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1
Fuller, Andrew D. "A flow rate measurement system for a mobile emissions measurement system." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1903.
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Thesis (M.S.)--West Virginia University, 2001.Title from document title page. Document formatted into pages; contains xv, 111 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 89-91).
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Evans, Jonathan M. "Measurement of blood flow volume rate by Doppler ultrasound." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292441.
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Martin, Edward C. "Measuring Water Flow and Rate on the Farm." College of Agriculture, University of Arizona (Tucson, AZ), 2014. http://hdl.handle.net/10150/333140.
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Revised; Originally Published: 20094 pp.
Proper water management involves two basic considerations: when and how much irrigation water to apply. The timing of an irrigation event (the when) involves utilizing information on plant needs and soil water conditions. How much depends primarily on the soil’s water holding capacity, the depletion level and the rooting depth of the crop. Once you have calculated how much water to apply, how can you be sure that you have accurately applied that amount? Or, if you miss your target amount, how do you determine how much water you actually applied? The amount of water applied to a field is a function of time, flow and area. The time of an irrigation is easily recorded. The amount of area irrigated is also easily calculated. However, estimating flow rate in an open ditch is often guess work, at best. In this bulletin we shall discuss ways to measure water flow in an open ditch.
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Paavilainen, Janne. "Characterization of Chimney Flue Gas Flows : Flow Rate Measurements with Averaging Pitot Probes." Licentiate thesis, Högskolan Dalarna, Energiteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:du-23481.
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Performance testing methods of boilers in transient operating conditions (start, stop and combustion power modulation sequences) need the combustion rate quantified to allow for the emissions to be quantified. One way of quantifying the combustion rate of a boiler during transient operating conditions is by measuring the flue gas flow rate. The flow conditions in chimneys of single family house boilers pose a challenge however, mainly because of the low flow velocity. The main objectives of the work were to characterize the flow conditions in residential chimneys, to evaluate the use of the Pitot-static method and the averaging Pitot method, and to develop and test a calibration method for averaging Pitot probes for low 𝑅𝑅𝑅𝑅.A literature survey and a theoretical study were performed to characterize the flow conditions in in single family house boiler chimneys. The flow velocities under normal boiler operating conditions are often below the requirements for the assumptions of non-viscous fluid justifying the use of the quadratic Bernoulli equation. A non-linear calibration coefficient is required to correct for these viscous effects in order to avoid significant measurement errors. The flow type in the studied conditions changes from laminar, across the transition regime, to fully turbulent flow, resulting in significant changes of the velocity profile during transient boiler operation. Due to geometrical settings occurring in practice measurements are often done in the hydrodynamic entrance region, where the velocity profiles are neither fully developed nor symmetrical. The predicted changes in velocity profiles are also confirmed experimentally in two chimneys.Several requirements set in ISO 10780 and ISO 3966 for Pitot-static probes are either met questionably or not met at all, meaning that the methods cannot be used as such. The main issues are the low flow velocity, viscous effects, and velocity profiles that change significantly during normal boiler operation. The Pitot-static probe can be calibrated for low 𝑅𝑅𝑅𝑅, but is not reliable because of the changing velocity profiles.The pressure averaging probe is a simple remedy to overcome the problems with asymmetric and changing velocity profiles, but still keeping low the irrecoverable pressure drop caused by the probe. However, commercial averaging probes are not calibrated for the characterized chimney conditions and the information available on the performance of averaging probes at low 𝑅𝑅𝑅𝑅 is scarce. A literature survey and a theoretical study were done to develop a method for calibrating pressure averaging probes for low 𝑅𝑅𝑒 flue gas flows in residential chimneys.The experimental part consists of constructing a calibration rig, testing the performance of differential pressure transducers, and testing a prototype pressure averaging probe. The results show good correlation over a wide operation range, but the low 𝑅𝑅𝑅𝑅 characteristics of the probe could not be identified due to instability in the chosen pressure transducer, and temperature correlation for one of the probes while not for the other. The differential pressures produced are close to the performance limitations of readily available transducers and it should be possible to improve the method by focusing on finding or building a suitable pressure transducer. The performance of the averaging method can be improved further by optimizing the geometry of the probe. Another way of reducing the uncertainty would be to increase the probe size relative to the conduit diameter to produce a higher differential pressure, at the expense of increasing the irrecoverable pressure drop.
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ACCIOLY, CARLA CITO. "METROLOGICAL RELIABILITY OF FLOW RATE MEASUREMENT IN HYDROELECTRICAL COOLING WATER SYSTEM." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10463@1.
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A supervisão da vazão da água de resfriamento em
equipamentos de
produção de energia de usinas hidrelétricas tem sido uma
questão de preocupação
devido à possibilidade de obstrução dos equipamentos de
medição pela água sem
tratamento. Outrossim, por razões econômicas, um
instrumento barato e confiável
deve ser escolhido para os vários pontos de monitoramento.
Neste trabalho, um
dispositivo não intrusivo foi desenvolvido, tendo seu
desempenho avaliado para a
medição da vazão da água na faixa de 0,7 a 7 m3/h. O
princípio básico de
operação é a variação da freqüência de formação de
vórtices como função da
vazão. Um acelerômetro colocado na parede externa de uma
tubulação mede a
freqüência de vibração induzida pelos vórtices. Vários
testes mostraram que o
instrumento é sensível a ruídos, que devem ser filtrados
para a redução da
incerteza de medição. O número de Strouhal foi avaliado
como função do número
de Reynolds do escoamento, mostrando um comportamento
assintótico para
números de Reynolds elevados. O instrumento diferencia
nitidamente a existência
ou não de escoamento. Presentemente, um esforço para
condicionamento do sinal
está sendo feito para a redução da incerteza de medição da
vazão, que é estimada
nesta dissertação.The supervision of the cooling water flow rate in power producing equipments of hydro-electric plants has been an issue of concern due to the possibility of clogging up measurement instruments by the used non treated flowing water. Furthermore, for economic reasons, a cheap and reliable instrument must be chosen for each of the many monitoring points. In this work, a non-intrusive device was developed and its performance analized for measuring water flow rate in the 0,7 to 7 m3/h range. The basic operating principle is the variation of the vortex shedding frequency with flow rate. An accelerometer placed outside the pipe wall measures the vortex induced vibration frequency. Several tests showed that the instrument is noise sensitive, which must be filtered to reduce the uncertainty of measurement. The Strouhal number was plotted as a function of the flow Reynolds number, showing an asymptotic trend towards an approximately constant value at high Reynolds numbers. The instrument sharply differenciates between flow and non-flow situations. Presently, a signal conditioning effort is being conducted to reduce the uncertainty of measurement of the flow rate, which is estimated in this dissertation.
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Barratt, Ian Robert. "Radiometric determination of the true mass flow rate of solids in a pneumatic suspension." Thesis, University of Greenwich, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313221.
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Hasan, Abbas. "Multiphase flow rate measurement using a novel conductance Venturi meter : experimental and theoretical study in different flow regimes." Thesis, University of Huddersfield, 2010. http://eprints.hud.ac.uk/id/eprint/9673/.
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Multiphase flows, where two or even three fluids flow simultaneously in a pipe are becoming increasingly important in industry. Although much research has been done to measure the phase flow rates of two-phase flows using a Venturi meter, accurate flow rate measurements of two phase flows in vertical and horizontal pipes at different flow regimes using a Venturi meter remain elusive. In water continuous multiphase flow, the electrical conductance technique has proven attractive for many industrial applications. In gas-water two phase flows, the electrical conductance technique can be used to measure the gas volume fraction. The electrical conductance is typically measured by passing a known electrical current through the flow and then measure the voltage drop between two electrodes in the pipe. Once the current and the voltage drop are obtained, the conductance (or resistance) of the mixture, which depends on the gas volume fraction in the water, can then be calculated. The principal aim of the research described in this thesis was to develop a novel conductance multiphase flow meter which is capable of measuring the gas and the water flow rates in vertical annular flows and horizontal stratified gas water two phase flows. This thesis investigates the homogenous and separated (vertical annular and horizontal stratified) gas-water two phase flows through Venturi meters. In bubbly(approximately homogenous) two phase flow, the universal Venturi meter (nonconductance Venturi) was used in conjunction with the Flow Density Meter, FDM (which is capable of measuring the gas volume fraction at the inlet of the Venturi) to measure the mixture flow rate using the homogenous flow model. Since the separated flow in a Venturi meter is highly complex and the application of the homogenous flow model could not be expected to lead to highly accurate results, a novel conductance multiphase flow meter, which consists of the Conductance Inlet Void Fraction Meter, CIVFM (that is capable of measuring the gas volume fraction at the inlet of the Venturi) and the Conductance Multiphase Venturi Meter, CMVM (that is capable of measuring the gas volume fraction at the throat of the Venturi) was designed and manufactured allowing the new separated flow model to be used to determine the gas and the water flow rates. A new model for separated flows has been investigated. This model was used to calculate the phase flow rates of water and gas flows in a horizontal stratified flow. This model was also modified to be used in a vertical annular flow. The new separated flow model is based on the measurement of the gas volume fraction at the inlet and the throat of the Venturi meter rather than relying on prior knowledge of the mass flow quality x. Online measurement of x is difficult and not practical in nearly all multiphase flow applications. The advantage of the new model described in this thesis over the previous models available in the literature is that the new model does not require prior knowledge of the mass flow quality which makes the measurement technique described in this thesis more practical.
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SANTOS, WAGNER JOSÉ DOS. "ANALYSIS OF THE INFLUENCE OF VISCOSITY ON THE PETROLEUM FLOW RATE MEASUREMENT BY ULTRASONIC METERS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=27893@1.
