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Hack, Brian E. "Analysis of MIT campus wind resources for future wind turbine installation." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45837.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 23).
As our nation's continuing dependence on fossil energy and the problems that result from that dependence grow more apparent, we must look to alternative sources of energy to power the country. As a global scientific and technological leader, MIT is expected to take a part in the search for and support of alternative energy sources. One such source that has tremendous potential, yet tends to be underrepresented, is wind energy. Following the previous wind resource analysis done by Richard Bates, Samantha Fox, Katherine McCusker, and Kathryn Pesce, I have expanded upon the suggestions made at the conclusion of their analysis. The Eastgate building on MIT's campus was identified as one possible location for small scale wind turbines. I completed a computational fluid dynamics (CFD) analysis on that building as well as the Johnson Athletic Center to determine if there were adequate wind resources to make the installation of a wind turbine on one of these buildings economical. The results of the CFD analysis show that the west edge of the roof on the Johnson Athletic Center is a promising location for the installation of a roof-top wind turbine. Further investigation of the wind resources at that location should be conducted.
by Brian E. Hack.
S.B.
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Vasudevan, Santhosh. "HURRICANE WIND RETRIEVAL ALGORITHM DEVELOPMENT FOR AN AIRBORNE CONICAL SCANNING SCATTEROMETER." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3222.
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Reliable ocean wind vector measurements can be obtained using active microwave remote sensing (scatterometry) techniques. With the increase in the number of severe hurricanes making landfall in the United States, there is increased emphasis on operational monitoring of hurricane winds from aircraft. This thesis presents a data processing algorithm to provide real-time hurricane wind vector retrievals (wind speed and direction) from conically scanning airborne microwave scatterometer measurements of ocean surface backscatter. The algorithm is developed to best suit the specifications for the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division's airborne scatterometer – Integrated Wind and Rain Airborne Profiler (IWRAP). Based on previous scatterometer wind retrieval methodologies, the main focus of the work is to achieve rapid data processing to provide real-time measurements to the NOAA Hurricane Center. A detailed description is presented of special techniques used. Because IWRAP flight data were not available at the time of this development, the wind retrieval performance was evaluated using a Monte Carlo simulation, whereby radar backscatter measurements were simulated with instrument and geophysical noise and then used to infer the surface wind conditions in a simulated (numerical weather model) hurricane wind fieldM.S.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
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Eppanapelli, Lavan Kumar. "Investigation of wind potential variation at three measurement sites based on atmospheric stability and power production." Thesis, KTH, Kraft- och värmeteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-136935.
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As tapping energy from wind expands rapidly worldwide, it is a common procedure to locate a practicable site to extract energy from abundant wind flow by building wind farms. Comprehensive understanding of wind resource at a site is important to perform the main activities say, wind flow modeling, wind turbines micro siting, annual energy yield calculation and cost of energy estimation. Wind measuring campaigns involve using of measuring instruments such as meteorological tower instrumented with anemometers, wind vanes and temperature sensors; remote sensing devices such as SoDAR, LiDAR. These meteorological devices provide detailed information on wind behavior with respect to the height, time and temperature. These systems were proven in providing promising wind measurements even though they are susceptible to certain weather conditions. The study progressed by focusing on the wind behavior at three locations to investigate the possible factors that varies the wind character. A location with one met mast and two AQ500 SoDAR systems was considered for this project where one AQ500 is 800m away and other AQ500 is 5515m away from the point of Met mast. The location is contemplated as a decent approach to the spatial analysis of the wind resource as there is a large scope to analyze the wind character between two nearby sites and two faraway sites. Monostatic 3-beam SoDAR systems from AQ System, Sweden and 100m meteorological tower with instruments are used in this project work for collecting the wind data. One-year worth of wind data at standard 10min intervals has been collected from the three systems. This report outlines the theoretical description of project location, AQ500 SoDAR and Met mast. A detailed explanation of the data quality control and filtering methods are discussed along with respective reasons. The conclusion is drawn after performing the statistical analysis between wind speed and other parameters such as turbulent intensity, wind direction, thermal stability and temperature. Mat lab is used for computing and analyzing the wind data from three systems.
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Corrigan, Daniel James. "Local Met-Ocean Conditions over Lake Erie as Measured at the Cleveland Water Intake Crib." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1396609064.
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Gaihre, Nirajan. "ANALYTICAL AND NUMERICAL MODELING OF FOUNDATIONS FOR TALL WIND TURBINE IN VARIOUS SOILS." OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2650.
