The present study utilizes the ultrasonic travel time technique to diagnose grid generated turbulence. Ultrasonic flow metering technology relies on the measurement and computation of small perturbations in the travel time of acoustic ultrasonic waves through the dynamic medium. The statistics of the travel time variations of ultrasonic waves that are caused by turbulence probably affect the performance of ultrasonic flow meters. Motivation for the study stems from the large travel time variations observed in typical ultrasonic flow and circulation meters. Turbulent flow data was collected downstream of a grid introduced in a uniform flow in the wind tunnel using ultrasonic techniques. Grid turbulence is well defined in literature, and is nearly homogeneous and isotropic. The experimental investigation was performed under well-controlled laboratory conditions. The grid mesh sizes varied from 0.25-0.5in, and flow velocities from 0-20m/s. The ultrasonic transducers were of 100 kHz working frequency; and all of the data was collected with them oriented perpendicular to the mean flow. Path lengths were increased from 2-10in; and the data acquisition and control system featured a very high speed data acquisition card with an analog to digital converter that enabled excellent resolution of ultrasonic signals. Experimental data was validated by comparison to other studies. The work aims to investigate the influence of the grid-generated turbulent flow on acoustic wave propagation, in terms of the variance of the travel time. The effect of turbulence on acoustic wave propagation was observed. The experimental data was used to compute average travel times, acoustic travel time variances, and standard deviation amplitude fluctuations. The data was collected in the region estimated to be homogeneous and isotropic. Average travel time data support the assumption that only the large (as compared to the wavelength ) turbulent inhomogeneities influence acoustic wave propagation. Variance data confirm the presence of a non-linear trend in the acoustic travel times with increasing path length. Amplitude fluctuations data confirm a correlation between areas of caustic formation and large amplitude fluctuations.

Este trabalho propõe uma soleira assimétrica elíptica-circular com apenas dois pontos de descontinuidade, com parâmetros geométrico associados à vazão específica de projeto, com possibilidade de padronização e cujas características hidráulicas (linha d´água, pressões, coeficiente de vazão) podem ser determinadas teoricamente. Um sistema de equações diferenciais parciais permite o desenvolvimento de um modelo computacional para determinação dos valores teóricos dessas características. A validação dos valores teóricos das características hidráulicas da soleira por um modelo computacional foi realizada com a confrontação desses mesmos valores obtidos em um modelo físico, permitindo a comparação de pressões, linha d´água, coeficiente de vazão e profundidade crítica. / In this work is proposed an asymmetrical (elliptical-circular) weir with two points of discontinuity only, with geometrical parameters associated to the specific design discharge, allowing the standardization, and whose hydraulic characteristics (water profile, pressures and discharge coefficient) may be theoretically determinate. Their hydraulic characteristics, developed by a system of partial differential equations, system allowing the development of a computational model to determine the theoretical values of the weir hydraulic characteristics. The validation of these theoretical values of the weir hydraulic characteristics, obtained by a computational model, was made by the comparison between the values of water profile, pressures, discharge coefficient and critical depth obtained by the theoretical model and the values obtained by the physical model.

A medição de vazão é fundamental para a gestão de processos que envolvem fluidos. Em empresas de saneamento, contabilizar as entradas e saídas de água é essencial para gerir faturamentos e perdas. A vazão pode ser mensurada através de diversos instrumentos com diferentes princípios de aplicação. O Tubo Pitot Cole é capaz de determinar a vazão em tubulações através do diferencial de pressão. Trata-se se um equipamento inventado em 1732 por Henri Pitot para determinar a velocidade, e aperfeiçoado por Eduard Cole, em 1896, permitindo sua aplicação em tubulações. As principais vantagens são o baixo custo e fácil instalação, que pode ocorrer com a tubulação em carga. Em contrapartida, a fragilidade e complexidade das suas peças motivaram este trabalho: a elaboração de um instrumento simples e robusto para medir a vazão. Propõe-se a construção de um protótipo com tomadas de pressão instaladas em faces opostas de um prisma hexagonal e a avalia-se a sua viabilidade na medição de vazão. Os resultados mostraram-se promissores dada a estabilidade e forte correlação linear obtida no coeficiente de calibração. / Flow measurements are essential for processes management that include fluids. In water companies, measuring inlets and outlets of water is essential to manage revenue and water losses. The water flow can be measured through different instruments with different application principles. The Pitot Cole Tube is able to determine flow in pipes through the pressure differential. This device was invented in 1732 by Henri Pitot to determine fluid velocity and it was improved by Eduard Cole in 1896, allowing to apply the instrument in pipes. The main advantages are the low cost and easy installation, that may occur with the pipe under load. However, the fragility and complexity of its pieces motivated this study: the construction of a simple and robust instrument to measure the water flow. It is proposed the construction of a prototype with pressure plugs installed on opposite faces of a hexagonal prism, then evaluation of its effectiveness in water flow measurements. The results were promising given the stability obtained in the calibration coefficient.