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No Brasil, a medição de petróleo é regulada pela ANP e pelo INMETRO. O
Regulamento Técnico de Medição de Petróleo e Gás Natural exige que os
medidores de vazão de petróleo sejam calibrados nas condições mais próximas
das encontradas no local de medição, tanto para o fluido (massa específica e
viscosidade) quanto operacionais (vazão, pressão e temperatura). Replicar todas
estas condições nos laboratórios de calibração nacionais é muito complicado e
dispendioso. Assim, neste trabalho foram avaliados os comportamentos de 7
medidores Altosonic V calibrados com 5 tipos de fluidos (oural, condensat, fuel,
heavy fuel e água). Os fatores de calibração dos medidores foram submetidos a
avaliações estatísticas e curvas de calibração foram ajustadas buscando
identificar possíveis tendências de comportamento. Após supor-se que vazões e
viscosidades teriam influência na aleatoriedade dos fatores, chegou-se à
conclusão que, utilizando as calibrações de fábrica (fingerprint) do medidor, que
cobrem toda a faixa de viscosidade e vazão de medição com a utilização do
número de Reynolds, os limites requeridos por norma de erros para medição
fiscal de são atendidos. Assim, sugere-se que as verificações periódicas do
Altosonic V sejam feitas com o fluido disponível no laboratório de calibração,
observando a coerência dos fatores obtidos nesta calibração e na calibração
inicial, buscando o atendimento aos limites legais da aplicação.In Brazil, the measurement of oil is regulated by ANP and INMETRO. The Technical Regulation for Petroleum and Natural Gas requires that the oil flow meters be calibrated in conditions close to those found at the measurement site, both regarding the fluid (density and viscosity) and operational conditions (flow rate, pressure and temperature). It is very difficult to replicate all these conditions in national calibration facilities and expensive too. Thus, this study evaluated the behavior of 7 Altosonic V meters calibrated with 5 types of fluids (oural, condensat, fuel, heavy fuel and water). The calibration factors of the meters were subjected to statistical evaluation and calibration curves were fitted looking for possible behavior trends. Supposing that flow rates and viscosities would influence randomly the factors, a conclusion was reached that, by using the factory meter calibrations (fingerprint), that cover the entire measurement range of viscosity and flow rates, by using Reynolds number, the required by norm fiscal measurement error limits are met. Thus, it is suggested that periodic checks of Altosonic V could be made with the fluid available in the calibration facility, verifying the consistency of the factors obtained in this calibration and in the fingerprint, aimed at complying with the legal limits of the application.
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OLIVEIRA, THIAGO BARRA VIDAL DE. "METROLOGICAL EVALUATION OF THE V-CONE TYPE METER PERFORMANCE FOR WET GAS FLOW RATE MEASUREMENT." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=32997@1.
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O objetivo deste trabalho é avaliar o desempenho metrológico e o potencial de aplicação do medidor tipo v-cone para medição de vazão de gás natural em condições de gás úmido. Observa-se que os medidores do tipo placa de orifício, geralmente utilizados na medição de vazão de gás no segmento de Exploração e
Produção (E e P), podem não representar a tecnologia mais adequada. O medidor v-cone representa uma tecnologia relativamente recente, que vem demonstrando bom desempenho para a medição de vazão e vem ganhando aceitação de órgãos reguladores. O interesse e a motivação do pesquisador residem na busca de maior exatidão na medição de vazão em condições operacionais adversas (gás úmido não especificado), sem impacto significativo sobre o custo do sistema. O presente trabalho, por meio de uma pesquisa bibliográfica e documental, apresenta o estágio atual de desenvolvimento da tecnologia de medição por v-cone e detalha as características dos sistemas de medição de vazão de gás natural, além de abordar as normas e regulamentos relacionados ao tema em questão. A fase experimental busca avaliar o
desempenho do medidor por meio de uma investigação empírica realizada em laboratório, simulando condições de gás úmido encontradas em campo. Essa análise envolve também a determinação de erros e incertezas de medição. A pesquisa realizada, em conjunto com a avaliação dos resultados dos testes e
das correlações utilizadas, demonstra que o medidor v-cone apresenta boa confiabilidade na medição de vazão de gás natural em escoamento de gás úmido, podendo ser utilizado em aplicações encontradas no segmento de E e P.The aim of this study is to evaluate the metrological performance and potential of use of the v-cone type meter for measuring the natural gas flow rate under wet gas conditions. The orifice plate type meters, that are usually used to measure the gas flow rate in the Exploration and Production segment (E and P), may not represent the most appropriate technology. The v-cone meter represents a relatively recent technology, which has shown good performance for the flow rate measurement and is gaining acceptance from the regulators. The interest and motivation of the researcher are related to the quest for greater flow rate measurement accuracy in adverse operating conditions (unspecified wet gas), with no significant impact on the cost of the system. This work, through a literature and documentary search, presents the current stage of development of the v-cone flow rate measurement technology and details the characteristics of natural gas flow rate measurement systems, in addition to addressing the standards and regulations relating to the subject. The experimental phase aims to evaluate the meter performance through an empirical research conducted in laboratory, by simulating wet gas conditions found in the field. This analysis also involves the determination of measurement errors and uncertainties. The research and the evaluation of test results and correlations show that the v-cone meter has good reliability in natural gas flow rate measurement under wet gas conditions, allowing it to be used in applications found in E and P.
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Zheng, Yingna. "Investigation of heat transfer to pneumatically conveyed solids as a means to mass flow rate measurement." Thesis, Glasgow Caledonian University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492390.
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Mass flow measurement of pneumatically conveyed solids is a common requirement in many industrial processes. The direct approach of solids mass flow measurement, in which an appropriate sensing element is used, which responds directly to the mass flow rate is less likely to be affected by interfering and modifying factors. As a possible direct approach, several thermal methods have been investigated and developed over last two decades, however all implementations up to the present have significant drawback. A reliable non-invasive and direct thermal mass flow measurement technique needs to be developed further to achieve an efficient utilization of energy and raw materials.
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Muller, Maria Aletta. "Development of an on-line entrainment measurement device for a bubbling fluidized bed." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/25312.
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A selective combination of the principles of a thermal mass flow meter and constant temperature anemometry was used to develop a solid mass flow meter that improves significantly on the flow meter developed by De Vos et al (2010). The flow meter has a measurement plate that is kept at a constant temperature. Due to conductive heat transfer between the entrained solids and the measurement plate, additional power is needed to maintain the plate at this setpoint temperature value. This additional power was correlated against the average solids flow rate. The calibration curve shows a linear relationship between the power measurement and the entrainment flux for entrainment fluxes between 3.4 x 10-4 kg/(m2.s) and 7.5 x 10-3 kg/(m2.s). Deviation from a linear response at lower entrainment fluxes may be caused by a longer residence time of fine particles on the measurement plate due to lower shear forces. At higher entrainment fluxes the power measurements were unreliable due to poor temperature control. The turndown ratio of the linear section of the calibration curve is approximately 3 times that of the linear part of the calibration curve of the flow meter developed by De Vos et al (2010). Even further improvement is possible with better temperature control. In a case study to test the applicability of the flow meter to measure changes in entrainment rate associated with hydrodynamic properties other than a change in gas superficial velocity, small amounts of ethanol were dosed to the inlet air. The continuously measured entrainment rate increased at lower ethanol dosing rates but decreased as the dosing rate of ethanol was increased. The increase in entrainment rate may be explained by a reduction in static electricity in the bed, while the decrease at higher dosing rates may be as a result of increased powder cohesivity.Dissertation (MEng)--University of Pretoria, 2012.
Chemical Engineering
unrestricted
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Solliec, Laurent. "Real time flow rate modelling in disturbed conditions from velocity profilers." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAD052.
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L'installation de systèmes de mesure est d'une utilisation cruciale pour la gestion des réseaux d'assainissement ou des canaux d 'irrigation. La plupart des structures gouvernementales ou privées ainsi que les agglomérations s'équipent de systèmes de mesure de débit afin de se conformer avec la législation européenne. La plupart des débitmètres fournissent des données en temps réel i.e. l'information est transmise en permanence. aux centrales d'acquisition pour une gestion de l'architecture du système de canaux. La mesure en canaux ouverts est souvent ultrasonore. L'objectif de cette thèse est de proposer une méthode en temps réel afin de corréler les vitesses locales en une vitesse moyenne dans les conditions observables par les utilisateurs en canaux ouverts. Les thématiques impliquées à cette étude sont multiples: les techniques de mesure, l'hydrodynamique en canaux ouverts représentée par la turbulence (ici plus particulièrement les courants secondaires), les lois de paroi, le nombre de Froude ... l'ensemble de ces thématiques doit être investi en canaux pleinement développés où les conditions sont stables dans l'espace mais aussi pour des conditions perturbées telles que les structures hétérogènes ou transitoires.La technique de mesure est un point clé: quelle est la technique la plus applicable aux conditions de mesure i.e. les canaux étroits? Les canaux étroits varient très rapidement en tem1es de taux de remplissage : la technique la plus adaptée est le profileur ultrasonique.La compréhension des effets hydrodynamiques est essentielle afin de développer un modèle de conversion. Les canaux droits sont influencés par l'hydrodynamique des écoulements, la géométrie mais aussi et principalement par leurs interactions. En canaux droits, les courants secondaires sont primordiaux même s'ils se traduisent par un effet le plus observable : le dip-phénomène, i.e. la présence d'un maximum de vitesse non pas à la surface d'eau mais en dessous pour les canaux étroits. Ces courants secondaires sont fortement sensibles au rapport d'aspect, la géométrie et la variabilité de la rugosité le long de la paroi, passablement sensible à la rugosité et indépendant du nombre de Froude .Les perturbations, à l'aval desquelles sont installés les débitmètres ultrasonores, sont majoritairement représentées par les coudes et les jonctions. Dans les coudes, les tourbillons sont liés aux forces centrifuges (gros tourbillon) et la turbulence (petit tourbillon). Pour les jonctions, les tourbillons diffèrent des deux précédentes configurations avec la présence à l'aval de la jonction de 3 tourbillons (due à un étirement des tourbillons par l'arrivée latérale). Les capteurs ne sont pas installés directement au niveau de la perturbation mais à l'aval. Dans la littérature, les distances requises pour retrouver des conditions proches de l'écoulement pleinement développé devraient excéder environ 50 hauteurs d'eau. En pratique, ces distances sont plus proches de5-10 fois la largeur du canal ou du tirant d'eau. L'application de modèle basée sur l'écoulement pleinement développé corrélé à un capteur n'est pas recommandableThe installation of flow rate measurement systems is an important factor in regard to the management of sewer and irrigation networks. Most cities and infrastructure succeed in obtaining sufficient flow measurements to satisfy European Regulation rules. Most flow meters comprise real time systems; this means that the information is permanently transferred to a data base for the management and optimization of the particular network. The measurement technology deployed is typically ultrasound based. Within the number of measurement points a high percentage are often deficient and create specific difficulties (>75% of Venturi flumes are inaccurate according to Anglian Water, a UK water and wastewater company). The study presented here focuses on flow meters which calculate discharge using measurement of level, cross sectional area and the correlation of local velocity to generate a mean value. The aim of this thesis is to propose a real time method to enable determination of this “conversion” under realistic configurations which Users find in open channels. The synthesis of measurement points through an understanding of hydraulic conditions (Bonakdari, 2006) provides a method to create flow data allowing local point velocities to be converted into an overall mean value. The approach has limitations and may fail in industrial situations but can be used for very complex configurations. It also requires specialists with knowledge of the technique who are rarely available to Users. What is proposed here is an alternative method to Bonakdari for simpler configurations. The aim is to evaluate the flow rate with acceptable accuracy using these technics and to establish a relationship between local velocities and the mean velocity according to Regulatory requirements (8% are required in UK, 5 to 8% in Germany depending on area). The individual components are here: the measurement techniques; the hydrodynamics represented with the turbulence (secondary currents in open channels); the wall / roughness effects; the Froude number … for fully developed conditions where conditions become stable in space but for disturbed conditions, as well such as heterogeneous structures or transition conditions
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Schaap, Robert. "Best Practices for Volume Flow Rate Measurements Using PIV at the Exit of a Turbulent Round Jet." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6274.