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Wind farm construction is increasing progressively, to cope-up with the current global energy scenario. The advantage of clean energy and sustainability helps wind turbine construction to flourish rapidly. Location of wind turbines is independent of foundation soil condition but depends on the wind speeds and socio-environment issues. Hence, a construction sites may not be favorable in terms of geotechnical demands. The taller wind towers facilitate the generation of high energy production, which will increase loads on the foundation, and eventually increase the dimension of the foundation. Hence, the choice of a suitable foundation system is necessary for geotechnical engineer to design tall wind towers. This study aims to analyze different foundation types e.g., raft/mat foundation, pile group foundation, and piled raft/mat foundation using analytical calculation verified with numerical models using PLAXIS 3D software. The foundation for steel wind turbine towers 100 m high was designed for different types of soils e.g., soft clayey soil, medium-stiff clayey soil, stiff clayey soil, and sandy soil. The design wind speed was taken from the ASCE 7-10 (2010) standard for Occupancy Category III and IV Buildings and Other Structures, as the Illinois region falls in that category. The parametric study was performed by varying the diameter of raft/mat, wind speed, number of piles, and soil types to evaluate the settlement in any type of foundation with load sharing proportion in piled raft/mat foundation. First, the raft/mat foundation design was carried out manually by changing the diameter of 15 m, 20 m, 25 m, 30 m, and 35 m, and changing load by considering different wind speed. Then the foundation was modeled using PLAXIS 3D software with a raft/mat diameter of 25 m, 30 m, and 35 m only, by considering the eccentricity and factor of safety criteria. With the increase in wind speed, the differential settlement on the raft/mat foundation was found to be increased. However, the increase in diameter of raft/mat caused the reduction in differential settlement. Soft clayey soil was found to be more sensitive than other soils used in the present study. For the same diameter of raft/mat, applied the same wind load, the differential settlement of foundation in soft clayey soil was found to be 6-10 times higher than the sandy soil.The position of piles was fixed based on the spacing criteria in the pile group foundation. The number of piles used in this study were 23, 32, and 46. Settlement was found to be varied with the number of piles in all soils used in this study. The lateral deflection for soft clayey soil decreased to half, when number of piles increased from 23 to 46. The differential settlement was found to be increased with the increase in wind speed in pile group foundation. Raft/mat foundation settlement was found to be 4 to 6 times higher than the settlement in pile group foundation in any soils, used in this study, for a given wind speed.The result of piled raft/mat foundation showed that the majority of the total load is shared by the piles (i.e., 60% to 94%) and remaining load is shared by the raft/mat (i.e., 6% to 40%), based on the stiffness of raft/mat and piles as well as pile-soil-pile interaction. The increase in wind speed in the wind turbines increased the differential settlement of piled raft/mat foundation in all soils. Similarly, the lateral deflection also increased with the increase in wind speed in pile raft/mat foundation in all soils. The PLAXIS 3D analysis revealed that the differential settlement in soft clayey soil was 1.5 to 2.0 times higher than the settlement in sandy soil.The validation of numerical modeling was carried out by the raft/mat foundation using Boussinesq’s theory and calculating settlement for single pile and group pile foundation. The current study showed that the soft clayey soil and medium-stiff clayey soil favor deep foundation, like pile group and piled raft/mat rather than shallow foundation, like raft/mat foundation. The results obtained from both analytical calculation and numerical modeling was found to be approximately matching. This study will help local construction company and geotechnical engineer to guide a proper foundation design of tall onshore wind turbine.
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Winde, Friederike [Verfasser], and Thomas [Gutachter] Meyer. "Blasenaugmentation mit Hilfe eines biokompatiblen Materials im Rattenmodell / Friederike Winde ; Gutachter: Thomas Meyer." Würzburg : Universität Würzburg, 2018. http://d-nb.info/1173616705/34.
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Gabrielli, M. "CHEMICAL MARKERS FOR THE EVALUATION OF SENSORY AND ANTIOXIDANT PROPERTIES OF WINES." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/230019.
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Sotolon (3-Hydroxy-4,5-dimethyl-2(5)-furanone) is a chiral lactone responsible for the oxidized flavour in fortified wines and wine produced by oxidative ageing. The perception threshold of the racemic mixture in wine is 8 – 10 μg/L and the flavour is reported as curry, aged honey, aged sake and fenugreek. Though it is considered a typical flavour note in Madera, Porto and Sherry, it is an off-flavour in dry white wine where its oxidative note is detrimental for the fresh taste and odour. The sotolon formation pathways, during winemaking, are affected by chemical and physical factors such as: oxygen concentration, storage temperature and time, reducing sugar concentration and antioxidant compounds concentration (e.g. sulphur dioxide or (GSH) glutathione). Due to the number of chemical and physical factors affecting the Sotolon formation in wine this compound has been suggested as chemical marker of white wine shelf-life.
