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Статті в журналах з теми "FOWT":
1
Zhang, Hongjian, Hao Wang, Xin Cai, Jiaojie Xie, Yazhou Wang, and Ningchuan Zhang. "Research on the Dynamic Performance of a Novel Floating Offshore Wind Turbine Considering the Fully-Coupled-Effect of the System." Journal of Marine Science and Engineering 10, no. 3 (March 1, 2022): 341. http://dx.doi.org/10.3390/jmse10030341.
Анотація:
Floating offshore wind turbines (FOWTs) still face many challenges in improving platform stability. A fully submersible FOWT platform with inclined side columns is designed to tackle the current technical bottleneck of the FOWT platform, combining the structural characteristics of the semi-submersible and Spar platform. An integrated numerical model of FOWT is established considering the fully coupled effect, and the hydrodynamic performance of the novel FOWT, the semi-submersible FOWT, and the Spar FOWT are compared and analyzed under different wave incidence angles and wave frequencies, as well as the blade and tower dynamic response of the three FOWTs under the coupling effect of wind, wave, and current. The results show that the novel floating platform can significantly optimize the hydrodynamic performance and has a better recovery ability after being subjected to external loads. The novel floating platform can significantly reduce the heave peak and its corresponding wave frequency compared to the semi-submersible platform, reducing the possibility of heave resonance. FOWT operation should ensure positive wave inflow as far as possible to avoid excessive wave forces in the lateral direction. Both blade and tower dynamic response are affected by rotor rotation and tower vibration to varying degrees, while tower dynamic response is mainly affected by platform motion. This study suggests that the application of the novel FOWT concept is feasible and can be an alternative in offshore wind exploitation in deep water.
2
Feng, Zhouquan, Yuheng Huang, Xugang Hua, Jinyuan Dai, and Haokun Jing. "Vibration-Resistant Performance Study of a Novel Floating Wind Turbine with Double-Rope Mooring System and Stroke-Limited TMD." Journal of Marine Science and Engineering 11, no. 1 (January 1, 2023): 58. http://dx.doi.org/10.3390/jmse11010058.
Анотація:
Floating offshore wind turbines (FOWTs) are generally located in the harsh deep-sea environment and are highly susceptible to extreme loads. In order to ensure the normal operation of FOWTs, this article takes the semi-submersible FOWT as an example, proposes a new double-rope mooring system, and studies the dynamic performance of the FOWT with the double-rope mooring system and its effectiveness in reducing the dynamic response of the wind turbine. At the same time, the tuned mass damper (TMD) is installed in the nacelle of the wind turbine, and the TMD parameters are optimized considering the space limitation of the nacelle by limiting the TMD’s stroke, which further reduces the dynamic response of the FOWT and improves its stability. Numerical simulation and analytical studies show that the new double-rope mooring system can reduce the dynamic response of the wind turbine to a greater extent than the traditional single-rope mooring system. Considering the stroke restriction, the control performance of TMD will be slightly weakened, but it is more in line with the actual engineering requirements. Compared with the original FOWT, the proposed new type of FOWT has better dynamic stability and has the prospect of extending to real engineering applications.
3
Xue, Lei, Jundong Wang, Liye Zhao, Zhiwen Wei, Mingqi Yu, and Yu Xue. "Wake Interactions of Two Tandem Semisubmersible Floating Offshore Wind Turbines Based on FAST.Farm." Journal of Marine Science and Engineering 10, no. 12 (December 9, 2022): 1962. http://dx.doi.org/10.3390/jmse10121962.
Анотація:
Wake effects commonly exist in offshore wind farms, which will cause a 10–20% reduction of whole power production as well as a 5–15% increase of fatigue loading on the wind turbine main structures. Obviously wake interaction between floating offshore wind turbine (FOWT) is more complicated, and needs careful assessment which is a prerequisite for active wake control (AWC). The primary objective of the present research is to investigate in detail how the wake inflow condition, streamwise spacing, turbulence intensity, and wind shear influence the power performance, platform motion dynamic and structural loading of FOWT. FAST.Farm, developed by the National Renewable Energy Laboratory (NREL), was used for simulating two tandem FOWTs in different conditions. Comparisons were made between FOWTs in different conditions on power performance and platform motion dynamic, which were presented through both time and frequency domain analysis. Damage equivalent loads change in FOWTs interference under typical working conditions were discussed and summarized. Half wake inflow would pose many challenges to the downstream FOWT. These research studies can be incorporated into further offshore wind farm wake models, providing applicable AWC strategies to reduce wake interference effects for higher energy production and for the longer life of FOWT.
4
Formosa, W., and T. Sant. "Modelling the loads and motions of a floating offshore wind turbine with asymmetric moorings." Journal of Physics: Conference Series 2362, no. 1 (November 1, 2022): 012013. http://dx.doi.org/10.1088/1742-6596/2362/1/012013.
Анотація:
Despite the improvements in wind energy conversion technology, wake effects present in wind farms still remain a challenge. In the case of floating offshore wind turbines (FOWTs), these can be mitigated by varying the mooring lengths to dynamically position the FOWTs according to the wind direction. As this introduces asymmetry in the mooring system, the stability of the FOWTs may be affected. With the aim of unlocking the full potential of floating offshore wind, this work investigates the loads and motions of a full-scale 6 MW spar-supported FOWT with four catenary moorings as its position is shifted along the crosswind direction. A hydrodynamic model developed in ANSYS® AQWA™ to obtain the dynamic response of the system in four metocean conditions is presented. Results indicate that asymmetry in the mooring system has a noticeable effect on the sway and roll motions as well as the cable tensions. The wave height and irregularity only appear to influence the FOWT motions. In general, the dynamic response of the FOWT system is not expected to be jeopardized as the typical permissible limits for a spar-supported FOWT and the proof load of the cables were not exceeded.
5
M’zoughi, Fares, Payam Aboutalebi, Izaskun Garrido, Aitor J. Garrido, and Manuel De La Sen. "Complementary Airflow Control of Oscillating Water Columns for Floating Offshore Wind Turbine Stabilization." Mathematics 9, no. 12 (June 12, 2021): 1364. http://dx.doi.org/10.3390/math9121364.
Анотація:
The implementation and integration of new methods and control techniques to floating offshore wind turbines (FOWTs) have the potential to significantly improve its structural response. This paper discusses the idea of integrating oscillating water columns (OWCs) into the barge platform of the FOWT to transform it into a multi-purpose platform for harnessing both wind and wave energies. Moreover, the OWCs will be operated in order to help stabilize the FOWT platform by means of an airflow control strategy used to reduce the platform pitch and tower top fore-aft displacement. This objective is achieved by a proposed complementary airflow control strategy to control the valves within the OWCs. The comparative study between a standard FOWT and the proposed OWC-based FOWT shows an improvement in the platform’s stability.
6
Mostafa, N., M. Murai, R. Nishimura, O. Fujita, and Y. Nihei. "Study of motion of spar-type floating wind turbines in waves with effect of gyro moment at inclination." Journal of Naval Architecture and Marine Engineering 9, no. 1 (June 30, 2012): 67–79. http://dx.doi.org/10.3329/jname.v9i1.10732.
