the recent years. Water energy, as a renewable source of energy, can help in reducing the dependency on fossil fuels. The number of installed water power systems is increasing every year and many nations have made plans to make large investments in hydropower in the near future. Many developed and developing countries have realized the importance of water as an important resource for power generation and necessary measures are being taken up across the globe to tap this energy for its effective utilization in power production. Remarkable advances in water turbines design have been possible due to developments in modern technology. In this context, we are interested in developing a design and a numerical study of the Impulse and the Cross flow hydro turbine‘s type. This book contains four chapters; in the first, a bibliographic study has been developed in order to present a general view about renewable energy, hydropower and different ways to gather it. A particular interest has been given to the water rotors concerning their different types and historical of some famous type like cross flow and Impulse turbines type, object of our study. Indeed, the bibliographic study summarized the considered parameters to improve the water turbine performances. The second chapter presents the numerical approach developed using the CFD code "CFX". I present also the mathematical formulation and the turbulence model will be presented. Then a background of the used methods in our numerical model will be undertaken. The third chapter presents the numerical simulations consisting on the characterization of the hydro dynamic structure of the impulse and the cross flow turbines The fourth chapter consist of the design of the test bench and the different components and solutions.
Table of Contents
1. Introduction
Chapter 1: Bibliographic research
1. Introduction
2. Renewable energy
2.1. Why should we use Renewable Energy?
2.2. What’s a renewable energy?
3. Hydropower
3.1. Hydroelectricity
3.2. Generating methods
3.2.1. Conventional dams
3.2.2. Pumped-storage hydroelectricity
3.2.3. Run-of-the-river hydroelectricity
3.2.4. Tidal power
3.3. Underground power station
4. Water turbine
4.1. Francis turbine
4.2. Kaplan turbine
4.3. Tyson turbine
4.4. Gorlov helical turbine
4.5. Impulse turbines
4.6. Horizontal wheel
4.7. Breast shot wheel
4.8. Overshot wheel
4.9. Reversible wheel
4.10. Back shot wheel
4.11. Pelton wheel
5. Efficiency calculation
5.1. Pressure measurement
6. Conclusion
Chapter 2: Numerical model
1. Introduction
2. CFD methodology
2.1. Creating the Geometry/Mesh
2.2. Solving the CFD Problem
2.3. Visualizing the Results in the Postprocessor
3. Mathematic formulation
3.1. Mass Conservation
3.2. Momentum Conservation
3.3. Volume of Fluid Model
3.4. Turbulence models
3.4.1. k-ε model
3.4.1.1 Standard k-ε model
3.5. Realizable k-ε model
3.6. RNG k-ε model
3.7.1. SST k-ω Model
3.8. Standard k-ω model
4. Finite Volume Method
5. Convergence Criteria
6. Conclusion
Chapter 3: Numerical simulations
1. Introduction
2. Impulse turbine
2.1. Meshing
2.2. Boundary conditions
2.3. Volume fraction
2.4. Velocity vectors
2.6 Dynamic pressure
2.7. Turbulent kinetic energy
2.8. Torque value
2.9. Efficiency
3. Cross flow turbine
3.1. Meshing
3.2. Boundary conditions
3.3. Volume fraction
3.4. Velocity vectors
3.5. Static pressure
3.6. Dynamic pressure
3.7. Turbulent kinetic energy
3.8. Efficiency
4. Study of the test section
4.1. Meshing
4.2. Boundary conditions
4.3. Velocity vectors
4.4. Static pressure
4.5. Dynamic pressure
4.6. Turbulent kinetic energy
4.7. Volume fraction
5. Conclusion
Chapter 4: Design of the test bench
1. Introduction
2. Test bench components
2.1. Turbine choice
2.2. Turbine box
2.3. Tank
2.4. Tank support
2.5. Water pump
2.6. Collector
3. Instrumentation
3.1 Torque meter
3.2. Rotation speed measurement
3.3. Alternator bearing system
3.4. Electricity production
3.5. Pitot tube
4. Test bench presentation
4.1. Advantages
4.2. Disadvantages
4.3. System installation
5. Steel rod section and thickness
5.1 Tank support
5.2. Turbine
6. Conclusion
Objectives & Core Topics
This work aims to perform a design and numerical study of impulse and cross-flow hydro turbines to improve their performance and optimize their deployment in local, low-cost hydropower projects. The research uses Computational Fluid Dynamics (CFD) to characterize the hydrodynamic structure of these turbines and presents a practical test bench design.
