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Van, Brunt Juli R. "And They Flew". ScholarWorks@UNO, 2013. https://scholarworks.uno.edu/td/1675.
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Queiroz, Júnior Ilton de. "A filosofia da religião de Antony Flew : do ateísmo ao deísmo". reponame:Repositório Institucional da UnB, 2012. http://repositorio.unb.br/handle/10482/12286.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Humanas,
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A presente dissertação trata da análise pormenorizada da filosofia da religião de Antony Flew, das teses ateístas às deístas, apresentadas por ele para justificar sua “conversão”, como ele mesmo denomina esta mudança. Antony Flew é considerado por muitos como um dos grandes filósofos do século XX. Escreveu sobre os mais diversos assuntos dentro da filosofia, principalmente nas áreas da lógica, linguagem, política e religião. Publicou em 1950 o seu primeiro e mais famoso artigo, Theology and Falsification, publicação filosófica mais reimpressa do século passado e citação constante em textos filosóficos ateístas. Aos 81 anos, em uma entrevista realizada em 2004 para a Associated Press, Flew afirmou ter mudado seu entendimento em relação à existência de Deus e que sim, é possível existir uma mente inteligente criadora do universo conhecido. Mas não seria um Deus interventor como as religiões reveladas afirmavam, Flew declarou acreditar no chamado “deus de Aristóteles”. Dividida em três partes, a dissertação trata primeiramente das principais teses filosóficas de Flew em que ele claramente muda de opinião, principalmente na interpretação da filosofia de David Hume e nas críticas à teologia natural. Na segunda parte analisa as teses que ele não muda de opinião, como o problema do mal e na questão da imortalidade humana. Na terceira parte aborda as principais questões não respondidas por Flew, em relação a sua mudança. Por ter poucos escritos na fase deísta, várias perguntas sobre possíveis contradições na sua vida filosófica surgiram e, a grande maioria ele não pôde responder, pois faleceu seis anos após a declaração de sua mudança para o deísmo, em abril de 2010. _______________________________________________________________________________________ ABSTRACT
This dissertation deals with a detailed analysis of Antony Flew’s philosophy of religion, from the atheist theses up to his deist “conversion”, as he calls this change. Antony Flew is considered by many as one of the great philosophers of the twentieth century. He wrote about various subjects within philosophy, especially in the areas of logic, language, politics and religion. In 1950, published his first and most famous paper, Theology and Falsification, the most reprinted philosophical publication of the last century and frequent quotation in atheistic philosophical texts. At 81, during an interview in 2004 for the Associated Press, Flew said to have changed his understanding about the existence of God and that yes, it is possible there to be an intelligent creator mind of the known universe. But, it would not be an intervenient God, as the revealed religions claimed, Flew declared to believe in the "Aristotle’s god". Divided into three parts, this dissertation deals primarily with the main philosophical theses about which Flew clearly changed his opinion, especially in the interpretation of the David Hume’s philosophy and the criticisms of natural theology. The second part analyzes the theses about which he did not change his opinion, as the problem of evil and the question of human immortality, and the third, discusses the major unanswered questions by Flew, in relation to this change. Due to having few writings in the deist phase, several questions about possible contradictions in his philosophical life emerged, the great majority could not be answered by him, because he died six years after the declaration of his move to deism, in April 2010.
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Jansson, Julia. "The Monster Behind the Smile : An Analysis of Nurse Ratched’s Character in Kesey’s One flew Over the Cuckoo’s Nest and Wasserman’s One Flew over the Cuckoo’s Nest: A Play in Two Acts". Thesis, Karlstads universitet, Institutionen för språk, litteratur och interkultur, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-35693.
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One Flew Over the Cuckoo’s Nest (1962) written by Ken Kesey tells the story at a ward where the patients who reside at the ward are exposed of oppression and humiliation by Nurse Ratched. One Flew Over the Cuckoo’s Nest: A Play in Two Acts (1963) written by Dale Wasserman is a theatrical play which is based on Kesey’s novel. The purpose of this essay is to argue that Nurse Ratched’s character is pictured as more evil in the novel than the play. In this essay, Ratched’s personality and outer looks was discussed as well as her methods she uses to humiliate and control the inmates. It was argued that Wasserman may have excluded information about Ratched’s character, so the actors have a chance to develop a personal view of Ratched. It was also argued that Ratched may have appeared as unnaturally evil if Wasserman had included all her evil traits, and thus picture her as a larger than life character.
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Bonzo, J. Matthew. "Death, identity, and immortality". Theological Research Exchange Network (TREN), 1991. http://www.tren.com.
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Ryan, Kathleen M. ""When flags flew high" : propaganda, memory, and oral history for World War II female veterans /". Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2008. http://hdl.handle.net/1794/8332.
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Thesis (Ph. D.)--University of Oregon, 2008.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 377-400). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
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Boo, Paula. "A Destructive Myth of Masculinity : Ken Kesey’s One Flew Over the Cuckoo’s Nest from a Men’s Studies Perspective". Thesis, Högskolan Dalarna, Engelska, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:du-25498.
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Miller, Liizl Helen. "An Evaluation of the film one flew over the cuckoo's nest as a medium for the training of psychotherapists". Thesis, University of Limpopo (Medunsa Campus), 2010. http://hdl.handle.net/10386/283.
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Thesis (MSc.(Clinical Psychology))University of Limpopo, 2010.The aim of the study is to analyse the film One flew over the cuckoo’s nest, from a clinical psychology perspective in order to evaluate the possible use of the film and significant concepts depicted therein in a training context. The objectives of the study are to describe the interactional dynamics of the psychiatric system as depicted in the film, to identify and describe the impact of the systems and/or subsystems on the psychotherapeutic growth of “patients” and to provide suggestions for the training of psychotherapists on the basis of the film and the present research. A qualitative, descriptive research design was used to achieve these aims. This allowed for systematic clinical descriptions by four clinical psychologists to be obtained. The study involved an exploration of relevant literature as well as an indepth study of a specific therapeutic group in interaction as depicted in the film. The film was shown to four clinical psychologists. Their findings were analysed, and common themes in their analyses identified. The researcher came to certain conclusions on the basis of the above-mentioned analyses. The findings of this study seem to indicate that the interactional style of the psychiatric staff, as portrayed in the film, contributed to the deterioration of the psychological well-being of the “patients”, thus inhibiting their psychological growth and promoting psychopathology. In spite of the findings, the researcher wishes to recommend the utilisation of this film as a training medium, on condition that a paradigm shift is made away from the traditional medical/psychiatric approach to a ii systems-based epistemology. This could result in viewing the psychiatric system as a hierarchy of interrelated subsystems-in-interaction, and open up possibilities for a redefinition of the various roles of those involved within the larger system. Further research in this direction is strongly indicated and recommended.
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Jarrett, Marcus. "Matricide and the natural man : a study of Mary Shelley's Frankenstein and Ken Kesey's One flew over the Cuckoo's nest /". Title page and introduction only, 1991. http://web4.library.adelaide.edu.au/theses/09AR/09arj37.pdf.
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Marceau, Catherine. "Socio-sonic control, deviant musicality, and countercultural resistance in Nineteen Eighty-Four, Player Piano, and One Flew Over the Cuckoo's Nest". Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69914.
