Дисертації з теми "Turbine fluid-structure"
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Nematbakhsh, Ali. "A Nonlinear Computational Model of Floating Wind Turbines." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-dissertations/170.
Повний текст джерелаLi, Yuwei. "Coupled computational fluid dynamics/multibody dynamics method with application to wind turbine simulations." Diss., University of Iowa, 2014. https://ir.uiowa.edu/etd/4681.
Повний текст джерелаArini, Nu Rhahida. "The influence of trailing edge shape on fluid structure interaction of a vertical axis tidal turbine blade." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/417857/.
Повний текст джерелаLothodé, Corentin. "Modélisation des pales d'éoliennes ou d'hydroliennes en environnement naturel à l'aide d'un code fluide-structure." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMIR15.
Повний текст джерелаA methodology to simulate blades of turbines is developed. A first part is dedicated to improving the performance of the fluid-structure coupling. New algorithms are presented. A new mesh morphing solution is shown. Developments are validated on many test cases. A second part is dedicated to applying the developments on turbines. A first validation is made on a water turbine. The vibration of a blade interacting with a mast is studied. Finally, some results of an industrial water turbine are shown
Hoerner, Stefan [Verfasser], and Dominique [Gutachter] Thévenin. "Characterization of the fluid-structure interaction on a vertical axis turbine with deformable blades / Stefan Joël Hoerner ; Gutachter: Dominique Thévenin." Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1220036471/34.
Повний текст джерелаHoerner, Stefan Joël [Verfasser], and Dominique [Gutachter] Thévenin. "Characterization of the fluid-structure interaction on a vertical axis turbine with deformable blades / Stefan Joël Hoerner ; Gutachter: Dominique Thévenin." Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1220036471/34.
Повний текст джерелаTaymans, Claire. "Solving Incompressible Navier-Stokes Equations on Octree grids : towards Application to Wind Turbine Blade Modelling." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0157/document.
Повний текст джерелаThe subject of the thesis is the development of a numerical tool that allows to model the flow around wind blades. We are interested in the solving of incompressible Navier-Stokes equations on octree grids, where the smallest scales close to the wall have been modelled by the use of the so-called Wall Functions. An automatic Adaptive Mesh Refinement (AMR) process has been developed in order to refine the mesh in the areas where the vorticity is higher. The structural model of a real wind blade has also been implemented and coupled with the fluid model. Indeed, an application of the numerical tool is the study of the effects of wind gusts on blades. An experimental work has been conducted with an in-service wind turbine with the measurement of wind speed upstream. This data will allow to calibrate and validate the numerical models developed in the thesis
Gissoni, Humberto de Camargo. "Método para análise da interação fluido-estrutura em travessas do pré-distribuidor de turbinas hidráulicas." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-11072016-153653/.
Повний текст джерелаOne of the biggest challenges for hydraulic turbine manufacturers is to prevent vortex-induced vibration on the stay vanes and runner blades. Only regarding stay vanes, 28 cases of cracks or unusual noises attributed to such vibrations were reported in the past decades leading to huge costs due to repair, delays and lack of generation. The state of the art today is to use powerful and expensive commercial computational fluid dynamics software to address the required transient phenomena. The present work carries out a comprehensive survey on occurred events in stay vanes during the last 50 years. Then, an alternative approach, based only on free open-source tools, is proposed. From due justified simplifying assumptions, the problem is formulated two-dimensionally, in the stay vane cross section plane, taking the fluid-structure interaction into account. In such a strategy, the Navier-Stokes equations are solved using oomph-lib, an object-oriented, finite-element library. A special C++ computational code is developed to deal with the fluid-structure interaction problem, in which turbulence is considered through a special algorithm, based on the Baldwin-Lomax model. The proposed method is validated through comparisons with an aerodynamics benchmark and an experimental measurement of oscillating rectangular bars both available in the literature. The method is finally applied to a case study of a particular stay vane. Keywords: Hydraulic turbine. Fluid-structure interaction. Vortex-induced vibration.
Xin, Bai. "Numerical simulation of a marine current turbine in turbulent flow." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/7900.
