Download or read book Design Modeling and Dynamic Analysis of a Mobile Underwater Turbine System for Harvesting Marine Hydro Kinetic Energy written by Shubham Tandon and published by . This book was released on 2017 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conceptual Design Feasibility Analysis Modeling and Simulation of the Dynamics and Control of a Mobile Underwater Turbine System to Harvest Marine Hydrokinetic Energy from the Gulf Stream written by Sathvik Divi and published by . This book was released on 2017 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook on the Geopolitics of the Energy Transition written by Daniel Scholten and published by Edward Elgar Publishing. This book was released on 2023-11-03 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy transition is fundamentally transforming geopolitics, with renewable energy and other decarbonization options reshaping existing energy markets, trade flows, and energy security strategies. What new opportunities and challenges await us? Will it pacify global energy relations or bring a perilous transition?
Download or read book Development of a Control Co Design Modeling Tool for Marine Hydrokinetic Turbines Preprint written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the ongoing and planned development of the software package CT-Opt (Current/Tidal Optimization), a control co-design modeling tool for marine hydrokinetic turbines. The commercialization of these turbines has faced significant challenges due to the complex, multidisciplinary nature of their design and the extreme environmental conditions of their operation. This project aims to create a modeling tool that will enable the efficient design of robust, cost-competitive hydrokinetic turbine systems. Rather than using traditional optimization methods, CT-Opt combines multiple models across a range of fidelities to enable coupled optimization of the system design and system controller via a control co-design approach. With this method, the parameters that affect system performance are considered more comprehensively at every stage of the design process. The lowest-fidelity, frequency-domain model called by CT-Opt is RAFT (Response Amplitudes of Floating Turbines), which was originally developed by the National Renewable Energy Laboratory (NREL) to model response amplitudes of floating offshore wind turbines. The highest-fidelity, time-domain model is OpenFAST, which was developed by NREL for land-based and offshore wind turbines. As part of the CT-Opt project, new functionalities will be added to RAFT and OpenFAST to enable the accurate simulation of fixed and floating marine hydrokinetic turbines. In addition to expanding the capabilities of RAFT and OpenFAST, new midfidelity models will be developed. These models will be based on RAFT and OpenFAST and will consist of linearized, state-space models derived from the fully coupled, nonlinear OpenFAST equations and derivative function surrogate models that approximate the nonlinear system behavior. Each model will be coupled with controllers to allow control co-design methods to be applied both within models and across fidelity levels, enabling efficient system optimization.
Download or read book Numerical Simulation of a Cross Flow Marine Hydrokinetic Turbine written by Taylor Jessica Hall and published by . This book was released on 2012 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the search for clean, renewable energy, the kinetic energy of water currents in oceans, rivers, and estuaries is being studied as a predictable and environmentally benign source. We investigate the flow past a cross flow hydrokinetic turbine (CFHT) in which a helical blade turns around a shaft perpendicular to the free stream under the hydrodynamic forces exerted by the flow. This type of turbine, while very different from the classical horizontal axis turbine commonly used in the wind energy field, presents advantages in the context of hydrokinetic energy harvesting, such as independence from current direction, including reversibility, stacking, and self-starting without complex pitch mechanisms. This thesis develops a numerical simulation methodology that applies the Reynolds Average Navier Stokes equations and the three-dimensional sliding mesh technique to model CFHTs. The methodology is validated against small scale experiments, available within NNMREC at the University of Washington and is used to investigate the efficiency of the energy capture and the hydrodynamic forces acting on the blades. First, we study the stationary turbine and conclude that the developed methodology accurately models the starting torque of a turbine initially in static conditions; some limitations are found, however, in predicting separated flow. The dynamic performance of the rotating turbine is predicted with reasonable accuracy using the sliding mesh technique. Excellent qualitative agreement with experimental trends is found in the results, and the actual predicted values from the simulations show good agreement with measurements. Though limitations in accurately modeling dynamic stall for the rotating turbine are confirmed, the good qualitative agreement suggests this methodology can be used to support turbine design and performance over a wide range of parameters, minimizing the number of prototypes to build and experiments to run in the pursuit of an optimized turbine. This methodology can also provide a cost-effective way of evaluating detailed full scale effects, such as mooring lines or local bottom bathymetry features, on both turbine performance and environmental assessment.