A fast, sensitive and easy to apply analytical method (UHPLC-UV) and it was applied to the evaluation of SO2-free Franciacorta DOCG wines in order to assess the effect of different disgorgement conditions (antioxidant additives, ageing time and temperature) on the sotolon formation. The sotolon concentration was measured in sparkling wine stored at 15°C and 25°C for 6 months added to three different antioxidant preparations (2 g/hL and 4 g/hL) potentially substituting the sulfur dioxide. Furthermore, we investigated the chemical and physical factors could affect the sotolon formation in synthetic wine. Model solution conitaing increasing concentration of pentoses, GSH, amino group, catechin, oxygen, ethanal, tartaric acid and iron are stored at two temperatures (70°C and 5°C) for five days in order to clarify the compositive factors affecting the sotolon synthesis in white wine. Finally, we compared the performances of analytical methods (HPLC-UV and UHPLC-MS) for sotolon quantification, which were previously developed. Separately, we developed a fast, sensitive and easy to apply analytical method (UHPLC-UV) for the biogenic amines (BAs) assessment in red wine treated with different malolactic fermentation condition (Spontaneous MLF; Inoculum and Co-inoculum techniques). Moreover was checked the trend of intra and extra-cellular glutathione and their effect on the aromatic matrix of South African Sauvignon blanc (Stellenbosch) must and wine during the alcholic fermentation and aging. The Must was treated with GSH and a GSH-enriched inactive dry yeast preparation (GSH-IDYs).
The proposed analytical methods (UHPLC-UV; HPLC-UV and UHPLC-MS) provide a sample preparation faster and easier-to-apply than those previously reported for the routine analyses of sotolon. The methods (HPLC-UV; UHPLC-MS/MS; UHPLC-UV) were proved suitable for the determination of sotolon concentrations in white wine and in model solution under its sensory perception threshold. Two analytical methods compared (HPLC-UV; UHPLC-MS/MS) were successfully used for the screening of 70 commercial South African wines’ sotolon levels. The samples of Franciacorta sparkling wines treated with SO2 show the best protection against wine oxidation whereas the other commercial antioxidants tested caused detrimental effects due to the sotolon production. The phenolic composition of commercial antioxidants has influenced the production of sotolon. The sotolon formation tests carried out showed which sotolon can be formed by several formation pathways indeed it was generated under both reducing and oxidative conditions. Sotolon formation is enhanced by simultaneous presence of Fe++ and O2, of amino groups and of phenols. Glutathione inhibited the formation of sotolon only when it was simultaneously added with amino groups and phenols in an oxidizing environment or when it was present in oxidative conditions. Under anoxic conditions the sotolon formation test has been demonstrated that there is a high dependence between sotolon and reducing sugar contents, whereas tartaric acid and acetaldehyde didn't affect the formation of sotolon. The formation of
sotolon in anoxic environment has not yet been clarified and further tests will be conduct to understand the role of tartaric acid, ethanol, ethanal and ribose on sotolon production in synthetic wine. The analytical method for the BAs quantification showed good linearity and repeatability and was able to quantify the ABs in red wine. The preliminary results concerning the different malolactic fermentation conditions, suggest that co-inoculum technique does not seem to prevent BAs formation in wine. The trial data on GSH (intra and extra-cellular) have yet to be processed and will be assessed in the future.
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Malekian, Boroujeni Kaveh. "Modellierung des Oberschwingungsverhaltens von Windparks mit probabilistischen Ansätzen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-202982.
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Oberschwingungen als ein Merkmal der Elektroenergiequalität gewinnen durch die starke Netzintegration leistungselektronisch geregelter Anlagen wie Windenergieanlagen und nichtlineare Lasten zunehmend an Bedeutung. Bestehende Normen entsprechen nicht den zukünftigen Erfordernissen des Elektroenergiesystems und bedürfen diesbezüglich einer Überarbeitung. In der Arbeit werden wesentliche Einflussfaktoren auf das Oberschwingungsverhalten von Windparks identifiziert, beschrieben und modelliert. Dabei wird der stochastische Charakter der Oberschwingungen mithilfe von probabilistischen Ansätzen erfasst. Des Weiteren wird ein neuer Ansatz zur Untersuchung der Wechselwirkung zwischen dem Windpark und dem vorgelagerten Netz entwickelt. Der Ansatz ermöglicht, die vom Windpark verursachte Änderung der Oberschwingungsspannung am Netzanschlusspunkt zu ermitteln. Diese Arbeit liefert einen Beitrag zur Verbesserung bestehender Normen für die Anbindung von WindparksHarmonics, as one of the power quality criteria, are increasingly gaining attention due to the progressive contribution of renewable energy resources and the application of the nonlinear load in the power system. Current standards do not conform to the future requirements of the power system, thus requiring a revision. In this work, main influence factors on the harmonic behavior of wind farms are identified, explained, and modelled. Thereby, the stochastic nature of harmonics is taken into account using probabilistic approaches. Moreover, a novel approach is developed to investigate the interaction between the wind farm and the upstream grid. With the aid of this approach, it is possible to determine the voltage change caused by the wind farm at the point of connection. This work contributes to improve the existing standards for the connection of wind farms
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Alfarra, Anas [Verfasser], and Andreas [Akademischer Betreuer] Dittrich. "Numerische Analyse von Bauwerk-Wind-Wechselwirkungen mit RANS-Turbulenzmodellen / Anas Alfarra ; Betreuer: Andreas Dittrich." Braunschweig : Technische Universität Braunschweig, 2015. http://d-nb.info/1175818682/34.