Повний текст джерелаFeilhauer, Michal. "Řešení dynamické odezvy vodohospodářských konstrukcí v interakci s kapalinou." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-355595.
Повний текст джерелаDe, Carvalho Duarte Leandro. "Conception et optimisation d'un système hydrolien à aile oscillante passive." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAD038.
Повний текст джерелаGiven the current energy transition conjuncture, where the electricity production and the electricity grid are challenged, the hydraulic potential of low current sites is relevant and remains under-exploited. In such context, this thesis studies a novel concept of an energy harvester device: the fully passive flapping foil turbine. Bioinspired from aquatic animals swimming technique, this hydrokinetic energy harvester consists of an oscillating foil describing periodic heaving and pitching motions, entirely induced by fluid-structure interactions. The first part of this thesis deals with the development of a numerical model for accurately simulating the harvester behavior. Then, a reduced scale prototype of the fully passive flapping foil has been designed and tested in a water channel. Thanks to an original dynamic tuning strategy of the structural parameters, experiments have been conducted for a wide range of configurations of the harvester. The investigation of the harvesting performances of the prototype helped identifying several optimized parameters sets. In such cases, hydraulic efficiencies as high as 30% have been reached. The main results of this thesis allow to consider a full scale fully passive flapping foil harvester in realistic conditions. As a matter of fact, the optimized cases identified for the reduced scale prototype can be naturally extended to real operating conditions
Cantoni, Lorenzo. "Load Control Aerodynamics in Offshore Wind Turbines." Thesis, KTH, Kraft- och värmeteknologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291417.
Повний текст джерелаPå grund av ökningen av rotorstorleken hos horisontella vindturbiner (HAWT) under de senaste 25 åren, en design som har uppstod för att uppnå högre effekt, måste alla vindkraftkomponenter och blad stå emot högre strukturella belastningar. Detta uppskalningsproblem kan lösas genom att använda metoder som kan minska aerodynamiska belastningar som rotorn måste tåla, antingen med passiva eller aktiva styrlösningar. Dessa kontrollanordningar och tekniker kan minska utmattningsbelastningen på bladen med upp till 40 % och därför behövs mindre underhåll, vilket resulterar i viktiga besparingar för vindkraftsägaren. Detta projekt består av en studie av lastkontrolltekniker för havsbaserade vindkraftverk ur en aerodynamisk och aeroelastisk synvinkel, i syfte att bedöma en kostnadseffektiv, robust och pålitlig lösning som kan fungera underhållsfri i tuffa miljöer. Den första delen av denna studie involverar 2D- och 3D-aerodynamiska och aeroelastiska simuleringar för att validera beräkningsmodellen med experimentella data och för att analysera interaktionen mellan fluiden och strukturen. Den andra delen av denna studie är en bedömning av de ojämna aerodynamiska belastningarna som produceras av ett vindkast över bladen och för att verifiera hur en bakkantklaff skulle påverka de aerodynamiska styrparametrarna för det valda vindturbinbladet.
Liu, Yuanchuan. "A CFD study of fluid-structure interaction problems for floating offshore wind turbines." Thesis, University of Strathclyde, 2018. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=30597.
Повний текст джерелаKorobenko, Artem. "Advanced Fluid--Structure Interaction Techniques in Application to Horizontal and Vertical Axis Wind Turbines." Thesis, University of California, San Diego, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3670451.
Повний текст джерелаDuring the last several decades engineers and scientists put significant effort into developing reliable and efficient wind turbines. As a wind power production demands grow, the wind energy research and development need to be enhanced with high-precision methods and tools. These include time-dependent, full-scale, complex-geometry advanced computational simulations at large-scale. Those, computational analysis of wind turbines, including fluid-structure interaction simulations (FSI) at full scale is important for accurate and reliable modeling, as well as blade failure prediction and design optimization.
In current dissertation the FSI framework is applied to most challenging class of problems, such as large scale horizontal axis wind turbines and vertical axis wind turbines. The governing equations for aerodynamics and structural mechanics together with coupled formulation are explained in details. The simulations are performed for different wind turbine designs, operational conditions and validated against field-test and wind tunnel experimental data.
