Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A descoberta de reservatórios de petróleo na camada do pré-sal abriu novas perspectivas para a economia brasileira. A grandes profundidades, com elevado teor de CO2 e submetidos a altas pressões e temperaturas, a exploração de petróleo das camadas de pré-sal constitui um considerável desafio tecnológico. Neste contexto, o conhecimento dos coeficientes de compressibilidade são fundamentais para o estudo do comportamento termodinâmico e escoamento dos fluidos destes campos de produção. Com este objetivo, foram determinadas experimentalmente nesta dissertação a massa específica e a velocidade do som de sistemas envolvendo quatro hidrocarbonetos puros: n-decano, n-hexadecano, decalina e tetralina, assim como para sistemas multicompostos envolvendo estes hidrocarbonetos e para uma amostra de condensado de petróleo. Os resultados obtidos permitiram o cálculo dos coeficientes de compressibilidade isentrópica, isotérmica e isentálpica. É apresentada uma avaliação sobre a capacidade de se correlacionar dados experimentais de velocidade do som aos dados calculados pelas equações de estado de Peng-Robinson e Lee-Kesler com regras de mistura: (i) Spencer e Danner e (ii) Lee-Kesler / The discovery of oil reservoirs in the pre-salt layer has opened new perspectives for Brazilian economy. In deep waters, with high levels of CO2 and subjected to high pressures and temperatures, the oil exploration in the pre-salt layer is a considerable technological challenge. In this context, knowledge of compressibility coefficients and phase equilibrium data are essential for studying the thermodynamic behavior and flow in these oil fields. With this objective, experimental data were obtained for density and sound velocity in systems involving four pure hydrocarbons: n-decane, n-hexadecane, decalin and tetralin, as well as in multi-component systems involving these hydrocarbons, and in a sample of oil condensate. The results obtained allowed the calculation of isentropic, isothermal and isenthalpic compressibility coefficients. An evaluation on the ability to correlate experimental data of sound velocity with data calculated from Peng-Robinson and Lee-Kesler equations of state with mixing rules: (i) Spencer and Danner and (ii) Lee-Kesler is presented

This thesis is part of the project undertaken to develop a diffusive acoustic confocal imaging system (DACI) that aims to differentiate between healthy and the diseased tissues in the prostate. Speed of sound is chosen as the tool to quantify the alterations in the tissues’ mechanical properties at different pathological states. The current work presents a scanning configuration that features three components: an acoustic emitter, a focusing mirror and a point receiver. The focusing mirror brings the collimated acoustic beam from the emitter into a focused probe position, which needs to be located within the bladder or at the near surface of the prostate. This position is introduced as the virtual source, where the acoustic intensity diffusively scatters into all directions and propagates through the specimen. The system design was simulated using ZEMAX and COMSOL to validate the concept of the virtual source. Lesions in a phantom prostate were found in the simulated amplitude and phase images. The speed of sound variation was estimated from the 1D unwrapped phase distribution indicating where the phase discontinuities existed. The measurements were conducted in a water aquarium using the tissue-mimicking prostate phantom. Two-dimensional projected images of the amplitude and the phase distributions of the investigating acoustic beam were measured. A USRP device was set up as the signal generation and acquisition device for the experiment. Two different signal extractions methods were developed to extract the amplitude and the phase information. The experimental results were found to generally agree with the simulation results. The proof-of-concept design was successful in measuring both the phase and the amplitude information of the acoustic signal passing through the prostate phantom. In future, the 2D/3D speed of sound variation needs to be estimated by an appropriate image reconstruction method. / Graduate / 2018-12-06

The work deals with the design of a system of orifices for high pressure difference. The task of this work is to design a device for controlled discharge of steam-gas mixture from a volume compensator with an overpressure of 12,27 MPa to a tank with an overpressure of 0,02 MPa at a constant mass flow of 40 kg/h. The first part of the thesis contains the theory and also the basic principles of calculations. In the next part of the work, the theoretical properties of flow, such as the speed of sound in wet steam, are determined. This knowledge then serves the main goal of the work, namely to design a system of orifices to release steam-gas mixture from the volume compensator.

The master thesis is focused on optimizing existing or proposal for a new exhaust tracts on the Volkswagen Polo moving series rally-cross A1 division. The car is powered by concern, water-cooled, atmospheric engine capacity 1599 ccm. To achieve the objectives of the lessons are applied as a theoretical nature (analytical calculation), especially the advanced approaches of the software environment from the firm Lotus. Exhaust treatment systems are designed to suit all rules FIA Sports Association.

