Escoamentos gás-líquido assim como escoamento líquido-líquido-gás em duto de geometria anular estão presentes em muitas aplicações industriais, por exemplo, em poços de petróleo direcionais. No entanto, até mesmo características globais de escoamento gás-líquido nessa geometria, como os padrões de escoamento ou gradiente de pressão, não são ainda totalmente compreendidas. E ainda, informações são escassas quando se refere a escoamento trifásico nessa geometria, cuja aplicação está relacionada ao fenômeno de inversão de fase, que é de extrema importância não apenas para ao setor petrolífero, como para a indústria alimentícia. O presente estudo experimental tem como objetivo avaliar o escoamento líquido-gás, apresentar dados inéditos de escoamento gás-líquido para três viscosidades de óleo, além de avaliar o fenômeno de inversão de fase em escoamento ascendente vertical em duto anular de grande diâmetro. Um aparato experimental inclinável com 10,5 m de comprimento foi projetado e construído para este trabalho. As dimensões radiais do duto anular estão em escala real, conforme se verifica em poços de petróleo e gás. A investigação em escoamento gás-líquido foi conduzida utilizando água, óleo e ar comprimido como fluidos de trabalho em escoamento ascendente vertical em duas geometrias: (i) um tubo com diâmetro de 95 mm e (ii) um duto de configuração anular e concêntrico, com diâmetro hidráulico de valor igual ao diâmetro do tubo. A avaliação do fenômeno de inversão de fase em escoamento trifásico foi conduzida em condições equivalentes em três geometrias: (i) tubo vertical menor com diâmetro de 50 mm, (ii) tubo com diâmetro de 95 mm e (iii) um duto anular concêntrico. Padrões de escoamento, queda de pressão e fração volumétrica de fase foram obtidos para ambos os escoamentos gás-líquido e líquido-líquido-gás. Os dados coletados nesse trabalho são de grande importância para o desenvolvimento de novas correlações de fechamento, que são essenciais para o projeto otimizado de poços de petróleo. Dados inéditos de escoamento bifásico óleo-gás são apresentados, bem como um estudo pioneiro em inversão de fase em escoamento trifásico com velocidade superficial de gás e viscosidade do óleo elevadas. / Two-phase flows as well as three-phase flow in annular geometry are present in many industrial applications, for example in oil directional wells. However, even global characteristics of gas-liquid flow in this geometry, such as flow patterns and pressure gradient are not fully understood. Moreover, information is scarce when it refers to three-phase flow in this geometry, which application is related to the phase inversion phenomenon, which is of extreme importance and not only for the oil industry. This experimental study aims to evaluate the liquid-gas flow, present new data from gas-liquid flow for three oil viscosities and evaluate the phase inversion phenomenon in vertical upward flow in large diameter annular duct. An experimental apparatus with 10.5 m length was designed and built for this work. The radial dimensions of the annular duct are similar to full scale, as observed in oil and gas wells. The investigation into gas-liquid flow was conducted using water, oil and compressed air as working fluids in an ascending vertical flow in two geometries: (i) a tube with 95 mm diameter and (ii) a concentric annular duct with hydraulic diameter equivalent to the tube internal diameter. The evaluation of the phase inversion phenomenon in three-phase flow was conducted under equivalent conditions for three geometries: (i) smaller vertical tube with 50 mm of internal diameter, (ii) tube with 95 mm of internal diameter and (iii) concentric annular duct with hydraulic diameter of 95 mm. Flow patterns, pressure drop and volumetric phase fraction were obtained for both gas-liquid and gas-liquid-liquid flows. The data collected in this study are of great importance for the development of new closing correlations, which are essential for the optimized design of oil wells. New two-phase flow data for three oil viscosities, not found in the literature, are presented as well as a pioneer study in three-phase-flow phase inversion with high oil viscosity and high superficial gas velocity.