Анотація:
Recently, a number of research groups have paid much attention to the study of Floating Offshore Wind Turbines (FOWTs). Similar to other offshore structures, the FOWTs are subjected to irregular waves and wind loads which cause a dynamic response in the structures. Under marine environmental conditions, they face many forces which prevent them from floating in the upright condition; they incline as a result of the winds, strong currents, typhoons, cyclones, storms etc. The motion of the FOWT might be changed by a change in gyroscopic effect which depends on the angular velocity and moment of inertia of the blade. Therefore, to investigate the effect of the gyro moment on the motion of the FOWT, two types of experiment were carried out in a water tank using a 1/360 scale model of a prototype FOWT. Firstly, the interaction between the rotary motion of the wind turbine blade and the dynamic motion of the SPAR-type FOWT was studied at small angles of inclination in regular waves. Secondly, the interaction between the change of rotational speed as well as moment of inertia of the blade and the motion of the FOWT was studied. In this paper, numerical calculations have been carried out using potential theory based on the 3D panel method. Finally, the experimental results are compared with the results of numerical simulation and findings are discussed. DOI: http://dx.doi.org/10.3329/jname.v9i1.10732 Journal of Naval Architecture and Marine Engineering 9(2012) 67-79
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Dong, Yehong, Yewen Chen, Hao Liu, Shuni Zhou, Yuanxiang Ni, Chang Cai, Teng Zhou, and Qing’an Li. "Review of Study on the Coupled Dynamic Performance of Floating Offshore Wind Turbines." Energies 15, no. 11 (May 27, 2022): 3970. http://dx.doi.org/10.3390/en15113970.
Анотація:
Floating offshore wind turbines (FOWT) have attracted more and more attention in recent years. However, environmental loads on FOWTs have higher complexity than those on the traditional onshore or fixed-bottom offshore wind turbines. In addition to aerodynamic loads on turbine blades, hydrodynamic loads also act on the support platform. A review on the aerodynamic analysis of blades, hydrodynamic simulation of the supporting platform, and coupled aero- and hydro-dynamic study on FOWTs, is presented in this paper. At present, the primary coupling method is based on the combination of BEM theory and potential flow theory, which can simulate the performance of the FOWT system under normal operating conditions but has certain limitations in solving the complex problem of coupled FOWTs. The more accurate and reliable CFD method used in the research of coupling problems is still in its infancy. In the future, multidisciplinary theories should be used sufficiently to research the coupled dynamics of hydrodynamics and aerodynamics from a global perspective, which is significant for the design and large-scale utilization of FOWT.
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Lee, Y.-J., C. Y. Ho, and Z. Z. Huang. "Hydrodynamic Responses of a Spar-Type Floating Wind Turbine in High Waves." Journal of Mechanics 31, no. 1 (October 21, 2014): 105–12. http://dx.doi.org/10.1017/jmech.2014.69.
Анотація:
AbstractFloating offshore wind turbines (FOWTs) can be used to exploit the enormous wind energy present over deep waters. Numerous studies have examined the dynamics of FOWTs, but few have focused on validating numerical results with experimental results, particularly for a deep draught FOWT in regions with frequent tropical storms. For this study, we developed a computer code and conducted experiments with a scale model to validate the simulation results. The computer code was first verified by comparing the results with those of the International Energy Agency Wind Task 23. Numerical simulations were implemented in both the frequency domain and the time domain. A comparison of the numerical and experimental results of the scale model in high waves showed good agreement. The flexibility of blades and the tower did not observably affect the motion of the deep draft spar-type FOWT. Therefore, it can be ignored in the preliminary design. The pitch motion of the scale model was within 1°. Therefore, the spar-type FOWT may be an effective power source for regions with frequent tropical storms.
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Jia, Zhaolin, Han Wu, Hao Chen, Wei Li, Xinyi Li, Jijian Lian, Shuaiqi He, Xiaoxu Zhang, and Qixiang Zhao. "Hydrodynamic Response and Tension Leg Failure Performance Analysis of Floating Offshore Wind Turbine with Inclined Tension Legs." Energies 15, no. 22 (November 16, 2022): 8584. http://dx.doi.org/10.3390/en15228584.
Анотація:
The tension legs are the essential parts of the tension legs platform-type (TLP-type) floating offshore wind turbine (FOWT) against the extra buoyancy of FOWT. Therefore, the TLP-type FOWT will face the risk of tension leg failure. However, there are seldom analyses on the hydrodynamic response and tension leg failure performance of FOWT with inclined tension legs. In this paper, a hydrodynamic model was established using three-dimensional hydrodynamic theory and applied in the motion response and tension analyses of FOWT with conventional and new tension leg arrangements on Moses. The influence of draft and tension leg arrangement on the performance of FOWT with inclined tension legs were studied. The optimum draft was the height of the column and lower tensions were obtained for the new tension leg arrangement. Moreover, the tension leg failure performance of FOWT with inclined tension legs was evaluated under different failure conditions. The results illustrated that the FOWT with the new tension leg arrangement can still operate safely after one tension leg fails.
10
Dinh, Van Nguyen, and Biswajit Basu. "On the Modeling of Spar-Type Floating Offshore Wind Turbines." Key Engineering Materials 569-570 (July 2013): 636–43. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.636.
Анотація:
In this paper an overview about floating offshore wind turbines (FOWT) including operating conditions, property and applicability of the barge, tension-leg, and spar floating platforms is described. The spar-floating offshore wind turbines (S-FOWT) have advantages in deepwater and their preliminary design, numerical modeling tools and integrated modeling are reviewed. Important conclusions about the nacelle and blade motions, tower response, effects of wind and wave loads, overall vibration and power production of the S-FOWT are summarized. Computationally-simplified models with acceptable accuracy are necessary for feasibility and pre-engineering studies of the FOWT. The design needs modeling and analysis of aero-hydro-servo dynamic coupling of the entire FOWT. This paper also familiarizes authors with FOWT and its configurations and modeling approaches.
Дисертації з теми "FOWT":
1
Aliyar, Sithik. "Extreme wave interaction with fixed and floating structures using hybrid coupling approach." Electronic Thesis or Diss., Ecole centrale de Nantes, 2022. http://www.theses.fr/2022ECDN0047.
Анотація:
La thèse vise à étudier l’efficacité et la précision des solveurs NS et SWENSE pour simuler des structures fixes et flottantes. Les deux solveurs sont basés sur OpenFOAM et sont couplés indépendamment avec HOS pour la générationd’onde en termes de domaine et d’approche de décomposition fonctionnelle. Les solveurs sont testés pour trois applications. Les première et deuxième applications présentent l’interaction d’ondes de focalisation avec des cylindresfixes et mobiles et la troisième est l’interaction d’ondes régulières et irrégulières avec la sousstructure de type OC3 Hywind SPAR. Les méthodes et paramètres de génération d’ondes pour les solveurs NS et SWENSE sont discutés endétail pour les ondes régulières, irrégulières et focalisées. Pour vérification, l’incertitude du cas est quantifiée à l’aide de l’approche d’extrapolation de Richardson et validée avec les mesures expérimentales. Une réduction significative de lataille du maillage est prévue dans les deux approches. Pour l’étude de l’interaction des ondes de corps flottant, les amarres sont modélisées de deux façons : en considérant les lignes d’amarrage comme un ressort linéaire avec une raideur de ressort définie et un couplage avec un modèle d’amarrage dynamique (MoorDyn). Les résultats numériques de l’élévation de surface, des mouvements du corps et des tensions d’amarrage sont validés par rapport aux expériences menées dans le projet SOFTWIND, et l’efficacité et la précision des deux solveurs sont comparéesThe thesis aims to study the effectiveness and accuracy of the NS and SWENSEbased solvers for simulating fixed and floating structures. Both solvers are OpenFOAM-based and are independently coupled with HOS for wave generation in terms of domain and functional decomposition approach. The solvers are tested for three applications. The first and second applications present the focusing wave interaction with fixed and moving cylinders and the third is the interaction of regular and irregular waves with the OC3 Hywind SPAR type substructure. The wave generating methods and parametersfor NS and SWENSE solvers are discussed in detail for regular, irregular, and focused waves. For verification, the case’s uncertainty is quantified using the Richardson extrapolation approach and validated with the experimental measurements.A significant reduction in the mesh size is predicted in both approaches. For the floating body wave interaction study, the moorings are modelled in two ways: by considering the mooring lines as a linear spring with defined spring stiffnessand coupling with a dynamic mooring model (MoorDyn). The numerical results of surface elevation, body motions, and mooring tensions are validated against the experiments carried out in the SOFTWIND project, and the efficiency andaccuracy of the two solvers are compared
2
Schliffke, Benyamin. "Caractérisation expérimentale de l'impact de la houle sur le comportement aérodynamique des éoliennes flottantes." Thesis, Ecole centrale de Nantes, 2022. http://www.theses.fr/2022ECDN0008.