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Particle image velocimetry (PIV) is an optical flow measurement technique that is used to measure volume flow rate at the exit of a turbulent, round nozzle. The objective of this thesis is to determine how to best make this measurement. The quality of the measurement is affected by a range of data acquisition parameters and how data are processed. Measurements are made over a range of different flows using the two main types of PIV: Two Component (2C), which uses one camera, and Stereo, which uses two cameras, similar to human eyes. Previous work done for data acquisition and processing of PIV in general is found to apply. Different parameters are tested, evaluated, and discussed. Both 2C PIV and Stereo PIV were found to underestimate flow by approximately 2%.
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Ghazi, Christopher. "Measurement of Fluid and Particle Transport through Narrow Passages." ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/297.
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There are many instances where fluid and particles traveling through a narrow passage, such as a crack in a window or door, have large but sometimes unseen effects on our daily lives. For instance, in the cold months of the year a pressure gradient can exists between the inside and outside of a building which causes cold, outdoor air to flow inside through any cracks; significantly decreasing heating efficiency. This inflow of atmospheric air can bring with it dangerous contaminant particles to the inside of a building. Pollution can also occur inside a structure from internal sources of contamination, such as smoke generation from a fire. This thesis represents a two-fold examination of these phenomena.
The first part of the thesis showcases a method for local measurement of air leakage flow rate, which can be used to quickly assess leakage rates across a surface, such as a window. The method uses a small local enclosure with constant volume placed about a region on the structure under investigation, which is depressurized and injected with a small concentration of carbon dioxide as a tracer gas. The time variation of the pressure and carbon dioxide concentration inside the enclosure are monitored and used to quantify the leakage flow rate as a function of pressure difference. Because of the small size of the enclosure, advanced data processing techniques are necessary to reduce uncertainty in determination of the rate of change of the carbon dioxide concentration that arises from sensor variability. Results of a laboratory demonstration of the proposed leakage detection and characterization device are reported for the problem of leakage through a circular hole in a plate with prescribed pressure differences. Experimental results from the laboratory tests are found to be in excellent agreement with results of a numerical simulation of leakage flow through a hole, as well as predictions from a number of empirical equations for this problem found in the literature.
The second part of the thesis is a numerical study of particle capture in the entrance region of a crack, which is a phenomenon previously not well understood or accounted for in empirical correlations. The computational domain for laminar flow through a crack consists of the crack channel and both inlet and exit reservoirs that are much larger than the channel width. The simulations examined different mechanisms for particle capture within the channel entrance region, including collision on the inlet reservoir wall just outside the crack channel, collision within the crack channel due to cross-stream inertia imparted by the entrance flow, collision induced by Brownian diffusion both on the inlet reservoir wall outside of the channel and within the channel, and gravitational collision within the channel. A detailed study of the variation of the entrance penetration factor with parameters such as the Stokes, Peclet, and Froude numbers was performed, and comparison of the numerical predictions with different theoretical expressions were made when the latter were available. Validity of the assumption of penetration factor independence was also examined for cases where both entrance region inertia and gravitational settling are significant.
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Pasquini, Enrico, Heiko Baum, Bebber David van, and Denis Pendovski. "Numerical Simulation of Transient Diabatic Pipe Flow by using the Method of Characteristics." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199881.
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The following paper presents a one-dimensional numerical model for simulating transient thermohydraulic pipe flow based on the Method of Characteristics. In addition to mass and momentum conservation, the proposed scheme also guarantees compliance with the laws of thermodynamics by solving the energy equation. The model covers transient changes in fluid properties due to pressure changes, heat transfer and dissipation. The presented methodology also allows the computation of the transient temperature distribution in the pipe wall through an additional ordinary finite difference scheme. The numerical procedure is implemented in the commercial simulation software DSHplus. The capability of the code is examined by comparing the simulation results with theoretical solutions and experimental data.
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Chatel, Juliette. "On the assessment of pollutant emissions: the role of flue gas flow rate measurement : Critical review and industrial feedback." Thesis, KTH, Energiteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-200393.
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From a bottom-up perspective, the assessment of flow rate of stack flue gases is crucial being the very first brick of the calculation. With the concentration of pollutant, it gives access to the amount of pollutant released in the atmosphere. Nevertheless, flow rate measurement has not been well-framed and can be poorly controlled, leading to large uncertainties. The recent launch of the European Standard EN 16 911 has enlighten the lack of expertise concerning the flow rate assessment in the industry. That is why RECORD, the project sponsor, conscious of the possible lack of expertise and the possible unreliability of the measurement is willing to understand the requirements; theoretical, technical and regulatory; for a reliable pollutant emissions measurement in accordance with the EU regulation in the field of waste treatment and incineration. Thus, this study offers the theoretical, operational and regulatory keys to realize a reliable flow rate measurement. 9 methods are identified for stack flue gases flow rate measurement. For each of these methods an ID-card, based on bibliographical researches, supplier’s interviews and representatives of the industry’s feedbacks, has been built containing information required for a reliable measurement. This thesis will contribute to a report that will offers all the keys for a reliable velocity/flow rate measurement in the waste treatment (domestic waste incineration mainly but it can also be useful in every industry that releases flue gas in the atmosphere: chemistry, steel manufacture, etc.). Moreover, this study proposes an analysis of the European Standard related to flow rate measurement in the industry and enlightens the key information related to these standards for an industrial operator. Finally, in relation with the complete report published on the RECORD website, a comparison tool of the 9 technologies is created to guide the industrial in their flow rate measurement. Once the best technology has been selected thanks to the comparison tool, the ID-card gives the key to realize a reliable measurement with the selected method. Finally, the theoretical part and the standard analysis have to be used as a frame for all the technologies.
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Davidson, Gregg Randall 1963. "Geochemical and isotopic investigation of the rate and pathway of fluid flow in partially-welded fractured unsaturated tuff." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/191194.
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Fluid flow rates and pathways in partially-welded, fractured, unsaturated tuff are investigated in a sloping borehole (DSB-1) cored from the surface to a perched aquifer at the Apache Leap near Superior, Arizona. Suspected water-bearing fractures were identified in the borehole using video and geophysical logs. Pore water extracted from cores associated with these fractures proved to have elevated ¹⁴C activity relative to pore waters from intermediate depths. Pore water from the deepest fracture interval contained post-bomb ¹⁴C. Low tritium concentrations in most samples indicates imbibition from each flow is small relative to the volume of water in the pores, but cumulative imbibition over time is significant based on ¹⁴C distribution through the unsaturated zone. The saturated zone beneath DSB-1 is a mixture of fracture flows with older aquifer water. Estimates based on ¹⁴C and ³H data indicate half of the water in the local aquifer originated from fractures near DSB-1. Geochernical models incorporating pore-water, surface-runoff, aquifer-water and mineral chemistry suggest that fracture flow may also be the predominant source of recharge for the older aquifer water. Water and carbon are extracted from core samples using uni-axial compression and a new vacuum distillation technique. Distillation is shown to be an effective method when carbon extraction is not possible by other methods. Mass yields from distillation provide evidence that there may be a substantial reservoir of carbon adsorbed to mineral phases. Carbon-14 activity of formation air samples from intervals with low air permeability reflect the composition of water imbibed from fracture flows at those depths. In zones of higher permeability, atmospheric contamination is suspected even though SF₆ (injected as a tracer during drilling) concentrations had not diminished. An independent investigation on the carbon isotopic composition of soil-zone CO₂ demonstrates the need to correct soil-respired CO₂ samples for CO₂ contamination in base reagents and for fractionation during sample collection. The minimum δ¹³C-shift from soil CO₂ to soil-respired CO₂ is also shown to be a function of the δ¹³C of soil organic material rather than a fixed 4.4%₀ as previously thought.
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Rahman, Mashuqur. "Rheology of cement grout : Ultrasound based in-line measurement technique and grouting design parameters." Doctoral thesis, KTH, Jord- och bergmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176885.
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Grouting is performed in order to decrease the permeability and increase the stiffness of the material, especially soil and rock. For tunnelling and underground constructions, permeation grouting is done where cement based materials are pumped inside drilled boreholes under a constant pressure, higher than the ground water pressure. The aim of permeation grouting is to reduce the water flow into tunnels and caverns and to limit the lowering of the surrounding groundwater table. Cement based materials are commonly used as grout due to their availability and lower costs. To obtain a proper water sealing and reduce the lowering of the ground water table, a desired spread of grout must be achieved and the rheology of the cement grout is the governing factor for estimating the required spread. Rheological properties of cement grout such as viscosity and yield stress are commonly measured off-line using laboratory instruments, and some simple tools are available to make field measurements. Although the rheological properties of the grout that is used play a fundamental role in design and execution, no method has yet been developed to measure these properties in-line in field work. In addition to the real time measurement, there is no standard method for determining the yield stress for grouting applications. Despite the common usage of Bingham model fitting to determine the yield stress, the range of shear rate is often not specified or is neglected. In this work, an in-line rheometry method combining the Ultrasound Velocity Profiling (UVP) technique with Pressure Difference (PD) measurements, known as “UVP+PD”, was successfully tested for continuous in-line measurements of concentrated micro cement based grouts. A major obstacle of using the ultrasound based methodology was the transducers, which would be capable of emitting sufficient acoustic energy and can be used in field conditions. The transducer technology was developed in a parallel project and the Flow-Viz industrial rheometer was found to be capable of detail measurement of the velocity profiles of cement grout. The shape of the velocity profiles was visualized, and the change in the shape of the profiles with concentration and time was observed. The viscosity and yield stress of the grout were determined using rheological models, e.g. Bingham and Herschel-Bulkley. In addition, rheological properties were determined using the non-model approach (gradient method) and the tube viscometry concept and were compared with results obtained using the rheological models. The UVP+PD method was found to be capable of determining the rheological behavior of cement grout regardless of the rheological model. The yield stress of cement grout was investigated using off-line rheometry techniques and UVP+PD in-line measurements. Tests were performed applying different shear histories and it was found that two ranges of yield stress indeed exist. Therefore, the design value of yield stress should be chosen with respect to the prevailing shear rate at the grout front for the required spread of grout. In addition, an appropriate shear rate range should be used when a Bingham fitting is done to determine the yield stress. In order to estimate the shear rate, plug thickness and velocity for one dimensional and two dimensional geometry, a non- dimensional nomogram was developed. The advantage of using the nomogram is that it does not depend on the applied pressure and the rheological properties of the grout and can therefore, be used as a simple design tool. Analytical approaches were used for the estimation and good agreements were found with numerical calculations and experimental results. In conclusion, in this work, it was found that it is possible to continuously measure the velocity profiles and determine the change of the rheological properties of cement grout using the ultrasound based UVP+PD method under field conditions. The yield stress was also investigated and it was found that two range of yield stress exist depending on the prevailing shear rate of the grout, which should be used for designing the grouting time at different conditions. In order to decide the design value of yield stress for grouting applications, a non-dimensional nomogram was developed that can be used to estimate the plug thickness, shear rate and velocity of the grout.Funding for the project was provided by the Swedish Rock Engineering Research Foundation (BeFo), The Swedish Research Council (FORMAS) and The Development Fund of the Swedish Construction Industry (SBUF), who are gratefully acknowledged. QC 20151112
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Shamu, John. "On the measurement and application of cement grout rheological properties." Licentiate thesis, KTH, Jord- och bergmekanik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-251745.