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Ce mémoire considère trois œuvres littéraires des décennies d'après-guerre dans lesquelles le contrôle social est omniprésent, soit Nineteen Eighty-Four de George Orwell, Player Piano de Kurt Vonnegut, et One Flew Over the Cuckoo's Nest de Ken Kesey. L'analyse propose que ces auteurs examinent les réponses individuelles et collectives possibles face au contrôle socio-sonique, incluant le conformisme et la déviance, à travers la musicalité de leurs personnages. Mon approche repose sur des théories reliées à la sociologie, la musicologie et les études sonores afin d'élaborer une perspective holistique des paysages sonores de la modernité qui caractérisent les romans. Ce cadre théorique permet de traiter deux idées centrales, soit le contrôle social par l'institutionnalisation de cultures sonores et la musicalité sous forme de carrière déviante. Mon argument principal est qu'Orwell, Vonnegut, et Kesey présentent la réception sonore de leurs personnages comme étant doublement liée à leurs réactions face à la répression. D'une part, les auteurs représentent la musique et le son en tant qu'outils de contrôle produits et utilisés par des pouvoirs autoritaires. Dans les romans, ces pouvoirs établissent des normes socio-soniques qui supportent un système social basé sur la subjugation de la population sous une idéologie hégémonique. D'autre part, les auteurs présentent la musicalité en tant que moyen de résistance : ils établissent un parallèle entre les réactions déviantes de leurs protagonistes envers le son et les postures contre-culturelles de ceux-ci. La musique et le son font partie intégrante de la prose d'Orwell, Vonnegut, et Kesey; je soutiens que leurs représentations de musicalité traduisent une évaluation des notions d'agentivité et d'opposition contre-culturelle à l'autoritarisme. Ce mémoire offre une approche innovatrice à l'analyse des œuvres de par son interdisciplinarité, qui mène à de nouvelles considérations illuminant la relation entre le contrôle socio-sonique et la musicalité déviante dans les dystopies antiautoritaires d'après-guerre.This thesis considers three literary works from the postwar decades in which social control is omnipresent: George Orwell's Nineteen Eighty-Four, Kurt Vonnegut's Player Piano, and Ken Kesey's One Flew Over the Cuckoo's Nest. The analysis posits that these authors depict potential individual and collective responses to socio-sonic control, including conformism and deviance, through the musicality of their characters. My approach, grounded in theorizations related to sociology, musicology, and sound studies, develops a holistic perspective of the soundscapes of modernity that characterize the novels. This theoretical framework allows for an examination of two central notions in the narratives; namely, the institutionalization of sonic cultures for purposes of social control, and the concept of musicality as part of a deviant career. My main argument is that Orwell, Vonnegut, and Kesey present their characters' reception of sound as being doubly tied to their reactions to repression. On one hand, the authors represent music and sound as tools of control produced and used by authoritarian powers. In the novels, such powers enforce socio-sonic norms that support a social system based on the subjugation of the population under a hegemonic ideology. On the other hand, the authors present musicality as means of resistance: they interlink their protagonists' deviant reactions vis-à-vis sound and their countercultural postures. Music and sound are an integral part of Orwell's, Vonnegut's, and Kesey's prose; I argue that, through their portrayals of musicality, they foreground the possibility for individual agency and countercultural resistance to oppose authoritarianism. The thesis offers an innovative approach to the narratives, as its theoretical interdisciplinarity leads to new considerations illuminating the relationship between socio-sonic control and deviant musicality in postwar anti-authoritarian dystopias.
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Mayo, Toni Rae. "Defining flight : the rich aviation history of Huntington County is the result of pilots and aviatrixes who flew during the early to mid-twentieth century". Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1217391.
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The focus of this creative six-hour non-fiction project has been the documentation of personal narratives (i.e., oral histories) of Huntington County pilots and aviatrixes who flew during the early to mid-twentieth century. Twenty profiles have been chronicled in alphabetical order. Types of flight experiences range from leisure, to military and private instruction, to cross-country trips, to wartime flight, and finally, to the work of an aerial photographer. From a local standpoint, regional aviation history has been documented. On a national scale, Huntington County aviation represents an era of flight occurring nationwide. By the inclusion of photographs, logbook entries, letters, journals, and poems a pictorial history reveals a depth of story that words alone can not convey. Each story in this project was read numerous times to the interviewee to ensure that names, quotes, dates, and facts were correct. Defining Flight documents a time period of aviation when men and women were adventurous, curious, daring, and willing to test the winds with kite-like machines.Department of English
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Hattangady, Nitin V. "Computer modeling of flow lines and flaw migration in bulk deformation prcesses". Ohio : Ohio University, 1987. http://www.ohiolink.edu/etd/view.cgi?ohiou1183045637.
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Hattangady, Nitin V. "Computer modeling of flow lines and flaw migration in bulk deformation processes". Ohio University / OhioLINK, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1183045637.
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Perry, Joshua L. "A Comparison of Gas Flow Resistane in Parker Flex-tip and Mallinckrodt RAE Nasal Endotracheal Tubes". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1380284347.
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O'Hara, Mark William. "Foucault and Film: Critical Theories and Representations of Mental Illness". Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1415896906.
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Song, Chao. "Micromachined flow sensors for velocity and pressure measurement". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/52304.
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This research focuses on developing sensors for properties of aerodynamic interest (i.e., flow and pressure) based on low-cost polymeric materials and simple fabrication processes. Such sensors can be fabricated in large arrays, covering the surface of airfoils typically used in unmanned vehicles, allowing for the detection of flow separation. This in turn potentially enables, through the use of closed-loop control, an expansion of the flight envelope of these vehicles. A key advance is compensation for the typically inferior performance of these low cost materials through both careful design as well as new readout methods that reduce drift, namely a readout methodology based on aeroelastic flutter.
An all-polymer micromachined piezoresistive flow sensor is fabricated, based on a flexible polyimide substrate and an elastomeric piezoresistive composite material. The flow sensor comprises a cantilever that is extended into the embedding flow; flow-induced stress on the cantilever is sensed through the piezoresistive composite material. Increasing the sensitivity of the sensor is achieved by either utilizing a long single-cantilever beam or using a dual-cantilever beam supporting a flap extending into the flow. In the latter case, the sensor demonstrates increased sensitivity with a reduced cantilever length. The increase in sensitivity helps to reduce sensor drift, which in turn is further reduced by a new measurement method, the vibration amplitude measurement method. In this drift reduction measurement method, the flow-induced vibration amplitude of the sensor structure (i.e., the amplitude of the aeroelastic flutter induced by the flow), instead of the absolute value of cantilever deflection, is measured in order to find the flow rate. Measurement of this relative resistance change instead of the absolute resistance in the piezoresistor rejects common-mode drift and greatly reduces overall drift. Experimental results verify the expected drift reduction. Sensor drift is also reduced when the elastomeric piezoresistive material is replaced by a Pt thin film piezoresistor.
Development of pressure sensors based on polymers proceeds by encapsulating a reference cavity within a multilayer polymer structure and forming capacitor plates on the polymeric membranes encapsulating the cavity. Measuring the capacitance change induced by changes in the embedding pressure (which cause changes in the positions of the bounding polymeric membranes) enables calculation of the pressure. The use of polymeric membranes requires understanding the leakage rate of gas into the reference cavity, which is a source of pressure drift. Developing a polymer-based pressure sensor that solves the problem of sensor drift as a result of gas permeation entails the fabrication of a silicon pressure reference cavity embedded in the polymer substrate, which results in a more hermetic and lower drift sensor while preserving the flexibility of the embedding polymer. Both wired and wireless versions of pressure and flow sensors of these types were developed and characterized. Further, the sensors were characterized on airfoils and their performance in a wind tunnel was determined.
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Lemée, Thomas. "Shear-flow instabilities in closed flow". Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112038.
