Download or read book Enhanced Layout Optimization and Wind Aerodynamic Models for Wind Farm Design written by Yen Jim Kuo and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed project is motivated by the need to develop wake models and optimization algorithms that can accurately capture the wake losses in an array of wind turbines and optimize the turbine placements. In the past 4 years, we have developed capabilities to improve the layout design of wind farms located on complex terrains, as contributions from four major tasks. The outcome of the first task was the creation of a wake interaction model capable of describing the effects of overlapping wakes that can be used in combination with existing mathematical optimization tools for wind farm layout design. Such a model was derived and evaluated against existing wake interaction methods. This wake interaction model enables a mechanistic approach to account for multiple overlapping wakes while remaining compatible with established mathematical optimization methods. In the second task, this wake interaction model was used in conjunction with full-scale CFD simulations to design wind farm layouts. We developed an optimization algorithm that intelligently integrates a mathematical optimization approach to design wind farm layout on complex terrains with full-scale CFD simulations. The two subsequent tasks were focused on developing a wake model capable of producing comparable accuracy as full-scale CFD simulations but at a significantly lower computational cost. The third task focused on studying the effects of turbine blade geometry and atmospheric turbulence on turbine wake development. The findings of this step contributed to the fourth task of developing a new wake model capable of simulating wakes on complex terrains. This model has been validated against full-scale CFD simulations of a turbine placed on the terrain of the Gros-Morne Wind Farm in Quebec. The proposed model allows for fast simulation of wakes, making it ideal for designing wind farm layouts on complex terrains.

Download or read book Fundamentals of Wind Farm Aerodynamic Layout Design written by Farschad Torabi and published by Academic Press. This book was released on 2022-01-20 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Wind Farm Aerodynamic Layout Design, Volume Four provides readers with effective wind farm design and layout guidance through algorithm optimization, going beyond other references and general approaches in literature. Focusing on interactions of wake models, designers can combine numerical schemes presented in this book which also considers wake models' effects and problems on layout optimization in order to simulate and enhance wind farm designs. Covering the aerodynamic modeling and simulation of wind farms, the book's authors include experimental tests supporting modeling simulations and tutorials on the simulation of wind turbines. In addition, the book includes a CFD technique designed to be more computationally efficient than currently available techniques, making this book ideal for industrial engineers in the wind industry who need to produce an accurate simulation within limited timeframes. - Features novel CFD modeling - Offers global case studies for turbine wind farm layouts - Includes tutorials on simulation of wind turbine using OpenFoam