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The rheological properties of cement-based grouts play a key role in determining the final spread in grouted rock formations. Rheologically, cement grouts are known to be complex thixotropic fluids, but their steady flow behavior is often described by fitting the simple Bingham constitutive law to flow curve data. The resultant Bingham parameters are then used in grouting design of e.g. tunnels, to estimate the penetration length. Since cement grouts are thixotropic suspensions, the interpretation of their flow curves as obtained from flow sweeps in concentric cylinder rotational rheometers is often complicated by: the presence of wall slip, sedimentation and unstable flow at low shear rates. A systematic approach to study these effects within the constraints of the concentric cylinder geometry (Couette) and for different cement grout concentrations was carried out as part of the Licentiate research work. Of particular interest was the influence of geometry and flow sweep measurement interval on flow curves, including the characteristic unstable flow branch that appears at applied shear rates that are below the critical shear rate. The unstable flow branch observed below the critical shear rate has been described as a characteristic feature in the flow curves of thixotropic suspensions, e.g. cement grouts, laponite. From a practical standpoint, this information can then be readily used to improve rheological measurements of cement grouts. The existence of the critical shear rate below which no stable flow occurs, plus the complex wall slip phenomenon are then discussed by considering how they affect actual spread in rough and smooth rock fractures. Another major part of the research presented in this thesis relates to the measurement of model yield stress fluid (YSF), i.e. Carbopol, velocity profiles within the radial flow geometry. Radial flow between parallel plates, is an idealized fundamental flow configuration that is often used as a basis for grout spread estimation in planar rock fractures. Compared to other flow configurations with YSFs, e.g. channels, only a limited amount of work has presented analytical solutions, numerical models and especially experimental work for radial flow. Thus, as a first step towards more systematic studies of the plug flow region of YSFs in radial flow the current work presents the design, manufacture and for the first time velocity profile measurements that were conducted by using the pulsed Ultrasound Velocity Profiling (UVP) technique. The current observations for tests carried out with different disk spacings and flow rates show a distinct plug region, coupled with wall slip effects for the Carbopol model YSF fluid that was used. The theoretically predicted velocity profiles and the measured ones agree reasonably well, and the main discrepancies are discussed. Future studies, would then be targeted at improving the current experimental setup, for detailed measurements of the plug flow region along the radial length, which remains a challenging issue for studies on YSFs and engineering applications such as rock grouting design.Cementbaserade injekteringsmedels reologiska egenskaper har en stor påverkan på strömning och inträngningslängd i sprickigt berg. Medlens reologi är komplex, inklusive tixotropi, men strömningen beskrivs ändå oftast med den enkla linjära Bingham modellen i injekteringssammanhang. De två parametrarna från denna modell, flytgräns och viskositet, används sedan inom injekteringsdesign, för t.ex. tunnlar och dammar, för att bedöma inträngningen. Eftersom cementbaserade medel är tixoptropa suspensioner försvåras utvärderingen vid mätning med konventionella rotationsviskometrar på grund av glidning vid fasta begränsningsytor, sedimentation/separation av partiklarna och instabila flöden vid låga deformationshastigheter. En systematisk mätprocedur för att studera ovanstående problem med rotationsviskometer och koncentriska cylindrar samt olika vanliga vattencementtal, har utförts inom ramen för detta licentiatarbete. Av särskilt intresse har varit att studera effekten av olika geometrier och tidsintervallet mellan mätningarna, inklusive den instabila delen av flödeskurvan då deformationshastigheten är lägre än ett kritiskt värde. Denna del av kurvan har i litteraturen beskrivits som karakteristisk för tixotropa suspensioner, som t.ex. cementbaserade injekteringsmedel. Praktiskt kan ovanstående kunskap användas för att förbättra mätningen av de reologiska egenskaperna. Existensen av en kritisk deformationshastighet under vilken det inte finns något stabilt flöde, i kombination med glidning vid fasta begränsningsytor, diskuteras särskilt med hänsyn till dess påverkan på faktisk inträngning i släta och råa bergsprickor. Ett annat fokus i licentiatarbetet har varit att studera icke-Newtonska modellvätskors (Carbopol) radiella strömning mellan parallella plattor. Denna typ av strömningsgeometri används ofta som en idealiserad konfiguration för strömning i bergsprickor. I jämförelse med andra enklare geometrier, finns endast en begränsad forskning utförd för denna geometri både då det gäller analytiska och numeriska beräkningar men framförallt då det gäller experiment. Som ett första steg inför en mer systematisk undersökning av icke-Newtonsk radiella strömning presenteras i detta arbete framtagandet av en fysisk laboratoriemodell där hastighetsprofilerna mellan plattorna för första gången visualiserats med hjälp av ultraljud. De utförda mätningarna med tre olika öppningar mellan plattorna sam tre olika värden på det konstanta flödet, visar på en distinkt plugg som är ett resultat av vätskans flytgräns samt glidning i gränsskiktet mellan vätskan och plattornas fasta begränsningsytor. En jämförelse mellan uppmätta hastighetsprofiler och analytiskt beräknade diskuteras där resultaten överensstämmer relativt väl, med beaktande av de långtgående förenklade antaganden som krävs för beräkningarna. Fortsatta studier kommer att fokuseras på att förbättra laboratoriemodellen för en mer detaljerad studie av icke-Newtonska vätskors strömning och hur pluggen utvecklas under den radiella inträngningen, vilket fortsättningsvis är av betydelse för design av injektering i bergsprickor.
QC 20190521
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Al-Yarubi, Qahtan. "Phase flow rate measurements of annular flows." Thesis, University of Huddersfield, 2010. http://eprints.hud.ac.uk/id/eprint/9104/.
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In the international oil and gas industry multiphase annular flow in pipelines and wells is extremely important, but not well understood. This thesis reports the development of an efficient and cheap method for measuring the phase flow rates in two phase annular and annular mist flow, in which the liquid phase is electrically conducting, using ultrasonic and conductance techniques. The method measures changes in the conductance of the liquid film formed during annular flow and uses these to calculate the volumetric and mass flow rates of the liquid film. The gas velocity in the core of the annular flow is measured using an ultrasonic technique. Combined with an entrainment model and the liquid film measurements described above, the ultrasonic technique enables the volumetric flow rate of the gas in the core and the volumetric and mass flow rates of entrained liquid droplets to be measured. This study was based on experimental work and the use of modelling techniques. The practical investigation comprised a series of experiments conducted on a purpose built flow loop in which the test section was a Perspex pipe of 50mm ID. The experimental work was limited to two-phase air-water flow. The flow loop was specifically designed to accommodate the different instruments and subsystems designed in this investigation including bespoke flow meters and a film extraction system. Most flow loop controls were automated using a MATLAB program. Reference measurement of the total water flow rate was made using a calibrated turbine flow meter and of the air flow rate using a calibrated rotameter. For the combined ultrasonic/conductance method investigated in this thesis, the velocity of the gas in the core was found using a novel Ultrasonic Flow Meter (USFM). The positioning and arrangement of the transducers have never been used previously. The flow velocity of the liquid film and the thickness of the film were measured using a novel Conductance Flow Meter (CFM). The CFM measured the liquid film thickness using novel wall conductance probes. By cross correlating the signals from a pair of such probes the film velocity was obtained. Good agreement of the experimental results obtained from the CFM and USFM with results published in the literature was found. Although not investigated experimentally in the work described in this thesis, annular flows encountered in the oil industry may contain a liquid phase comprising a mixture of oil and water. For such flows, the volume fractions of the oil and water can be measured using an automated bypass system developed during this project. The bypass system periodically extracts part of the liquid film, measures its density and then releases the sample back into the pipeline. The liquid phase volume fractions are determined from this density measurement which can be performed more than once per minute. An entrainment model was developed, which is required by the ultrasonic/conductance flow metering technique described in this thesis, in which the mass fraction of the liquid flowing as entrained droplets in the core can be determined from the liquid film thickness and velocity measurements. A mathematical model was also developed to describe the properties of the liquid film, such as liquid velocity profile within the film, and the model’s results were found to agree with the experimental results obtained during the project and also with previous work cited in the literature. The complexity of this latter model was reduced by making a number of simplifying assumptions, which are presented and discussed in the thesis, including the assumption that in annular flow there is a dynamic balance liquid entrainment and droplets being deposited back onto the film. The combination of the designed CFM and USFM with the bypass tube and the entrainment model offer the opportunity for a ‘wet gas’ flow meter to be developed to measure two and three phase annular flows at relatively low cost and with enhanced accuracy. Such a device would have the advantage that it would by substantially smaller than systems using separators and it could even be retrofitted onto off-shore platforms. The integration of the subsystems developed in this project into a single system capable of giving on-line measurements of annular flow would be a major benefit to the author’s sponsor, Petroleum Development of Oman.
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Shaban, Hassan. "Experimental Investigations of Internal Air-water Flows." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32952.