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Cette étude se concentre sur la compréhension de la physique des instabilités dans différents écoulements de cisaillement, particulièrement la cavité entraînée et la cavité thermocapillaire, où l'écoulement d'un fluide incompressible est assuré soit par le mouvement d’une ou plusieurs parois, soit par des contraintes d’origine thermique.Un code spectral a été validé sur le cas très étudié de la cavité entrainée par une paroi mobile. Il est démontré dans ce cas que l'écoulement transit d'un régime stationnaire à un instationnaire au-delà d'une valeur critique du nombre de Reynolds. Ce travail est le premier à donner une interprétation physique de l'évolution non monotonique du nombre de Reynolds critique en fonction du facteur d'aspect. Lorsque le fluide est entraîné par deux parois mobiles, la cavité entraînée possède un plan de symétrie particulièrement sensible. Des solutions asymétriques peuvent être observés en plus de la solution symétrique au-dessus d'une certaine valeur du nombre de Reynolds. La transition oscillatoire entre la solution symétrique et les solutions asymétriques est expliquée physiquement par les forces en compétition. Dans le cas asymétrique, l'évolution de la topologie permet à l'écoulement de rester stationnaire avec l'augmentation du nombre de Reynolds. Lorsque l'équilibre est perdu une instabilité se manifeste par l'apparition d'un régime oscillatoire dans l'écoulement asymétrique.Dans une cavité thermocapillaire rectangulaire avec une surface libre, Smith et Davis prévoient deux types d'instabilités convectives thermiques: des rouleaux longitudinaux stationnaires et des ondes hydrothermales instationnaires. L'apparition de ses instabilités a été mis en évidence à plusieurs reprises expérimentalement et numériquement. Alors que les applications impliquent souvent plus d'une surface libre, il semble qu'il y ait peu de connaissances sur l'écoulement thermocapillaire entraînée avec deux surfaces libres. Un film liquide libre soumis à des contraintes thermocapillaires possède un plan de symétrie particulier comme dans le cas de la cavité entrainée par deux parois mobiles. Une étude de stabilité linéaire avec deux profils de vitesse pour le film liquide libre est présentée avec différents nombres de Prandtl. Au-delà d'un nombre de Marangoni critique, il est découvert que ces états de base sont sensibles à quatre types d'instabilités convectives thermiques qui peuvent conserver ou briser la symétrie du système. Les mécanismes qui permettent de prédire ces instabilités sont également découverts et interpréter en fonction de la valeur du nombre de Prandtl du fluide. La comparaison avec les travaux de Smith et Davis est faite. Une simulation numérique directe permet de valider les résultats obtenus avec l'étude de stabilité de linéaireThis study focuses on the understanding of the physics of different instabilities in driven cavities, specifically the lid-driven cavity and the thermocapillarity driven cavity where flow in an incompressible fluid is driven either due to one or many moving walls or due to surface stresses that appear from surface tension gradients caused by thermal gradients. A spectral code is benchmarked on the well-studied case of the lid-cavity driven by one moving wall. In this case, It is shown that the flow transit form a steady regime to unsteady regime beyond a critical value of the Reynolds number. This work is the first to give a physical interpretation of the non-monotonic evolution of the critical Reynolds number versus the size of the cavity. When the fluid is driven by two facing walls moving in the same direction, the cavity possesses a plane of symmetry particularly sensitive. Thus, asymmetrical solutions can be observed in addition to the symmetrical solution above a certain value of the Reynolds number. The oscillatory transition between the symmetric solution and asymmetric solutions is explained physically by the forces in competition. In the asymmetric case, the change of the topology allows the flow to remain steady with increasing the Reynolds number. When the equilibrium is lost, an instability manifests by the appearance of an oscillatory regime in the asymmetric flow. In a rectangular cavity thermocapillary with a free surface, Smith and Davis found two types of thermal convective instabilities: steady longitudinal rolls and unsteady hydrothermal waves. The appearance of its instability has been highlighted repeatedly experimentally and numerically. While applications often involve more than a free surface, it seems that there is little knowledge about the thermocapillary driven flow with two free surfaces. A free liquid film possesses a particular plane of symmetry as in the case of the two-sided lid-driven cavity. A linear stability analysis for the free liquid film with two velocity profiles is presented with various Prandtl numbers. Beyond a critical Marangoni number, it is observed that these basic states are sensitive to four types of thermal convective instabilities, which can keep or break the symmetry of the system. Mechanisms that predict these instabilities are discovered and interpreted according to the value of the Prandtl number of the fluid. Comparison with the work of Smith and Davis is made. A direct numerical simulation is done to validate the results obtained with the linear stability analysis
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KASLIWAL, AMIT. "FLOW SEPARATION CONTROL FOR CYLINDER FLOW AND CASCADE FLOW USING GENERATOR JETS". University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1141413192.
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Wang, Yueping. "Flow-dependent corrosion in turbulent pipe flow". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq23972.pdf.
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Kasliwal, Amit. "Flow separation control for cylinder flow and cascade flow using vortex generator jets". Cincinnati, Ohio : University of Cincinnati, 2006. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1141413192.
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Thesis (M.S.)--University of Cincinnati, 2006.Title from electronic thesis title page (viewed Apr. 18, 2006). Includes abstract. Keywords: Flow Separation; Low Pressure Turbine Cascade; LPT Cascade; Flow over Cylinder; Vortex Generator Jets; VGJ; Multiblock Grid. Includes bibliographical references.
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Engin, Erjona. "Dynamic Analysis Of Flow In Two Dimensional Flow". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609374/index.pdf.
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The Poiseuille Flow is the flow of a viscous incompressible fluid in a channel between two infinite parallel plates. The behaviour of flow is properly described by the well-known Navier-Stokes Equations. The fact that Navier-Stokes equations are partial differential equations makes their solution difficult. They can rarely be solved in closed form. On the other hand, numerical techniques can be applied successfully to the well-posed partial differential equations.
In the present study pseudo-spectral method is implemented to analyze the Poiseuille Flow. The pseudo-spectral method is a high-accuracy numerical modelling technique. It is an optimum choice for the Poiseuille flow analysis due to the flows simple geometry. The method makes use of Fourier Transform and by handling operations in the Fourier space reduces the difficulty in the solution. Fewer terms are required in a pseudo-spectral orthogonal expansion to achieve the same accuracy as a lower order method.
Karhunen-Loève (KL) decomposition is widely used in computational fluid dynamics to achieve reduced storage requirements or construction of relatively low-dimensional models. In this study the KL basis is extracted from the flow field obtained from the direct numerical simulation of the Poiseuille flow.
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Fraunhofer, Wolfgang. "Asymmetrical flow field-flow-fractionation in pharmaceutical analytics". Diss., lmu, 2003. http://nbn-resolving.de/urn:nbn:de:bvb:19-84503.
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Abdelwahab, Ahmed Farouk. "Through-flow model for fan/flow-resistance configurations". Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2002. http://wwwlib.umi.com/cr/syr/main.
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Somoano, Rodríguez Miguel. "Performance and flow dynamics in cross-flow turbines". Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/553240.
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Aquesta tesi doctoral presenta l'estudi que l'autor va realitzar per comprendre l'efecte de l'angle pitch de la pala sobre les interaccions pala-estela que tenen lloc dins el rotor i, per tant, sobre el rendiment d'una turbina de flux creuat amb tres pales rectes.