The use of residential secondary or dual water systems for irrigation purposes is common in the western United States where water supplies are scarce. While the use of non-potable water in secondary systems has successfully curtailed demands on potable systems, experience has shown that overall water use actually increases with the introduction of a secondary supply because users commonly pay a fixed fee and have unlimited water use. While water metering and billing effectively reduce water use, there are two main obstacles to the widespread installation of meters in secondary systems. The first obstacle is that standard residential water meters do not normally function in debris-filled secondary water. Metering mechanisms can clog or be degraded by suspended debris of both organic and inorganic nature in the water. By way of innovative meter designs or filtration, a few secondary systems have had success metering their secondary water. Other systems have experimented with possible debris-resistant meters but have had little success. In addition to the physical limitations of water meters, secondary systems face economic obstacles from the increased expense of metering. Since secondary water is intended to be an inexpensive alternative to potable water for outdoor irrigation, any cost increase due to the expense of meters, filtration, meter reading, etc., interferes with the main objective of a secondary system. A system-specific economic analysis is necessary to determine the financial feasibility of the implementation of metering in any secondary system. The objective of this research is to identify feasible ways for metering secondary water systems. An overall analysis is made of the performance, benefits, and drawbacks of each technological approach. Approximate costs and design requirements of these technologies are identified, thereby allowing water suppliers to determine the economic feasibility of metering. In addition, other design precautions for implementing secondary metering and investigations of residential meter performance in secondary systems using filtration are discussed.

Seafloor hydrothermal systems play a key role in Earth fs energy and geochemical budgets. They also support the existence and development of complex chemosynthetic biological ecosystems that use the mineral-laden fluids as a source of energy and nutrients. This dissertation focuses on two inter-related topics: (1) heat output and geochemical fluxes at mid-ocean ridges, and (2) structural deformation of oceanic lithosphere related to subsurface serpentinization in submarine settings. The determination of heat output is important for several reasons. It provides important constraints on the physics of seafloor hydrothermal processes, on the nature of the heat sources at mid-ocean ridges, and on nutrient transport to biological ecosystems. Despite its importance, measurements of hydrothermal heat outputs are still scarce and cover less than 5% of active hydrothermal vent sites. In this work, we report development of two new devices designed to measure fluid flow velocities from the submersible at temperatures of up to 450 C and depths 5,000 m. By using these instruments on 24 Alvin dives, new measurements of hydrothermal heat output have been conducted at the Juan de Fuca Ridge, including first measurements from the High Rise and Mothra hydrothermal fields. The collected data suggest that the high-temperature heat output at the Main Endeavour Field (MEF) may be declining since the 1999 eruption. The flow measurement results, coupled with in-situ geochemical measurements, yielded the first estimates of geochemical fluxes of volatile compounds at MEF and Mothra. Our findings indicate that geochemical flux from diffuse flows may constitute approximately half of the net geochemical flux from Juan de Fuca Ridge. It has recently been recognized that serpentinization of mantle peridotites, due to its exothermic nature, may be a mechanism contributing to the heat output at mid-ocean ridges. The tectonic response of the crust to serpentinization of extensively distributed peridotites at mid-ocean ridges and subduction zones could provide a means of characterizing serpentinized regions in the oceanic lithosphere. These regions are often associated with surface topographic anomalies that may result from the volume expansion caused by the serpentinization reactions. Although there is a clear correlation between tectonics and serpentinization, the link is complex and still not understood. In this dissertation, we calculated the transformation strain and surface uplift associated with subsurface serpentinization of variously shaped ultramafic inclusions. Application of the results to explain the anomalous topographic salient at the TAG hydrothermal field (Mid-Atlantic Ridge) suggests that this feature may result from a serpentinized body beneath the footwall of a detachment fault. Because the depth of the potential serpentinized region appears to be more than 1.5 times the size of the inclusion, the uplift profile is relatively insensitive to the exact location or shape of the serpentinized domain. The rate of exothermic heat release needed to produce the serpentinized volume may contribute to the ongoing diffuse flow. Application of the results to an uplift feature associated with the Kyushu ]Palau subduction zone in the western Pacific, shows that approximately 3% transformational strain in an inclined serpentinized region of the mantle wedge near the subducted Kyushu ]Palau Ridge may result in the observed uplift on the Miyazaki Plain. Using the uplift data may help to constrain the level of the subsurface serpentinization.