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The objective of the present thesis research is to apply state-of-the-art experimental and data analysis techniques to the study of gas-liquid pipe flows, with a focus on conditions occurring in header-feeder systems of nuclear reactors under different accident scenarios. Novel experimental techniques have been proposed for the identification of the flow regime and measurement of the flow rates of both phases in gas-liquid flows. These techniques were automated, non-intrusive and economical, which ensured that their use would be feasible in industrial as well as laboratory settings. Measurements of differential pressure and the gas and liquid flow rates were collected in vertical upwards air-water flow at near-atmospheric pressure. It was demonstrated that the probability density function of the normalized differential pressure was indicative of the flow regime and using non-linear dimensionality reduction (the Elastic Maps Algorithm), it was possible to automate the process of identifying the flow regime from the differential pressure signal. The relationship between the probability density function and the power spectral density of normalized differential pressure with the gas and liquid flow rates in air-water pipe flow was also established and a machine learning algorithm (using Independent Component Analysis and Artificial Neural Networks) was proposed for the estimation of the phase flow rates from these properties. The proposed methods were adapted for use with single and dual conductivity wire-mesh sensors in vertical upwards and downwards air--water flows. A thorough evaluation of the performance and measurement uncertainty of wire-mesh sensors in gas-liquid flows was also performed. Lastly, measurements of the flow distribution in feeder tubes supplied with air-water mixtures by a simplified header model were collected and correlated to the observed flow patterns in the header.
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Nabhani, Nader. "Hot-wire anemometry study of confined turbulent swirling flow : development of a hot-wire technique for measurement in confined turbulent swirling flow and an investigation of the effect of inlet flow rate and geometrical conditions on the velocity field." Thesis, University of Bradford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.256901.
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Sande, Leif Andrew. "Experimental Studies on Infiltration/Soil-Water Movement Processes and Green-AMPT Modeling." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29329.
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Experimental studies on infiltration/soil-water movement processes are vital to
better understanding movement of soil-water in the vadose zone. The objective of this
experimental research was to investigate infiltration/soil-water movement processes
utilizing laboratory experiments and computer modeling. Small scale laboratory soil box
infiltration experiments were conducted and utilized for the improved parameterization of
the Green-Ampt (GA) saturated moisture content parameter to produce an effective
moisture content parameter (Be) for utilization in a modified GA model. By incorporating ?e
values into GA modeling, modeling results showed greatly improved wetting front
prediction across different soil conditions. A new soil packing method was proposed for
replicating complex microtopographical surfaces with uniform bulk densities in laboratory
soil box experiments which proved efficient and effective at accomplishing both objectives.
A rainfall simulator and an instantaneous-profile laser scanner were used to simulate
rainfall and quantify surface microtopography for experiments. The results clearly show the
effect of microtopography on infiltration and soil-water movement characteristics. This
offers valuable insight into infiltration/soil-water movement processes as affected by
different soil and surface microtopographic conditions.National Science Foundation (Grant No. EAR-0907588)
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Hartmann, Christoph [Verfasser], Wolfram [Akademischer Betreuer] Volk, den Boogaard Ton [Gutachter] van, and Wolfram [Gutachter] Volk. "Spatio-temporal optical flow methods for process analysis : Robust strain, strain rate, and crack propagation measurement in shear cutting / Christoph Hartmann ; Gutachter: Ton van den Boogaard, Wolfram Volk ; Betreuer: Wolfram Volk." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1240832680/34.
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Umstätter, Christina. "Tier-Technik-Beziehung bei der automatischen Milchgewinnung." Doctoral thesis, Humboldt-Universität zu Berlin, Landwirtschaftlich-Gärtnerische Fakultät, 2002. http://dx.doi.org/10.18452/14750.
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Durch die zunehmende Automatisierung der Tierhaltung gewinnt die Tier-Technik-Beziehung zunehmend an Bedeutung. Es besteht ein wachsendes Interesse am Tierverhalten, den Möglichkeiten des Lernens der Tiere und den Anpassungsstrategien. In der Dissertation untersuchte ich die Melk-, und Milchparameter und das Tierverhalten bei der automatischen Milchgewinnung. Die Messungen haben gezeigt, dass auf die Milchabgabe einzelner Individuen und insbesondere auf deren Euterviertel sehr differenziert einzugehen ist. Das Automatische Melksystem (AMS) vermag auf die speziellen Unterschiede der einzelnen Viertel, im Sinne einer verbesserten Tiergerechtheit, Rücksicht zu nehmen. Ein weiterer wichtiger Aspekt die Tiergerechtheit zu verbessern ist es, eine zuverlässige Prozesskontrolle durchzuführen. Dazu muss zunächst einmal festgestellt werden, wie sich die natürliche Variationsbreite der einzelnen Parameter darstellt, um pathologisch bedingte Abweichungen signifikant erkennen zu können. Die Gewinnung von verlässlichen Aussagen über den Gesundheitszustand von Kühen im AMS setzen voraus, dass verschiedene interdependente Parameter so verknüpft oder deren Messungen sooft wiederholt werden, bis ein intelligentes Entscheidungssystem seine Schlüsse ziehen kann. Dabei ist zu beachten, dass stark auffällige Werte ein hohes Maß an Information haben, aber eine entsprechend geringe Verlässlichkeit aufweisen. Sich wiederholende Werte haben hingegen einen geringen Informationsgehalt, dafür aber ein hohes Maß an Redundanz bzw. Verlässlichkeit, soweit sie nicht durch systematische Fehler entstehen. Für eine zuverlässige Prozesskontrolle kann es manchmal vorteilhafter sein, eine automatisierte Datengewinnung zu installieren, auch wenn der einzelne Parameter (z. B. die Leitfähigkeit) zwar wenig aussagekräftig, dafür aber die Durchführung deutlich zuverlässiger ist als bei Tests, die von Menschen manuell durchgeführt werden. Ähnliches gilt für die Haltungsumwelt von Tieren. Eine durch Automation dominierte Umwelt kann für Tiere deutlich berechenbarer und damit zuverlässiger gestaltet werden. Das bedeutet, dass für die Individuen weniger Stresssituationen mit den für sie unabsehbaren Folgen entstehen. Es sollte aber dabei beachtet werden, dass es zwingend ist, auf die Lerngeschwindigkeit der einzelnen Tiere, in Abhängigkeit von ihrer jeweiligen Lernsituation, einzugehen, um zuverlässige Umweltbedingungen für die Kühe mit einem AMS bereitzustellen. Es konnte weiterhin festgestellt werden, dass das Melken in einem AMS bei den Kühen nicht als belastender Stressfaktor identifiziert werden kann, wenn man die Herzfrequenz als Indikator heranzieht und diese über eine längere Zeit analysiert. Der zunehmende Einsatz von Technik in der Milchviehhaltung kann einen wichtigen Beitrag dazu leisten, die Haltungsumwelt der Kühe human und tiergerecht zu gestalten.Relationship between animal and technology in automatic milk production: Due to the fact of the increasing automation in husbandry systems becomes the relationship between the animal and the technology more and more important. There is a growing interest to know more about animal behaviour, the ability of learning and the coping strategies in such systems. In the thesis I investigated the parameter of milking, of milk and of animal behaviour in an Automatic Milking System (AMS). The measurement has shown that the milk yield differs very much between the quarters of the udder. An AMS has the possibility to take such differences into consideration. This is one step towards more animal welfare. Another improvement of animal welfare is a better control of the process. For that, it is important to have a certain knowledge about the natural variation of different parameters, such as electrical conductivity of the milk, milk ingredients or milk yield. This makes the basis of the identification of anomalies depending on pathological problems. To get a reliable declaration about the state of health one has to connect different interdependent parameters and/or the measurement has to be repeated so often until an intelligent decision system can draw conclusions. Besides it is important to know, that a conspicuous value is highly informative, but it is less reliable, otherwise is an often repeatable value less informative but highly redundant, if there is no systematic failure. For a control of the process it is important to get reliable information, so it is sometimes better to automat the tests, instead of using human knowledge, which is often more informative, but less reliable (i.e. electrical conductivity). There is a similarity in husbandry systems because an automated system can be much more reliable and calculable for animals. That means less stressing situations because of incalculable reactions. For such a reliable environment in an AMS it is necessary to give every cow their individual time to learn the facts about the AMS. The milking in an AMS cannot be identified as a negative stress factor, if one uses the measurement of heart rate for identification. The increasing automation in the dairy husbandry can be an important contribution to create a humane environment for dairy cows and improve animal welfare.
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Hajn, Pavel. "Analýza řídicí roviny mobilních sítí 4. generace." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220329.
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The thesis is focused on the description of LTE system in terms of signaling on interfaces of LTE and EPC subsystems, such as UE initial network connection. The next section describes the types of diagnostic methods for mobile networks using OSS, drive testing and flow analysis. The thesis also aims at description of key performance indicators (RSRP, RSSI, etc.) and the proposal for measuring of the LTE network physical layer and the data transmission speed.
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Lakkadi, Navneeth Sagar Reddy. "Flow Measurements in Turbulent Flow Fields with Magnetic Resonance Phase Velovity Mapping." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1251412647.
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Willis, C. A. "Continuous mass flow rate and velocity measurements of pneumatically conveyed powder." Thesis, Nottingham Trent University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354922.
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Philips, Amy. "THE UNIVERSALITY OF TRANSITIONAL FLOW BEHAVIOR IN ENTANGLED POLYMER SOLUTIONS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1152720738.
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Svanholm, Ulrika. "Evaluation of measurements of pulsating flow under controlled conditions using phase contrast MRI." Thesis, Stockholm University, Medical Radiation Physics (together with KI), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7222.
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The accuracy and precision of measurements of pulsating flow obtained with phase contrast magnetic resonance imaging (PC MRI) was studied. Measurements were carried out using known flow rates through a phantom connected to a pump that created pulsation in the flow. Repeated measurements were made in both the negative and positive encoding direction, using both breath-hold and non breath hold sequences. The obtained data was analyzed using code written in MATLAB and also using the FLOW software that is offered by the manufacturer of the MRI system.
A range of different flow velocities was scanned, and results show that the overall accuracy of the measurements is relatively good, with an average error of between 1.2% to 5.7% using the clinically employed flow calculation software. There is however indication of a systematic phase offset in the data that influences the measurements. The effect of the offset on the results depends on the direction of flow and the sequence used. The results also show the importance of properly selecting the area over which the flow rate is calculated.
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Adamsson, Carl. "Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions." Licentiate thesis, Stockholm : Fysik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3881.
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Alarcón, Reyes Rodrigo. "Average downlink traffic rate estimation in IP networks using flow-based measurements." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114543.