Cardoso, OnÃzimo Carlos Viana. "Partitioned analysis of Offshore wind turbines using the Lagrange Localized Methods." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13241.
Повний текст джерелаAmong the new-found data about the availability of fossil fuels, which affirms that oil and natural gas sources will be almost depleted in the next century and the coal in the following two centuries. There is a global pursuit about new ways to produce energy. Another important fact that ratify this quest, lies at rise of the environment imbalance arouse from the burn of fossil fuels which, through the greenhouse effect, leads, for instance, to melting glaciers and increasing the temperature in the earth. The wind power, already used to move ships since antiquity is a relevant alternative way to produce energy, since it dispose of, at least, two great advantages, namely, it is endless and produce low negative consequences to environment. A place is considered to be good to receive the wind power engines called wind turbines, which convert the wind kinetic energy in electricity, if it is a ground plane with little amount of barriers. The sea, especially the regions far from the coast, satisfy the two latter requirement, and, furthermore, it is a place in which there are less obstructions about the noise pollution from the offshore wind turbines and there is not concern about deceases arouse in people who leave near of wind farms. In order to install the wind turbines in those spots away from the seashore, is required that its towers must be attached at the sea floor or must be develop a system that allow the turbine to float. Therefore the objective of the present work is to develop a structural modelling of the Monopile, TLP (Tension Leg Platform) and Spar type wind turbines subject using Finite Element Methods with the coupling method accomplished by Localized Lagrange Multipliers, jointly with the software SolidWorks and Autocad (drawing creation), ANSYS (mesh development) and Matlab (solver). The obtained results are relevant since such models are those which are most commonly used in offshore wind power plants. Lastly, due to the use of the latter coupling method, there is not the requisition to develop the study using meshes that agree each other. On the contrary, the analysis can be performed with non match meshes adjusting them with the Zero Moment Rule described in this present study.
Diante dos mais recentes dados com respeito a quantidade de combustÃveis fÃsseis ainda disponÃveis na natureza, os quais atestam que nÃo hà mais nem um sÃculo sequer para que o petrÃleo e o gÃs natural sejam praticamente extintos e que as reservas de carvÃo mineral suprirÃo somente mais 2 sÃculos de consumo, levando em conta o gasto atual. A preocupaÃÃo quanto a novas formas de extraÃÃo de energia se tornam necessÃrias e urgentes. Outro importante fator que ratifica o imediatismo de se buscar diferentes fontes de energia em detrimento de combustÃvel fÃssil, à o fato de que as emissÃes intrÃnsecas à sua queima estÃo gerando desequilÃbrio no clima global pela intensificaÃÃo do efeito estufa, apontado como um dos principais contribuidores do derretimento de geleiras e aquecimento da temperatura da terra. A energia eÃlica, jà utilizada desde a antiguidade para auxÃlio de locomoÃÃo de embarcaÃÃes e em moinhos de vento, se mostra uma alternativa de extrema relevÃncia, jà que, ela nÃo à portadora dos dois problemas crÃticos citados anteriormente. A saber, ela à infindÃvel e tem baixa consequÃncia negativa ao meio ambiente. Quanto aos locais que oferecem maior rendimento e produÃÃo para instalaÃÃo dos aerogeradores, responsÃveis pela conversÃo da energia cinÃtica do vento em energia elÃtrica, sÃo os que dispÃem de terreno mais plano e ausente de barreiras que impeÃam a continuidade do fluxo de vento. O mar, sobretudo as regiÃes mais distantes da costa, satisfazem Ãs duas necessidades citadas anteriormente, e, ainda se tratam de um local no qual nÃo hà a preocupaÃÃo quanto a poluiÃÃo sonora gerada pelos aerogeradores e nem com distÃrbios e doenÃas que possam ser desencadeadas em pessoas que residam pertos de grandes parques