Анотація:
La décarbonation du secteur de l'énergie est un défi majeur de notre époque. Les énergies renouvelables offrent une solution viable. L'éolien offshore peut contribuer à une grande partie de la demande énergétique. Pour accéder à l'importanteressource éolienne en mer, il est nécessaire d'installer des éoliennes flottantes. Comme la technologie est encore à l'état préindustriel, plusieurs questions restent à résoudre. En utilisant la modélisation physique à une échelleréduite, cette thèse vise à étudier le comportement instationnaire et le développement du sillage d’un modèle simplifié d’éolienne. Le modèle est placé dans une soufflerie atmosphérique et soumis à une gamme de mouvements idéalisés et réalistes. Les valeurs de vitesse moyenne restent globalement inchangées mais l’intensité de turbulence et l’énergie cinétique turbulente (TKE) sont modifiées. Le bilan TKE révèle que la production et la dissipation turbulentes sont augmentées avec l'introduction du mouvement de vague idéalisé. Les spectres d'énergie de l'écoulement sont affectés par l'introduction du mouvement. Un mouvement idéalisé à fréquence unique entraîne une signature claire dans les spectres d'énergie du sillage. Un déplacement vers des fréquences plus élevées peut être observé pour plusieurs régimes de mouvement. Un mouvement réaliste à 3 degrés de liberté affecte le sillage différemment d'un mouvement idéalisé à 3 degrés de libertéDecarbonising the energy sector is a major challenge of our times. Renewable energies offer a viable solution. Offshore windalone can contribute a large portion of the energy demand. To access the large wind resource further offshore floating wind turbines are necessary. Floating offshore wind turbines (FOWTs) are a potential source for increased offshore energy production. As the technology is still in a pre-industrial state several questionsremain to be addressed. Using physical modelling at a reduced scale, this thesis aims to investigate the unsteady behaviour and the development of the wake in a simplified FOWT model. The model is placed in an atmospheric wind tunnel and subjected to a. range of idealised and realistic motions. Each degree of freedom is studied separately and all three degrees of freedom (Dof) together. The effects of induced sinusoidal surge motion on the characteristics of the model’s wake up to 8D downstream are studied. The results show globally unchanged mean velocity values but modified turbulence intensity and turbulent kinetic energy (TKE). A TKE budget analysis reveals that the turbulent production and dissipation are increased with the introduction of idealised surge motion. The energy spectra of the flow are affected by the introduction of motion. Idealised single frequency motion leaves a clear signature in the wake spectra. A shift to higher frequencies can be observed for several motion regimes. Realistic 3 Dof motion affects the wake differently compared to idealised 3 Dof motion
3
ILARDI, DAVIDE. "Data-driven solutions to enhance planning, operation and design tools in Industry 4.0 context." Doctoral thesis, Università degli studi di Genova, 2023. https://hdl.handle.net/11567/1104513.
Анотація:
This thesis proposes three different data-driven solutions to be combined to state-of-the-art solvers and tools in order to primarily enhance their computational performances. The problem of efficiently designing the open sea floating platforms on which wind turbines can be mount on will be tackled, as well as the tuning of a data-driven engine's monitoring tool for maritime transportation. Finally, the activities of SAT and ASP solvers will be thoroughly studied and a deep learning architecture will be proposed to enhance the heuristics-based solving approach adopted by such software. The covered domains are different and the same is true for their respective targets. Nonetheless, the proposed Artificial Intelligence and Machine Learning algorithms are shared as well as the overall picture: promote Industrial AI and meet the constraints imposed by Industry 4.0 vision. The lesser presence of human-in-the-loop, a data-driven approach to discover causalities otherwise ignored, a special attention to the environmental impact of industries' emissions, a real and efficient exploitation of the Big Data available today are just a subset of the latter. Hence, from a broader perspective, the experiments carried out within this thesis are driven towards the aforementioned targets and the resulting outcomes are satisfactory enough to potentially convince the research community and industrialists that they are not just "visions" but they can be actually put into practice. However, it is still an introduction to the topic and the developed models are at what can be defined a "pilot" stage. Nonetheless, the results are promising and they pave the way towards further improvements and the consolidation of the dictates of Industry 4.0.
4
Nygren, Maria. "Web Font Optimization for Mobile Internet Users : A performance study of resource prioritization approaches for optimizing custom fonts on the web." Thesis, Linnéuniversitetet, Institutionen för datavetenskap och medieteknik (DM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-85481.
Анотація:
According to the HTTP Archive, 75% of websites are using web fonts. Multiple conditions have to be met before modern web browsers like Chrome, Firefox and Safari decide to download the web fonts needed on a page. As a result, web fonts are late discovered resources that can delay the First Meaningful Paint (FMP). Improving the FMP is relevant for the web industry, particularly for performance-conscious web developers. This paper gives insight into how the resource prioritization approaches HTTP/2 Preload and HTTP/2 Server Push can be used to optimize the delivery of web fonts for first-time visitors. Five font loading strategies that use HTTP/2 Server Push and/or Preload were implemented on replicas of the landing pages from five real-world websites. The font loading strategies were evaluated against each other, and against the non-optimized version of each landing page. All the evaluated font loading strategies in this degree project improved the time it took to deliver the first web font content to the user’s screen, resulting in a faster FMP. It was also discovered that HTTP/2 Server Push, on its own, is not a more performance efficient resource prioritization approach than HTTP/2 Preload when it comes to delivering web font content to the client. Further, HTTP/2 Server Push and HTTP/2 Preload appears to be more efficient when used together, in the context of optimizing the delivery of web font content. However, all conclusions in this paper are based on the results gathered from testing the font loading strategies in an emulated environment and are yet to be confirmed on actual mobile devices with real network conditions.
5
Richardson, Paul Anthony. "Fort Glenelg : the fort that never was /." Title page, contents and introduction only, 1987. http://web4.library.adelaide.edu.au/theses/09AR/09arr521.pdf.
6
Jiříček, Milan. "Živý font." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219475.