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Having a complete knowledge about average traffic rates on different links in a network is highly desirable for network operators, particularly when performing tasks such as capacity planning and traffic engineering, or when making decisions on network redesigning.In this thesis, we propose a technique for estimating the average downlink traffic rate on internal links from a single measurement point. Our main contribution is a solution that does not assume a specific statistical model for the traffic, relying only on a constant ratio between the uplink and the downlink traffic on each link, and a constant proportion of traffic that goes to each of the remaining links during each time interval. We show that in a real scenario and on each link the assumption of a constant ratio between the uplink and the downlink traffic holds at least for the visible portion of the traffic at the measurement point. In order to validate our technique, we implement different simulation scenarios using NetFlow to report flow records. Our simulations and subsequent error analysis show that, if the aforementioned assumptions hold, our proposed technique produces accurate estimates on the average downlink traffic rate of internal subnetworks in all the considered simulation scenarios. We also show that it is possible to use Sampled NetFlow in our estimation scheme without a considerable loss of accuracy, which reduces the requirements for additional CPU when NetFlow is implemented in routers.Our estimates are computed using only existing and widely-supported protocols and features (e.g., NetFlow and SNMP polling), while reducing the amount of additional traffic and processing resources compared to existing approaches, if our technique is deployed in networks where flow-based monitoring is already implemented. We are confident that the results and contributions of this work are valuable as a first step towards the deployment of a practical solution for estimating the average traffic rate in real networks.Avoir une connaissance complète du débit moyen des differents liens d'un réseau est hautement souhaitable pour les opérateurs de réseaux, en particulier lors de l'exécution de tâches telles que la planification de capacités et l'ingénierie de trafic, ou lors de la prise de décisions sur le redesigne des réseaux. Dans cette thèse, nous proposons une technique pour l'estimation des débits descendants moyens des liens internes à partir d'un seul point de mesure. Notre principale contribution est une solution qui ne suppose pas de modèle statistique spécifique pour le trafic, mais qui s'appuie uniquement sur l'hypothèse d'un rapport constant entre le débit montant et le débit descendant sur chaque lien, ainsi qu'une proportion constante du trafic qui va à chacun des autres liens à chaque intervalle de temps. Nous montrons que dans un scénario réel et sur chaque lien l'hypothèse d'un rapport constant entre les débits montants et descendants est valide au moins pour la partie du trafic qui est visible au point de mesure. Afin de valider notre technique, nous mettons en oeuvre des différents scénarios de simulation en utilisant NetFlow pour rapporter des registres de flux. Nos simulations et analyse d'erreurs subséquente montrent également que, si les suppositions susmentionnées sont valides, notre technique produit des estimations précises du débit moyen descendant pour les sous-réseaux internes dans tous les scénarios considérés pour les simulations. Nous montrons également qu'il est possible d'utiliser Sampled NetFlow dans notre schéma d'estimation, sans perte considérable de précision, en réduisant l'exigence additionnelle de la CPU lorsque NetFlow est mis en oeuvre dans les routeurs. Nos estimations sont calculées en utilisant des protocoles et des caractéristiques existantes et largement supportées (par exemple, NetFlow et SNMP Polling), tout en réduisant la quantité de trafic supplémentaire et les ressources de traitement par rapport aux approches existantes, si notre technique est déployée dans des réseaux où la surveillance basée sur flux est déjà mise en oeuvre. Nous sommes confiants que les résultats et les contributions de ce travail sont importantes en tant que premier pas pour le déploiement d'une solution pratique d'estimation des débits moyens dans des réseaux réels.
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Navarro, Hernan Ricardo. "Flume Measurements of Erosion Characterstics of Soil at Bridge Foundations in Georgia." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7267.
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Shelby tube sediment samples collected from the foundations of ten (10) bridges located in the state of Georgia were tested in the laboratory to find their erosional behavior and the correlation of erosion parameters with sediment properties in order to improve the prediction of scour around bridge foundations. These sites were spatially distributed in order to fall into different major river basins and in different physiographic regions. A description of the Valley and Ridge, Blue Ridge, Piedmont, and Coastal Plain physiographic regions of Georgia is included, and the erosion parameters found from flume measurements are associated with their respective regions. Flume measurements were performed using a rectangular, tilting, recirculating flume located in the hydraulics lab in the School of Civil and Environmental Engineering at Georgia Tech. Velocities up to 1.7 m/s and bed shear stresses up to 21 Pa can be achieved in the flume. Regression analysis was performed on erosion rates as a function of applied shear stress to determine the parameters of the erosion function. The resulting parameters, the critical shear stress and the erosion rate constant, were correlated with soil properties and physiographic regions.
Experimental methodology was chosen to approach this problem because the involvement of interparticle forces for fine-grained materials makes it difficult to deal with the erosion phenomenon through other means. Nevertheless, analytical description of the erosion phenomenon was included in order to provide a better understanding of it.
Linear, exponential and power regression mathematical models for erosion rate were compared, and the two best-fit regression models of erosion rate as a function of shear stress are proposed to formulate a methodology intended to characterize the behavior of a soil exposed to erosive flow conditions. One of them is a linear model to calculate critical shear stresses and low erosion rates. The second model, which is exponential, has the advantage of describing the erosion rate response for a wider range of shear stress values. It is shown that one of the most relevant predictors for the critical shear stress and erosion rate constant in the regression models is the fine material content present in the sample, which is an indirect indicator of the contribution of interparticle forces to the erosion process. Applying the described methodology, a more case-specific calculation of the erosion at bridge foundations can be performed taking into account the actual material in situ.
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Azzouz, Ali. "Conception d'un thermoanemometre et application a l'evaluation des transferts thermiques lors de l'ouverture d'une chambre froide industrielle." Paris, CNAM, 1988. http://www.theses.fr/1988CNAM0096.
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Les pertes thermiques d'une chambre froide s'ouvrant par glissement lateral sont mesurees a l'aide d'un thermoanemometre a fil chaud, ayant seize capteurs de mesure de la vitesse du courant d'air. Les resultats experimentaux sont correles par une loi qui exprime le debit massique en fonction de l'ecart de temperature. Des rideaux d'air protecteurs sont experimentes. Ils permettent un gain de 38% sur le debit massique d'air chaud entrant en chambre froide
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Cressall, Rick. "Best Practices for Volume Flow Rate Measurements Using PIV at the Exit of a Turbulent Planar Jet." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5218.
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Particle image velocimetry (PIV) is used to make volume-flow-rate measurements at the exit of a turbulent, planar nozzle. The objective of this report is to assess a range of data acquisition and processing parameters. Data is acquired for volume flow rates of Reynolds numbers between 10,000 and 100,000 for both two-component (2C) and stereo PIV. The parameters are systematically changed one at a time and evaluated using differences in uncertainty, calculation time, and volume- flow-rate deviation. Data acquisition parameters follow the trends of previous work. A multitude of processing parameters were varied for several PIV processing methods. Recommendations for each method are developed and listed with potential drawbacks. 2C PIV was found to underestimate volume-flow-rate by 3-4% depending on the integration scheme and stereo PIV underestimated volume-flow-rate by 2%.
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Creech, Taylor N. "A Comparison of Measurements of a Pediatric Supplement: How Thin Is Thin?" Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1493380165444074.
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Terry, Aaron David. "Modeling Vocal Fold Intravascular Flow with Synthetic Replicas." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/8820.
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Communication by voice is foundational in our society and many rely on their voices for their occupations. Voice disorders affect a significant number of individuals each year, and diagnosis and treatment improvements are therefore sought via advancements in voice research. Contained in this thesis is a description of work intended to contribute to vocal fold research by using synthetic, self-oscillating vocal fold replicas to study the impact of replica vibration on perfusion fluid flow through the replica. Methods for manufacturing vocal fold replicas containing imbedded channels allowing for fluid perfusion are discussed. Experimental procedures developed for delivering perfusion fluid to the imbedded channel at a constant pressure during replica vibration are described. Methods for measuring perfusion parameters of perfusion fluid pressure, imbedded channel diameter, flow rate, and vibration parameters (subglottal pressure, frequency, amplitude, channel length, and glottal width) are detailed. Experiments performed using both stationary and vibrating vocal fold replicas are presented. Correlations between perfusion pressure and channel diameter are discussed. Vibration parameters were correlated to perfusion flow parameters and it is shown that perfusion flow rate through the channels decreased significantly with model vibration. Potential mechanisms for changes in perfusion flow resistance with vibration are discussed and analyzed. Output of a theoretical model, developed to incorporate some of the possible flow resistance mechanisms, was compared to vibrating replica experimental data.
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Daggupati, Naga Prasad. "Assessment of the varitarget nozzle for variable rate application of liquid crop protection products." Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/414.
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Červinková, Kateřina. "Citlivostní analýza metody tlak-čas na nepřesnosti měření." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400848.
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The pressure-time method is one of two methods of measuring the flow rate on large hydraulic structures applicable to IEC 60041, which is based on the temporal integration of the measured pressure difference and the formation of a water hammer in a closed pipe. The aim of this master thesis is to perform a literature review of this method and to evaluate the flow rate of the measured data. Furthermore, the thesis deals with determination of the sensitivity of the evaluated flow rate to the weights of individual pressure sensors and to numerical modifying of the measured pressures. The first part is made using MS Excel. The flow rate is always evaluates with only one pressure sensor and it is compared with the original flow rate. There is research, how absence of the sensor has an impact on the evaluated flow rate. In the second part of the determination of the sensitivity of the evaluated flow rate, various encroachment (signal smoothing, noise, time delay, frequency band removal) are performed of measured pressure signal in Matlab. Various surrounding influences or sensors failures are simulated.
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Ober, Thomas J. (Thomas Joseph). "Spatially resolved measurements of kinematics and flow-induced birefringence in worm-like micellar solutions undergoing high rate deformations." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61915.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 203-213).
Worm-like micellar solutions are model non-Newtonian systems on account of their well understood linear viscoelastic behavior. Their high deformation rate, non-linear rheological response, however, remains inadequately characterized and poorly understood. In this study, two worm-like micellar systems composed of either cetylpyridinium chloride (CPyCl) with sodium salicylate (NaSal) or cetyltrimethylammonium bromide (CTAB) with NaSal have been characterized across several orders of magnitude of deformation rate (10-2 < i6 < 104 s- 1 ). This range enables us to span both the linear and non-linear regimes of rheological behavior for both systems. The low deformation rate rheology was characterized using conventional rheometer fixtures. The high deformation rate rheology was determined using microfluidic rheometric devices, which may be exploited to observe the response of a fluid undergoing very large deformation rates at moderate volumetric throughputs, on account of the small lengthscales associated with microfluidic devices. In these experiments, micro-particle image velocimetry (p-PIV) was used to measure the flow kinematics and a commercial birefringence microscopy instrument (ABRIOTM System, CRi., Inc.) was adapted for making full-field measurements of flow-induced birefringence (FIB) in order to obtain high-resolution measurements of the evolution of the average stress and molecular conformation in the fluids undergoing strong deformations. First, the shear banding response of the CPyCl:NaSal system and shear thinning response of the CTAB:NaSal system were observed in Poiseuille flow through a rectilinear microchannel. Then the corresponding behavior in an extension-dominated flow through a converging microchannel was characterized. Qualitative as well as quantitative features of the flow kinematics and conformation were assessed in order to understand how the linear rheological properties of these systems effect their respective constitutive responses in high rate extensional flows.
by Thomas J. Ober.