En primer lloc, hem estudiat experimentalment el rendiment d'aquest tipus de turbina en un túnel de vent de capa límit. Ho vam fer per a diferents pitches fixos de les pales, i amb diferents nombres de Reynolds basats en el diàmetre de la turbina que cobreixen la regió de transició en què el parell produït per les pales va superar el parell resistiu oposat. La forma i els valors de la corba de rendiment van canviar dràsticament amb només un increment de l'angle pitch fix. Com més gran sigui el nombre de Reynolds, menor és el tip speed ratio òptim i més cap al toe-out es mou l'angle pitch ideal.
Posteriorment, vam estudiar experimentalment la dinàmica de flux dins el rotor per diferents pitches de la pala en un tanc d'aigua amb carro, usant Digital Particle Image Velocimetry. Els assajos es van realitzar a un nombre de Reynolds basat en el diàmetre de la turbina constant, i per a un rang de tip speed ratios. L'atenció se centra en l'anàlisi de les interaccions pala-estela dins el rotor. Angles toe-in i excessius toe-out s'han associat a baixos rendiments d'aquest tipus de turbines. La investigació ens ha permès relacionar les interaccions pala-estela amb les diferències de rendiment en aquest tipus de turbines, en funció del tip speed ratio i de l'angle pitch de la pala.Esta tesis doctoral presenta el estudio que el autor realizó para comprender el efecto del ángulo pitch de la pala sobre las interacciones pala-estela que tienen lugar dentro del rotor y, por lo tanto, sobre el rendimiento de una turbina de de flujo cruzado con tres palas rectas. En primer lugar, hemos estudiado experimentalmente el rendimiento de este tipo de turbina en un túnel de viento de capa límite. Lo hicimos para diferentes pitches fijos de las palas, y con diferentes números de Reynolds basados en el diámetro de la turbina que cubren la región de transición en la que el par producido por las palas superó al par resistivo opuesto. La forma y los valores de la curva de rendimiento cambiaron drásticamente con sólo un incremento del ángulo pitch fijo. Cuanto mayor sea el número de Reynolds, menor es el tip speed ratio óptimo y más hacia el toe-out se mueve el ángulo pitch ideal. Posteriormente, estudiamos experimentalmente la dinámica de flujo dentro del rotor para diferentes pitches de la pala en un tanque de agua con carro, usando Digital Particle Image Velocimetry. Los ensayos se realizaron a un número de Reynolds basado en el diámetro de la turbina constante, y para un rango de tip speed ratios. La atención se centra en el análisis de las interacciones pala-estela dentro del rotor. Ángulos toe-in y excesivos toe-out se han asociado a bajos rendimientos de este tipo de turbinas. La investigación nos ha permitido relacionar las interacciones pala-estela con las diferencias de rendimiento en este tipo de turbinas, en función del tip speed ratio operativo y del ángulo pitch de la pala.
This doctoral thesis presents the study that the author have carried out in order to understand the effect of the blade pitch angle on the blade-wake interactions that take place inside the rotor, and hence on the performance of a three straight bladed cross-flow turbine. Firstly, we have experimentally studied the performance of this kind of turbine in a boundary layer wind tunnel. We did it for different fixed blade pitches, and at different turbine diameter Reynolds numbers covering the transitional region in which the torque produced by the blades overtook the opposed resistive torque. Shape and values of the performance curve changed drastically with just an increment of the fixed pitch angle. The higher the Reynolds number, the lower the optimal tip speed ratio and the more towards toe-out the ideal pitch angle is moved. Afterwards, we study experimentally the flow dynamics inside the rotor for different blade pitches in a water towing tank, using planar Digital Particle Image Velocimetry. Tests were made at a constant turbine diameter Reynolds number, and for a range of tip speed ratios. The focus is given to the analysis of the blade-wake interactions inside the rotor. Toe-in and excessive toe-out angles have been associated to low performances of this type of turbines. The investigation has allowed us to relate the blade-wake interactions with the performance differences in this type of turbines, as a function of both the operational tip speed ratio and the blade pitch angle.
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Su, Chih-Chun. "Flow characteristics and performance of mixed-flow turbines". Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416862.
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Manshoor, Bukhari bin. "Fractal flow conditioners for orifice plate flow meters". Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574554.
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The orifice plate flow meter is the most common form of differential pressure flow meter used in industry. The standard discharge coefficient, which is defined by both British Standard and [SO 5167, is only valid if the flow approaching the meter is perfectly settled and fully developed. However, in practical applications the flow approaching the orifice meter is often disturbed by pipe-fittings and consequently the measurements become inaccurate. Basically, the design of the orifice plate meters that are independent of the upstream disturbances is a main goal for orifice plate metering. Either using a long straight pipe, or a flow conditioner upstream of an orifice plate, usually achieves this goal. In this project the effect of the fractal flow conditioner for both standard and non-standard flow conditions has been investigated in an experimental rig and simulation work. The results of using a combination of the fratal flow conditioner and orifice plate for non-standard flow conditions including swirling flow and asymmetric flow show that this package can preserve the accuracy of metering up to the level required in the Standards. The simulation results also show that the device can be used as a part of a flow metering package that will considerably reduce installation lengths. According to the main idea to introduce a predetermined turbulence flow caused by a flow conditioner for orifice plate flow metering, author was introduced another type of flow conditioner known as a metal foam flow conditioner. Open-cell metal foams with a porosity of 78.8% was formed and fashioned as a flow conditioner. Again the experimental results using the metal foam flow conditioner showed this metal foam flow conditioner demonstrated a good performance in terms of removing swirl and producing a repeatedly same flow profile within a short distance downstream of the flow conditioner. Furthermore, the low pressure drop across the metal foam is another advantage of this flow conditioner where the pressure loss coefficient for this flow conditioner is approximately 2.5.
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FERREIRA, ANA LUISA AULER DA SILVA. "ULTRASONIC TECHNOLOGY IN FLOW MEASUREMENT OF INCOMPRESSIBLE FLOW". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=16724@1.
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O presente trabalho avalia a influência da instalação em medidores de vazão
ultrassônicos, utilizando simulação numérica. Foram apresentadas características
dos medidores ultrassônicos e questões sobre a configuração da modelagem do
escoamento que podem influenciar nos resultados numéricos. Foram descritos os
procedimentos utilizados para traçar as linhas e para calcular a velocidade média
no medidor e o erro de medição. Foi mostrado o efeito de uma curva, duas curvas
no mesmo plano e duas curvas em planos perpendiculares, em medidores
ultrassônicos de 1, 2, 3, 4, 5 e 8 canais, com diferentes arranjos. Também foi
analisado o efeito de um degrau no resultado do medidor ultrassônico por meio de
simulação de medidores 1 a 5 canais e por calibração de medidores de 3 canais.