Анотація:
The work describes the theoretical foundations of modern methods of creating new fonts, that is, using information technology, specifically vector programs. It also marginally shows the history of the font, Roman writing, the basic division of its compositions and describes its individual elements. The next part of the project focuses on creating digital fonts and continues with bringing it to live using algorithms and methods that can easily be processed in Matlab programming language. The method of implementation of the bringing the typeface to live is described and presentation of the generated results are then shown in few examples. Attention is also paid to the coordinates system, which is very important to solve geometric transformations, and two-dimensional vector graphics, which are widely used in the design and to render the fonts. Bézier curves and cubic Bézier curves are described in further detail along with vector graphics rasterization. One part of this text describes very important de Casteljau algorithm. The last chapter focuses on implementation in Matlab programming language, the creation of curves, that means single font characters, and the ways of how the algorithm works with transformations. Some sample images showing transformations using different input arguments are displayed in this section as well. There is evaluation of the contribution of this application and the possibilities of further expansion at the end.
7
Taspunar, Ceren Sultan, and Raniah Al-Sammak. "Diabetespatienters behov av kunskap och undervisninggällande primär prevention av fotsår. : En litteraturstudie." Thesis, Malmö universitet, Malmö högskola, Institutionen för vårdvetenskap (VV), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-42255.
Анотація:
Bakgrund: Diabetes mellitus är en kronisk sjukdom som ökar över hela världen. De drabbade individerna får diabetesrelaterade komplikationer som uppkommer vid sjukdomen, bland annat fotkomplikationer såsom fotsår som är vanligt förekommande. Komplikationerna leder till stort lidande för personen. Förutom att det leder till lidande för personen så medför det stora kostnader för hälso- och sjukvården. Uppkomst av fotsår kan motverkas och förhindras genom kunskap och utbildning. Syfte: Författarna vill i denna litteraturstudie belysa diabetespatienters behov av kunskap och undervisning gällande primär prevention av fotsår. Metod: Studien har utförts som en kvalitativ litteraturstudie där tio vetenskapliga artiklar har inkluderats. Artiklarna söktes via de två databaserna PubMed och CINAHL. De inkluderande artiklarna var med kvalitativ ansats. Resultatet av artiklarna bearbetades, analyserades, kvalitetsgranskades och sammanställdes. Resultat: Resultatet framfördes genom två huvudkategorier som är egenvårdsåtgärder och patientutbildning. Genom egenvård är patienterna delaktiga i sin vårdplan. Informationen av egenvårdsåtgärder ska inkluderas i första informationsmötet med patienten. I patientutbildning ges den information och rådgivningen som behövs för att patienten ska kunna hantera sin sjukdom. Dessutom leder patientutbildning till motivation och bättre hälsofrämjande vanor. Konklusion: För att fotsår ska undvikas bör patienten ha kunskaper om vilka komplikationer diabetes kan orsaka. Genom att ha en tydlig bild om hur komplikationerna förhindras leder det till förbättrad omhändertagandet av fötterna. Kommunikationen mellan patienten och vårdpersonalen är en avgörande faktor för hur väl informationen nås fram.Background: Diabetes mellitus is a chronic disease that is on the rise worldwide. The affected individuals get diabetes-related complications that arise from the disease, including foot complications that are common. The complications lead to great suffering for the person. In addition to suffering for people, it also entails huge costs for health care. The onset of foot ulcers can be counteracted and prevented through knowledge and education. Purpose: In this literature study, the authors want to shed light on diabetic patients' need for knowledge and education regarding the primary prevention of foot ulcers. Method: The study was conducted as a qualitative literature study where ten scientific articles have been included. The articles were searched through the two databases PubMed and CINAHL. The included articles were with a qualitative approach. In the background, both qualitative and quantitative articles were included. Only qualitative articles were included in the results. The results of the articles were processed, reviewed and compiled. Results: The results were presented through two main categories, which are self-care measures and patient education. Through self-care, patients are involved in their care plan. The information of self-care measures must be included in the first information meeting with the patient. In patient education, the information and advice need to enable the patient to manage that their illness is provided. In addition, patient education leads to motivation and better health-promoting habits. Conclusion: To avoid foot ulcers, the patient should have knowledge of what complications diabetes can cause. By having a clear picture of how the complications are prevented, it leads to improved care of the feet. The communication between the patient and the care staff is a decisive factor in how well the information is obtained.
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Nicolopoulos, Christos. "Evaluation of the treatment of foot deformities using foot orthoses." Thesis, University of Strathclyde, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.344073.
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Barisch-Fritz, Bettina. "Dynamic Foot Morphology." Doctoral thesis, Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-150328.
Анотація:
Background: The foot has to fulfil important and complex functions which are, in most regions of the world, supported by shoes. The interface of feet and footwear has often been considered with respect to comfort and function but also to negative effects of shoes. One main contribution to the improvement of footwear fit is provided by matching the shape of the shoe to the shape of the foot. However, current approaches for implementation only include static information. There is still a lack of dynamic information about foot morphology and deformation. Recent advancements in scanner technology allow capturing the foot during natural walking. These advancements and the development of a dynamic foot scanner system (DynaScan4D) are preconditions for this thesis. The research question is: How does foot morphology differ between static and dynamic situations? This question is further specified toward three hypotheses by findings and deficits of the current state of research. The examination of the three hypotheses and their contribution to the research question are topic of this thesis. Furthermore, the findings are combined with comprehensive knowledge of the literature to formulate recommendations for last and footwear construction. Methods: The three hypotheses (H1, H2, H3) are evaluated within three research articles. The first research article aims to identify the differences in dynamic foot morphology according to age, gender, and body mass (H1). The plantar dynamic foot morphology of 129 adults is recorded and analysed by two statistical methods: (1) comparison of matched groups and (2) multiple linear regression analysis. The second and third research article is dealing with differences between static and dynamic foot morphology in developing feet (H2) and their inter-individual differences (H3). For this reason, a large sample of 2554 children, aged between 6 and 16 years, is analysed. Foot measures, corresponding to last measures, are used to identify the differences between static and dynamic foot morphology (H2) by Student's t-test for paired samples. The influences of gender, age, and body mass (H3) are analysed within the whole sample by multiple linear regression analysis and within matched groups by Student's t-test for independent samples. Results: There are differences in dynamic foot morphology according to age, gender, and body mass in adults which confirm H1. In general, the differences are rather small. Furthermore, the differences must be considered in a more differentiated way, as they are not consistent regarding all plantar foot measures. H2 is confirmed as there are statistically signiffcant differences between static and dynamic foot