S.M.
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Gallagher, Paul. "Developing an experimental system identification method to extract air flow rates from room temperature measurements." Thesis, Boston University, 2013. https://hdl.handle.net/2144/12104.
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Thesis (M.S.)--Boston UniversityThis thesis develops a system identification method which is capable of determining individual room air change rates by utilizing a combined low order physical modeling and experimental approach. Important aspects of this work include the development of the low order model, insight into the dominant thermal dynamics, development of the system identification method, and experiments which confirm the method. The low order model is shown to capture the dominant dynamics of the room air temperature response to a step change in the supply air flow rate with minimum levels of model complexity. Such a combined modeling and experimentally based system identification method is advantageous because it can be used to determine air flow rates for rooms throughout the building without utilizing numerically intensive CFD to model air flow or the more labor intensive methods of room-by-room air flow measurements. The energy used in operating a large buildings HVAC system scales with the air flow rate in the building, since a higher air volume results in higher energy expenditure for the fans to push the air and for the heating and cooling coils to condition the air. Older buildings, designed when energy costs were lower, typically utilize high air flow rates since this is the easiest way to meet ventilation and thermal requirements. However, HVAC energy usage can be reduced by minimizing these air flow rates while still meeting ventilation requirements. In order to achieve this, a tool capable of determining the air change rates on a room-by-room basis is required. This air change rate calculation method needs to be capable of performing the task without any pre-knowledge of the building and HVAC layout, since as buildings age their layouts can change, floor plans can be lost, and HVAC equipment can fall into disrepair. [TRUNCATED]
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Alshawaf, Hussain M. J. A. A. M. A. "A Novel Thermal Method for Pipe Flow Measurements Using a Non-invasive BTU Meter." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/101528.
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This work presents the development of a novel and non-invasive method that measures fluid flow rate and temperature in pipes. While current non-invasive flow meters are able to measure pipe flow rate, they cannot simultaneously measure the internal temperature of the fluid flow, which limits their widespread application. Moreover, devices that are able to determine flow temperature are primarily intrusive and require constant maintenance, which can shut down operation, resulting in downtime and economic loss. Consequently, non-invasive flow rate and temperature measurement systems are becoming increasingly attractive for a variety of operations, including for use in leak detection, energy metering, energy optimization, and oil and gas production, to name a few. In this work, a new solution method and parameter estimation scheme are developed and deployed to non-invasively determine fluid flow rate and temperature in a pipe. This new method is utilized in conjunction with a sensor-based apparatus--"namely, the Combined Heat Flux and Temperature Sensor (CHFT+), which employs simultaneous heat flux and temperature measurements for non-invasive thermal interrogation (NITI). In this work, the CHFT+ sensor embodiment is referred to as the British Thermal Unit (BTU) Meter. The fluid's flow rate and temperature are determined by estimating the fluid's convection heat transfer coefficient and the sensor-pipe thermal contact resistance. The new solution method and parameter estimation scheme were validated using both simulated and experimental data. The experimental data was validated for accuracy using a commercially available FR1118P10 Inline Flowmeter by Sotera Systems (Fort Wayne, IN) and a ThermaGate sensor by ThermaSENSE Corp. (Roanoke, VA). This study's experimental results displayed excellent agreement with values estimated from the aforementioned methods. Once tested in conjunction with the non-invasive BTU Meter, the proposed solution and parameter estimation scheme displayed an excellent level of validity and reliability in the results. Given the proposed BTU Meter's non-invasive design and experimental results, the developed solution and parameter estimation scheme shows promise for use in a variety of different residential, commercial, and industrial applications.MS
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Strandberg, Marcus. "Determination and implementation of polymer parameters into simulations of the twin-screw extrusion process." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Maskinteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-27184.
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This thesis was conducted in cooperation with a Swedish company that develops and manufactures plastic compounds. An increasing need for identifying material properties is seen within the industry in order to predict the outcome of the extrusion process by using simulations. The purpose of this study was to expand a material database with the results obtained through various measurements of the material parameters in order to enable simulations. The numerical descriptions would be analyzed and validated in relation to the obtained results and conducted methods to enable implementation of the material data into the industry. In order to fulfill the purpose, scientific methods was applied by chosen literature studies, research approaches and experimental research. Machine tests were conducted to collect relevant output data that was compared with the results obtained during the simulation process where the experimentally determined material parameters were applied in a material database. Typical injection molding qualities of PET, POM, PC/ABS, SAN and PA66 has been investigated by conducting measurement methods described by standards of the melt flow rate, specific heats, viscosity, crystallinity and melt- and glass transition temperatures. With exception of the viscosity, the material parameters are considered to have high external validity and high reliability and can be implemented into the industry. The bulk- and melt density was determined by adapted methods that need further investigations. The external validity is reduced until these methods and measurements have been validated. The determined material parameters proved to be able to generate reliable simulation results that indicate of how the extrusion process will turn out based on the output values investigated. The data obtained through machine tests was compared with the results that were achieved through simulations and deviated at most 10.9% from the actual outcomes. The viscosity is considered to be the main factor that affects the differences of the output data between the machine tests and the simulation results.
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Hadj, nacer Mustafa. "Tangential momentum accommodation coefficient in microchannels with different surface materials (measurements and simulations)." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4764/document.
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Cette thèse est consacrée à l'étude des écoulements de gaz raréfiés à travers divers micro-conduits de type circulaire et rectangulaire dans des conditions isotherme et stationnaire. L'objectif de la thèse est de contribuer à l'étude de l'interaction gaz-surface notamment en déterminant le coefficient d'accommodation de la quantité de mouvement pour différent matériaux de surface (Or, Silice, Acier inoxydable et Sulfinert) associés à différents types de gaz (hélium, azote, argon et dioxyde-de-carbone). Afin d'atteindre cet objectif, on adopte un triple point de vue : expérimental, théorique et numérique. L'aspect expérimental est réalisé par des mesures de débit massique à travers les micro-conduits, en utilisant la méthode dite « à volume constant ». L'aspect théorique original est développé à travers une nouvelle approche basée sur la résolution de l'équation de Stokes. Cette approche a permis d'écrire une expression analytique de débit massique en régime de glissement, qui prenne en compte les effets bidimensionnels dans une section de conduit rectangulaire. Cette approche complètement explicite, est conduite au deuxième ordre. Enfin l'aspect numérique permet de calculer le débit massique, en régimes transitionnel et moléculaire libre, en résolvant numériquement l'équation cinétique BGK linéarisée. La comparaison des mesures de débit massique avec l'équation analytique, en régime de glissement, ou avec les calculs numériques, en régimes transitionnel et moléculaire libre, nous a permis de déduire des coefficients de glissement et les coefficients d'accommodation correspondant à chaque couple gaz-surface dans tous les régimes de raréfactionThis thesis is devoted to the study of rarefied gas flows through micro-channels of various cross sections (circular and rectangular) under isothermal and stationary conditions. The objective of this thesis is to contribute to the study of gas-surface interaction by determining the tangential momentum accommodation coefficient for different surface materials (gold, silica, stainless steel and Sulfinert) and associated to various gases (helium, nitrogen, argon and carbon-dioxide). To achieve this goal three aspects are considered: experimental, theoretical and numerical. The experimental aspect is considered by measuring the mass flow rate through microchannels using the constant volume technique. The theoretical aspect is considered by the development of a new approach based on the Stokes equations. This approach yields to the analytical expression of the mass flow rate in the slip regime, which takes into account the second order effects. The last aspect, numerical, is considered by the numerical simulations of the mass flow rate in the transitional and free molecular flow regimes by solving the linearized BGK kinetic model. The comparison between the measured mass flow rates and the analytically expressions in the slip regime or with the results of numerical simulations in the transitional and free molecular regimes enabled to deduce the tangential momentum accommodation coefficients corresponding to each pair gas-surface in all flow regimes
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SÁ, FAGNER GEOVANI DE. "METROLOGICAL EVALUATION OF THE INFLUENCE OF THE COMPOSITION OF THE NATURAL GAS ON FLOW RATE MEASUREMENTS IN PRESSURE RELIEF FLARE SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24338@1.
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Esta dissertação de mestrado teve por objetivo avaliar a influência da composição do gás natural na medição de vazão pela técnica de ultrassom em sistemas de alívio de pressão tipo tocha. A inclusão da composição do gás na correção da medição da vazão do gás em sistemas de tocha constitui uma exigência legal imposta pelo regulador brasileiro do setor de petróleo, gás natural e biocombustíveis. A histórica dificuldade técnica associada à coleta de amostras de gás em sistemas de tocha e os constantes questionamentos sobre a representatividade das amostras coletadas são as principais motivações para a realização deste estudo. A metodologia utilizada fundamentou-se em pesquisa bibliográfica, documental e de campo. Por meio de pesquisa bibliográfica, documental e normativa realizou-se o embasamento técnico e teórico do estudo. A pesquisa de campo teve por finalidade coletar informações de estações de medição de gás em sistemas de tocha de uma unidade marítima de produção de petróleo e gás. A partir do tratamento das informações coletadas, os resultados da pesquisa permitiram quantificar que o erro máximo na medição de vazão de gás por ultrassom devido ao desconhecimento de sua real composição é 0,04 porcento. Dentre as conclusões, (i) as amostras de gás coletadas em sistemas de tocha não representam de forma adequada o volume de gás medido e (ii) o erro máximo estimado associado à totalização do volume de gás mostrou-se desprezível quando comparado ao volume total de gás documentado nos históricos de medição e aos erros aleatórios aceitáveis para o tipo de estação de medição considerado.The objective of this dissertation is to evaluate the influence of the composition of the natural gas on the flow rate measurements in pressure relief flare systems. The consideration of the gas composition in the correction of the gas flow rate measurements in the flare system is a legal requirement imposed by the Brazilian regulating agency for oil, natural gas and biofuels. The historical technical difficulties associated with collecting gas samples from flare systems and the constant questions about the representativeness of the collected samples are the main motivations for this study. The methodology used was based on literature, documental and field research. Through literature, documental and normative research was conducted at the technical and theoretical foundation of the study. The field research aimed at collecting information of measurement systems of gas flare in a maritime unit of oil and gas production. From the treatment of collected information, the research results allowed to quantify that the maximum error in the measurement of gas flow rate by ultrasonic meters due to the lack of knowledge of its actual composition is 0.04 percent. Among the conclusions, (i) the collected gas samples in flare systems do not adequately represent the volume of measured gas and (ii) the estimated maximum error associated with the totalization of the gas volume was found to be negligible compared to the documented total volume gas on historical measurements and to acceptable random errors for the type of the considered measurement system.