This diploma thesis is concerned about installation of AR64304 engine into Alfa Romeo 75. The main goal of this thesis is a design of exhaust system for AR64304 engine installed in the engine bay of the vehicle. The design of the exhaust system was done with a respect to the noise and emission requirements, as well as with a respect to the performance of the engine. Lotus Engine Simulation software was used for the simulation of the engine with proposed exhaust system. Input data for the simulation were obtained from measurements of the cylinder head on a flow bench and precise measurement of camshaft profile. The essential contribution of this work is a set of construction parameters of the exhaust system. This thesis also contains technical specifications of AR64304 engine and the installation process.

Coherent plane-wave compounding (CPWC) ultrasound is an important modality enabling ultrafast biomedical imaging. To perform CWPC image reconstruction for a stratified (horizontally layered) medium, one needs to know how the speed of sound (SOS) varies with the propagation depth. Incorrect sound speed and layer thickness assumptions can cause focusing errors, degraded spatial resolution and significant geometrical distortions resulting in poor image reconstruction. We aim to determine the speed of sound and thickness values for each horizontal layer to accurately locate the recorded reflection events to their true locations within the medium. Our CPWC image reconstruction process is based on phase-shift migration (PSM) that requires the user to specify the speed of sound and thickness of each layer in advance. Prior to performing phase-shift migration (one layer at a time, starting from the surface), we first estimate the speed of sound values of a given layer using a cosine similarity metric, based on the data obtained by a multi-element transducer array for two different plane-wave emission angles. Then, we use our speed estimate to identify the layer thickness via end-of-layer boundary detection. A low-cost alternative that obtains reconstructed images with fewer phase shifts (i.e., fewer complex multiplications) using a spectral energy threshold is also proposed in this thesis. Our evaluation results, based on the CPWC imaging simulation of a three-layer medium, show that our sound speed and layer thickness estimates are within 4% of their true values (i.e., those used to generate simulated data). We have also confirmed the accuracy of our speed and layer thickness estimation separately, using two experimental datasets representing two special cases. For speed estimation, we used a CPWC imaging dataset for a constant-speed (i.e., single-layer) medium, yielding estimates within 1% of their true values. For layer thickness estimation, we used a monostatic (i.e., single-element) synthetic-aperture (SA) imaging dataset of the three-layer medium, also yielding estimates within 1% of their true values. Our evaluation results for the low-cost alternative showed a 93% reduction in complex multiplications for the three-layer CPWC imaging dataset and 76% for the three-layer monostatic SA imaging dataset, producing images nearly similar to those obtained using the original PSM methods. / Graduate

[pt] Medidores do tipo ultrassônicos são calibrados para medição de vazão de um único fluido. Entretanto, ao extrair petróleo de um poço, a separação trifásica não é suficiente para separar totalmente a água do óleo e a medição de vazão indicada do fluido acaba sendo maior do que o mensurando devido à presença de água não contabilizada na mistura, o que muitas vezes acontece nos escoamentos dentro de tubulações. Foi desenvolvida uma metodologia para medição contínua e automática do teor de água na mistura óleo-água, medindo-se a velocidade do som, por medidores ultrassônicos que podem ser intrusivos ou não intrusivos (clamp-on) para medição de vazão que foram anteriormente instalados e compõem as malhas de processo das plantas de exploração e refino de petróleo, em conjunto com a determinação da velocidade do som e massas específicas da água pura e do óleo diesel. Este trabalho mostra uma redução da incerteza de medição quando a indicação da fração de água através da medição da velocidade do som na mistura óleo-água é diretamente relacionada a medições rastreáveis da fração de água e temperatura de uma mistura óleo-água previamente preparada e conhecida, que foi utilizada como sistema de calibração para medições do teor de água. A incerteza de medição calculada para medição da fração de água é de 0,25 por cento com um grau de confiança de 95,45 por cento, sendo obtida através de uma curva de ajuste dos dados em uma faixa de medição de 0 por cento - 2,5 por cento. A incerteza calculada é menor e, portanto, atende aos requisitos de medição fiscal (menor que 1 por cento) vigentes no país. / [en] Ultrasonic meters are calibrated for flowrate measurement of pure oil flows. However, the multiphase separation is not enough to totally separate water and oil and the indicated oil flow rate is larger than its true value when water is mixed with oil in the flow, as usual in pipeline flows. A methodology was developed to measure the water content of water-oil mixtures automatically, using the already measured speed of sound by installed intrusive or non-intrusive (clamp on type) ultrasonic meters for flowrate measurement. That measure together with the previously determined speed of sound and density of pure water and oil as a function of temperature, thus avoiding additional meters. This dissertation shows a reduction of the uncertainty of measurement when the meter indicated water-oil mixture speed of sound is directly related to the traceable measurements of water content and temperature of previously prepared water-oil mixtures, what turns out to be the meter calibration for water content measurement. Water content uncertainty value of 0.25 per cent, 95.45 per cent level of confidence, is obtained when curve fitting de data in the 0 per cent - 2.5 per cent range, that covers the fiscal measurement range (less than 1 per cent).