morphology in developing feet. Theses differences are found for all foot measures. However, the magnitude of these differences varies depending on each foot measure. Relevant differences, in particular the forefoot width and midfoot girth measures as well as the angles of the forefoot, must be considered for footwear construction. Influences of gender, age, and body mass are found for the dynamic foot morphology and the differences between static and dynamic foot morphology of developing feet. Thus, H3 is verified. However, these findings are small, especially considering the high variance within each foot measure. The variables gender, age, and body mass cannot appropriately explain the variance of the differences between static and dynamic foot morphology. Thus, the customization of footwear to dynamic foot morphology can be conducted without individual adjustments to gender, age, or body mass. Conclusion: This thesis presents different aspects to answer the question of differences between static and dynamic foot morphology. The findings of this thesis are critically discussed and recommendations for improvements of dynamic fit of footwear are formulated, taking into account the current state of research as well as practical aspects. The findings of the thesis contribute to the field of fundamental research, i.e. to broaden the knowledge about three-dimensional characteristics of dynamic foot morphology. Furthermore, this thesis can help to improve the fit of footwear and thus contributes to applied research in the field of footwear scienceHintergrund: Der Fuß erfüllt wichtige und komplexe Funktionen, die in den meisten Regionen der Welt, durch Schuhe unterstützt werden. Die Berührungspunkte zwischen Schuhen und Füßen wurden im Hinblick auf komfortable und funktionelle Schuhe, aber auch hinsichtlich negativer Effekte von Schuhen, häufig betrachtet. Ein wesentlicher Beitrag zur Verbesserung der Passform von Schuhen liefert die Annäherung der Schuhform an die Fußform. Jedoch beschränken sich bisherige Umsetzungsansätze auf statische Informationen. Bislang fehlen umfangreiche dynamische Informationen zur Fußgestalt und Verformung. Erst aktuelle Fortschritte der Scanner-Technologie ermöglichen es, den Fuß während des natürlichen Gehens zu erfassen. Diese Fortschritte und die Entwicklung eines dynamischen Fuß-Scanner-Systems (DynaScan4D), stellen die Grundlage für diese Dissertation dar. Die Forschungsfrage ist: Wie unterscheidet sich die statische Fußgestalt von der dynamischen? Mit der Aufarbeitung von Ergebnissen und Defiziten aktueller Forschungsarbeiten wird diese Frage durch die Formulierung von drei Hypothesen weiter spezifiziert. Diese drei Hypothesen, sowie deren Beitrag zur Forschungsfrage, sind Thema dieser Dissertation. Darüber hinaus wird umfassendes Wissen aus der Literatur verwendet um Empfehlungen für die Konstruktion von Schuhen zu geben. Methoden: Die drei Hypothesen (H1, H2, H3) werden in drei wissenschaftlichen Veröffentlichungen untersucht. Die erste Veröffentlichung zielt darauf ab, die Unterschiede zwischen der dynamischen Fußgestalt in Abhängigkeit von Alter, Geschlecht und Körpermasse zu ermitteln (H1). Die plantare dynamische Fußgestalt von 129 Erwachsenen wird hierzu erfasst und durch zwei statistische Verfahren analysiert: (1) Vergleich von gepaarten Probandengruppen und (2) multiple lineare Regressionsanalyse. Die zweite und dritte Hypothese befassen sich mit den Unterschieden der statischen und dynamischen Fußgestalt bei heranreifenden Füßen (H2) und deren inter-individuellen Unterschieden (H3). Aus diesem Grund wird eine große Stichprobe mit 2554 Kindern im Alter zwischen 6 und 16 Jahren untersucht. Fußmaße, die den Maßen im Leistenbau entsprechen, werden verwendet um die Unterschiede zwischen der statischen und der dynamischen Fußgestalt (H2) durch einen gepaarten Student's t-Test zu identifizieren. Der Einfluss des Geschlechtes, des Alters und der Körpermasse (H3) werden in der gesamten Stichprobe durch eine multiple lineare Regressionsanalyse und innerhalb gepaarter Probandengruppen durch Student's t-Test für unabhängige Stichproben untersucht. Ergebnisse: Es gibt Unterschiede in der dynamischen Fußgestalt von Erwachsenen, beeinflusst durch Alter, Geschlecht und Körpermasse, welche die Verifizierung von H1 erlauben. Im Allgemeinen sind diese Unterschiede jedoch gering. Die ermittelten Unterschiede müssen differenziert betrachtet werden, da sie nicht konsistent in Bezug auf die gesamte plantare Fußgestalt auftreten. H2 kann verifiziert werden, da es zwischen der statischen und der dynamischen Fußgestalt von heranreifenden Kindern statistisch signifikante Unterschiede gibt. Diese Unterschiede wurden bei allen Fußmaßen gefunden, wobei das Außmaß dieser Unterschiede in Abhängigkeit vom jeweiligen Fußmaß variiert. Relevante Unterschiede, insbesondere Breitenmaße und Winkelmaße des Vorfußes sowie Umfangsmaße des Mittelfußes, müssen bei der Konstruktion von Schuhen berücksichtigt werden. Es zeigen sich Einflüsse von Geschlecht, Alter und Körpermasse auf die dynamische Fußgestalt sowie auf die Differenzen zwischen der statischen und der dynamischen Fußgestalt. Somit ist H3 verifiziert. Jedoch sind diese Einflüsse gering, besonders wenn die Varianz innerhalb der Fußmaße betrachtet wird. Die Variablen Alter, Geschlecht und Körpermasse können die Varianz der Differenzen zwischen der statischen und der dynamischen Fußgestalt nicht angemessen erklären. Damit kann die Anpassung an die dynamische Fußgestalt ohne eine Individualisierung hinsichtlich Alter, Geschlecht oder Körpermasse vollzogen werden. Schlussfolgerungen: Die vorliegende Dissertation stellt unterschiedliche Aspekte zur Beantwortung der Frage, welche Unterschiede zwischen der statischen und der dynamischen Fußgestalt bestehen, vor. Die Ergebnisse der Arbeit werden kritisch diskutiert und es werden, unter Berücksichtigung des aktuellen Forschungsstandes sowie praktischer Aspekte, Empfehlungen zur Optimierung der dynamischen Passform von Schuhen gegeben. Die Ergebnisse der Dissertation liefern einen Beitrag zur Grundlagenforschung, insbesondere durch die Erweiterung des Wissensstands der dreidimensionalen Eigenschaften der dynamischen Fußgestalt. Darüber hinaus kann diese Arbeit helfen die dynamische Passform von Schuhen zu verbessern und trägt damit zur angewandten Schuhforschung bei
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Blaya, Joaquin A. (Joaquin Andres) 1978. "Force-controllable ankle foot orthosis (AFO) to assist drop foot gait." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/28282.
Анотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2003.Includes bibliographical references (leaves 81-85).
Drop foot, a loss of use of the muscles that lift the foot, can be caused by stroke, cerebral palsy (CP), multiple sclerosis (MS), or neurological trauma. The two major complications of drop foot are slapping of the foot after heel strike (foot slap) and dragging of the toe during swing (toe drag). The current assistive device is the Ankle Foot Orthosis (AFO), which though offering some biomechanical benefits, is nonadaptive and fails to eliminate significant gait complications. An Active Ankle Foot Orthosis (AAFO) is presented where the impedance of the orthotic joint is modulated throughout the walking cycle to treat drop foot gait. To prevent foot slap, a biomimetic torsional spring control is applied where orthotic joint stiffness is actively adjusted to minimize forefoot collisions with the ground. Throughout late stance, joint impedance is minimized so as not to impede powered plantar flexion movements, and during the swing phase, a torsional spring-damper (PD) control lifts the foot to provide toe clearance. To assess the clinical effects of variable-impedance control, kinetic and kinematic gait data were collected on two drop foot participants wearing the AAFO. For each participant, zero, constant and variable impedance control strategies were evaluated, and the results were compared to the mechanics of three age, weight and height matched normals. It was found that actively adjusting joint impedance significantly reduces the occurrence of slap foot, allows greater powered plantar flexion, and provides for greater biological realism in swing phase ankle dynamics. These results indicate that a variable-impedance orthosis may have certain clinical benefits for the treatment of drop foot gait compared to conventional AFO having zero or constant stiffness joint behaviors.
by Joaquin A. Blaya.
S.M.