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Bauer-Pfundstein, Matthias [Verfasser]. "Bestimmung von Turbulenzparametern und der Schallabsorption mit einem Wind-Temperatur-RADAR / Matthias Bauer-Pfundstein." Karlsruhe : KIT-Bibliothek, 1999. http://d-nb.info/1198223731/34.
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PETRONIO, Filomena. "A stochastic model for a small producer with termal units, wind power plants and storage technologies." Doctoral thesis, Università degli studi di Bergamo, 2012. http://hdl.handle.net/10446/26714.
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Renewable energy plays an important role in the world. Especially wind is considered one of the most important renewable resources and is probably the fastest growing renewable energy source in the world. However, renewable energy has been exploited only to a small fraction of its potential. This is due to the existence of several types of barriers to the penetration of this kind of resources. For this reason, in recent years, is considered increasingly important the development of storage technologies, that seems to have the potential to play key role in providing renewable energy.
We develop a stochastic optimization model whereby a small energy producer aims at meeting a part of the market demand, in order to maximize his own profits. In our formulation, the producer can use both traditional energy sources and wind energy, and some specific kind of storage technology. The stochastic model represents a decision support tool, on a short time horizon, that allows to evaluate the variability of both wind resource and energy prices, and the impact of using innovative storage technologies. We focus also on the role of spinning reserve, that is requested when the producer uses an intermittent energy source.
An overview, of both renewable energy and storage technologies, is presented. Some results are shown, concerning the use of some types of storage technologies and both thermal and wind energy. In particular, it highlights how the model is proposed as a tool to evaluate the effectiveness of a storage technology.
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Mendes, Flávio Henrique. "Vulnerabilidade à queda de árvores por meio de simulações microclimáticas." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-22062016-165232/.
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Muitos são os benefícios provenientes da arborização de vias públicas, como aumento da vida útil do asfalto por meio do sombreamento, filtragem de poluentes, absorção de CO2, interceptação da água da chuva e da radiação solar e mitigação de ilhas de calor; porém, por questões culturais, é considerada muitas vezes pela população como algo negativo, cujas folhas entopem calhas, raízes destroem calçadas, troncos e folhas atrapalham fiação elétrica e, principalmente, elas estão susceptíveis às quedas. A pesquisa teve como objetivo estudar o comportamento das quedas de árvores no município de Piracicaba/SP, Brasil, com atenção especial ao regime de ventos na cidade, baseado em dados fornecidos pelo Corpo de Bombeiros de Piracicaba, Secretaria de Defesa do Meio Ambiente de Piracicaba (SEDEMA) e Estação Meteorológica da Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ). De caráter inédito, o principal resultado foi a relação direta entre quedas e zonas urbanizadas, que, em constantes alterações no uso do solo, acabam por danificar a sustentação das árvores (raízes), fato justificado pela alta concentração de quedas na parte central (36,7%), com destaque para as estações da primavera e do verão, ou seja, ventos e chuvas, na qual, juntas, somaram 78,0% do total. O período de retorno esperado para ventos superiores a 75 km h-1, classificados como temporais na Escala de Vento de Beaufort, foi de 2,8 eventos por ano. Enquanto verificou-se o predomínio de ventos alísios de sudeste, pertencentes ao quarto quadrante, a direção das rajadas de vento teve maior variação e, assim, com predomínio daqueles ventos, é recomendável instalações de parques industriais nas zonas norte, noroeste e oeste, haja vista a importância de evitar que os poluentes adentrem a cidade. As espécies de maior vulnerabilidade foram: Pachira aquatica Aubl. (monguba), Handroanthus sp. (ipê roxo) e Tipuana tipu (Benth.) Kuntze (tipuana). Por meio de simulação microclimática computacional, utilizando o programa ENVI-met versão 3.1, em dois estudos de caso, sendo um em bairro residencial e outro na Praça José Bonifácio, foi possível identificar locais de maior atenção quanto às quedas de árvores, em função da rugosidade do local, capaz de alterar a velocidade e a direção do vento.There are many benefits from public roads afforestation, such as longer pavement life through shading, filtering pollutants, CO2 absorption, intercepting rainfall and solar radiation and mitigating heat islands; however, due cultural issues, is often regarded by the population as something negative, whose leaves clog gutters, roots destroy sidewalks, stems and leaves disrupt electrical wiring and, mainly, they are susceptible to falls. The research aimed to study the behavior of falling trees in Piracicaba/SP, Brazil, with special attention to the wind regime in the city, based on data provided by the Piracicaba Fire Department, Secretariat of Defense of the Environment of Piracicaba (SEDEMA) and Meteorological Station Luiz de Queiroz College of Agriculture (ESALQ). From unedited character, the main result was the direct relationship between falls and urbanized areas, which, in constant changes in land use, end up damaging the support of trees (roots), a fact explained by the high concentration of falls in the central part (36.7%), highlighted to the spring and summer seasons, i.e., winds and rains, which, together, totaling 78.0% of the total cases. The payback period expected to winds who exceeding 75 km h-1, classified as storms in the Beaufort Wind Scale, was 2.8 events per year. While there was a predominance of trade winds from the Southeast, belonging to the fourth quadrant, the direction of the gusts of wind had greater variation and, thus, with those predominant winds, it recommend installation of industrial parks in North, Northwest and West areas, since the importance of avoiding that pollutants enter into the city. The most vulnerable species were: Pachira aquatica Aubl. (Guiana Chestnut), Handroanthus sp. (Purple Ipe) and Tipuana tipu (Benth.) Kuntze (Tipuana). Through computational microclimate simulation, using the software ENVI-met version 3.1, in two case studies, being one in a residential area and another in the José Bonifácio Square, it was possible to identify locals of more attention as the falling trees, based on the local roughness, able to change the speed and direction of the wind.