Ãolicos. A utilizaÃÃo de aerogeradores no mar (offshore) distantes da costa, e por conseguinte, em grandes profundidades, requer torres de sustentaÃÃo fixadas ao solo ou um sistema que proporcione que a turbina flutue. Diante do exposto, o trabalho em questÃo tem por objetivo realizar a modelagem estrutural do aerogerador flutuante (Spar), do portador de torre de tripà e do modelo monopile, sujeitos a carregamentos decorrentes de situaÃÃes normais e extremas, utilizando os mÃtodos dos Elementos Finitos juntamente com o MÃtodo de Acoplamento por Multiplicadores de Lagrange Localizados, atrelados aos softwares SolidWorks e Autocad (criaÃÃo do desenho), ANSYS (malha) e Matlab (solver). E, em decorrÃncia do fato da utilizaÃÃo do mÃtodo de acoplamento, nÃo hà necessidade de que as malhas dos subdomÃnios envolvidos sejam coincidentes. Pelo contrÃrio, pode-se utilizar malhas nÃo encaixantes para discretizar o sistema e, nas regiÃes onde hà contato entre malhas que nÃo coicidem, aplica-se a Regra do Momento Zero, descrita no presente trabalho. Nesse tipo de abordagem, pode haver uma separaÃÃo dos cÃdigos computacionais utilizados para o fluido e para a estrutura, os quais sÃo inicialmente tratados como entidades individuais e sà apÃs terem sido discretizados à que a informaÃÃo sobre suas malhas à recebida pela parte do cÃdigo responsÃvel por realizar o acoplamento dos subdomÃnios. Problemas de malhas que nÃo se encaixam podem surgir por diversos motivos, dentre eles, o fato de um subdomÃnio requerer uma malha mais refinada do que outros para que dele resultem resultados acurados. Pesquisadores de diferentes Ãreas podem gerar malhas separadas de distintos subdomÃnios e desejarem unÃ-los pelo mÃtodo abordado nesse trabalho em uma simulaÃÃo, ou a conformidade das malhas pode requerer muito tempo dispendido devido ao grande esforÃo computacional para a geraÃÃo de malhas conformes. Por fim, a aplicaÃÃo do mÃtodo produz resultados de grande relevÃncia, visto que, os modelos a que dizem respeito sÃo os mais comumente utilizados em projetos de aproveitamento de energia eÃlica offshore.
Pekar, Marek. "Modální analýza lopatek oběžného kola vírové turbíny." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231288.
Повний текст джерелаGiovanetti, Lucas. "Análise estrutural dinâmica de grade de proteção de turbina de uma usina hidroelétrica." Universidade de Taubaté, 2015. http://www.bdtd.unitau.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=853.
Повний текст джерелаTrashracks are very important equipment because they are responsible for protecting turbines of hydroelectric plants against floating bodies. These structures are subjected to the action of dynamic loads due to the water flow through the vertical and horizontal bars. The objective of this study was to analyze trashracks submitted by action of water flow. In other words, to analyze the responses of the structure and the behavior of water flow using dynamic of structures calculations coupled with computational fluid dynamics techniques (CFD) for a turbulent regime, through the use of commercial software CFX version 14. This analysis is elaborated by the process of fluid structure interaction. First of all, a simplified structural model of vertical bars is defined from other similar projects. For this model is defined a volume of control that represents fluid flow. Due to the Reynolds number calculated, it is utilized a turbulence model in order to obtain the results. These results are: stresses and displacements of vertical bars; and profile of velocities of flow. The results are analyzed and discussed. After that, considering the simplified model, analyzes with seven different values of speed are executed in order to compare the results between the data calculated numerically by finite elements method, and the values obtained experimentally. Considering the model verified, an analysis, of an inclined trashrack subjected to a parallel flow, is presented.
Bordin, Franciele Stail. "Análise do efeito da interação fluido-estrutura nas forças fluidodinâmicas em um elemento de pá flexível 3D." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/108499.