Книги з теми "FOWT":
1
Hayward, Linda. Wet foot, dry foot, low foot, high foot: Learn about opposites and differences. New York: Random House, 1996.
2
Perkins, Clay. The fort in Fort Worth. Keller, Tex: Cross-Timbers Heritage Pub. Co., 2001.
3
Potter, Ellen. Big Foot and Little Foot. New York: Amulet Books, 2018.
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Visto, Joy. Whose foot is a foot? Mankato, Minnesota: Creative Education/Creative Paperbacks, 2016.
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Kozar, Richard. Fort Duquesne and Fort Pitt. Philadelphia: Mason Crest Publishers, 2004.
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Lemoine, Patrick. Fort-Dimanche, fort-la mort. Uniondale, N.Y: Fordi9, 2011.
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Lemoine, Patrick. Fort-Dimanche, fort-la mort. 2nd ed. Port-au-Prince: Éditions Regain, 1996.
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Zarzad Okregu Zwiazku Polkich Artstów Plastów w Krakowie., ed. Fort sztuki =: Fort of art. Kraków: Zarzad Okregu Zwiazku Polkich Artystów Plastyów w Krakowie, 1993.
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Hondl, Susie, and Lotte Dinse. FORT. Hannover: Kestnergesellschaft, 2015.
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E, Overhaussen Petr, ed. Foot ulcers: Causes, diagnosis, and treatments. Hauppauge, NY: Nova Science, 2009.
Частини книг з теми "FOWT":
1
Cruse, Jens, Moustafa Abdel-Maksoud, Alexander Düster, Andreas Bockstedte, Gerrit Haake, and Sönke Siegfriedsen. "Design of Floating Offshore Wind Turbine (FOWT) “SelfAligner”." In EKC 2019 Conference Proceedings, 55–67. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-8350-6_5.
2
Hallak, T. S., D. Karmakar, and C. Guedes Soares. "Hydrodynamic performance of semi-submersible FOWT combined with point-absorber WECs." In Developments in Maritime Technology and Engineering, 577–85. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003216599-61.
3
Ladeira, Í., H. Le Sourne, S. Echeverry, and P. Rigo. "Assessment of the energy balance gap for ship-FOWT collision simulations with LS-DYNA/MCOL." In Developments in the Analysis and Design of Marine Structures, 221–28. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003230373-26.
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Shim, Chunsik, Min Suk Kim, Kangho Kim, and Daseul Jeong. "Mooring system optimization of 12MW FOWT in environment condition in the southwest sea of Korea." In Advances in the Analysis and Design of Marine Structures, 255–62. London: CRC Press, 2023. http://dx.doi.org/10.1201/9781003399759-28.
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Zheng, T., and N. Z. Chen. "Impact of preload loss on fatigue strength of blade root bolts of a Floating Offshore Wind Turbine (FOWT)." In Advances in the Analysis and Design of Marine Structures, 529–36. London: CRC Press, 2023. http://dx.doi.org/10.1201/9781003399759-59.
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Gerok, Karl. "Fahre fort, fahre fort." In Schwäbische Orgelromantik, 27–28. Stuttgart: J.B. Metzler, 1987. http://dx.doi.org/10.1007/978-3-476-04458-7_23.
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Hamel, Johannes. "Skew Foot/Serpentine Foot." In Foot and Ankle Surgery in Children and Adolescents, 79–90. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-58108-4_2.
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Seidenbusch, Michael, Veronika Rösenberger, and Karl Schneider. "Foot." In Imaging Practice and Radiation Protection in Pediatric Radiology, 885–87. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-18504-6_26.
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Hansen, S. T. "Foot." In Manual of INTERNAL FIXATION, 613–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-662-02695-3_15.
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Visser, Jan Douwes. "Foot." In Pediatric Orthopedics, 261–98. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-40178-2_13.
Тези доповідей конференцій з теми "FOWT":
1
Peng, Cheng, Fasuo Yan, and Jun Zhang. "Coupled Dynamic Response of a Spar Type Floating Offshore Wind Turbine." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23560.
Анотація:
FOWTs (Floating Offshore Wind Turbine) are feasible renewable devices to harness the wind energy in the near future. However, because of the complicated interactions among wind turbine, mooring system and the hull, the motion of a FOWT under the impact of severe wind, wave and current has not been well studied yet. This research focuses on the coupled numerical analysis of a FOWT. A numerical code COUPLE-FAST is developed by integrating two existing codes, namely, COUPLE and FAST, to carry out the task. In this study, a particular FOWT model is chosen for the numerical simulation, which consists of a NREL 5-MW baseline wind turbine and OC3-Hywind Spar. Although the numerical simulation is limited to this particular type of FOWTs, the results and related code (COUPLE-FAST) may be helpful to the design of FOWTs in the future.
2
Li, Xin, Zhixin Zhao, Dongdong Han, and Haisheng Zhao. "Structural Control of the Ultra-Large Semi-Submersible Floating Offshore Wind Turbine." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18391.
Анотація:
Abstract Taking the DTU 10 MW braceless semi-submersible floating offshore wind turbine (FOWT) as the research object, an ideal tuned mass damper (TMD) installed in platform of the 10 MW semi-submersible FOWT is investigated to dynamically compensate the vibrations and reduce the structural loads. Considering the hydrodynamic and mooring effects, a simplified model of FOWT with four degrees of freedom (DOFs) including platform surge, pitch, tower fore-aft bending and TMD translation is established according to the D’Alembert’s principle. Then, based on the Levenberg-Marquardt (LM) algorithm, the unknown parameters related to the simplified model are estimated. Compared with results from FAST-SC, the simplified dynamic model is validated. Furthermore, the response surface method and genetic algorithm (GA) are used to determine the optimized TMD parameter. Finally, the fully coupled time-domain simulation of the FOWT with active TMD subjected to environmental loadings is conducted by using FAST-SC, and the effect of the TMD on the load reduction of the 10 MW braceless semi-submersible FOWT is analyzed. The study provides a feasible method for the structural control of the ultra-large semi-submersible FOWTs.
3
Huang, Yang, Qing Xiao, and Decheng Wan. "Wake Interaction Between Two Floating Offshore Wind Turbines With Blade Deformation." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-78288.
Анотація:
Abstract With the increasing size and flexibility of wind turbine blades, the impacts of blade deformation on the aerodynamic performance of wind turbines are becoming more and more important. To better understand the influence of blade flexibility on the wake interaction of FOWTs, a coupled analysis tool composed of an improved ALM and in-house CFD code based on OpenFOAM is employed to perform numerical simulations for two spar-type FOWTs with a tandem layout under given regular wave and uniform wind conditions. Coupled aero-hydro-elastic responses of the floating wind turbine are compared for rigid blades and flexible blades scenarios to examine the impacts of blade deformation on the wake interaction. The variations of aerodynamic loads, wake characteristics, and floating platform dynamics motions’ responses are fully examined. Our results show that the blade deformation of downstream FOWT is smaller than that of upstream FOWT due to the turbine wake. The time-mean aerodynamic load coefficients of both upstream and downstream FOWT decrease due to the shape deformation of the blade. Moreover, the wake vortexes are found to be more stable when the blade is flexible.
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Srinivasamurthy, Sharath, Kazuki Hashimoto, Kazuhiro Iijima, and Yasunori Nihei. "Weathervane Performance and Stability of Single Point Moored FOWTs Under Wind-Current Coexisting Field." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95404.