Download or read book Advanced Computational Modeling for Marine Tidal Turbine Farm written by Zhisong Li and published by . This book was released on 2012 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the global effort of exploring low-cost renewable energy and reducing greenhouse gas emissions, energy sources in the ocean are receiving more and more attentions. The kinetic energy from ocean currents is enormous and virtually inexhaustible. Among the different kinds of ocean currents, the tidal flow is most predictable and sufficiently rapid for power generation to many well-chosen sites. To convert the stream momentum into electrical power, a device called marine tidal turbine, predominantly horizontal-axis, is used. Working like a windmill underwater, the tidal turbine operates in a unique environment constrained by water-free surfaces and seabeds. The present study will concentrate on the numerical modeling of tidal turbine operations in standalone and array configurations. Dedicated computational fluid dynamics (CFD) models are first created for this particular research application. Based on the solutions obtained from simulations, comparative investigations are then taken to assess the wake characteristics in a turbine farm scenario in order to minimize any unfavorable wake/turbine interactions. The effects of free surface waves and uneven bed terrains are also studied. To establish the simulations, one steady and one time-transient code are developed using modular programming and parallel processing design. The core solver uses a classic projection method to solve the three-dimensional incompressible flow problem and an efficient s-coordinate method to model the free surface, both of which are well verified with analytical solutions. An actuator disc model and an actuator line model are numerically implemented for the steady and unsteady codes respectively, validated by experimental data. To include the natural water waves and ambient turbulence unsteadiness, the inflow boundary condition in time-transient code incorporates a fifth-order Stokes wave generator and artificial velocity fluctuations. Foreseeing the rotational movements and anisotropic turbulence from turbine spinning, a second-moment closure or nonlinear eddy viscosity assumption is needed for turbulence modeling. The project adopts an explicit algebraic Reynolds stress model, balancing the demand for solution accuracy and computational economy. Extensive tests and case running have been performed using the simulation codes with parametric modifications for different evaluation purposes. In scalability tests, both codes can give acceptable speedup up to 30 nodes and the steady state code achieves better performance due to its highly explicit formulations. The steady and unsteady codes are compared as baselines cases and they agree well in predicting wake velocity deficits. In steady state modeling of a single turbine, the study appraises the influence on turbine wake from rotor size, inflow profiles, and three different simple bed terrains. In unsteady modeling, turbine wake under long waves exhibits some velocity superposition behavior. Turbine array simulations first probe the steady state flow features in a number of rotor configurations: side-by-side, transverse, streamwise, co-rotating, and contra-rotating. They are examined for their wake restoration rates and turbulence intensities. Then the time-averaged wake activities in the staggering and tilted line layout are inspected and compared to settle a fluid dynamic preference. Finally an unsteady modeling is carried out for a pair of upstream-downstream and contra-rotating rotors, enabling a dynamic analysis on the turbine interactions.
Download or read book Modeling and Simulation of Hydrokinetic Composite Turbine System written by Haifeng Li and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The utilization of kinetic energy from the river is promising as an attractive alternative to other available renewable energy resources. Hydrokinetic turbine systems are advantageous over traditional dam based hydropower systems due to "zero-head" and mobility. The objective of this study is to design and analyze hydrokinetic composite turbine system in operation. Fatigue study and structural optimization of composite turbine blades were conducted. System level performance of the composite hydrokinetic turbine was evaluated. A fully-coupled blade element momentum-finite element method algorithm has been developed to compute the stress response of the turbine blade subjected to hydrodynamic and buoyancy loadings during operation. Loadings on the blade were validated with commercial software simulation results. Reliability-based fatigue life of the designed composite blade was investigated. A particle swarm based structural optimization model was developed to optimize the weight and structural performance of laminated composite hydrokinetic turbine blades. The online iterative optimization process couples the three-dimensional comprehensive finite element model of the blade with real-time particle swarm optimization (PSO). The composite blade after optimization possesses much less weight and better load-carrying capability. Finally, the model developed has been extended to design and evaluate the performance of a three-blade horizontal axis hydrokinetic composite turbine system. Flow behavior around the blade and power/power efficiency of the system was characterized by simulation. Laboratory water tunnel testing was performed and simulation results were validated by experimental findings. The work performed provides a valuable procedure for the design and analysis of hydrokinetic composite turbine systems"--Abstract, page iv.