Download or read book Optimization of Wind Turbine Airfoils blades and Wind Farm Layouts written by Xiaomin Chen (Mechanical engineer) and published by . This book was released on 2014 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape optimization is widely used in the design of wind turbine blades. In this dissertation, a numerical optimization method called Genetic Algorithm (GA) is applied to address the shape optimization of wind turbine airfoils and blades. In recent years, the airfoil sections with blunt trailing edge (called flatback airfoils) have been proposed for the inboard regions of large wind-turbine blades because they provide several structural and aerodynamic performance advantages. The FX, DU and NACA 64 series airfoils are thick airfoils widely used for wind turbine blade application. They have several advantages in meeting the intrinsic requirements for wind turbines in terms of design point, off-design capabilities and structural properties. This research employ both single- and multi-objective genetic algorithms (SOGA and MOGA) for shape optimization of Flatback, FX, DU and NACA 64 series airfoils to achieve maximum lift and/or maximum lift to drag ratio. The commercially available software FLUENT is employed for calculation of the flow field using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a two-equation Shear Stress Transport (SST) turbulence model and a three equation k-kl-[omega] turbulence model. The optimization methodology is validated by an optimization study of subsonic and transonic airfoils (NACA0012 and RAE 2822 airfoils). All the optimization results have demonstrated that the GA technique can be employed efficiently and accurately to produce globally optimal airfoils with excellent aerodynamic properties using a desired objective value (minimum Cd and/or maximum Cl /Cd). It is also shown that the multi-objective genetic algorithm based optimization can generate superior airfoils compared to those obtained by using the single objective genetic algorithm. The applications of thick airfoils are extended to the assessment of wind turbine performance. It is well established that the power generated by a Horizontal-Axis Wind Turbine (HAWT) is a function of the number of blades B, the tip speed ratio [lambda] (blade tip speed/wind free stream velocity) and the lift to drag ratio (Cl /Cd) of the airfoil sections of the blade. The airfoil sections used in HAWT are generally thick airfoils such as the S, DU, FX, Flat-back and NACA 6-series of airfoils. These airfoils vary in (Cl /Cd) for a given B and [lambda], and therefore the power generated by HAWT for different blade airfoil sections will vary. Another goal of this study is to evaluate the effect of different airfoil sections on HAWT performance using the Blade Element Momentum (BEM) theory. In this dissertation, we employ DU 91-W2-250, FX 66-S196-V1, NACA 64421, and Flat-back series of airfoils (FB-3500-0050, FB-3500-0875, and FB-3500-1750) and compare their performance with S809 airfoil used in NREL Phase II and III wind turbines; the lift and drag coefficient data for these airfoils sections are available. The output power of the turbine is calculated using these airfoil section blades for a given B and [lambda] and is compared with the original NREL Phase II and Phase III turbines using S809 airfoil section. It is shown that by a suitable choice of airfoil section of HAWT blade, the power generated by the turbine can be significantly increased. Parametric studies are also conducted by varying the turbine diameter. In addition, a simplified dynamic inflow model is integrated into the BEM theory. It is shown that the improved BEM theory has superior performance in capturing the instantaneous behavior of wind turbines due to the existence of wind turbine wake or temporal variations in wind velocity. The dissertation also considers the Wind Farm layout optimization problem using a genetic algorithm. Both the Horizontal -Axis Wind Turbines (HAWT) and Vertical-Axis Wind Turbines (VAWT) are considered. The goal of the optimization problem is to optimally position the turbines within the wind farm such that the wake effects are minimized and the power production is maximized. The reasonably accurate modeling of the turbine wake is critical in determination of the optimal layout of the turbines and the power generated. For HAWT, two wake models are considered; both are found to give similar answers. For VAWT, a very simple wake model is employed. Finally, some preliminary investigation of shape optimization of 3D wind turbine blades at low Reynolds numbers is conducted. The optimization employs a 3D straight untapered wind turbine blade with cross section of NACA 0012 airfoils as the geometry of baseline blade. The optimization objective is to achieve maximum Cl /Cd as well as maximum Cl. The multi-objective genetic algorithm is employed together with the commercially available software FLUENT for calculation of the flow field using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a one-equation Sparlart-Allmaras turbulence model. The results show excellent performance of the optimized wind turbine blade and indicate the feasibility of optimization on real wind turbine blades with more complex shapes in the future.

Download or read book Wind Turbine Airfoils and Blades written by Jin Chen and published by Walter de Gruyter GmbH & Co KG. This book was released on 2017-12-04 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind Turbine Airfoils and Blades introduces new ideas in the design of wind turbine airfoils and blades based on functional integral theory and the finite element method, accompanied by results from wind tunnel testing. The authors also discuss the optimization of wind turbine blades as well as results from aerodynamic analysis. This book is suitable for researchers and engineers in aeronautics and can be used as a textbook for graduate students.

Download or read book CFD based Methodology for Wind Farm Layout Optimization written by Enrico Antonini and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by concerns on climate change and global warming, increasing oil prices, government support and public receptiveness, wind energy harvesting is emerging as one of the fastest growing renewable energy technologies. Most wind energy is nowadays produced by wind farms, which consist of hundreds of turbines to take advantage of economies of scale. Wind farm performance is however affected by the wakes generated by the turbines which can significantly diminish their annual energy production. Accurate wake effect predictions and reliable wind farm layout design become therefore critical aspects to the economic success of a wind farm project. The present research project aims therefore to define an innovative design framework that integrates accurate wake effect predictions for the development of the next generation wind farms as part of the strategy for promoting the transition to a renewable energy generation. Computational fluid dynamics (CFD) provides a unique tool to simulate wind turbine wakes because of its capability to provide a complete solution for the flow field in complex configurations. Nevertheless, CFD simulations are strongly influenced by the choice of the turbulence model used to close the Reynolds-averaged Navier-Stokes (RANS) equations. We therefore conducted an analysis of different turbulence models and their influence on the results of CFD wind turbine simulations to suggest the most suitable for such applications. Even though proper turbulence modeling is adopted, several studies showed however that the effectiveness of RANS models in wind farm simulations has not always been consistent. We therefore hypothesized this limitation to arise from uncertainties generated by the wind direction variability and proposed a modeling framework that, by accounting for such uncertainties, consistently improved the agreement of the CFD predictions with the experimental observations. To integrate the CFD models in a design methodology, we developed an innovative continuous adjoint formulation for gradient calculations within the framework of a gradient-based wind farm layout optimization. By testing this optimization methodology under different wind farm configurations, wind resource distributions and terrain topography, we showed that this unique CFD-based design framework effectively improved the annual energy production of a proposed wind farm by optimally siting its turbines.