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Garutti, Maria Carolina. "Simulação dos ventos e tomografia de impulso: sinergia na avaliação do risco de queda de árvores." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-03022016-152350/.
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Os efeitos ambientais negativos da urbanização podem ser mitigados pela presença de espaços verdes dentro e ao redor das cidades. Os elementos mais valiosos de tais áreas são reconhecidamente as árvores. Entretanto, existem também alguns riscos associados com a sua presença, os quais expressam a possibilidade de queda da árvore ou de seus galhos por perda de resistência biomecânica, resultando em perigo de morte e estragos a propriedades, bens e infraestrutura. Nesse sentido, a tomografia de impulso tem se mostrado como uma técnica bastante eficaz em detectar fragilidades biomecânicas no lenho. Considerando ainda que o vento é a principal força dinâmica atuante na copa das árvores, este estudo se propôs a (a) simular o comportamento dos ventos sobre a região do Parque Zoobotânico do Museu Paraense Emílio Goeldi, localizado em Belém-PA, durante quatro eventos de chuvas e ventos fortes usando o ENVI-met, (b) quantificar a perda de resistência biomecânica através da tomografia de impulso em 12 árvores presentes no referido parque e (c) identificar as árvores que possuem um maior risco de queda. Os modelos gerados pelo ENVI-met foram capazes de mostrar zonas de turbulência atuando sobre a copa das árvores tomografadas, e levando em conta a perda de resistência biomecânica, o Guajará foi identificado como apresentando o maior risco de queda entre todas as árvores estudadas. Concluiu-se que o ENVI-met prestou-se perfeitamente para a identificação de zonas de turbulência atuando na copa das árvores. Uma vez conhecidas essas turbulências e considerando a perda de resistência biomecânica acusada pela tomografia, ações de manejo pontuais podem ser propostas e executadas visando diminuir o risco de queda de árvores por ventos fortes em eventos futuros.Negative environmental effects of urbanization can be mitigated by the presence of green spaces in and around cities. The most valuable elements of such green spaces are considered to be trees. Nonetheless, trees can pose some risks, which encompass the likelihood of mechanical failure of trunk or branches, causing injury to people or damaging buildings and properties. Accordingly, impulse tomography has proven to be a very effective technique in detecting biomechanical weaknesses in the wood. Considering wind as the main dynamic force acting on the tree crown, this study aimed to (a) simulate the behavior of winds over the region of the Goeldi Museum (located in Belém, Pará State, Brazil) during four events of heavy rain and strong winds using the ENVI-met software, (b) quantify the loss of biomechanical resistance for 12 trees located at the Museum and (c) identify trees with high possibility of failure. The models generated by ENVI-met were able to find areas of turbulence influencing the canopy of those trees. Together with the loss of biomechanical resistance, it was possible to identify the Guajará as having the greatest risk of failure among all the analyzed trees. It was concluded that ENVI-met represents a great tool in the identification of turbulence areas that influence trees. Once these areas are identified, and considering the loss of biomechanical resistance given by the impulse tomography, punctual management actions can be proposed and put into action for the sake of reducing risk of failure in future events of strong winds.
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Lange, Martin, and Christoph Jacobi. "Einfluß des winterlichen stratosphärischen Polarwirbels auf die zonale Symmetrie des Windfeldes in der oberen Mesosphäre und unteren Thermosphäre simuliert mit dem COMMA-Modell." Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-216894.