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Dubovikova, Nataliia [Verfasser], Christian [Akademischer Betreuer] Karcher, Andrey Gutachter] Kuznetsov, and Puits Ronald [Gutachter] [Du. "Non-contact flow rate measurements in turbulent liquid metal duct flow using time-of-flight Lorentz force velocimetry / Nataliia Dubovikova ; Gutachter: Andrey Kuznetsov, Ronald! Du Puits ; Betreuer: Christian Karcher." Ilmenau : TU Ilmenau, 2016. http://d-nb.info/1178168336/34.
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Henry, Brad A. "STABILIZATION OF EXTENDED DIFFUSE OPTICAL SPECTROSCOPY MEASUREMENTS ON IN VIVO HUMAN SKELETAL MUSCLE DURING DYNAMIC EXERCISE." UKnowledge, 2014. http://uknowledge.uky.edu/cbme_etds/22.
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This research investigates various applications of diffuse correlation spectroscopy (DCS) on in-vivo human muscle tissue, both at rest and during dynamic exercise. Previously suspected muscle tissue relative blood flow (rBF) baseline shift during extended measurement with DCS and DCS-Near infrared spectroscopy (NIRS) hybrid optical systems are verified, quantified, and resolved by redesign of optical probe and alteration in optical probe attachment methodology during 40 minute supine bed rest baseline measurements. We then translate previously developed occlusion techniques, whereby rBF and relative oxygen consumption rV̇O2 are calibrated to initial resting absolute values by use of a venous occlusion (VO) and arterial occlusion (AO) protocol, respectively, to the lower leg (gastrocnemius) and these blood flows are cross validated at rest by strain gauge venous plethysmography (SGVP). Methods used to continuously observe 0.5Hz, 30% maximum voluntary isometric contraction (MVIC) plantar flexion exercise via dynamometer are adapted for our hybrid DCS-Imagent diffuse optical flow-oximeter in the medial gastrocnemius. We obtain healthy control muscle tissue hemodynamic profiles for key parameters BF, V̇O2, oxygen saturation (StO2), deoxyhemoglobin, oxyhemoglobin, and total hemoglobin concentrations ([Hb], [HbO2], and THC respectively), as well as systemic mean arterial pressure (MAP) and pulse rate (PR), at rest, during VO/AO, during dynamic exercise and during 15 minute recovery periods. Next, we began investigation of muscle tissue hemodynamic disease states by performing a feasibility pilot study using limited numbers of controls and peripheral arterial disease (PAD) patients using the translated methods/techniques to determine the ability of our technology to assess differences in these populations.
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Billanou, Ian. "Modélisation expérimentale et théorique pour la quantification du débit sanguin par Tomographie à Emission de Positrons." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0006/document.
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La Tomographie à Emission de Positrons (TEP) permet d'obtenir une mesure dynamique et résolue en espace de la concentration d'un traceur radioactif injecté au patient. La quantification du débit sanguin cérébral par TEP repose sur l'utilisation d'un modèle cinétique le reliant à la variation spatio-temporelle de la concentration du traceur dans le cerveau. Différents modèles cinétiques sont proposés dans la littérature. Cependant, la majorité d'entre eux repose sur une modélisation compartimentale de l'organe observé. Dans ce cas, l'organe est subdivisé en un compartiment capillaire échangeant avec un compartiment tissulaire par une cinétique le plus souvent du premier ordre. Les résultats obtenus avec ce type de modèle sous-estiment le débit et ne permettent pas de prédire les premiers instants de la dynamique de répartition du traceur. Ces faiblesses ont été confirmées suite à l'amélioration de la résolution temporelle des tomographes, conduisant à l'élaboration de modèles incorporant plus de réalité physiologique. Cependant, tous ces modèles sont développés pour modéliser les échanges entre la micro-circulation et le tissu environnant à l'échelle d'un capillaire (échelle microscopique). Or la résolution spatiale des tomographes utilisés en clinique ne permet pas de distinguer la micro-circulation et le tissu. L'utilisation de ces modèles cinétiques avec des mesures de concentrations macroscopiques dépasse donc leur cadre théorique de validité et peut introduire des résultats faussés. Dans ce contexte, nous proposons un modèle cinétique basé sur le changement d'échelle (utilisant la méthode de prise de moyenne volumique). Ce changement d'échelle permet de remplacer l'ensemble micro-circulation/tissu par un volume fictif, homogène, dont les propriétés macroscopiques sont calculées à partir des propriétés microscopiques d'un Volume Elémentaire Représentatif (VER) du milieu. Dans un premier temps, afin de pouvoir comparer les résultats de ce modèle avec ceux du modèle compartimental standard, le VER considéré est constitué d'un capillaire unique et de son enveloppe de tissu, puis une complexité géométrique supplémentaire est introduite en considérant un réseau de capillaire isotrope à l'échelle de Darcy. Ces modèles sont utilisés pour identifier le débit à l'aide d'une méthode inverse. Pour cela, l'évolution temporelle du champ de concentration dans notre géométrie de référence, qui ne peut être mesurée par TEP en raison de sa faible résolution spatiale, est déterminée par des simulations numériques ainsi que par des mesures in vitro à l'aide d'un modèle expérimental, également développé au cours de ce travail, permettant de reproduire l'écoulement dans un canal traversant une matrice diffusante (gel d'alginate)Positron Emission Tomography (PET) provides a dynamic and space-resolved measurement of the concentration field of a radioactive tracer previously injected to the patient. Quantification of cerebral blood flow by PET is based on the use of a kinetic model linking cerebral blood flow to the spatial and temporal variations of tracer concentration in the brain. Various kinetic models have been proposed in the literature. However, most of the mare based on a compartmental approach of the observed organ In this case, the organ is divided in two compartments, the capillary and the tissue, and the exchanges between these two compartments are often described by a first order kinetic model. Results obtained with this kind of model under estimate the flow rate and are notable to predict the first instants of the tracer dynamics distribution. With the continuous improvement of the temporal resolution of PET, these weaknesses have been confirmed, which led to the development of models incorporating more physiological reality. However, all these models have been developed to describe exchanges between micro-circulation and surrounding tissue at the scale of capillary vessels (microscopic scale). Because the spatial resolution of PET inclinical practice is insufficient to allow the distinction between micro-circulation and tissue, using of these models with kinetic measurement of macroscopic concentrations exceeds their theoretical validity and can introduce false results. In this context, we propose a kinetic model based on up-scaling (using the method of volume averaging). This up-scaling technique allows to replace the two previous compartments (tissue and micro-circulation) by an homogeneous fictive volume, whose macroscopic properties are calculated from the microscopic properties of are presentative elementary volume (REV) of the medium. First, in order to compare the results of this model with those of the standard compartmental model, the considered REV consists of a single capillary and its surrounding tissue. Second, additional geometric complexity is introduced by considering an isotropic capillary network at the Darcy scale. These models are used to identify the flow rate using an inverse method. For that purpose, the temporal evolution of concentration field in a geometry of reference, which can't be measured by PET due to its low spatial resolution, is determined by numerical simulations and by in vitro measurements. These measurements are performed using an experimental model developed during this work to reproduce the flow in a channel passing through a diffusive matrix (alginate gel)
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Wilson, Greg J. "Combining field measurement of nitrate removal rates and a flow model to predict nitrate removal in the Walker River riparian zone." abstract and full text PDF (free order & download UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1460789.
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Ghaffarian, Roohparvar Hossein. "Study of driftwood dynamics in rivers for hazard assessment." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI094.
Full textAbstract:
Le bois flottant fait partie intégrante des systèmes fluviaux et joue un rôle important dans l'écologie et la morphologie des rivières. Au cours des dernières décennies, la quantité de bois transportée dans certaines rivières d’Europe a augmenté, notamment en raison de modifications de l'occupation et de la gestion des zones boisées le long des rivières, entraînant une augmentation des aléas pour les ouvrages hydrauliques et les zones urbaines. Dans ce contexte, l'objectif de cette thèse est d'étudier la dynamique du bois flottant dans les rivières afin de fournir des éléments pour l'estimation des risques. Cela a été effectué de deux manières: (i) en utilisant la vidéographie in situ au bord d'un cours d'eau pour mesurer la quantité de bois transporté lors d’une crue et (ii) en analysant la dynamique de morceaux de bois isolés, à la fois sur le terrain et par une étude expérimentale de laboratoire complétée par des modèles théoriques. Ce travail présente plusieurs contributions scientifiques et techniques. Tout d'abord, en étudiant le lien entre le débit de bois et les caractéristiques de crue, telles que son amplitude, son hydrogramme et le délai entre deux crues, nous renforçons et élargissons les connaissances actuelles sur le lien entre les débits de crue et de bois. Ensuite, nos études montrent que lorsqu'un tronc est pris dans la rivière, il est accéléré sur une distance limitée, d’ordre de grandeur donné par la longueur du bois dans la direction de l’écoulement. Une fois la vitesse d'écoulement atteinte, le bois se comporte comme un traceur de l'écoulement. En termes de contributions techniques, se basant sur deux sites différents, nous fournissons des recommandations utiles aux praticiens pour l'installation de nouvelles stations de surveillance. Ces travaux s’intègrent dans le cadre de l’évaluation des aléas et des risques liés au bois flottant, pour lesquelles des quantités précises de la dynamique du bois sont nécessairesDriftwood is an integral part of river corridors where it plays an important role both in river ecology and morphology. During the last decades, the amount of large wood transported in some of the European rivers has increased, notably due to modifications in the human pressure and management of riparian forest buffers along rivers. This causes an increase of potential hazards for hydraulic structures and urban areas. In this context, the aim of this thesis is to study the driftwood dynamics in rivers in order to provide elements for hazard assessment. This is carried out in two ways: (i) using in-situ streamside videography to measure the amount of wood transported by the river during floods and (ii) analyzing the dynamics of individual pieces of wood both on the field and in a well-controlled experimental environment combined with theoretical models. The present work provides several scientific and technical contributions. First by studying the link between wood discharge and flood characteristics, such as flood magnitude, hydrograph and inter-flood time, we consolidate and extend the present knowledge about the link between flow and wood discharges. Second, our studies show that when a piece of wood is recruited into the river, it is accelerated on a limited distance, which scales as the wood length in the flow direction. Once the wood piece reaches the flow velocity, it behaves as a flow tracer. In terms of technical contributions, by comparing the video monitoring technique in two different sites, we provide some recommendations that are useful for practitioners for installing new monitoring stations. This work will be part of the driftwood hazard and risk assessments, for which accurate wood dynamics quantities are required