Dans le cadre de la lutte pour la réduction des émissions de gaz à effet de serre, les biocarburants présentent un potentiel intéressant, en raison notamment de leur bilan CO2 "du puits à la roue" souvent très bon. Ainsi de nombreux programmes sont mis en œuvre, notamment en Europe, pour le développement de nouveaux carburants, et de moteurs automobiles adaptés à ces derniers. La conception de ces derniers nécessite une bonne maîtrise du système d’injection qui doit être aussi parfait que possible. Une meilleure connaissance du comportement et des propriétés sous haute pression de ces biocarburants revêt un caractère important. Le projet français NADIABIO rentre dans ce cadre et a pour principal objectif une meilleure maîtrise de l'injection (de la propagation d'onde dans la ligne HP à l'auto inflammation et la combustion) et de l'impact des biodiesels via une analyse fine à la fois numérique et expérimentale. En effet, dans le domaine des hautes pressions, la détermination des propriétés thermophysiques comme la densité ou les coefficients de compressibilité, présente souvent des difficultés contrairement à la vitesse du son qui peut se mesurer d’une manière simple et directe. Des dispositifs expérimentaux permettant d’effectuer des mesures de vitesses ultrasonores et de densité ont été mis au point pendant ce travail de thèse. Ils ont permis de fournir des données expérimentales de vitesses ultrasonores (pour des pressions et températures allant respectivement de 0,1 à 250 MPa et de 263,15 à 423,15K) et de densité (pour des pressions et températures allant respectivement de 0,1 - 100 MPa et de 283,15 à 393,15K). La campagne de mesure a été effectuée sur 12 biodiesels et sur un ensemble de 7 corps purs (EMHV, EEHV) représentatifs des mélanges étudiés. Cependant, pour des raisons de confidentialité, seuls les résultats relatifs aux corps purs et au Normafluid sont accessibles dans ce mémoire. Parallèlement, dans le but de proposer des méthodes de calcul prédictifs, nous nous somme intéressés à une procédure de type « predictor corrector », à une méthode de contribution de groupes moléculaires ainsi qu’à la théorie des états correspondants. Ces techniques de modélisation ont permis de déduire d’autres propriétés thermophysiques comme les coefficients de compressibilité, sous le même domaine de pression et de température. / Within the politic changes for the reduction of greenhouse gas emissions, biofuels present an interesting potential because of their very well CO2 balance sheet. Numerous projects were engaged in Europe, for the development of new fuels and for the design of automobile engines adapted to these carburant. The conception of new engine requires specific systems of injection which must be perfectly designed. With this aim in mind thermophysical properties such as density and compressibility must be known with accuracy. The French project “NADIABIO” goes into this industrial issue and its main objective consist in a better control of the injection (wave distribution in the High Pressure line, during the automobile inflammation and combustion process) and the impact of biodiesels (FAME and synthetic materials) on the environment through fine numerical and experimental analyses. The direct measurement of the density or the coefficients of compressibility often presents difficulties under high pressure. It is therefore easier to determine it indirectly from the velocity of sound, which can be measured in a simple and direct way with a good accuracy. Therefore, experimental devices allowing to make measurements of ultrasound speeds and density were finalized during this work. Experimental data of ultrasound speeds (from 0,1 to 250 MPa and from 263,15 to 423,15 K) and of density (0,1 to 100 MPa and 283,15 to 403,15K) have been determined with good precision on 19 biodiesels (mixtures and synthetic products (FAME, FAEE)). However, for reasons of confidentiality, only the results relative to the synthetic products and to Normafluid appear in this report. At the same time, with the aim of proposing predictive methods, we are interested in the procedure like “predictor-corrector”, in the method contribution of molecular groups and to the theory of the corresponding states which allowed deducting the other thermophysical properties like the coefficients of compressibility as a function of temperature and pressure.