Повний текст джерелаElements of flexible materials are employed in several engineering applications, for instance, in wind turbine blades. The flow behavior is affected by any change in the shape of the structure. Often, its displacement and deformation are induced by the fluid-dynamic forces themselves. This paper presents the study of an external flow using fluid-structure interaction (FSI), focused on the behavior of wind turbine blades. Numerical simulations are performed in order to evaluate the effect that the deformation of the structure, caused by the elastic response to the flow forces, has on the fluid-dynamic forces themselves. The ANSYS Workbench platform is used, combining the software ANSYS CFX for the fluid analysis and ANSYS Mechanical for the structural analysis. As a form of validation of this method, the laminar flow over an elastically mounted cylinder is studied and compared with literature data. The chosen case for this work is a turbulent flow over a 3D blade element, fixed at one end and free at the other. The blade geometry is rectangular with the NACA 0012 profile and the turbulence model used is the k-ω SST. The results demonstrate the significant influence that the deformation of the structure has on the fluid-dynamic lift and drag forces, leading to an agreement with the existing literature.
Boujelben, Abir. "Géante éolienne offshore (GEOF) : analyse dynamique des pales flexibles en grandes transformations." Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2442.
Повний текст джерелаIn this work, a numerical model of fluid-structure interaction is developed for dynamic analysis of giant wind turbines with flexible blades that can deflect significantly under wind loading. The model is based on an efficient partitioned FSI approach for incompressible and inviscid flow interacting with a flexible structure undergoing large transformations. It seeks to provide the best estimate of true design aerodynamic load and the associated dynamic response of such system (blades, tower, attachments, cables). To model the structure, we developed a 3D solid element to analyze geometrically nonlinear statics and dynamics of wind turbine blades undergoing large displacements and rotations. The 3D solid bending behavior is improved by introducing rotational degrees of freedom and enriching the approximation of displacement field in order to describe the flexibility of the blades more accurately. This solid iscapable of representing high frequencies modes which should be taken under control. Thus, we proposed a regularized form of the mass matrix and robust time-stepping schemes based on energy conservation and dissipation. Aerodynamic loads are modeled by using the 3D Vortex Panel Method. Such boundary method is relatively fast to calculate pressure distribution compared to CFD and provides enough precision. The aerodynamic and structural parts interact with each other via a partitioned coupling scheme with iterative procedure where special considerations are taken into account for large overall motion. In an effort to introduce a fatigue indicator within the proposed framework, pre-stressed cables are added to the wind turbine, connecting the tower to the support and providing more stability. Therefore, a novel complementary force-based finite element formulation is constructed for dynamic analysis of elasto-viscoplastic cables. Each of theproposed methods is first validated with differents estexamples.Then,several numerical simulations of full-scale wind turbines are performed in order to better understand its dynamic behavior and to eventually optimize its operation
Li, Wei-Shiue, and 李韋學. "Fluid-Structure Coupling Analysis of Large Wind Turbine." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/33863209142808983500.
Повний текст джерела國立宜蘭大學
機械與機電工程學系碩士班
99
This research uses finite element analysis software ANSYS, CFD software CFX and three-dimensional computer-aided design software SolidWorks analyzes the flow field of the wind turbine. First, the model of large wind turbine is designed, then the fluid analysis is performed the fluid-structural analysis is also used to find the stress and strain distribution of the wind turbine. In this research, the flow field analysis for the upwind turbine and downwind turbine are considered. The results can find the higher velocity of the blade surface is observed. The stream lines are denser near the blade surface. That represents the velocity change is fast. Behind the rotating blade, the stream lines are not so dense that indicated the fluid has to travel long distance to blade to the original velocity value. The vortex distribution for the downwind turbine is more significant than that of the upwind turbine because the wind route is different for both of the wind turbine that they also have the different tilt angle rotor of shaft design. Through the fluid-structural coupling analysis for the wind turbine, the stress distribution of the structure can be observed, then the new design can be proposed, the transient fluid analysis is also performed, the force and torque variation based on the time can be obtained to see their differences.
Jiang, Jau-Ching, and 江昭慶. "Design and Fluid-Structure Coupling Analysis of Wind Turbine Blade." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/30279034374017907248.