Foram utilizados fatores, calculados pela razão entre a velocidade indicada pelo
medidor em um dado local e a velocidade que seria indicada pelo mesmo medidor
em escoamento completamente desenvolvido. Logo após uma curva, os fatores
para medidores de 1 canal variaram de 0,40 a 1,28; para medidores de 3 canais, de
0,5 a 1,42; e para medidores de 4 e 5 canais, as diferenças chegaram a ultrapassar
10%. A 20D após uma curva, medidores de 2 e 3 canais indicaram fatores de 0,9 a
1,08 e medidores de 4 e 5 canais, fatores de 0,99 a 1,04. Os parâmetros de
diagnóstico analisados não se mostraram eficazes e sua utilização não é
recomendada. Pela simulação, um degrau convergente de -4% gera diferenças na
ordem de 0,3% para medidores de 3 canais e, para degrau divergente de 4%, as
diferenças ultrapassam 0,5%. A diferença entre os resultados das calibrações com
e sem degrau ficou entre 0,18% a 0,3%. A simulação numérica é uma ferramenta
útil na análise dos medidores ultrassônicos e mostrou a sensibilidade desses
medidores a variações no perfil de velocidades.The present work evaluates the influence of the installation in ultrasonic flow meters, using numerical simulation. Ultrasonic meter characteristics and issues about the flow modeling configuration that may influence the numerical results were presented. Procedures used to draw the lines and to calculate the meter mean velocity and the measurement error were described. The effect of one curve, two curves at the same plane and two curves at perpendicular planes at 1, 2, 3, 4, 5 and 8-path meters with different arrangements were shown. Also, the effect of one step at the results of ultrasonic meters was analyzed by the simulation of 1 to 5-paths meters and by the calibration of a 3 path meters. Factors calculated by the ratio between the velocity indicated by the meter in a certain position and the velocity that would be indicated by the meter in a fully developed flow. Just after one curve, the factors for 1-path meters varied from 0.40 to 1.28; for 3-path meters, from 0.5 to 1.42; and for 4 and 5-path meters, the differences were higher than 10%. At 20D downstream of one curve, 2 and 3-path meters indicated factors equal to 0.9 and 1.08; and 4 and 5-path meters, factors equal to 0.99 to 1.04. The diagnostic parameters analyzed were not efficient and their use is not recommended. By the simulation, a convergent step of -4% generates differences about 0.3% for 3-path meters and for a divergent step -f 4%, the differences are higher than 0.5%. The differences between the calibration results with and without steps were from 0.18% to 0.3%. The numerical simulation is a useful tool in the ultrasonic meter analyses and showed the sensitivity of these meters to velocity profile variations.
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Sobek, Daniel. "Microfabricated fused silica flow chambers for flow cytometry". Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10262.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (leaves 107-116).
by Daniel Sobek.
Ph.D.
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Ariyoshi, Gen. "Flow Characteristics of Lead-Bismuth Two-phase Flow". Kyoto University, 2019. http://hdl.handle.net/2433/242325.
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Fält, Åsa. "Flow Office". Thesis, Linnéuniversitetet, Institutionen för design (DE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-43554.
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Armstrong, Holly. "Natural Flow". VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd/694.
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Nature never ceases to amaze me with momentary observations of fluid energy: the purposeful curvature of a blue heron's neck; the pattern of water as it sweeps across a rock sculpted by that very motion; the changing light and shadows created as wind blows through tall grasses. The spark of beauty in these moments lies in the energy that causes this constant change. To capture this energy, either potential or kinetic, and embody it through textures and flow of mass, is my essential goal as an artist.
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Åsén, Per-Olov. "Stability of plane Couette flow and pipe Poiseuille flow". Doctoral thesis, KTH, Numerisk Analys och Datalogi, NADA, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4368.
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This thesis concerns the stability of plane Couette flow and pipe Poiseuille flow in three space dimensions. The mathematical model for both flows is the incompressible Navier--Stokes equations. Both analytical and numerical techniques are used. We present new results for the resolvent corresponding to both flows. For plane Couette flow, analytical bounds on the resolvent have previously been derived in parts of the unstable half-plane. In the remaining part, only bounds based on numerical computations in an infinite parameter domain are available. Due to the need for truncation of this infinite parameter domain, these results are mathematically insufficient. We obtain a new analytical bound on the resolvent at s=0 in all but a compact subset of the parameter domain. This is done by deriving approximate solutions of the Orr--Sommerfeld equation and bounding the errors made by the approximations. In the remaining compact set, we use standard numerical techniques to obtain a bound. Hence, this part of the proof is not rigorous in the mathematical sense. In the thesis, we present a way of making also the numerical part of the proof rigorous. By using analytical techniques, we reduce the remaining compact subset of the parameter domain to a finite set of parameter values. In this set, we need to compute bounds on the solution of a boundary value problem. By using a validated numerical method, such bounds can be obtained. In the thesis, we investigate a validated numerical method for enclosing the solutions of boundary value problems. For pipe Poiseuille flow, only numerical bounds on the resolvent have previously been derived. We present analytical bounds in parts of the unstable half-plane. Also, we derive a bound on the resolvent for certain perturbations. Especially, the bound is valid for the perturbation which numerical computations indicate to be the perturbation which exhibits largest transient growth. The bound is valid in the entire unstable half-plane. We also investigate the stability of pipe Poiseuille flow by direct numerical simulations. Especially, we consider a disturbance which experiments have shown is efficient in triggering turbulence. The disturbance is in the form of blowing and suction in two small holes. Our results show the formation of hairpin vortices shortly after the disturbance. Initially, the hairpins form a localized packet of hairpins as they are advected downstream. After approximately $10$ pipe diameters from the disturbance origin, the flow becomes severely disordered. Our results show good agreement with the experimental results. In order to perform direct numerical simulations of disturbances which are highly localized in space, parallel computers must be used. Also, direct numerical simulations require the use of numerical methods of high order of accuracy. Many such methods have a global data dependency, making parallelization difficult. In this thesis, we also present the process of parallelizing a code for direct numerical simulations of pipe Poiseuille flow for a distributed memory computer.QC 20100825
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Mushyam, Aditya. "Effects of flow control on flow past bluff bodies". Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/398031.
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The aim of this Ph.D. thesis, "Effects of flow control on flow past bluff bodies" is to study and analyzes the effects of Flow Control on various aspects and proverbs of flow past bluff bodies. Flow control techniques are presently researched and studied across the world to gauge their effectiveness in altering flow properties and patterns in different flow scenarios. The inspiration for the present work is derived from automobile industry, as analyzing the flow over backward step and inclined step shall help in understanding the characteristics of the rear vehicle wake. Since a considerable percentage of the energy needed to propel the vehicle is dissipated by the vorticity generated in the rear of the vehicle, hence it is of utmost importance to understand the properties of the wake. In the present study various possibilities were explored for application and examine effectiveness of active flow control techniques in bluff bodies to increase the aerodynamic efficiency. The primary aim of the study is to reduce the drag acting on bluff bodies by determining an effective active flow control technique and configuration.
Two different kinds of Active Flow Control techniques have been used in this thesis namely, "Zero Net Mass Flow Actuator" and "Fluidic Actuator". The characteristics of laminar and turbulent boundary layer were analyzed and the effectiveness of flow control in delaying the detachment of the boundary layer was analyzed. Numerical simulation programs were developed in C language for simulating various cases in the thesis and a 3D LES turbulence modeling finite volume code was developed using Smagorinsky-Lilly model in C language for the simulating the flow over backward step in turbulence regime. All the numerical simulation codas were validated with previous research works. The thesis is divided into five chapters analyzing flow over square cylinder, backward step and inclined step geometries in 2D and 3D in laminar and turbulent regimesL'objectiu de aquesta tesi doctoral, "Effects offlow control on flow past bluff bodies", és estudiar i analitzar els efectes del control de flux sobre diferents aspectes del flux al voltant de cossos genèrics, Bluff bodies. Les tècniques de control de flux estan en la actualitat sota recerca a nivell mundial, doncs és necessari estudiar l'efectivitat del flux aportat sobre les propietats i els patrons vermiculars del corrent de flux principal. El present treball està inspirat en la indústria del automòbil, així l’anàlisi del flux sobre un esgraó o be una superfície inclinada, ha de permetre entendre les característiques de l'estela de flux a la part del darrera de un vehicle automòbil. Aquest estudi es especialment rellevant quan es considera que una quantitat important de l'energia necessària per desplaçar un vehicle es dissipa gràcies a les estructures vorticulars formades a la part de darrera del vehicle. En aquesta tesi s'han examinat diverses possibilitats de aplicació de les tècniques de control actiu de flux per millorar la efectivitat a l'hora de incrementar la eficiència aerodinàmica sobre cossos genèrics, Bluff bodies. La finalitat bàsica de aquest estudi, és reduir les forces de arrossegament sobre cossos genèrics, gràcies a la determinació de la tècnica de control de fluid més efectiva i la seva implementació pràctica. Dues tècniques diferents de control actiu de fluid han sigut avaluades en aquesta tesi, la definida per un actuador amb flux net nul, "Zero Not Mass Flow Actuator", i la definida per la utilització de un actuador amb un flux net positiu, o be actuador fluídic, "Fluidic Actuator". Les característiques de la capa límit laminar i turbulenta han sigut analitzades així com la efectivitat del control de flux respecte el desplaçament aigües avall del despreniment de la capa límit. Tots els programes utilitzats per toles les simulacions numèriques han sigut creats per el autor de la tesi en llenguatge C, per el que fa referència a les simulacions tridimensionals en règim turbulent, el model de turbulència LES implementat
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Bogner, Christina. "Analysis of flow patterns and flow mechanisms in soils". Thesis, Bayreuth Bayreuth Center of Ecology and Environmental Research, 2009. http://d-nb.info/997214058/34.