Depuis 2005, il existe un intérêt important dans la communauté internationale de métrologiepour de nouvelles déterminations précises de la constante de Boltzmann kB ; lebut étant de redéfinir en 2015 l’unité internationale de température, le kelvin. Actuellement,cinq techniques sont utilisées pour déterminer kB avec comme objectif d’atteindreune incertitude relative inférieure à 1 × 10−6. La méthode retenue pour cette thèse est latechnique acoustique.La constante de Boltzmann est liée à la vitesse du son u dans un gaz parfait par l’équationdu viriel acoustique. La méthode décrite dans cette thèse consiste à mesurer u en utilisantun résonateur de forme quasi sphérique et de volume intérieur de 0,5 L, rempli d’argon.Ces mesures sont effectuées lors d’un isotherme à la température du point triple de l’eau,T = 273,16 K, pour des pressions statiques P allant de 0,05 MPa à 0,7 MPa. La constantede Boltzmann est ensuite déterminée en estimant u à pression nulle par une régressionpolynomiale.Dans cette thèse, un modèle de propagation des ondes acoustiques dans un résonateur quasisphérique est défini. Aussi, les moyens techniques utilisés pour contrôler soigneusement lesparamètres de l’expérience qui ont un effet sur les mesures de u (comme la température,la pression statique, la composition du gaz, etc) sont présentés. De nouvelles techniquesexpérimentales et des nouveaux moyens d’analyse des données sont proposés, comme lamesure du rayon du résonateur par spectroscopie électromagnétique, mais aussi l’utilisationde l’écart-type d’Allan comme un outil efficace pour étudier la présence d’impuretélors d’une expérience de longue durée. Les effets systématiques sont analysés puis corrigés.Pour certains, la correction est estimée grâce à un modèle analytique, comme l’effet lié auxcouches limites thermiques. Pour d’autres, des corrections basées sur des fonctions empiriquessont proposées ; c’est le cas pour l’effet du débit de gaz continu sur les mesures deu, effet qui est caractérisé expérimentalement dans cette thèse.Enfin, l’analyse des données acquises en 2009 au LCM/LNE-CNAM lors de deux isothermeseffectuées avec de l’argon est présentée. Celle-ci a permis d’obtenir la valeur kB =1, 3806475 (16) × 10−23 J · K−1, c’est à dire avec une incertitude relative de 1, 14 × 10−6. / Since 2005, there is an important interest in the international metrology community fornew accurate determinations of the Boltzmann constant kB ; the purpose is to redefine in2015 the unit of thermodynamic temperature, the kelvin. Currently, five techniques areimplemented for determining kB with the objective to achieve a relative uncertainty below1 × 10−6. The method used in the present work is based on acoustic measurements.The Boltzmann constant is linked to the speed of sound u in a noble gas by the virial acousticalequation. The method described here consists in measuring u inside a quasi-sphericalacoustic resonator of inner volume of 0.5 L filled with argon. Measurements are performedduring an isotherm process at the temperature of the triple point of water, T = 273.16 K,at static pressures P from 0.05 MPa to 0.7 MPa. The Boltzmann constant is then determinedby estimating u at zero pressure limit with a polynomial regression.In the present work an acoustic wave propagation model within a quasi-spherical resonatoris defined. Also, the technical means used to carefully control the parameters of theexperiment with an effect on the measurement of u (like temperature, static pressure, gascomposition, etc.) are presented. New exprimental methods and data analyses are described,like the measurement of the radius of the resonator by electromagnetic spectroscopy,as well as the use of the Allan deviation as an efficient tool to study the gas impuritypresence during a long-term experience. Systematic effects are analyzed and corrected. Insome cases the corrections are based on analytical models like the thermal layer boundaryeffect. In other cases, empirical correction functions are proposed, as for the case of changesin the measurements of u related to the continuous gas flow, which was experimentally characterizedin the present work.Finally, the analysis of the data acquiered in 2009 at LCM/LNE-CNAM during two isothermprocesses using argon is presented. This leads to the value kB = 1.3806475 (16) ×10−23 J · K−1, i.e. with a relative uncertainty of 1.14 × 10−6.