Download or read book Numerical Simulation for Moored Marine Hydrokinetic Turbines written by Basil L. Hacker (Jr.) and published by . This book was released on 2013 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this thesis utilizes Blade Element Momentum (BEM) theory with a dynamic wake model to customize the OrcaFlex numeric simulation platform in order to allow modeling of moored Ocean Current Turbines (OCTs). This work merges the advanced cable modeling tools available within OrcaFlex with well documented BEM rotor modeling approach creating a combined tool that was not previously available for predicting the performance of moored ocean current turbines. This tool allows ocean current turbine developers to predict and optimize the performance of their devices and mooring systems before deploying these systems at sea. The BEM rotor model was written in C++ to create a back-end tool that is fed continuously updated data on the OCT's orientation and velocities as the simulation is running. The custom designed code was written specifically so that it could operate within the OrcaFlex environment. An approach for numerically modeling the entire OCT system is presented, which accounts for the additional degree of freedom (rotor rotational velocity) that is not accounted for in the OrcaFlex equations of motion. The properties of the numerically modeled OCT were then set to match those of a previously numerically modeled Southeast National Marine Renewable Energy Center (SNMREC) OCT system and comparisons were made. Evaluated conditions include: uniform axial and off axis currents, as well as axial and off axis wave fields. For comparison purposes these conditions were applied to a geodetically fixed rotor, showing nearly identical results for the steady conditions but varied, in most cases still acceptable accuracy, for the wave environment. Finally, this entire moored OCT system was evaluated in a dynamic environment to help quantify the expected behavioral response of SNMREC's turbine under uniform current.
Download or read book Wave and Tidal Energy written by Deborah Greaves and published by John Wiley & Sons. This book was released on 2018-07-23 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eine umfassende Publikation zu sämtlichen Aspekten der Wellen- und Gezeitenenergie. Wave and Tidal Energy gibt einen ausführlichen Überblick über die Entwicklung erneuerbarer Energie aus dem Meer, bezieht sich auf die neueste Forschung und Erfahrungen aus Anlagentests. Das Buch verfolgt zwei Ziele, zum einen vermittelt es Einsteigern in das Fachgebiet eine Überblick über die Wellen- und Gezeitenenergie, zum anderen ist es ein Referenzwerk für komplexere Studien und die Praxis. Es vermittelt Detailwissen zu wichtigen Themen wie Ressourcencharakterisierung, Technologie für Wellen- und Gezeitenanlagen, Stromversorgungssysteme, numerische und physikalische Modellierung, Umwelteffekte und Politik. Zusätzlich enthält es eine aktuelle Übersicht über Entwicklungen in der ganzen Welt sowie Fallstudien zu ausgewählten Projekten. Hauptmerkmale: - Ausführliches Referenzwerk zu allen Aspekten der interdisziplinären Fachrichten Wellen- und Gezeitenenergie. - Greift auf die neuesten Forschungsergebnisse und die Erfahrung führender Experten in der numerischen und laborgestützten Modellierung zurück. - Gibt einen Überblick über regionale Entwicklungen in aller Welt, repräsentative Projekte werden in Fallstudien vorgestellt. Wave and Tidal Energy ist ein wertvolles Referenzwerk für eine breite Leserschaft, von Studenten der Ingenieurwissenschaften und technischen Managern über politische Entscheidungsträger bis hin zu Studienabsolventen und Forschern.