Повний текст джерела國立宜蘭大學
機械與機電工程學系碩士班
98
In this research, aerodynamic characters of the wind turbine blade will be designed. Blade Element Theory and CAD software Blade Calculator are used to design two-dimensional shape curves of the wind turbine blades. Pro/E used to draw three-dimensional model of blades bused on two-dimensional curves. The finite element analysis software ANSYS and the computational fluid dynamics software CFX are used to perform, the fluid flow analysis to get the noise, blade surface pressure power with different wind speed. Through these analysis, we can combine the blade efficiency, noise, and angle adjustment devise to design a blade that will obtain the lower noise and avoid the blade stall. Fluid-structure coupling analysis is also performed. The maximum stress and strain are observed at the center line of the windward blade side. Blade deformation is similar to that of the cantilever beam, because the maximum deformation is observed at the blade terminal. Finally the natural frequencies with prestress and without prestress for the blade are analyzed. The vibration results showed that three is no much difference between these two cases.
LIN, YU-HUI, and 林育暉. "Application of ANSYS CFX in Wind Turbine fluid-structure interaction Simulation." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/99917313165364828549.
Повний текст джерела中華大學
機械工程學系
105
In recent years with the country's active development of renewable energy and development and research, and wind power is a kind of renewable energy, but also the world is committed to the development of renewable energy. Taiwan's western coastal and outer islands have considerable wind resources, the average annual wind speed of up to 5 ~ 6 m/s above the density of 250 w/m2, showing that China has a wind turbine development of shallow power. In this study, the structural analysis software ANSYS was used to analyze the structural mechanics behavior of the 660 kW Vestas V47 trilobalic horizontal shaft fan at the wind speed (15 m/s). In the study, Workbench under ANSYS was used to analyze the fluid-structure coupling, that is, the computational fluid dynamics software CFX and ANSYS structural mechanics software were combined with each other. And according to the relationship between different pitch angle, tilt angle and wind speed, different terrain corresponds to the ground roughness coefficient α. In addition to the general external flow field, the portion of the flow field region establishes a circular rotational domain flow field in the blade rotor section, since the setting of the blade portion during the calculation of the fluid analysis is to rotate, The wind speed is based on the wind velocity distribution method of IEC61400-1. The formula is Vinlet = Vhub (Z / Hhub) α, and the response of the blade to the fluid-solid coupling is discussed. The results are analyzed. Part of the speed in the first model has the maximum value, YZ plane under the maximum value will appear in the third model, the rotation field pressure field and YZ plane pressure field maximum is appear in the third model, Structural stress maximum value In addition to the first model is present on the left side of the blade, the other two models are present on the right side of the blade, and the maximum value appears on the first model. This study hopes to study the distribution of the flow field, the distribution of the pressure field and the stress distribution of the structure, and then the noise problem is discussed.
Chen, Tai-Yu, and 陳泰瑜. "Fluid-Structure Interaction of Wind Turbine and Failure Analysis of Composite Blades." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/29237258068229345619.
Повний текст джерела國立宜蘭大學
機械與機電工程學系碩士班
104
A wind turbine is one of widely used green power generation devices at present. Since most of the turbine blades are made of composite materials, the effect of ply-angle need to be considered. 2 MW onshore wind turbine is studied in this paper, and ANSYS Composite PrepPost (ACP) was used to input the laminated composite properties for the wind turbine blades. The failure of the composite structure is investigated through fluid-structure interaction analysis and Tsai-Wu failure criterion. The results show that the structure of the wind turbine blade during abnormal operation (wind speed = 11.5 m/s, pitch angle = 0°) is safe, even under negative attack angle conditions. The results for normal operation (wind speed = 25 m/s, pitch angle = 0°) indicates that the tower may be hit by the blade due to tip deformation. The highest stress is observed at the blade root due to significant deformation, but the blade structure is not expected to fail because the maximum Tsai-Wu failure indicators is only 0.875 (<1). In contrast, stress concentration is observed at 30 m from the blade root. It is caused by the structural weakness in the area with the least number of plies in the blade. Since the highest Tsai-Wu failure indicator is up to 1.1696, the composite laminates are expected to be damaged. Layers 5, 11 and 12 will fail according to the values of failure indicator. These findings will be useful to improve the design of composite wind turbine blades in the future.
Huang, Chi-Chung, and 黃啟忠. "Numerical Analysis of Fluid-Structure Interactions in Steam Turbine Low-Pressure Blades." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/99785108659041207784.
