Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains v, 44 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 39-40).

Master of Science

Ce travail de maîtrise a pour objectif le développement, la construction et la validation d'une sonde de pression cinq trous instationnaire avec capteurs embarqués. Celle-ci s'intègre dans le programme de recherche du laboratoire de machines hydraulique de l'université Laval et vient compléter les systèmes de mesures P.I.V. et L.D.V. que le laboratoire possède déjà. La première phase de ce travail a été l'établissement d'un cahier des charges ainsi qu'une revue bibliographique sur les sondes du même type déjà existantes. Puis les deux phases principales de ce travail ont été les phases de conception et de construction de la sonde. Plusieurs modifications de plans ont été nécessaires afin d'arriver à une sonde la plus petite possible tout en respectant les nombreuses contraintes du cahier des charges de l'étalonnage et de la construction. La majeure partie de la construction a été effectuée à l'atelier du département de génie mécanique de l'université, mais le montage des capteurs ainsi que l'usinage de la tête de la sonde ont dû être sous-traités à des entreprises extérieures. L'étalonnage de la sonde a été réalisé en deux parties. La première partie est l'étalonnage des capteurs. Il a été réalisé au moyen d'un réservoir d'air comprimé, ce qui nous a aussi permis de vérifier l'étanchéité de la sonde. La seconde partie est l'étalonnage de la sonde elle-même, qui, pour des raisons de disponibilité n'a pu être réalisé dans un canal hydraulique mais dans un jet d'air calibré. L'utilisation de l'air a posé deux principaux problèmes : l'impossibilité d'atteindre les mêmes vitesses que dans l'eau (en similitude de Reynolds) et les pressions dynamiques mesurées sont beaucoup plus faibles dans l'air que dans l'eau. Pour les faibles vitesses on arrive à la limite de sensibilité des capteurs. Une autre série de mesures a permis de mettre en évidence les limites d'utilisation de la sonde selon cet étalonnage, soit 31 m /s dans l'air, équivalent à 2 m /s dans l'eau et une plage de direction pour l'angle d'écoulement entre ± 25° pouvant aller jusqu'à ± 45° suivant les conditions. Afin de valider totalement la sonde il faut encore réaliser des essais de réponse en fréquences et réaliser un système permettant d'étalonner la sonde dans un canal hydraulique afin de vérifier son comportement (vibrations) ainsi que la réponse des capteurs à 10 '7S. / This work is presented in partial fulfillment of a Master Degree. Its objectives arc the development, construction and validation of a five-hole probe with embedded sensors to measure non stationary pressures. This new measuring instrument will be used for the research programme of the Laboratory of hydraulic machines of Laval University. It is additional to the P.I.V. and L.D.V measurement Systems already existing at the laboratory. The first phase of this work consisted of the establishment of specifications as well as a bibliographical review of existing probes of the same type. Then two important phases of this work were the design and construction of the probe. Several design modifications were necessary in order to produce the smallest possible probe while respecting the many constraints of the specifications calibration and construction. The major portion of the actual construction was carried out at the workshop of the Mechanical Engineering Department of the University, but the assembly of the sensors as well as the machining of the probe head were sub-contracted to external firms. The calibration of the probe was carried out in two parts. The first part was the calibration of the sensors. This was done by means of a compressed air tank which allowed us to verify also if the probe is waterproof. The second part was the calibration of the probe it self, which, for reasons of availability, could not be produced in a hydraulic channel but in a gauged air jet. The use of air brought two principal problems: the impossibility of reaching the high speeds encountered in water (following similarity of Reynolds number) and a much weaker measured dynamic pressures in air than in water. For low speeds, one reaches the limit of sensitivity of the sensors. Another series of measurements made it possible to highlight the operational limits of the probe according to the calibrated zone, that is to say 31 m/s in the air corresponding to 2 m/s in water and the direction of the flow angle between ± 25°, and ± 45° for certain conditions. In order to completely validate the probe, it is still necessary to carry out tests for the frequency response and to build a hydraulic channel to check the probe's behavior regarding vibrations as well as to calibrate the response of the sensors up to 10 m/s.