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Kim, Youngho. "Online traffic flow model applying dynamic flow density relations". [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964751909.
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Wongl, Li Shing. "Flow and heat transfer in buoyancy induced rotating flow". Thesis, University of Sussex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250118.
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Basnet, Keshav. "Flow around porous barriers: fundamental flow physics and applications". Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1824.
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Investigating flow and turbulence structure around a barrier mounted on the ground or placed in its vicinity is a fundamental problem in wind engineering because of many practical applications related to protection against adverse effects induced by major wind storms (e.g., hurricanes) and snow events (e.g., snow fences used to reduce adverse effects of snow drifting on the roads). In this work the focus is on the case when the obstacle/barrier is porous and the shape of the obstacle is close to a high-aspect-ratio rectangular cylinder situated in the vicinity of the ground. The study employs a range of numerical and experimental techniques to achieve this goal that include 3D LES and 2D RANS numerical simulations, and RTK survey and 3D photogrammetry techniques to measure ground elevations and snow deposits in the field.
In the first part of the study, high-resolution large eddy simulations are used to understand the fundamental flow physics of flow past 2D solid and porous vertical plates with a special focus on describing the unsteady wind loads on the obstacle, vortical structure of the turbulent wake, spectral content of the wake, the separated shear layers and of the characteristics of the large-scale vortex shedding behind the plate, if present. Results show that LES can accurately predict mean flow and turbulence statistics around solid/porous cylinders. Then, a detailed parametric study of flow past vertical solid and porous plates situated in the vicinity of a horizontal bed is performed for the purpose of understanding changes in the mean flow structure, turbulence statistics and dynamics of large scale coherent structures as a function of the main nondimensional geometrical parameters (bottom gap for solid and porous plates, and porosity and average hole size of porous plates) and flow variables (e.g., bed roughness) that affect the wake flow. In particular, the LES flow fields allowed clarifying how the interactions between the bottom and the top separated shear layers change with increasing bottom gap and what is the effect of the bleeding flow on the interactions between the separated shear layers that determine the coherence of the large-scale eddies at large distances from the wake.
In the second part of the thesis, a novel methodology based on field monitoring of the snow deposits and RANS numerical simulations is proposed to improve the design of snow fences and in particular the design of lightweight plastic snow fences that are commonly used to protect roads in the US Midwest against the snow drifting. The goal of the design optimization procedure is to propose a snow fence design that can retain a considerable amount of snow within a shorter downwind distance compared to fences of standard design. A major contribution of the present thesis was the development of a novel non-intrusive image-based technique that can be used to quantitatively estimate the temporal evolution of the volume of snow trapped by a fence over long periods of time. This technique is based on 3-D close range photogrammetry. Results showed that this technique can produce estimations of the snow deposits of comparable accuracy to that given by commonly used methods. This is the first application of this type of techniques to measurements of the snow deposits.
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Kerekes, Rudolf. "Electrolyte flow rate control for Hydrogen Bromine Flow Batteries". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263240.
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The need for energy storage solutions became more significant with the increasing penetration of renewable energy sources in the electricity grid. In the last decades, the flow batteries have gained increasing attention. They have several advantages compared to the conventional battery technologies. Among these, the Hydrogen Bromine Flow Batteries offer a low cost energy storage solution by using globally abundant materials, since Hydrogen and Bromine can be found in large quantities in the oceans. This study was conducted to find out the relation between electrolyte flow rate and electrochemical cell performance and to give a suggestion for dynamic flow rate control to maximize the battery system performance. First, a theoretical model was built to describe the behaviour of the system in various conditions. However, the lack of information of the parameters led the research towards experimental analysis. A small scale system with cell power range of 10 to 14 W and pump power range of 2.6 to 6.8 W was built for the experiments to analyse the cell power at different flow rate values (122 ml/min, 185 ml/min and 230 ml/min). Also, the aim was to observe the gains of using dynamic flow rate (122 ml/min and 230 ml/min used at specific periods of the cycles). The results show that for small scale systems there is no net positive energy gain due to the small power of the battery compared to the power of the pump. However, there were improvements found in battery capacity with 28 % increase, and in Coulombic efficiency with 2.47 % increase, if the largerflow rate was used. Furthermore, a 55% pumping energy saving was reached if the dynamic flow rate was used instead of constant maximum flow rate. In addition, a large scale system was designed, which would be able to integrate a PID control concept for dynamic flow rate control in kW scale batteries. Further work will be required for building and testing the proposed large scale system, which tend to model a commercial size Hydrogen Bromine Flow Battery.Behovet av energilagringslösningar blev mer betydande med den ökande penetrationen av förnybara energikällor i elnätet. Under de senaste decennierna har flödesbatterierna fått ökad uppmärksamhet. De harflera fördelar jämfört med konventionella batteriteknologier. Då väte och brom finns i stora mängder i haven, erbjuder vätebromflödesbatterier en billig lösning för energilagring genom att använda globalt rikligt förekommande material. Denna studie genomfördes för att ta reda på sambandet mellan elektrolytflödeshastighet och elektrokemisk cellprestanda och för att ge ett förslag för dynamisk flödeshastighetskontroll för att maximera batterisystemets prestanda. Först byggdes en teoretisk modell för att beskriva systemets beteende under olika förhållanden. Emellertid ledde bristen på information om parametrarna forskningen mot experimentell analys. Ett småskaligt system med celleffektintervall från 10till 14 W och pumpeffektintervall på 2.6 till 6.8 W byggdes för experimenten för att analysera celleffekten vid olika flödeshastighetsvärden (122 ml / min, 185 ml / min och 230 ml / min). Syftet var också att observera vinsterna med att använda dynamisk flödeshastighet (122 ml / min och 230 ml / min använd vidspecifika perioder av cyklerna). Resultaten visar att för småskaliga system finns det ingen nettopositiv energivinst på grund av batteriets lilla effekt jämfört med pumpens effekt. Det fanns emellertid förbättringari batterikapacitet med en ökning på 28% och i Coulombic effektivitet med en ökning på 2.47% om den större flödeshastigheten användes. Det uppnåddes även en energibesparing på 55% om den dynamiska flödeshastigheten användes istället för konstant maximal flödeshastighet. Dessutom utformades ett storskaligt system som skulle kunna integrera ett PID-kontrollkoncept för dynamisk flödeshastighetskontroll i kW-skalbatterier. Ytterligare arbete kommer att krävas för att bygga och testa det föreslagna storskaliga systemet, som tenderar att modellera ett kommersiellt vätebromflödesbatteri.