Анотація:
Abstract The objective of this study is to understand the weathervane performance and stability of FOWTs moored to SPM systems under wind and current coexisting field. Two types of FOWT systems, a semi-submersible and a spar (1/200 scale) are designed and manufactured based on Froude’s scaling law. A series of scaled model experiments are conducted and compared during wind-current coexisting field in a circulating water tank at Osaka Prefecture University, Osaka, Japan. Weathervane performance is evaluated under various conditions of wind and current. It is found during experiments that the weathervane performance of the SPM-FOWT systems is acceptable in rated wind and slow current condition. However, in the rated wind and high speed current condition, the weathervane performance is found to be not acceptable and unstable oscillation is observed. A numerical program is also developed to understand the behavior using the maneuvering equations. Further, attempts are made to understand the stability of SPM-FOWT systems based on Eigenvalue analysis.
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Hsu, Wei-ting, Krish P. Thiagarajan, Michael MacNicoll, and Richard Akers. "Prediction of Extreme Tensions in Mooring Lines of a Floating Offshore Wind Turbine in a 100-Year Storm." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-42015.
Анотація:
Floating offshore wind turbines (FOWTs) contribute to an emerging green energy technology, by exploiting higher and consistent wind speeds above the ocean. There are several challenges facing the design of mooring system of FOWTs, including installation costs, stability of light-weight minimalistic platforms, and shallow depths (50–300m). The extreme tension in mooring lines of a light displacement platform in shallow-water is dominated by snap loads. This is because light pre-tension requirements in the line may be insufficient to prevent the mooring lines from being exposed to wave motion induced slack and shock events. In this paper, we present a comparative analysis of a semi-submersible based FOWT exposed to a 100-year storm condition, based on model test data and numerical simulations of well-known industry standard software. The data was obtained from a 1/50th-scale FOWT with the wind turbine modeled after the NREL 5MW wind turbine. The software, OrcaFlex, was used for numerical simulations of the mooring system. NREL’s FAST software was coupled to OrcaFlex to obtain aerodynamic loads along with hydrodynamic load for FOWT analyses. The numerical simulation of the moored FOWT in a 3-hour storm was executed in both the frequency-domain and the time-domain to determine the dynamic behavior of the platform and mooring system, respectively. Snap–type impact events were observed in both test data and numerical simulation. Tension maxima were fitted into extreme value distributions and comparisons are made between simulated and measured data. It is seen that snap events follow a different exceedance probability distribution compared to the cycle-to-cycle tension maxima.
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Masciola, Marco, Xiaohong Chen, and Qing Yu. "Evaluation of the Dynamic-Response-Based Intact Stability Criterion for Floating Wind Turbines." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-42008.
Анотація:
As an alternative to the conventional intact stability criterion for floating offshore structures, known as the area-ratio-based criterion, the dynamic-response-based intact stability criteria was initially developed in the 1980s for column-stabilized drilling units and later extended to the design of floating production installations (FPIs). Both the area-ratio-based and dynamic-response-based intact stability criteria have recently been adopted for floating offshore wind turbines (FOWTs). In the traditional area-ratio-based criterion, the stability calculation is quasi-static in nature, with the contribution from external forces other than steady wind loads and FOWT dynamic responses captured through a safety factor. Furthermore, the peak wind overturning moment of FOWTs may not coincide with the extreme storm wind speed normally prescribed in the area-ratio-based criterion, but rather at the much smaller rated wind speed in the power production mode. With these two factors considered, the dynamic-response-based intact stability criterion is desirable for FOWTs to account for their unique dynamic responses and the impact of various operating conditions. This paper demonstrates the implementation of a FOWT intact stability assessment using the dynamic-response-based criterion. Performance-based criteria require observed behavior or quantifiable metrics as input for the method to be applied. This is demonstrated by defining the governing load cases for two conceptual FOWT semisubmersible designs at two sites. This work introduces benchmarks comparing the area-ratio-based and dynamic-response-based criteria, gaps with current methodologies, and frontier areas related to the wind overturning moment definition.
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Teo, Wei Ywin, and Paul Pang Awn Ong. "A Modelling Study of Hamakaze Fowt." In Offshore Technology Conference Asia. OTC, 2022. http://dx.doi.org/10.4043/31468-ms.
Анотація:
Abstract Offshore wind farms are venturing into deeper water, where wind is steadier and stronger, to tap on more wind energy. The installation of wind turbines in deeper waters requires the use of a floating wind turbine. Designing the floating platforms is challenging as dynamic effects waves, wind, and currents, have to be considered. Hydrodynamic behaviours can only be modelled accurately in time domain analysis, which requires an immense computational effort, when several load cases are taken into consideration. A more efficient approach is to first conduct stability analysis to identify the modal frequencies, and subsequently carry out time domain analysis using those modal frequencies. This paper describes a static study and time domain analysis on an innovative offshore spar turbine with hulls. Ansys Aqwa, a finite-element software, is used to study a model proposed by Mitsubishi Heavy Industries. The key objective is to explore a more cost-effective offshore platform by investigating the relationship between the geometry of hulls and the responses of the platform.
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Allen, Christopher K., Andrew J. Goupee, Habib J. Dagher, and Anthony M. Viselli. "Validation of Global Performance Numerical Design Tools Used for Design of Floating Offshore Wind Turbines." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41437.
Анотація:
In an effort to harness the abundant offshore wind resource over deepwater, the development of numerical design tools for floating offshore wind turbines (FOWTs) has progressed steadily in recent years. However, at present, a validated model capable of completely coupling the full elastodynamic response between the mooring system, floating support structure, turbine tower and the wind turbine is not commercially available. The University of Maine has developed a new FOWT design, VolturnUS, which utilizes a concrete semi-submersible hull. For the VolturnUS design effort a number of numerical models were developed to analyze the system’s global performance. This paper presents the results of a validation study conducted to quantify the accuracy and suitability of a subset of these models for use in the design of the VolturnUS FOWT. Validation was conducted via comparisons of numerical model results to test data obtained from a 1:50 scale model testing campaign conducted by the University of Maine at the Maritime Research Institute, Netherlands offshore basin. The validation study evaluated the performance and capabilities of the numerical models over a range of design conditions. Emphasis was placed on design load cases (DLCs), which were found to govern the design of the FOWT. The DLCs follow the American Bureau of Shipping’s (ABS) Guide for Building and Classing Floating Offshore Wind Turbines. Through this method of model validation this work sought to quantify the numerical models’ accuracy, highlight their limitations, justify design assumptions, and identify areas requiring further development in the field of FOWT numerical modeling.
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Utsunomiya, Tomoaki, Tomoki Sato, Hidekazu Matsukuma, and Kiyokazu Yago. "Experimental Validation for Motion of a SPAR-Type Floating Offshore Wind Turbine Using 1/22.5 Scale Model." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79695.
Анотація:
In this paper, motion of a SPAR-type floating offshore wind turbine (FOWT) subjected to wave loadings is examined. The proposed prototype FOWT mounts a 2MW wind turbine of down-wind type, whose rotor diameter is 80m and hub-height 55m. The SPAR-type floating foundation measures 60m in draft, having circular sections whose diameter is 12m at the lower part, 8.4m at the middle (main) part and 4.8m at the upper part. The FOWT is to be moored by a conventional anchor-chain system. In order to design such a FOWT system, it is essential to predict the motion of the FOWT subjected to environmental loadings such as irregular waves, turbulent winds, currents, etc. In this paper, the motion of the FOWT subjected to regular and irregular waves is examined together with the application of steady horizontal force corresponding to steady wind. The wave-tank experiment is made in the deep sea wave-basin at NMRI (National Maritime Research Institute), using a 1/22.5 scale model of the prototype FOWT. The experimental results are compared with the numerical simulation results for validation of the simulation method.