Download or read book Underwater Wireless Power Transfer written by Taofeek Orekan and published by Springer. This book was released on 2019-01-28 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses, for the first time, wireless power transfer in the ocean environment. Topics covered include power electronic techniques, advanced control strategies, as well as classic and emerging applications such as smart ocean energy systems and wireless power transfer and charging of underwater autonomous vehicles. Emerging research topics are presented, along with methodologies, approaches, and industrial development of intelligent and energy-efficient techniques. Apart from the basic principles with an emphasis on inductive power transfer and mathematical analysis, the book discusses the emerging implementation for underwater wireless power transfer such as energy encryption, power and data transfer through common links, and secured data- and cyber-security. Specifically, the book comprehensively introduces significant discussions on UWPT coil theoretical and experimental analysis in seawater, optimal design, and intelligent controls. For example, since fast communication is not viable in an underwater environment, the proposed book discusses Maximum Power Efficiency Tracking (MPET) control, which achieves a maximum power efficiency (>85%) without communication or feedback from the transmitting side of the UWPT system. A k-nearest-neighbors-based machine learning approach is used to estimate the coupling coefficiency between the coils. This machine learning-based intelligent control method can offer important guidance for graduate students, academic researchers, and industrial engineers who want to understand the working principles and realize the developing trends in underwater wireless power transfer. Finally, the book includes details on the modeling and design of a smart ocean energy system--a new type of power harvesting system designed to convert ocean energy into electricity, which has the capability of making underwater wireless power connections with distributed marine devices.
Download or read book Design of a Vortex Induced Vibration Based Marine Hydro kinetic Energy System written by Varun Michael Lobo and published by . This book was released on 2012 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Hydrokinetic energy harvesting based on vortex induced vibration (VIV) of a bluff body is discussed. VIV is defined as the vibration incurred on a bluff body due to an external fluid flowing over it. These vibrations are the results of boundary layer separation from the surface of the body. An optimized VIV generator has been developed, that utilizes a non-contact type linear magnetic device for generation of energy. The cylinder was chosen such that at the mass ratio (m*) was always lower than the critical mass (m*[subscript critical] = 0.52). The studies were based on two complementary techniques: (a) computational fluid dynamics study to derive the initial design guidelines of our laboratory prototype; and, (b) experimental study to identify optimized design parameters that would allow such a device to maximize the net energy production. A detailed two-dimensional CFD study was performed at laminar and turbulent flow regimes (45
Download or read book Computational Fluid Dynamic Simulation of Vertical Axis Hydrokinetic Turbines written by Edwin Lenin Chica Arrieta and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrokinetic turbines are one of the technological alternatives to generate and supply electricity for rural communities isolated from the national electrical grid with almost zero emission. These technologies may appear suitable to convert kinetic energy of canal, river, tidal, or ocean water currents into electricity. Nevertheless, they are in an early stage of development; therefore, studying the hydrokinetic system is an active topic of academic research. In order to improve their efficiencies and understand their performance, several works focusing on both experimental and numerical studies have been reported. For the particular case of flow behavior simulation of hydrokinetic turbines with complex geometries, the use of computational fluids dynamics (CFD) nowadays is still suffering from a high computational cost and time; thus, in the first instance, the analysis of the problem is required for defining the computational domain, the mesh characteristics, and the model of turbulence to be used. In this chapter, CFD analysis of a H-Darrieus vertical axis hydrokinetic turbines is carried out for a rated power output of 0.5 kW at a designed water speed of 1.5 m/s, a tip speed ratio of 1.75, a chord length of 0.33 m, a swept area of 0.636 m2, 3 blades, and NACA 0025 hydrofoil profile.
Download or read book Vertical Axis Hydrokinetic Turbines Numerical and Experimental Analyses written by Mabrouk Mosbahi and published by Bentham Science Publishers. This book was released on 2021-12-14 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook is a guide to numerical and experimental processes that are used to analyze and improve the efficiency of vertical axis rotors. Chapters present information that is required to optimize the geometrical parameters of rotors or understand how to augment upstream water velocity. The authors of this volume present a numerical model to characterize the water flow around the vertical axis rotors using commercial CFD code in Ansys Fluent®. The software has been used to select adequate parameters and perform computational simulations of spiral Darrieus turbines. The contents of the volume explain the experimental procedure carried out to evaluate the performance of the spiral Darrieus turbine, how to characterize the water flow in the vicinity of the tested turbine and the method to assess the spiral angle influence on the turbine performance parameters. Results for different spiral angles (ranging from 10° to 40°) are presented. This volume is a useful handbook for engineers involved in power plant design and renewable energy sectors who are studying the computational fluid dynamics of vertical axis turbines (such as Darrieus turbines) that are used in hydropower projects. Key features: - 4 chapters that cover the numerical and experimental analysis of vertical axis rotors and hydrokinetic turbines - Simple structured layout for easy reading (methodology, models and results) - Bibliographic study to introduce the reader to the subject - A wide range of parameters included in experiments - A comprehensive appendix of tables for mechanical parameters, statistical models, rotor parameters and geometric details.