Download or read book Wind Energy Design written by Thomas Corke and published by CRC Press. This book was released on 2018-04-27 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind Energy Systems is designed for undergraduate engineering courses, with a focus on multidisciplinary design of a wind energy system. The text covers basic wind power concepts and components - wind characteristics and modeling, rotor aerodynamics, lightweight flexible structures, wind farms, aerodynamics, wind turbine control, acoustics, energy storage, and economics. These topics are applied to produce a new conceptual wind energy design, showing the interplay of various design aspects in a complete system. An ongoing case study demonstrates the integration of various component topics, and MATLAB examples are included to show computerized design analysis procedures and techniques.

Download or read book Wind Farm Layout Optimization Using Approximate Inference in Graphical Models written by Aditya Dhoot and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerodynamics of Wind Turbines 2nd edition written by Martin O. L. Hansen and published by Routledge. This book was released on 2013-05-13 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural response of the wind turbine structure. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method is also covered, as are eigenmodes and the dynamic behaviour of a turbine. The new material includes a description of the effects of the dynamics and how this can be modelled in an ?aeroelastic code?, which is widely used in the design and verification of modern wind turbines. Further, the description of how to calculate the vibration of the whole construction, as well as the time varying loads, has been substantially updated.

Download or read book Topics in Wind Farm Layout Optimization written by Yun Zhang and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Farm Dynamics and Power Optimization in Realistic Atmospheric Boundary Layer Conditions written by Michael Frederick Howland and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of wind farms within realistic atmospheric boundary layer (ABL) conditions is critical to understand the governing physics of the system and to design optimal operational protocols. Aerodynamic wake interactions between individual wind turbines typically reduce total wind farm energy production 10-20% and increase the cost of electricity for this resource. Further, in large wind farms, the collective farm efficiency is in part dictated by the interaction between the wind farm and the turbulent ABL and, correspondingly, the vertical transport of kinetic energy into the turbine array. Coriolis forces, arising from the projection of Earth's rotation into a non-inertial rotating Earth-fixed frame, modify the interaction of a wind farm with the ABL. The traditional approximation made in typical ABL simulations assumes that the horizontal component of Earth's rotation is negligible in the atmospheric boundary layer. When including the horizontal component of Earth's rotation, the boundary layer and wind farm physics are a function of the geostrophic wind direction. The influence of the geostrophic wind direction on a wind farm atmospheric boundary layer was characterized using conventionally neutral and stable boundary layer large eddy simulations (LES). In the Northern hemisphere, geostrophic winds from west-to-east establish the horizontal component of Earth's rotation as a sink term in the shear Reynolds stress budget whereas the horizontal component manifests as a source term for east-to-west geostrophic winds. As a result, the magnitude of entrainment of mean kinetic energy into a wind turbine array is modified by the direction of the geostrophic wind, and correspondingly, the boundary layer height and wind speed and direction profiles depend on the geostrophic wind direction. Historically, wind farm control protocols have optimized the performance of individual wind turbines which results in aerodynamic wake interactions and a reduction in wind farm efficiency. Considering the wind farm as a collective, a physics- and data-driven wake steering control method to increase the power production of wind farms is developed. Upwind turbines, which generate turbulent energy-deficit wake regions which impinge on downwind generates, are intentionally yaw misaligned with respect to the incident ABL wind. While the yaw misaligned turbine may produce less power than in yaw aligned operation, the downwind generators may significantly enhance their production, increasing the collective power for the farm. The wake steering method developed combines a physics-based engineering wake model with state estimation techniques based on the assimilation of the wind farm power production data, which is readily available for control decisions at operational wind farms. Analytic gradients are derived from the wake model and leveraged for efficient yaw misalignment set-point optimization. The open-loop wake steering control methodology was tested in a multi-turbine array at a utility-scale operational wind farm, where it statistically significantly increased the power production over standard operation. The analytic gradient-based wind farm power optimization methodology developed can optimize the yaw misalignment angles for large wind farms on the order of seconds, enabling online real-time control. The dynamics of the ABL range from microscale features on the order of meters to mesoscale meteorological scales on the order of hundreds of kilometers. As a result of the broad range of scales and diversity of competing forces, the wind farm interaction with the turbulent ABL is a complex dynamical system, necessitating closed-loop control which is able to dynamically adapt to the evolving wind conditions. In order to rapidly design and improve dynamic closed-loop wind farm controllers, we developed wind farm LES capabilities which incorporate Coriolis and stratification effects and which permit the experimentation of real-time control strategies. Dynamic, closed-loop wake steering controllers are tested in simulations with full Coriolis effects and, altogether, the results indicate that closed-loop wake steering control can significantly increase wind farm power production over greedy operation provided that site-specific wind farm data is assimilated into the optimal control model.