This thesis is an account of various phenomena caused by the interaction of the motion of electrically conducting fluids with magnetic fields. Such phenomena, the study of which is usually known as Magnetohydrodynamics (MHD), occur on a galactic, planetary or laboratory length scale; however in this thesis we concentrate on those phenomena which can be reproduced in the laboratory. In chapter 2 we study the laminar flow of uniformly conducting, incompressible fluids in rectangular ducts under the action of transverse magnetic fields. We begin by proving that when the duct has a constant cross-section the solution is unique and then analyse theoretically some of the curious effects on the flow of the duct's walls being electrically conducting. We find close agreement between the results of these theories and the experiments of Alty (1966) and Baylis (1966). We then analyse the flow in ducts with varying cross-sections. In chapter 3 we analyse some of the curious flows and current streamline patterns produced by placing electrodes on the non-conducting walls of a container, filled with a conducting fluid, and passing electric currents between the electrodes in the presence of a strong magnetic field. In chapter 4 we analyse some of the theoretical limitations on the use of Pitot tubes and electric potential (e.p.) probes in MHD flows, and provide some estimates of the errors to be expected. In chapter 5 we analyse the stability of parallel flows in parallel magnetic fields and also some aspects of the stability of the flows analysed in chapters 2 and 3. In chapters 6, 7 and 8 we describe our experimental apparatus, the experiments to investigate directly some of the flows analysed theoretically in chapters 2 and 3 by means of Pitot and e.p. probes, and experiments to measure the MHD errors inherent in the use of these probes. We concluded that the curious phenomena predicted actually exist. We also learnt much about the use of Pitot and e.p. probes, especially as some of the experimental results were as predicted in chapter 4.

Made available in DSpace on 2016-12-23T14:08:09Z (GMT). No. of bitstreams: 1 Felipe Carvalho da Silva.pdf: 4181457 bytes, checksum: 8aef395272a667525a72d34c5ffb865f (MD5) Previous issue date: 2012-07-25 / With recent discoveries by the oil industry related to the reserves in Brazilian pre-salt, flow measurement technology is being re-evaluated in view of the large CO2 concentrations found in these reserves. A technology that has accuracy levels similar to those obtained with flow meters currently used and also measures independent characteristics to the composition and thermodynamic properties of gases is optical flow measurement velocimetry (OFM). The present work is related to experimental study, comparison of the speed readings from Pitot tube flow meters and optical velocimetry. This experimental study consists of qualifying and quantifying the velocity profiles among the possible configurations of flow in the wind tunnel, proposing methodology using flow conditioners and damping of the readings obtained with the Pitot tube, and analysis of readings taken with the optical sensor to evaluate the device installation effects in the results. The results indicate that transit-time optical flow meters for medium to high speed levels, could provide readcohesive flow even in a misalignment of up to ± 5 °, although it appears in the installation manual of the manufacturer guarantees of results meter when a misalignment of at most up to ±2º. Regarding the optical sensor intrusive effect in the readings simultaneous with the Pitot tube, it is perceived, in general, from approximately Re> 2,05x105, the intrusive effect of this influence is suppressed by other effects. Finally, for a proper flow study through Pitometry in order to make the comparison with the optical flow metering and achieve satisfactory results with the Pitot tube, the use of specific devices of flow conditioning and damping of the measured values had to be made / Com as recentes descobertas da indústria petrolífera brasileira, relacionadas às reservas no pré-sal, a tecnologia de medição de vazão está sendo reavaliada, tendo em vista as grandes concentrações de CO2 encontradas nessas reservas. A tecnologia de medição de vazão por velocimetria óptica (OFM) possui níveis de precisão semelhantes aos obtidos com os medidores de vazão utilizados atualmente. Essa tecnologia possui as características de independência com relação à composição química e às propriedades termodinâmicas dos gases. O presente trabalho se dedica ao estudo experimental de comparação das leituras de velocidade entre tubo de Pitot e medidor de vazão por velocimetria óptica. Para isso foi efetuada qualificação e quantificação dos perfis de velocidades em escoamento no túnel de vento, propondo metodologia de uso de retificadores de fluxo e amortecimento das leituras obtidas com o tubo de Pitot, e análises de leituras realizadas com o sensor óptico visando avaliar os efeitos de instalação do dispositivo nos resultados obtidos. Os resultados indicam que medidores de vazão ópticos por tempo de trânsito, para níveis médios e altos de velocidade, podem fornecer a leitura esperada da vazão mesmo estando num desalinhamento de ±5º, apesar de constar no manual de instalação do fabricante garantia destes resultados do medidor quando num desalinhamento de, no máximo, até ±2º. Com relação ao efeito intrusivo do sensor óptico nas leituras simultâneas com o tubo de Pitot, percebe-se, em geral, que a partir de aproximadamente Re> 2,05x105, o efeito intrusivo desta influência foi suprimido por outros efeitos. Por fim, para uma devida caracterização do escoamento por meio de pitometria, a fim de efetuar a comparação com a medição Laser, e alcançar satisfatórios resultados com o tubo de Pitot, foi necessário fazer uso de dispositivos específicos como retificadores de fluxo e de amortecimento (damping) dos valores medidos