Download or read book Tidal Energy Systems written by Vikas Khare and published by Elsevier. This book was released on 2018-10-12 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tidal Energy Systems: Design, Optimization and Control provides a comprehensive overview of concepts, technologies, management and the control of tidal energy systems and tidal power plants. It presents the fundamentals of tidal energy, including the structure of tidal currents and turbulence. Technology, principles, components, operation, and a performance assessment of each component are also covered. Other sections consider pre-feasibility analysis methods, plant operation, maintenance and power generation, reliability assessment in terms of failure distribution, constant failure rate and the time dependent failure model. Finally, the most recent research advances and future trends are reviewed. In addition, applicable real-life examples and a case study of India's tidal energy scenario are included. The book provides ocean energy researchers, practitioners and graduate students with all the information needed to design, deploy, manage and operate tidal energy systems. Senior undergraduate students will also find this to be a useful resource on the fundamentals of tidal energy systems and their components. - Presents the fundamentals of tidal energy, including system components, pre-feasibility analysis, and plant management, operations and control - Explores concepts of sustainability and a reliability analysis of tidal energy systems, as well as their economic aspects and future trends - Covers the assessment of tidal energy systems by optimization technique and game theory
Download or read book Marine Energy Harvesting from Low Cut in Speeds Horizontal Axis Ocean Current Turbine written by Reza Chini and published by . This book was released on 2012 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment and Nonlinear Modeling of Wave Tidal and Wind Energy Converters and Turbines written by Madjid Karimirad and published by . This book was released on 2020-09-04 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue "Assessment and Nonlinear Modeling of Wave, Tidal, and Wind Energy Converters and Turbines" contributes original research to stimulate the continuing progress of the offshore renewable energy (ORE) field, with a focus on state-of-the-art numerical approaches developed for the design and analysis of ORE devices. Particularly, this collection provides new methodologies, analytical/numerical tools, and theoretical methods that deal with engineering problems in the ORE field of wave, wind, and current structures. This Special Issue covers a wide range of multidisciplinary aspects, such as the 1) study of generalized interaction wake model systems with elm variation for offshore wind farms; 2) a flower pollination method based on global maximum power point tracking strategy for point-absorbing type wave energy converters; 3) performance optimization of a Kirsten-Boeing turbine using a metamodel based on neural networks coupled with CFD; 4) proposal of a novel semi-submersible floating wind turbine platform composed of inclined columns and multi-segmented mooring lines; 5) reduction of tower fatigue through blade back twist and active pitch-to-stall control strategy for a semi-submersible floating offshore wind turbine; 6) assessment of primary energy conversion of a closed-circuit OWC wave energy converter; 7) development and validation of a wave-to-wire model for two types of OWC wave energy converters; 8) assessment of a hydrokinetic energy converter based on vortex-induced angular oscillations of a cylinder; 9) application of wave-turbulence decomposition methods on a tidal energy site assessment; 10) parametric study for an oscillating water column wave energy conversion system installed on a breakwater; 11) optimal dimensions of a semisubmersible floating platform for a 10 MW wind turbine; 12) fatigue life assessment for power cables floating in offshore wind turbines.
Download or read book Marine Hydrokinetic Turbine Power take off Design for Optimal Performance and Low Impact on Cost of energy written by and published by . This book was released on 2012 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a Power-Take-Off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drive train, power generator and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency, low maintenance and cost with a low impact on the device Cost-of-Energy (CoE).