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Sundström, Elias. "Centrifugal compressor flow instabilities at low mass flow rate". Licentiate thesis, KTH, Mekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-184869.
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Turbochargers play an important role in increasing the energetic efficiency andreducing emissions of modern power-train systems based on downsized recipro-cating internal combustion engines (ICE). The centrifugal compressor in tur-bochargers is limited at off-design operating conditions by the inception of flowinstabilities causing rotating stall and surge. They occur at reduced enginespeeds (low mass flow rates), i.e. typical operating conditions for a betterengine fuel economy, harming ICEs efficiency. Moreover, unwanted unsteadypressure loads within the compressor are induced; thereby lowering the com-pressors operating life-time. Amplified noise and vibration are also generated,resulting in a notable discomfort. The thesis aims for a physics-based understanding of flow instabilities andthe surge inception phenomena using numerical methods. Such knowledge maypermit developing viable surge control technologies that will allow turbocharg-ers to operate safer and more silent over a broader operating range. Therefore,broadband turbulent enabled compressible Large Eddy Simulation (LES) cal-culations have been performed and several flow-driven instabilities have beencaptured under unstable conditions. LES produces large amounts of 3D datawhich has been post-processed using Fourier spectra and Dynamic Mode De-composition (DMD). These techniques are able to quantify modes in the flowfield by extracting large coherent flow structures and characterize their relativecontribution to the total fluctuation energy at associated. Among the mainfindings, a dominant mode was found which describes the filling and emptyingprocess during surge. A narrowband feature at half of the rotating order wasidentified to correspond to co-rotating vortices upstream of the impeller faceas well as elevated velocity magnitude regions propagating tangentially in thediffuser and the volute. Dominant mode shapes were also found at the rotatingorder frequency and its harmonics, which manifest as a spinning mode shapelocalized at the diffuser inlet. From the compressible LES flow solution one can extract the acoustic infor-mation and the noise affiliated with the compressor. This enable through datacorrelation quantifying the flow-acoustics coupling phenomena in the compres-sor. Detailed comparison of flow (pressure, velocity) and aeroacoustics (soundpressure levels) predictions in terms of time-averaged, fluctuating quantities,and spectra is carried out against experimental measurements.QC 20160406
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Wong, Wai-Lid. "Flow development and mixing in three phase slug flow". Thesis, Imperial College London, 2003. http://hdl.handle.net/10044/1/7780.
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Welderufael, W. A. y Y. E. Woyessa. "Stream flow analysis and comparison of methods for base flow separation : case study of the Modder River basin in central South Africa". Interim : Interdisciplinary Journal, Vol 8, Issue 2: Central University of Technology Free State Bloemfontein, 2009. http://hdl.handle.net/11462/375.
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Published ArticleA stream flow at an outlet of a catchment can be entirely a base flow or direct flow or a combination of both. The base flow component of a stream is mainly contributed from the ground water storage which often is an open aquifer whereas the direct flow component is mainly the result of a direct response of a rainfall event. The Upper Modder river basin catchment is considered to be the origin of the Modder River which supplies water to Rustfontein Dam, situated at the outlet of the C52A with an area of 928 km2. Nine years of daily stream flow showed a continuous none zero discharge throughout the year. During the rainy season the discharge of the stream increases significantly. Thus, it is necessary to separate the direct and base flow of the stream in order to understand the important component that is more likely to be affected by different land use changes in a catchment. The Modder river daily mean flow at the inlet of Rustfontein dam (in Central South Africa) was analysed using four base flow separation methods, the Nathan & McMahon (N&M), the Chapman, Smakhtin & Watkins (S&W) method and the frequency duration analysis. All the methods gave higher percentage of the low flow component, except for the S&W method which underestimated it. The N&M filtering equation gave base flow components greater than 66% in 1999 and increased to 84% in 2007 while the Chapman equation revealed 65% and 74% in 1999 and 2007, respectively. Similarly, the frequency duration analysis gave 62% in 1999 and increased to 79% in 2007. The frequency duration analysis gave up to 13% lower percentage than the N&M (1990) filtering equation. The nine year base flow averages are 69%, 69% and 75% for frequency duration analysis, Chapman (1999) and N&M (1990) filtering equations, respectively. The result revealed that the Modder River is largely supplied by the ground water discharge. The result seemed to concur with the fact that for a semi-arid catchment such as the Modder river basin, with an average annual runoff coefficient of approximately 6%, the contribution of annual rainfall to direct runoff is very minimal.
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Kosakowski, Cindy. "Betydelsen av flow i bildskapande och pedagogers betydelse för flow : En uppsats inom bildpedagogik om flow och kreativitet och vilka förutsättningar som gynnar flow". Thesis, Högskolan i Gävle, Avdelningen för kultur-, religions- och utbildningsvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14630.
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Goz, Caglayan. "Instream Flow Methodologies: Hydrological Environmental Flow Assessment In Pazarsuyu River". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615004/index.pdf.
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In Turkey with increasing energy demand by industrialization and urbanization, hydropower seemed to be the most environmental friendly and sustainable solution for
the problem. However, hydropower has also environmental effects especially when hydropower projects are numerous on a single river, and they use almost entire water in
the river. Environmental flow as a new term became popular in media with increased density of small hydropower projects in Turkey. It is the required flow in the part of diversion for Run-off River type of hydropower plant in order to protect health of the riverin other words, to balance components of the river, including physico-chemical quality standards, surface and groundwater, geomorphological dynamics, social, economic, cultural and landscape values. In this study, an analysis utilizing hydrological (desktop) environmental flow assessment methods is prepared for Turkey, focusing on the Pazarsuyu Basin as a case study, and the results are compared with the applications done by the Governmental Institutions. Moreover, insufficient applications with regard to environmental flow assessment are given and reasons for public concerns are pointed out due to small hydropower development in Turkey.
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Gordon, David R. "Computational unsteady flow dynamics : oscillating flow about a circular cylinder". Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28053.
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Thompson, Andrew S. "Experimental charactarization of flow induced vibration in turbulent pipe flow /". Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3162.pdf.
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Conder, Thomas E. "Thermal and flow impact of cylindrical grooves in channel flow". Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Summer2009/T_Conder_072209.pdf.
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Thesis (M.S. in mechanical engineering)--Washington State University, August 2009.Title from PDF title page (viewed on Aug. 11, 2009). "Department of Mechanical Engineering." Includes bibliographical references (p. 75-76).
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Thompson, Andrew S. "Experimental Characterization of Flow Induced Vibration in Turbulent Pipe Flow". BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1906.