Made available in DSpace on 2014-06-11T19:29:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-27Bitstream added on 2014-06-13T20:59:27Z : No. of bitstreams: 1 camapumfilho_na_me_ilha.pdf: 1741621 bytes, checksum: 8d03cd3c15e2515c463152711b059b6c (MD5) / PROPG / Este trabalho teve o objetivo de avaliar os medidores de vazão com uma ou múltiplas tomadas de pressão em sistemas de água. Esses medidores de vazão são de fácil construção, utilizando materiais de baixo custo, podem ser instalados em locais que apresentem perfis de velocidades axialmente assimétricos em decorrência da existência de singularidades e/ou incrustações internas. Este estudo também foi idealizado para auxiliar os programas de redução de perdas físicas de água, uma vez que existe uma demanda reprimida na instalação de medidores de vazão em redes públicas de abastecimento. O trabalho foi desenvolvido em escala real nas instalações da ETA de Presidente Prudente-SP que abastece a zona de distribuição denominada de Alto ETA. Como padrão de medição foi utilizado um tubo de Pitot do tipo Cole, calibrado em túnel de vento pelo IPT. Além da aferição em diversos perfis de velocidade, medidores de múltiplos furos foram instalados em vários locais da rede, o que proporcionou uma verificação do comportamento do medidor em relação à variação do tipo de materiais e diâmetros das redes de abastecimento e uma avaliação geral do seu emprego em condições reais de uso em sistemas de abastecimento público. Os resultados demonstram que o medidor multifuros foi menos sensível à variação do perfil de velocidades, ou seja, a utilização da curva de calibragem obtida em condições ideais numa situação de perfil assimétrico levou a erros de medição menores que os obtidos com medidor de tomada única. A possibilidade de contar com um medidor de vazão adequado às condições brasileiras, de baixo custo e facilidade de construção, abre perspectivas para alavancar os programas de redução de perdas físicas de água, uma vez que existe uma grande demanda reprimida na instalação de medidores de vazão em redes de abastecimento público. / This work had the objective of evaluating the flow meters with one or multiple orifices in water supply systems. Those flow meters are of easy construction, using inexpensive materials, and can be installed in places that present asymmetric velocity profiles as a consequence the existence of singularities and internal incrustations. This study was also conceived to aid the programs of reduction of physical losses of water, since a repressed demand for flow meters exists in water distribution systems. The work was developed in real scale in the Water Treatment Station - ETA of Presidente Prudente city-SP, that provisions the zone of distribution denominated High ETA. The measurement standard was a Pitot-Cole meter calibrated in wind tunnel by IPT. Besides calibration in several velocity profiles, meters of multiple orifices were installed at several places of the net, that provided a verification of the behavior of the meter related to the variation of the type of material and diameters of water distribution systems and a general evaluation of its employment in real conditions of use in public supply systems. The results demonstrate that the multi-port meter was less sensitive to the variation of the velocity profiles, in other words, the use of the calibration curve obtained in ideal conditions in a situation of asymmetric velocity profiles, led to smaller measurement errors than that obtained with a meter of only one orifice. The possibility to count on a flow meter adequate to the Brazilian conditions, inexpensive and easily constructed, opens perspectives for support the programs of reduction of physical losses of water, since there is a great unsatisfied demand for flow meters in water public supply systems.

Numerical estimates of the ability of a green roof to reduce energy consumption in buildings are plagued by a lack of accuracy in thermal properties that are input to the model. An experimental study into the thermal conductivity at different temperatures and moisture contents was performed using four different commercially available substrates for green roofs. In the unfrozen state, as moisture content increased, thermal conductivity increased linearly. In the phase transition zone between +5 ºC and -10ºC, as temperature decreased, thermal conductivity increased sharply during the transition from water to ice. When the substrate was frozen, thermal conductivity varied exponentially with substrate moisture content prior to freezing. Power functions were found between thermal conductivity and temperature (when shifted up by +10.001ºC). Two equally sized, green roof test cells were constructed and tested to compare various roof configurations including a bare roof, varying media thickness for a green roof, and vegetation. The results show that compared with the bare roof, there is a 75% reduction in the interior temperature amplitude for the green roof with 150mm thick substrate. When a sedum mat was added, there’s a 20% reduction in the amplitude of the inner temperature as compared with the cell without sedum mat. / Graduate