- Numerical analysis of turbine geometry using Ansys CFX.
- Characterization of hydro-dynamic flow features like velocity, pressure, and turbulence.
- Parametric study of turbine performance under varying conditions.
- Design and dimensioning of a laboratory test bench for performance verification.
- Assessment of installation feasibility for local electricity production.
Book Excerpt
4. Water turbine
A water turbine is a rotary engine that takes energy from moving water. Water turbines were developed in the 19th century and were wide1y used for industrial power prior to e1ecnical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy source. Water wheels have been used for thousands of years for industrial power. Their main shortcoming is size, which limits the flow rate that can be harnessed. The migration from water wheels to modern turbines took about one hundred years. Development occurred during the industrial revolution, using scientific principles and methods. They also made extensive use of new materials and manufacturing methods developed at the time. The word turbine was introduced by the French engineer Claude Bourdin in the early 19th century and is derived from the Latin word for "whirling" or a "Vortex". The main difference between early water turbines and water wheels is a swirl component of the water which passes energy ta a spinning rotor. This additional component of motion allowed the turbine to be smaller than a water wheel of the same power. They could process more water by spinning faster and could harness much greater heads. (Later, impulse turbines were developed which didn't use swirl. Flowing water is directed on the blades of a turbine runner, creating a force on the blades. Since the runner is spinning, the force acts through a distance in this way, energy is transferred from the water flow to the turbine Water turbines divided into two groups; reaction turbines and impulse turbines. The precise shape of water turbine blades is a function often supply pressure of water, and the type of impeller selected.
Summary of Chapters
Introduction: Outlines the importance of renewable energy and hydropower, stating the research objective to perform a design and numerical study of impulse and cross-flow turbines.
Chapter 1: Bibliographic research: Provides an overview of renewable energy sources and historical developments in hydropower and water turbine technology.
Chapter 2: Numerical model: Describes the theoretical background of CFD, including Navier-Stokes equations, turbulence modeling, and convergence criteria used in Ansys CFX simulations.
Chapter 3: Numerical simulations: Details the simulation results for both impulse and cross-flow turbines, analyzing hydrodynamic properties like velocity, pressure distribution, and efficiency.
Chapter 4: Design of the test bench: Explains the practical design and dimensioning of the laboratory test bench components, including the tank, turbine box, and instrumentation.
Keywords
Hydropower, Water turbine, Impulse turbine, Cross-flow turbine, CFD, Ansys CFX, Renewable energy, Hydrodynamic structure, Test bench design, Torque, Turbulence model, Numerical simulation, Sustainable energy, Fluid dynamics, Power efficiency.
Frequently Asked Questions
What is the core focus of this research project?
The project focuses on the design and numerical analysis of impulse and cross-flow hydro turbines to improve performance and facilitate the development of low-cost, small-scale hydropower solutions.
What are the primary fields of study included in this paper?
The key themes are renewable energy, computational fluid dynamics (CFD) for turbine simulation, and mechanical engineering for test bench design.
What is the primary objective or research question?
The goal is to select optimal turbine geometries and evaluate their performance characteristics through numerical simulations to enhance power production efficiency.
Which scientific methods are employed?
The study utilizes Computational Fluid Dynamics (CFD) using the Ansys CFX code to simulate water flow and analyze turbulence models, combined with experimental validation from literature.
What topics are covered in the main body of the text?
The text covers bibliographic research, numerical modeling techniques (equations and turbulence models), numerical simulation results of turbines, and the technical design/dimensioning of a laboratory test bench.
Which keywords characterize this work?
Primary keywords include Hydropower, Water turbine, Impulse turbine, Cross-flow turbine, CFD, Ansys CFX, and Test bench design.
How does the project handle turbulence modeling?
The research compares different turbulence models like standard k-ε, Realizable k-ε, RNG k-ε, and SST k-ω to accurately represent flow behavior in the turbine simulation.
What is the significance of the test bench design presented?
The test bench design allows for laboratory experimentation to determine actual turbine performance metrics, serving as a critical bridge between numerical theory and real-world installation.
Why are impulse and cross-flow turbines chosen for this study?
These specific turbine types were selected for their suitability in small hydro schemes, particularly for medium and low head sites, where they can be produced locally at a low cost.
- Quote paper
- Ahmed Ben Chalbi (Author), 2018, Conception and Numerical Study of the Cross Flow and Impulse Hydroturbine, Munich, GRIN Verlag, https://www.hausarbeiten.de/document/441047