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Langzeitmessungen des Windfeldes in der Mesopausenregion (~ 92km) an verschiedenen Stationen in den mittleren Breiten der Nordhemisphäre zeigen systematische zonale Variationen beim (zeitlich) gemittelten Zonal- und Meridionalwind und bei den Amplituden und Phasen der halbtägigen Gezeiten. Als eines der herausragenden Muster, die zonale Variationen in der unteren mittleren Atmosphäre anregen, wird der Einfluß der Geopotentialstörungen zur zonalen Wellenzahl 1 und 2, die mit dem winterlichen stratosphärischen Polarwirbel verbunden sind, auf das Windfeld in der oberen Mesosphäre / unteren Thermosphäre numerisch mit dem COMMA-Modell der mittleren Atmosphäre untersucht. Die Modellergebnisse zeigen eine gute Übereinstimmung der zonalen Variationen des mittleren Zonalwindes, die im Breitenbereich 52ÆN bis 56ÆN beobachtet werden und in der Größenordnung von 10 - 20 m/s liegen. Auch die halbtägigen Gezeitenamplituden und -phasen zeigen qualitative und quantitative Übereinstimmungen zwischen Beobachtungen und ModellergebnissenLong-term time series of wind field observations in the upper mesosphere / lower thermosphere region at different locations in the midlatitude region indicate longitudinal variability in the (time-) mean zonal and meridional wind and in the amplitudes and phases of the semidiurnal tide, too. Being one of the prominent patterns forcing zonal inhomogenities in the lower middle atmosphere, the influence of the zonal wavenumber 1 and wavenumber 2 disturbances connected with the winter Northern Hemisphere stratospheric polar vortex on the mesosphere- / lower thermosphere wind field is numerically investigated with the COMMA model. The model results show that the zonal variations through the stationary waves coincide with typical observed mean zonal wind differences between different stations along the midlatitude belt between 52ÆN and 56ÆN with values about 10- 20 m/s. Also, the amplitude and phase variations of the semidiurnal tide show qualitative and quantitative agreements between model results and observations
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Tackenberg, Oliver. "Methoden zur Bewertung gradueller Unterschiede des Ausbreitungspotentials von Pflanzenarten : Modellierung des Windausbreitungspotentials und regelbasierte Ableitung des Fernausbreitungspotentials; mit 18 Tabellen im Text und als Anhang /." Berlin : J. Cramer, 2001. http://archiv.ub.uni-marburg.de/diss/z2001/0107/pdf/dot.pdf.
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Lange, Martin, and Christoph Jacobi. "Einfluß des winterlichen stratosphärischen Polarwirbels auf die zonale Symmetrie des Windfeldes in der oberen Mesosphäre und unteren Thermosphäre simuliert mit dem COMMA-Modell: Einfluß des winterlichen stratosphärischen Polarwirbels auf die zonale Symmetrie des Windfeldes in der oberen Mesosphäre und unteren Thermosphäresimuliert mit dem COMMA-Modell." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 22 = Meteorologische Arbeiten aus Leipzig ; 6 (2001), S. 111-120, 2001. https://ul.qucosa.de/id/qucosa%3A15212.
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Langzeitmessungen des Windfeldes in der Mesopausenregion (~ 92km) an verschiedenen Stationen in den mittleren Breiten der Nordhemisphäre zeigen systematische zonale Variationen beim (zeitlich) gemittelten Zonal- und Meridionalwind und bei den Amplituden
und Phasen der halbtägigen Gezeiten. Als eines der herausragenden Muster, die zonale Variationen in der unteren mittleren Atmosphäre anregen, wird der Einfluß der Geopotentialstörungen zur zonalen Wellenzahl 1 und 2, die mit dem winterlichen stratosphärischen Polarwirbel verbunden sind, auf das Windfeld in der oberen Mesosphäre / unteren Thermosphäre numerisch mit dem COMMA-Modell der mittleren Atmosphäre untersucht. Die Modellergebnisse zeigen eine gute Übereinstimmung der zonalen Variationen des mittleren Zonalwindes, die im Breitenbereich 52ÆN bis 56ÆN beobachtet werden und in der Größenordnung von 10 - 20 m/s liegen. Auch die halbtägigen Gezeitenamplituden und -phasen zeigen qualitative und quantitative Übereinstimmungen zwischen Beobachtungen und Modellergebnissen.Long-term time series of wind field observations in the upper mesosphere / lower thermosphere region at different locations in the midlatitude region indicate longitudinal variability in the (time-) mean zonal and meridional wind and in the amplitudes and phases of the semidiurnal tide, too. Being one of the prominent patterns forcing zonal inhomogenities in the lower middle atmosphere, the influence of the zonal wavenumber 1 and wavenumber 2 disturbances connected with the winter Northern Hemisphere stratospheric polar vortex on the mesosphere- / lower thermosphere wind field is numerically investigated with the COMMA model. The model results show that the zonal variations through the stationary waves coincide with typical observed mean zonal wind differences between different stations along the midlatitude belt between 52ÆN and 56ÆN with values about 10- 20 m/s. Also, the amplitude and phase variations of the semidiurnal tide show qualitative and quantitative agreements between model results and observations.
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Jonuschies, Ingo, and Klaus Brökel. "Ansatz für die Modellierung und Simulation von Hybridgleitlagern für Wellen mit großen Durchmessern und geringen Drehzahlen am Beispiel einer Windkraftanlage." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-228246.