Download or read book Modeling and Analysis of Doubly Fed Induction Generator Wind Energy Systems written by Lingling Fan and published by Academic Press. This book was released on 2015-04-16 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind Energy Systems: Modeling, Analysis and Control with DFIG provides key information on machine/converter modelling strategies based on space vectors, complex vector, and further frequency-domain variables. It includes applications that focus on wind energy grid integration, with analysis and control explanations with examples. For those working in the field of wind energy integration examining the potential risk of stability is key, this edition looks at how wind energy is modelled, what kind of control systems are adopted, how it interacts with the grid, as well as suitable study approaches. Not only giving principles behind the dynamics of wind energy grid integration system, but also examining different strategies for analysis, such as frequency-domain-based and state-space-based approaches. Focuses on real and reactive power control Supported by PSCAD and Matlab/Simulink examples Considers the difference in control objectives between ac drive systems and grid integration systems

Download or read book Comparison of Wind Farm Layout Optimization Results Using a Simple Wake Model and Gradient based Optimization to Large eddy Simulations written by Jared J. Thomas and published by . This book was released on 2019 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Turbine Aerodynamics written by Wen Zhong Shen and published by MDPI. This book was released on 2019-10-04 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbine aerodynamics is one of the central subjects of wind turbine technology. To reduce the levelized cost of energy (LCOE), the size of a single wind turbine has been increased to 12 MW at present, with further increases expected in the near future. Big wind turbines and their associated wind farms have many advantages but also challenges. The typical effects are mainly related to the increase in Reynolds number and blade flexibility. This Special Issue is a collection of 21 important research works addressing the aerodynamic challenges appearing in such developments. The 21 research papers cover a wide range of problems related to wind turbine aerodynamics, which includes atmospheric turbulent flow modeling, wind turbine flow modeling, wind turbine design, wind turbine control, wind farm flow modeling in complex terrain, wind turbine noise modeling, vertical axis wind turbine, and offshore wind energy. Readers from all over the globe are expected to greatly benefit from this Special Issue collection regarding their own work and the goal of enabling the technological development of new environmentally friendly and cost-effective wind energy systems in order to reach the target of 100% energy use from renewable sources, worldwide, by 2050

Download or read book Wind Array Performance Evaluation Model for Large Wind Farms and Wind Farm Layout Optimization written by Simeng Li and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The grouping of wind turbines in arrays introduces two major issues: (1) reduced power production caused by wake wind speed deficits and (2) increased dynamic loads on the blades caused by higher turbulence levels. Depending on the layout and local wind conditions, the drop in power production of downstream turbines can easily reach 40% of the upstream turbines in fully developed wake conditions. These power drops across arrays arise due to wake wind speed deficits. Even when averaged over different wind directions, drops in power production of 8% (onshore arrays), and 12% (offshore arrays) have been recorded. In this dissertation, a large wind array performance evaluation model (LWAP) to evaluate wake effects in large wind farms is developed. The model accounts for multiple wake interactions and the effect on the vertical wind profile in the atmosphere boundary layer by the wind farm itself. The model predicts wind speed deficits at each turbine and for specific turbine power curves and assesses power for individual turbines and for the entire wind farm. The calculation method converges within seconds for a large wind farm evaluation. To assess the efficacy of the wake model, measured wind speed deficits and turbine power deficits along two wind directions and wind turbine rows in the Horns Rev wind farm were compared with deficits calculated using the model. The mean absolute percentage error is around 2% on average in wind speed evaluation and around 4% on average in wind turbine power evaluation. Case studies predicting row-wise power deficits of turbines arrays in Horns Rev and Nysted wind farms on multiple wind directions were compared to observations. LWAP exhibits the same accuracy on power deficit evaluation as with the CFD based models such as WindFarmer, WakeFarm and NTUA and performs better than the WAsP Park model. The computing time to process an entire full wind farm (e.g., Horns Rev) is on the order of a few seconds, significantly less than the CFD based models. In addition, a wind array layout optimization model (WALOM) is proposed to simulate, evaluate and optimize wind array performance for real wind farm site. Results of optimized wind array layouts are obtained and analyzed on case studies of multiple wind distributions conditions and site conditions. It is found that the optimized results are affected by factors such as wind distribution, wind data resolution, wake model and wind farm site conditions.