Повний текст джерела國立高雄應用科技大學
機械與精密工程研究所
96
The low-pressure blades crack near root location occurs occasionally in steam turbine. A possible occurrence of the blade failure is due to the interaction between unsteady flow and blades. The interaction between fluid field and structure should not be ignored for the low-pressure turbine blades with high aspect ratio. In this paper, solid-fluid interaction analysis of numerical simulated for the L-1 low-pressure turbine blades by using commercial software ANSYS with ALE (Arbitrary Lagrangian-Eulerian) method. The results showed that the blade vibration comes from the fluid flow generated impact pressure wave, and the maximum stress of blades occurred at the trail 15 mm from the root, and the largest displacement points at the top of the tail.
Jhan, Yu-Ti, and 詹育禔. "Fluid-Structure Interaction and Mold-flow Manufacturing Analysis in Wind Turbine Blades." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/28455557491595546771.
Повний текст джерела國立臺灣大學
工程科學及海洋工程學研究所
99
Wind turbine blades are long, thin, composite structures and therefore will have bending deflection in the flapwise direction as well as foil-section twist during rotational motion. The twist phenomenon accompanies the change of flow filed around blades and then leads to the change of loading condition on blades. The blade design without considering the aerodynamic and aeroelastic effect makes a wind turbine could not performance the best power generation efficiency. Otherwise, blades are usually built by the vacuum assisted resin transfer molding method. The successful manufacture depends on the proper infusion strategy and well realization of permeated characteristics of various laminates. Large-scale blades make the complicated permeated behavior of laminates and increase the infusion difficulty. First, the study confirmed the relationship between fiber orientation angle and structural response by the bend-twist experiments of small wind turbine blades. Then the calculating procedure of fluid-structure interaction with considering the aerodynamic effect was established by calculating attack angles of a blade (BEM), pressure distribution on the foil sections (2D flow field analysis), and structural analyses (FEM). The fluid-structure coupling effect was specifically discussed by calculating the power efficiency of a wind turbine. The adjustment of fiber orientation angle in the blade laminates was also utilized to improve the operating efficiency of wind turbines. The mold-flow manufacturing analyses focused on discussing the permeating characteristics of composite laminates under the VARTM process. The operation of 3D model composed of 1D pipe elements and laminates simulated the groove-flowing behavior of sandwich laminates and then substituted for complicated infusion experiments. The idea of equivalent thickness contributed to derive the permeability of sandwich laminates. The permeability predictive equations that were derived on the basis of the infusion experiments produced permeability of various laminates conveniently and were beneficial for the numerical analyses of large structures manufactures under the VARTM process.
Lin, Jiean-Hua, and 林建華. "Analysis of Fluid-Structure Interaction of a 2D Blade for a Small Wind Turbine." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/22jdpd.
Повний текст джерела國立虎尾科技大學
航空與電子科技研究所
98
Wind turbines have being attracted a lot of interest in engineering applications as the requirement for clear energy increases. Appropriate blade design has a significant effect on the efficiency of a wind turbine. To design an efficient wind turbine, it is necessary to understand the interaction between wind loads and blades. Many present studies focus on these two topics separately because highly dissimilar characteristics between them. The present study aims to investigate the coupling effect of wind loads and 2D blades for a small scale wind turbine. The present study applies the analysis software ANSYS and the computational fluid mechanics software CFX to conduct a two-way fluid structural analysis of a 2D blade. The effect of factors, include angle of attack, wind speed and Young modulus of blades, on the drag and lift are covered in the study. The information of displacement and force along the fluid structural interface are hand-shaked through stagger iteration between the fluid solver and the solid solver that individual calculation of field variables are carried out in the fluid solver and the solid solver until the displacement and force along the interface of fluid and structure are convergent. The analysis results show a blade with a flexible material under a high wind speed can reduce the drag coefficients by2.05 % and the lift coefficient by63.79%. This study provides a good insight for the design of blades for a small scale wind turbine.