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This thesis presents results of an experimental investigation that characterizes the wall vibration of a pipe with turbulent flow passing through it. Specifically, experiments were conducted using a water flow loop to address three general phenomena. The topics of investigation were: 1) How does the pipe wall vibration depend on the average flow speed, pipe diameter, and pipe thickness for an unsupported pipe? 2) How does the behavior change if the pipe is clamp supported at various clamping lengths? 3) What influence does turbulence generation caused by holed baffle plates exert on the pipe response? A single pipe material (PVC) was used with a range of internal diameters from 5.08 cm to 10.16 cm and diameter to thickness ratios ranging from 8.90 to 16.94. The average flow speed that the experiments were conducted at ranged from 0 to 11.5 m/s. Pipe vibrations were characterized by accelerometers mounted on the pipe wall at several locations along the pipe length. Rms values of the pipe wall acceleration and velocity time series were measured at various flow speeds. Power spectral densities of the accelerometer data were computed and analyzed. Concurrent wall pressure fluctuation measurements were also obtained. The results show that for a fully developed turbulent flow, the rms of the wall pressure fluctuations is proportional to the rms of the wall acceleration and each scale nominally as the square of the average fluid velocity. Also, the rms of the pipe wall acceleration increases with decreasing pipe wall thickness. When changes were made in the pipe support length, it was observed that, in general, pipe support length exercises little influence on the pipe wall acceleration. The influence of pipe support length on the pipe wall velocity is much more pronounced. A non-dimensional parameter describing the pipe wall acceleration is defined and its dependence on relevant independent non-dimensional parameters is presented. Turbulence was induced using baffle plates with various sizes (2.54 cm to 0.159 cm) and numbers of holes drilled through them to provide a constant through area of 35.48 cm2 for each plate. Cavitation exists at high speeds for the largest holed baffle plates and this significantly increases the rms of the pipe wall acceleration. As the baffle plate hole size decreases, vibration levels were observed to return to levels that were observed when no baffle plate was employed. Power spectral densities of the accelerometer data from each baffle plate scenario were also computed and analyzed.
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Carneal, Jason Bradley. "Integration and Validation of Flow Image Quantification (Flow-IQ) System". Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/35322.
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The first aim of this work was to integrate, validate, and document, a digital particle image quantification (Flow-IQ) software package developed in conjunction with and supported by Aeroprobe Corporation. The system is tailored towards experimental fluid mechanics applications. The second aim of this work was to test the performance of DPIV algorithms in wall shear flows, and to test the performance of several particle sizing algorithms for use in spray sizing and average diameter calculation. Several particle sizing algorithms which assume a circular particle profile were tested with DPIV data on spray atomization, including three point Guassian, four point Gaussian, and least squares algorithms. A novel elliptical diameter estimation scheme was developed which does not limit the measurement to circular patterns. The elliptic estimator developed in this work is able to estimate the diameter of a particle with an elliptic shape, and assumes that the particle is axisymmetric about the x or y axis. Two elliptical schemes, the true and averaged elliptical estimators, were developed and compared to the traditional three point Gaussian diameter estimator using theoretical models. If elliptical particles are theoretically used, the elliptical sizing schemes perform drastically better than the traditional scheme, which is limited to diameter measurements in the x-direction. The error of the traditional method in determining the volume of an elliptical particle increases dramatically with the eccentricity. Monte Carlo Simulations were also used to characterize the error associated with wall shear measurements using DPIV. Couette flow artificial images were generated with various shear rates at the wall. DPIV analysis was performed on these images using PIV algorithms developed by other researchers, including the traditional multigrid method, a dynamically-adaptive DPIV scheme, and a control set with no discrete window offset. The error at the wall was calculated for each data set. The dynamically adaptive scheme was found to estimate the velocity near the wall with less error than the no discrete window offset and traditional multigrid algorithms. The shear rate was found to be the main factor in the error in the velocity measurement. In wall shear velocity measurement, the mean (bias) error was an order of magnitude greater than the RMS (random) error. A least squares scheme was used to correct for this bias error with favorable results. The major contribution of this effort stems from providing a novel elliptical particle sizing scheme for use in DPIV, and quantifies the error associated with wall shear measurements using several DPIV algorithms. A test bed and comprehensive user's manual for Flow-IQ v2.2 was also developed in this work.Master of Science
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Catlett, Matthew Ryan. "Flow Induced Noise from Turbulent Flow over Steps and Gaps". Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/32926.
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The existence of small surface discontinuities on a flow surface generate significant pressure fluctuations which can manifest as radiated far field sound and affect the fluctuating near wall pressure field exerted on the flow surface. A significant amount
of research has been performed on various step and gap flows; however few have dealt with step heights that are small relative to the incoming boundary layer. Fewer still have been concerned with measuring the effect on the fluctuating wall pressure field or the radiated far field sound from these small surface discontinuities. This study presents the work aimed at scaling the radiated sound from small forward and backward steps, detailing the surface pressure field as a result of these steps, and detailing the far field sound radiated from gap configurations of similar dimension. These measurements were
performed in the Virginia Tech Anechoic Wall Jet facility for step heights that ranged from approximately 10% to 100% of the incoming boundary layer height. The results show the influence of step height and boundary layer velocity on the far field sound from forward and backward steps. Very little directivity is seen for either source and the larger step heights considered in this study are shown to not be acoustically compact. A new
mixed scaling normalization is proposed for the far field spectra from both types of step, which is shown to reliably collapse the data. Backward steps are shown to be much weaker producers of far field sound than a similarly sized forward step. The implications of this behavior are discussed with respect to the far field sound measured from various gap flows. The fluctuating wall pressure field was measured upstream and downstream of both step configurations. The data shows a slow recovery of the wall pressure field with lasting disturbances up to 100 step heights downstream of the step feature.Master of Science
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Gebbie, Timothy John. "Fluid and gas models in FLRW and almost FLRW universes". Master's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/17936.
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Includes bibliographical references.Recently the universe has been modeled in the covariant sense, in terms of fluid models and perturbations thereof, leading to Gauge Invariant Covariant (GIC) perturbations of these fluid models. It is well known that kinetic theory provides a physically sound and consistent description of the matter and radiation in the universe, so a perturbative theory of gas models using kinetic theory would be most helpful. This has been done to a large degree in the Gauge Invariant (GI) Bardeen approach to perturbation theory by studies of gases based on the relativistic Boltzmann equation. These treatments, however, were not fully covariant. The GI Bardeen approach is dependent on a co-ordinate choice, while in the full GIC perturbation theory full covariance is maintained along with gauge invariance by describing the theory in a particular set of perturbation variables that differ from the Bardeen choice but can be related to the Bardeen variables. The covariant formulation of the relativistic Boltzmann equation in terms of variables that are of use in the GIC theory for gases has been well described. In this thesis, I provide both a good introduction to the full GIC perturbation theory of a photon gas and matter fluid system in the linear theory as well as a solid grounding with respect to the exact FLRW fluid model upon which most of the original ideas and concepts of modern cosmology are based. The introduction to the exact FLRW model is done in the sense of the dynamical systems approach to cosmology which provides the easiest access to understanding the evolution of single and multi-fluid FLRW models.
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Tocher, Benjamin. "Bifurcation contrasts between plane Poiseuille flow and plane magnetohydrodynamic flow". Thesis, Aston University, 2013. http://publications.aston.ac.uk/19269/.
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The stability characteristics of an incompressible viscous pressure-driven flow of an electrically conducting fluid between two parallel boundaries in the presence of a transverse magnetic field are compared and contrasted with those of Plane Poiseuille flow (PPF). Assuming that the outer regions adjacent to the fluid layer are perfectly electrically insulating, the appropriate boundary conditions are applied. The eigenvalue problems are then solved numerically to obtain the critical Reynolds number Rec and the critical wave number ac in the limit of small Hartmann number (M) range to produce the curves of marginal stability. The non-linear two-dimensional travelling waves that bifurcate by way of a Hopf bifurcation from the neutral curves are approximated by a truncated Fourier series in the streamwise direction. Two and three dimensional secondary disturbances are applied to both the constant pressure and constant flux equilibrium solutions using Floquet theory as this is believed to be the generic mechanism of instability in shear flows. The change in shape of the undisturbed velocity profile caused by the magnetic field is found to be the dominant factor. Consequently the critical Reynolds number is found to increase rapidly with increasing M so the transverse magnetic field has a powerful stabilising effect on this type of flow.