Depleting oil reserves and fluctuating oil prices have necessitated to increase the efficiency of oil production process. This thesis is focused on developing low-cost sensors, which can increase oil production efficiency through real-time monitoring of oil wells and help in safe transport of oil products from the wells to the refineries. Produced fluid from an oil well is a complex mixture of oil, water and gases, which needs to be quantified for various strategic and operational decisions. For many years, test separators have been used to separate oil, water and gases into three separate streams and then to analyse them individually. However, test separators are being replaced by multiphase flow meters (MPFM) which can analyse the complex mixture of oil, water and gas without separating it. However, existing MPFMs are either intrusive or require fluid mixing before the sensing stage. In contrast to existing techniques, first part of this thesis presents a microwave sensor, which can measure water fraction in oil in a non-intrusive way without requiring it to be mixed. Gas fraction sensing can also be performed using the same microwave sensor, which is an on-going work. The sensor operates on dielectric measurement principles and comprises a microstrip T-resonator that has been optimized for a 3D pipe surface. Certain locations on an oil field have limited available space, for which we have also presented a compact version of the microwave water-fraction sensor in this thesis. In this version, metallic housing of the sensor has been used to function as a ground plane for the coaxially located spiral resonator. This housing also protects the sensor from environmental effects. In addition to the efficient production of oil, its safe transport is also a concern for the industry. It is physically impossible to inspect a network of thousands of kilometres of pipelines manually. The existing leak detectors suffer from low sensitivity, high false alarms and dependence on environmental effects. In the last part of this thesis, we present a flexible ringresonator based leak detector, which can be clamped at vulnerable locations along the pipeline for early leak detection.

Thesis describes the design and realization of linearization display unit that will receive pulses from a gear flow meter KRACHT whose frequency corresponds to a flow. The measured value is flow that nonlinearly depends on the temperature and viscosity of the medium. The dependency is described by calibration curves for each flow meter. The task of the diploma thesis is to design, implement, and verify the operation of the display unit, which calculates the actual flow rate from the input data (pulse rate, temperature, viscosity, and flow meter calibration curves). The device will contain a suitable user interface to display all measured values, inputs for connecting measuring sensors, and outputs for transmission of measured data. A part of the device will be a USB interface for configuration and uploading calibration curves from a PC application, which is designed by diploma student.

This master thesis project has been carried out in cooperation with the Endress+Hauser Flowtec AG in Switzerland. The project was part of a bigger predevelopment project for a vortex flow meter in the research and development department of Endress+Hauser. Prowirl (vortex) flow meters are often used for measuring the volume flow in steam applications. This measurement method is based on the phenomena of vortices occurring behind obstacles in a stream which are registered by a sensor. Aim of the project was to develop and test a new vortex flow transducer concept for highest pressure applications (line pressure of 250 bars). Endress+Hauser already had a sensor for such applications which was outdated and not compatible to the newer generation of sensors. Two concepts with and without a temperature sensor option have been generated. The concepts have been modeled and verified via FE-analysis and analytical calculations according to the relevant standards (ASME Boiler and Pressure Vessel Code and EN 13445). After the calculations prototypes have been manufactured and tested. The conducted tests matched the simulations well and proved that the concept worked. More detailed tests after this thesis project are necessary to transfer the concept into a final product. However, it has been shown that the new concept has significant advantages over the existing highest pressure sensor. These are a bigger pressure range, the option of integrating a temperature sensor and a cost reduction for the flow meters compared to the existing design. Keywords: Vortex, Flow meter, Sensor, Water hammer / Detta examensprojekt har utförts i samarbete med Endress+Hauser Flowtec AG i Schweiz. Projektet har varit en del av ett större inledande projekt kring en virvelflödesmätare under avdelningen för forskning och utveckling hos Endress+Hauser. Prowirl(virvel)flödesmätare används ofta för mätning av volymflöde i ångapplikationer och tekniken bygger på sensorregistrering av fenomenet virvelbildning som uppstår nedströms hinder i ett flöde. Målet med projektet var att utveckla och testa en ny virvelflödesmätare för högtrycksapplikationer (ledningstryck upp till 250 bar). Sensorn som Endress+Hauser redan hade för sådan applikation var föråldrad och inte kompatibel med nyare generationer av sensorer. Två koncept har tagits fram, ett med och ett utan temperatursensor. Koncepten har modellerats och verifierats genom FEM och analytiska beräkningar enligt relevanta standarder (ASME Boiler and Pressure Vessel Code och EN 13445), efter vilket prototyperna tillverkats och testats. De utförda testerna överensstämde väl med simulationerna och bevisade att koncepten fungerade. Mer utförliga tester efter detta examensprojekt är nödvändigt för att med koncepten som utgångspunkt skapa en klar produkt. Men det har visats att dessa koncept har väsentliga fördelar över den befintliga högtryckssensorn. Bland dem kostnadsreducering, möjlighet för integrering av temperatursensor och breddat tryckspann jämfört mot den existerande designen. Nyckelord: Virvel, Flödesmätare, Sensorer, Vattenslag