LIN, YU, and 林宇. "Aerodynamic Prediction of Horizontal-Axis Offshore Wind Turbine via a Two-Way Fluid-Structure Interaction Approach." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/56664717617324229539.
Повний текст джерела國立臺灣科技大學
機械工程系
102
This study predicts the aerodynamic performance of the NREL 5MW offshore wind turbine via a two-way fluid-structure Interaction (FSI) approach. This simulations are performed under the rated wind velocity 11.4 m/s and rated rotor speed 12.1 rpm at full scale. The flow field around the wind turbine is computed by solving the Navier–Stokes equations incorporated with the k-Omiga turbulence model, where air is assumed as an incompressible viscous fluid. The equations are discretized using a finite volume method. In this study STAR-CCM+ and Abaqus are employed to solve the FSI problem, where a weak coupling approach is used. A remeshing process is adopted to obtain the required grid quality of sliding grid system as well as the mesh around the deformed blades. The simulation suggests that the deformation of reference point for flexible blade is about 6.45% of the total blade length. while the wind turbine with flexible blades delivers a power decrease by 9.56% when compared with the power delivered by rigid blades.
Jiang, Jung-Ming, and 江俊明. "Numerical Study on Aerodynamic Loading of Horizontal-Axis Wind Turbine via a Fluid-Structure Interaction Approach." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/11321790903860628644.
Повний текст джерела國立臺灣科技大學
機械工程系
101
This study investigates the aerodynamic characteristics of a 2MW three-blade horizontal wind turbine in operation condition via flow simulation with taking the fluid-structure interaction into account. The incompressible flow field around wind turbine is obtained by solving the continuity and momentum equations incorporated with a k-? turbulence model, and the forces and moments exerted on the wind turbine by wind can be then calculated. Two approaches, i.e. moving reference frame and sliding mesh method are adopted to find their differences in predicting aerodynamic performance, where the measured power is employed to validate the numerical result. Five different fiber reinforced plastic materials for blades under isotropic assumption are used to study their effects on the aerodynamic characteristics. The results suggest that the former method is less accurate than the later one, where the error in power prediction is about 5% for investigated cases. The deformation of blade tip varies from 0.2 m and 0.8 m for the studied materials, while the predicted power gives 2% difference between the wind turbines with flexible and rigid blades, which is mainly due to the small deformation of blades.
Huang, Chin-Chieh, and 黃俊傑. "Analysis of solid-fluid coupling of structure and flow field for a radial-inward cutback shape turbine impeller." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/34144921924683658802.
Повний текст джерела中華大學
機械與航太工程研究所
94
In this study we performed the solid-fluid coupling for radial-inward cutback shape turbine impeller with STAR-CD package software. The interactive analysis of structure and flow field for the impeller has been studied. In this research, the impeller outer diameter is 380mm, the axial length is 155 mm, and the analysis of structure and flow field changes are carried under the rotational speed of 30000RPM. The results of simulation analysis are as follows: The three-dimensional flow field analysis changed by multiple loads (temperature, centrifugal force) show 20MPa decrease in stress, 3.195mm increase in displacement. Flow field analysis shows 19Psi decrease in inlet pressure and no defect in pressure concentration at the bottom of the blades. Flow field velocity shows obvious vortex generation at shifted flow channels between two blades. The temperature of shifted flow field entering rotary zone is 56K higher than the temperature downstream of middle section before changing. The pressure drop ratio of flow field before shifting is 5.5, and is 3.77 after changing. The vibration and noise can be reduced by this 45% reduction in pressure drop. Traditional structure and flow field analysis can only be discussed solely. The discussion of solid-fluid coupling effect is to investigate the interactive impact between solid and surrounding flow field, so as to demonstrate a more realistic analysis and research when a turbine works. This study discusses the most important factor (temperature, displacement) in the interaction between impeller and flow field. The results for the varied effect of impeller and flow field has been obtained.
Lee, Waltfred. "Influence of the sweep angle on the leading edge vortex and its relation to the power extraction performance of a fully-passive oscillating-plate hydrokinetic turbine prototype." Thesis, 2021. http://hdl.handle.net/1828/12749.
Повний текст джерелаGraduate