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Motivation
"Am stetig steigenden Anteil der erneuerbaren Energien, der auf der einen Seite durch die ehrgeizigen Ziele der Politik forciert und auf der anderen Seite durch wirtschaftliche Interessen beflügelt wird, stellt die Windenergie den größten und aussichtsreichsten Bestandteil dar (BMU 2012). Setzt sich der gegenwärtige Trend fort, so ist in den nächsten Jahren mit Multimegawattanlagen im mehrstelligen Megawattbereich zu rechnen."
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SIFACE, Dario. "A statistical characterization of wind generation and development of a stochastic LP model for the solution of the unit commitment problem in power systems with high RES penetration." Doctoral thesis, Università degli studi di Bergamo, 2012. http://hdl.handle.net/10446/26711.
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In the last decade national Power Systems faced a large increase in penetration of Renewable Energy Sources (RES) generation. In particular, the largest increase was met by Photovoltaic generation (PV) and Wind Generation (WG), both affected by substantial uncontrollability and high levels of uncertainty and volatility. As a consequence, high levels of uncertainty are transferred to Power System, thus new tools are needed, capable of analyzing RES uncertainty and use the resulting characterization in helping Power System operation.
In the present PhD work of thesis both of these topics are treated. Firstly, statistical and clustering techniques are considered in order to characterize actual WG data, coming from Spanish Power System, in particular with respect to the criticalities of the Demand of power.
In a second part, Stochastic Programming techniques are introduced in an existing Medium Term Power System Simulator. The resulting model, named sMTSIM, is able solve the large scale Unit Commitment (UC) Problem for Zonal Power Systems with high level of RES penetration. The high levels of uncertainty and volatility characterizing RES generation are taken into account by means of their statistical characterization; then the UC problem is solved by coupling Stochastic Linear Programming techniques and an heuristic technique able to reintroduce the intrinsic Mixed Integer nature of UC problem.
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Jonuschies, Ingo, and Klaus Brökel. "Ansatz für die Modellierung und Simulation von Hybridgleitlagern für Wellen mit großen Durchmessern und geringen Drehzahlen am Beispiel einer Windkraftanlage." TUDpress - Verlag der Wissenschaften GmbH, 2012. https://tud.qucosa.de/id/qucosa%3A30503.
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Motivation
"Am stetig steigenden Anteil der erneuerbaren Energien, der auf der einen Seite durch die ehrgeizigen Ziele der Politik forciert und auf der anderen Seite durch wirtschaftliche Interessen beflügelt wird, stellt die Windenergie den größten und aussichtsreichsten Bestandteil dar (BMU 2012). Setzt sich der gegenwärtige Trend fort, so ist in den nächsten Jahren mit Multimegawattanlagen im mehrstelligen Megawattbereich zu rechnen."
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DAVO', Federica. "Optimization and Forecasting Models for Electricity Market and Renewable Energies." Doctoral thesis, Università degli studi di Bergamo, 2017. http://hdl.handle.net/10446/77349.
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This thesis presents different optimization and forecasting models, with the focus on energy markets and renewable energy sources. The analysis approach is related to models for wind and solar power forecasts and those for electricity prices forecasts. The first study explores a Principal Component Analysis in combination with two post-processing techniques for the prediction of wind power and of solar irradiance produced over two large areas. The Principal Component Analysis is applied to reduce the datasets dimension. A Neural Network and an Analog Ensemble post-processing are then applied on the PCA output to obtain the final forecasts. The study shows that combining PCA with these post-processing techniques leads to better results when compared to the implementation without the PCA reduction.
The second work explores two different techniques for the prediction of the Italian day-ahead electricity market prices. The predicted Italian prices are the zonal prices and the uniform purchase price (Prezzo Unico Nazionale or PUN). The study is conducted using hourly data of the prices to be predicted and a large set of variables used as predictors (i.e. historical prices, forecast load, wind and solar power forecasts, expected plenty or shortage of hydroelectric production, net transfer capacity available at the interconnections and the gas prices). A Neural Network and a Support Vector Regression are applied on the different predictors to obtain the final forecasts. Different predictors’ combinations are analysed to find the best forecast. The results show that the best configuration is obtained using all the predictors together and applying the Neural Network to find the forecasted prices.
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Bruse, Michael. "Die Auswirkungen kleinskaliger Umweltgestaltung auf das Mikroklima Entwicklung des prognostischen numerischen Modells ENVI-met zur Simulation der Wind-, Temperatur- und Feuchteverteilung in städtischen Strukturen /." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=960203869.
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Fister, Wolfgang [Verfasser], and Johannes B. [Akademischer Betreuer] Ries. "Ein mobiler Windkanal mit integrierter Beregnungsanlage zur experimentellen Erfassung der Bodenerosion durch Wind, Wasser und ihrer kombinierten Wirkung im Gelände / Wolfgang Fister ; Betreuer: Johannes B. Ries." Trier : Universität Trier, 2011. http://d-nb.info/1197806091/34.