Download or read book Wind Turbine Aerodynamics and Vorticity Based Methods written by Emmanuel Branlard and published by Springer. This book was released on 2017-04-05 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces the fundamentals of fluid-mechanics, momentum theories, vortex theories and vortex methods necessary for the study of rotors aerodynamics and wind-turbines aerodynamics in particular. Rotor theories are presented in a great level of details at the beginning of the book. These theories include: the blade element theory, the Kutta-Joukowski theory, the momentum theory and the blade element momentum method. A part of the book is dedicated to the description and implementation of vortex methods. The remaining of the book focuses on the study of wind turbine aerodynamics using vortex-theory analyses or vortex-methods. Examples of vortex-theory applications are: optimal rotor design, tip-loss corrections, yaw-models and dynamic inflow models. Historical derivations and recent extensions of the models are presented. The cylindrical vortex model is another example of a simple analytical vortex model presented in this book. This model leads to the development of different BEM models and it is also used to provide the analytical velocity field upstream of a turbine or a wind farm under aligned or yawed conditions. Different applications of numerical vortex methods are presented. Numerical methods are used for instance to investigate the influence of a wind turbine on the incoming turbulence. Sheared inflows and aero-elastic simulations are investigated using vortex methods for the first time. Many analytical flows are derived in details: vortex rings, vortex cylinders, Hill's vortex, vortex blobs etc. They are used throughout the book to devise simple rotor models or to validate the implementation of numerical methods. Several Matlab programs are provided to ease some of the most complex implementations.

Download or read book The Development of a Vertical axis Wind Turbine Wake Model for Use in Wind Farm Layout Optimization with Noise Level Constraints written by Eric Blaine Tingey and published by . This book was released on 2017 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: As VAWTs could be used in urban environments near residential areas, the noise disturbance coming from the turbine blades is an important consideration in the layout of a wind farm. Noise restrictions may be imposed on a wind farm to limit the disturbance, often impacting the wind farm's power producing capability. Two specific horizontal-axis wind turbine farm designs are studied and optimized using the FLORIS wake model and an acoustic model based on semi-empirical turbine noise calculations to demonstrate the impact a noise level constraint has on maximizing wind farm power production. When a noise level constraint was not active, the average power production increased, up to 8.01% in one wind farm and 3.63% in the other. Including a noise restriction in the optimization had about a 5% impact on the optimal average power production over a 5 decibel range. By analyzing power and noise together, the multi-modality of the optimization problem can be used to find solutions were noise impact can be improved while still maximizing wind farm power production.

Download or read book Efficient Design of Wind Farm Layouts Utilizing Exact Gradient Information written by David Saad Guirguis and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Wind Farm Layout Optimization (WFLO) problem has attracted a lot of attention from researchers and industry practitioners, as it has been proven that better placement of wind turbines can increase the overall efficiency and the total revenue of a wind farm. Common approaches found in the WFLO literature focus on minimizing turbine wake interactions based on analytical models. However, the literature seems to have settled on using metaheuristics and stochastic optimization approaches. In this thesis, a gradient optimization approach is proposed to solve highly constrained WFLO problems, by using an interior point method with the exact gradients of the objective and constraints. The superiority of the proposed approach has been demonstrated, and the computational cost is reduced by 1 to 2 orders of magnitude, in terms of objective function evaluations. Additionally, it has been extended to solve the multi-criteria problem considering electrical infrastructure, land usage and environmental aspects.