10
Wang, Baoxuan, Xu Liang, and Xue Jiang. "Experimental and Numerical Investigation on the Dynamic Response of Platform for a Spar-Type Floating Wind Turbine Under Aerodynamic and Hydrodynamic Forces." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-81290.
Анотація:
Abstract Developing floating offshore wind turbines (FOWTs) operating in the deep sea is crucial for reducing carbon emissions and exploiting marine renewable energy. Compared with a fixed-bottom wind turbine, the FOWT with a moving floating platform faces more complex external environment and challenging operating conditions. Its 6-DOF motions with long periods and significant amplitudes will, in turn, affect the dynamic response and performance of FOWT. Therefore, it is necessary to take a deep insight into the dynamic response of floating platforms for FOWTs under aerodynamic and hydrodynamic forces. In this regard, the present study carried out a series of tank tests based on a scaled spar-type FOWT, employing AI-based software-in-the-loop hybrid testing method. Tests were performed in wave-only cases, wind-only cases and combined wind-wave cases to investigate the effect of wave frequency and wind speed on platform motions. Corresponding simulations were also conducted to compare with the test results. In this study, attention was focused on the law reflected by test results and evaluating the applicability and validity of the employed hybrid testing approach. Results show that the natural frequency of yaw can be affected by constant thrust force generated by fan. Wind speed rather than regular wave frequencies have a significant impact on the mean value of platform motions. The amplitude and standard deviation of motions are simultaneously controlled by wind speed and wave frequency. The spectral peak frequencies of surge, sway and yaw are wind-speed dependent in wind-only cases. With the increase of wave frequency, the spectral peak frequencies of 6-DOF motions gradually change from wave frequency into their own natural frequencies. Moreover, numerical calculations generally coincide with the testing results. This work attempts to provide reference and guide for understanding the dynamic response of FOWTs and develop a more reliable hybrid scaled testing method.
Звіти організацій з теми "FOWT":
1
Schmidt, Aaron, Adam Smith, Megan Tooker, and Sunny Adams. Old Post reevaluation, Fort Huachuca, AZ. Engineer Research and Development Center (U.S.), October 2022. http://dx.doi.org/10.21079/11681/45701.
Анотація:
The US Congress codified the National Historic Preservation Act of 1966 (NHPA), the nation’s most effective cultural resources legislation to date, mostly through establishing the National Register of Historic Places (NRHP). The NHPA requires Federal agencies to address their cultural resources, which are defined as any prehistoric or historic district, site, building, structure, or object. Section 110 of the NHPA requires Federal agencies to inventory and evaluate their cultural resources, and Section 106 requires them to determine the effect of Federal undertakings on those potentially eligible for the NRHP. Fort Huachuca is situated at the foot of the Huachuca Mountains in southern Cochise County, Arizona. It is located approximately 15 miles north of the border with Mexico and 75 miles southeast of Tucson. It was founded in 1877 as a frontier cavalry fort and remains one of the oldest military installations in the West. The objective of this report is to inventory the real property within Fort Huachuca’s Old Post, the historic core of the installation. Each resource is enumerated and accompanied by a list of reports discussing its potential NHL or NRHP eligibility. Subsequently, each resource is accompanied by a short description, which includes its location and current status within the recently created Old Post Historic District.
2
Morrison, Dawn, and Adam Smith. Fort Huachuca history of development : existing reports and contexts. Engineer Research and Development Center (U.S.), January 2021. http://dx.doi.org/10.21079/11681/39479.
Анотація:
The Fort Huachuca Environmental and Natural Resources Division (ENRD) tasked ERDC-CERL to compile a history of the development of Fort Huachuca for use in evaluating existing facilities and how they fit within the larger, overarching history of the fort. Fort Huachuca desires a comprehensive history of the fort for use in better understanding how its various facilities integrate into the overall history and development of the fort and its existing National Historic Landmark (NHL) and proposed existing evaluated, eligible, and listed National Register of Historic Places (NRHP) properties and districts. This comprehensive history will help ENRD in making determinations on how to address future National Register of Historic Places (NRHP) nominations and/or recommendations for adding new historic districts or expanding the existing historic district. ERDC-CERL compiled content from 18 existing historic contexts, building inventory and cultural re-sources reports, NRHP nomination and registration forms, and Historic American Buildings Survey (HABS) forms previously completed for the ENRD, and used these resources to compile the current history.
3
Verrill, Steve P., Victoria L. Herian, and Henry N. Spelter. Estimating the board foot to cubic foot ratio. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, 2004. http://dx.doi.org/10.2737/fpl-rp-616.
4
Enscore, Susan, Dawn Morrison, Adam Smith, and Sunny Adams. Fort Huachuca ranges : a history and analysis. Engineer Research and Development Center (U.S.), December 2021. http://dx.doi.org/10.21079/11681/42720.
Анотація:
Fort Huachuca Environmental and Natural Resources Division (ENRD) sent funds to ERDC-CERL to develop a historic context that assists Fort Huachuca personnel in identifying the likely history and provenance of numerous historic range features located across Fort Huachuca's training lands. The historic context will be used by cultural resources personnel to evaluate and manage the resources appropriately. Various historic training range features (e.g., structures, fragments, and items left over from previous activities) are located across the ranges of Fort Huachuca, representing its long and storied history. To help identify and catalog these features, ERDC-CERL conducted a field survey of the training ranges in 2016 in or-der to photograph the historic range features. Forty-one historic range features were identified. Researchers conducted archival research, literature reviews, and image analysis of historic and current maps and photographs to identify the 41 historic range features and place them within a chronological context of Fort Huachuca's training ranges. The report concludes with guidance on how to identify and associate sites and features within the overall historic training range chronology and evaluate them appropriately for significance and National Register of Historic Places (NRHP) eligibility.
5
Busch, Robert D., Karl E. Scheuch, and Thomas T. Shishman. Fort Polk EEAP. Fort Belvoir, VA: Defense Technical Information Center, July 1986. http://dx.doi.org/10.21236/ada330503.
6
Lyle A. Johnson Jr. FORT UNION DEEP. Office of Scientific and Technical Information (OSTI), September 2002. http://dx.doi.org/10.2172/822148.
7
Lyle A. Johnson Jr. FORT UNION DEEP. Office of Scientific and Technical Information (OSTI), March 2002. http://dx.doi.org/10.2172/822149.
8
Collins, J. Portable Font Resource (PFR) - application/font-tdpfr MIME Sub-type Registration. RFC Editor, March 2001. http://dx.doi.org/10.17487/rfc3073.
9
Lin, Mike C., John L. Vavrin, Walter Smith, and Clay Conner. Process Optimization Assessment: Fort Leonard Wood, MO and Fort Carson, CO. Fort Belvoir, VA: Defense Technical Information Center, November 2003. http://dx.doi.org/10.21236/ada432762.
10
TRANSPORTATION CORPS WASHINGTON DC. Surrounded by History: Memorializing Our Past, Fort Eustis and Fort Story. Fort Belvoir, VA: Defense Technical Information Center, July 2000. http://dx.doi.org/10.21236/ada383165.