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / A velocidade do som é uma propriedade que vem sendo cada vez mais utilizada em diferentes áreas tecnológicas. Além disso, a velocidade do som é uma propriedade termodinâmica que está associada a outras propriedades do meio como a compressibilidade isentrópica e isotérmica, entre outras. Neste contexto, muitos estudos foram realizados a fim de obter modelos precisos que possam representar fielmente a velocidade do som, sendo observados desvios absolutos médios entre 0,13 e 24,8%. Neste trabalho, um banco de dados de velocidade do som e massa específica à pressão atmosférica de n-alcanos, alcanos ramificados, n-alcenos, aromáticos, alcoóis, éteres e ésteres, foram compilados da literatura aberta. Utilizando estes dados e baseando-se no modelo de Wada por contribuição de grupo recentemente proposto, foi desenvolvido um novo modelo por contribuição atômica para predizer a velocidade do som de todas as famílias dos compostos investigados neste trabalho. É mostrado que o modelo proposto é capaz de prever a velocidade do som para os compostos destas famílias com desvios próximos da incerteza experimental calculada a partir de diferentes dados da literatura. Este trabalho também discute o efeito da ramificação das cadeias na constante Wada, ressaltando a importância de novas medições para este tipo de compostos. Além disso, observou-se que a literatura necessita de mais dados experimentais de velocidade do som, à pressão atmosférica e diferentes temperaturas para substâncias puras presentes em biodiesel e bio-óleo de pirólise rápida. Neste contexto, o presente trabalho fornece novos dados experimentais de velocidade do som e massa específica de cinco ésteres metílicos de ácidos graxos, também conhecidos como FAMEs, (caprilato de metila, caprato de metila, palmitato de metila, estearato de metila e linoleato de metila), e sete componentes puros presentes em bio-óleo de pirólise à pressão atmosférica, de vários fenóis (fenol, o-, m- e p-cresol), dois éteres fenólicos (2-metoxifenol e eugenol) e um éster fenólico (salicilato de metila), a temperaturas de (288,15-343,15) K. O modelo preditivo de Wada atômico foi utilizado para calcular a velocidade do som dos FAMEs estudados neste trabalho, e os desvios foram comparados com o modelo de Wada por contribuição de grupo. O modelo atômico de Wada foi utilizado para prever a velocidade do som dos componentes puros presentes no bio-óleo de pirólise rápida experimentalmente estudados nesta dissertação. Além disso, os dados de massa específica e velocidade de som foram correlacionados com o modelo de Prigogine-Flory-Patterson (PFP). As propriedades foram bem representadas pelo modelo PFP, no entanto, para a velocidade do som o modelo apresenta desvios sistemáticos na dependência com a temperatura. O desempenho do modelo preditivo de Wada atômico foi considerado satisfatório, devido os desvios observados serem compatíveis ou até menores do que os desvios típicos obtidos na literatura com outros modelos correlativos para o cálculo da velocidade do som de outras substâncias / Speed of sound is a property that is being increasingly used in different technological areas. Furthermore, the speed of sound is a thermodynamic property which is associated with other properties of the medium, such as isentropic and isothermal compressibility, among others. In this context, many studies were carried out to obtain accurate models that can faithfully represent the speed of sound, with average absolute deviations between 0.13 and 24.8%. In this work a database of speed of sound and density at atmospheric pressure for n-alkanes, branched alkanes, n-alkenes, aromatics, alcohols, ethers and esters were collected from the open literature. Using these data a Wada group contribution model recently proposed was used as basis for the development of a new atomic contribution model to predict speed of sound for all families of compounds investigated in this work. It is shown that the proposed model is able to predict the speed of sound for compounds of these families with deviations close to the experimental reproducibility. This work also discusses the effect of branching on the Wadas constant, pointing out the importance of new measurements for this type of compounds. It was also observed that the literature needs more experimental data of speed of sound at atmospheric pressure and different temperature for pure compounds present in biodiesel and fast pyrolysis bio-oil. In this context, this work provides new experimental data of speed of sound and density for five Fatty Acid Methyl Esters, also know FAMEs, (Methyl Caprylate, Methyl Caprate, Methyl Palmitate, Methyl Stearate and Methyl Linoleate), and seven pure components of pyrolysis bio-oil at atmospheric pressure for several phenols (phenol, o-, m- and p-cresol), two phenolic ethers (2-methoxyphenol and eugenol) and one phenolic ester (methyl salicylate) at temperatures ranging from (288.15 to 343.15) K. The predictive atomic Wada model was used to calculate speed of sound of FAMEs studied in this work, and the deviations were compared with group contribution Wada model. An extension of atomic Wada model was used to predict the speed of sound of pure compounds of fast pyrolysis bio-oil experimentally studied in this thesis. Furthermore, data of densities and speed of sound are correlated with the Prigogine-Flory-Patterson (PFP) model. The properties are well described by the PFP model, however the model presents a systematical deviation on the temperature dependency of the speed of sound. The performance of the predictive atomic Wada model was very satisfactory because its deviations are comparable to, or better than, those obtained in the literature with other models