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Knöß, Tobias [Verfasser], Günther [Gutachter] Winde, and Christophe Andrè [Gutachter] Müller. "Altersgruppenspezifisches Outcome des Kolon-Karzinoms mit adjuvanter oder palliativer Chemotherapie im Vergleich zu nicht erfolgter Chemotherapie im UICC-Stadium III+IVa im Patientengut des Darmzentrums am Klinikum Herford in den Jahren 2008-2012 / Tobias Knöß ; Gutachter: Günther Winde, Christophe Andrè Müller ; Medizinische Fakultät." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1195221029/34.
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Windt, Roland [Verfasser]. "Analyse der medikamentösen Versorgung von Asthma-Patienten im Erwachsenenalter mit Routinedaten / vorgelegt von Roland Windt." 2010. http://d-nb.info/1005663955/34.
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Bashir, Dogara. "Thatched mat windbreaks influences on the harmattan wind and millet production in the Sahel." 1990. http://catalog.hathitrust.org/api/volumes/oclc/22759734.html.
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Thesis (Ph. D.)--University of Wisconsin--Madison, 1990.Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 203-213).
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Merklein, Johannes. "Modellierung turbulenter Strömungen mit Anwendungsfällen in der Bioklimatologie und Astrophysik." Doctoral thesis, 2014. http://hdl.handle.net/11858/00-1735-0000-0022-5E15-1.
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Wenn auf dem Foto oben der Westwind Zephyr und in seinen Armen die Morgenbrise Aura nicht Venus an die Gestaden Zyperns treibt, sondern stattdessen den Geburtstagskuchen ausbläst , dann ist sein Atem das, was in der Strömungsmechanik als „laminare Strömung“ bezeichnet wird. Eine Strömung, deren Stromlinien parallel zueinander verlaufen und deren Einzelelemente, hier die Luftmoleküle, einen gleichgerichteten Weg verfolgen.
„Turbulent“ ist hingegen der von den Kerzen aufsteigende Rauch über dem Kuchen, der „Richtung Osten“ hinweggeblasen wird. Diese Turbulenz von Flüssigkeiten und Gasen ist allgegenwärtig in unserer Welt, ob für unser Auge direkt sichtbar oder unsichtbar: die Luft, die tief in unsere Lunge eingesogen wird bis hin zu den Lungenbläschen, die Spuren der Milch beim Umrühren in einer Kaffeetasse, der Rauch, der von einem Schornstein aufsteigt, das Wasser rund um die großen und kleinen Kiesel in einem Bach, der Wind, der den Kirchturm und die Hausecke umwirbelt, das heiße Plasma, das in Feuerfackeln von der Sonnenoberfläche ins Weltall hinauslodert, oder die großen Wolken kosmischen Staubs, die sich in Strudeln und Wirbeln zu Galaxien oder Sternen verdichten.
„Turbulent“ ist also eine Strömung, deren Stromlinien sich zu überkreuzen scheinen und deren Einzelelemente keinen gleichgerichteten Weg verfolgen. Stattdessen existieren vielfältigste Formen und Muster von miteinander verschränkten Wirbeln auf allen Größenskalen.
Aufgrund dieser Komplexität in Formen und Skalen gehört die Beschreibung und Vorhersage von Turbulenz schon seit Jahrhunderten zu den großen Rätseln in Physik und Mathematik. Da turbulente Strömungen gleichwohl derart zentral sind für viele Bereiche menschlichen Lebens und Handelns, werden Grundlagen- und Anwendungsforschung mit Nachdruck vorangetrieben. Die vorliegende Arbeit umfaßt gleich drei Anwendungsfälle von Turbulenzforschung, und es darf als bezeichnend für die Allgegenwart der Turbulenz angesehen werden, daß sich diese drei Anwendungen in solch unterschiedlichen Größenskalen abspielen. Die Windabkühlung von Rindern, die bis in den Sub-Millimeter-Maßstab im Bereich von Fell und Hautoberfläche hinein betrachtet werden muß, die Sturmge-fährdung von Wäldern, für die Größen zwischen einem halben Meter an den Bäumen und mehreren Kilometern in der Landschaft relevant sind, und zu guter Letzt das turbulente Geschehen in kos-mischen Gaswolken und Galaxienhaufen, das sich im Größenbereich von vielen Millionen Lichtjahren abspielt. Nicht nur in den Techniken der Modellierung, sondern auch in der physikalischen Wirklich-keit sind diese Phänomene trotz der gewaltigen Größenunterschiede eng verwandt. In diesem Sinne: vom Kosmos zur Kuh.
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Bruse, Michael [Verfasser]. "Die Auswirkungen kleinskaliger Umweltgestaltung auf das Mikroklima : Entwicklung des prognostischen numerischen Modells ENVI-met zur Simulation der Wind-, Temperatur- und Feuchteverteilung in städtischen Strukturen / eingereicht von: Michael Bruse." 1999. http://d-nb.info/960203869/34.
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