La propagation acoustique guidée est étudiée dans ce travail. La propagation des ondes acoustiques dans une direction principale est privilégiée. La méthode des éléments finis ondulatoires est donc exploitée pour extraire les nombres d'ondes. Les déformées des différents modes de conduit rigide sont aussi obtenues. Pour des conduits avec des discontinuités d'impédance, la matrice de diffusion peut être calculée à l'aide d'une modélisation par éléments finis de la partie traitée acoustiquement. Une modélisation tridimensionnelle des conduits traités acoustiquement permet une étude de la propagation pour tous les ordres des modes, de leur diffusion et du comportement acoustique des matériaux absorbants. Les réponses forcées de diverses configurations de guides d'ondes aux conditions aux limites imposées sont également calculées. L'étude est finalement étendue à la propagation acoustique dans les guides d'ondes avec un écoulement moyen uniforme. / The guided acoustical propagation is investigated in this work. The propagation of the acoustic waves in a main direction is privileged. A Wave Finite Element method is therefore exploited to extract the wavenumbers. Rigid duct's mode shapes are moreover obtained. For ducts with impedance discontinuities, the scattering matrix can be then calculated through a Finite Element modelling of the lined part. A three dimensional modelling of the lined ducts allows a study of the propagation for the full modes orders, their scattering and the acoustic behaviour of the absorbing materials. The forced responses of various configurations of waveguides with imposed boundary conditions are also calculated. The study is finally extended to the acoustical propagation within waveguides with a uniform mean flow.

The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. Simulations are an important tool for enhanced understanding; they give insight into the flow-acoustic interaction in components where it is difficult to perform measurements. In this work the acoustics is obtained directly from a compressible Large Eddy Simulation (LES). With this method complex flow phenomena can be captured, as well as sound generation and acoustic scattering. The aim of the research is enhanced understanding of the acoustics of engine gas exchange components, such as the turbocharger compressor.In order to investigate methods appropriate for such studies, a simple constriction, in the form of an orifice plate, is considered. The flow through this geometry is expected to have several of the important characteristics that generate and scatter sound in more complex components, such as an unsteady shear layer, vortex generation, strong recirculation zones, pressure fluctuations at the plate, and at higher flow speeds shock waves. The sensitivity of the scattering to numerical parameters, and flow noise suppression methods, is investigated. The most efficient method for reducing noise in the result is averaging, both in time and space. Additionally, non-linear effects were found to appear when the amplitude of the acoustic velocity fluctuations became larger than around 1~\% of the mean velocity, in the orifice. The main goal of the thesis has been to enhance the understanding of the flow and acoustics of a thick orifice plate, with a jet Mach number of 0.4 to 1.2. Additionally, we evaluate different methods for analysis of the data, whereby better insight into the problem is gained. The scattering of incoming waves is compared to measurements with in general good agreement. Dynamic Mode Decomposition (DMD) is used in order to find significant frequencies in the flow and their corresponding flow structures, showing strong axisymmetric flow structures at frequencies where a tonal sound is generated and incoming waves are amplified.The main mechanisms for generating plane wave sound are identified as a fluctuating mass flow at the orifice openings and a fluctuating force at the plate sides, for subsonic jets. This study is to the author's knowledge the first numerical investigation concerning both sound generation and scattering, as well as coupling sound to a detailed study of the flow.With decomposition techniques a deeper insight into the flow is reached. It is shown that a feedback mechanism inside the orifice leads to the generation of strong coherent axisymmetric fluctuations, which in turn generate a tonal sound. / <p>QC 20121113</p>

<p>  Sound transmission loss of vehicle seals was studied in this thesis. Reverberation room test and semi-anechoic chamber test were respectively studied. By comparing the sound pressure level, sound intensity level and average sound power level at the receiving side, it proved that a simple sound pressure level test may obtain same measurement accuracy when there is little reflected sound. A semi-anechoic chamber was designed for testing sound transmission losses of the seals on a trial vehicle. By comparing the sound pressure levels between the location of the passenger ear and door area, it proved that most of outside sound energy passed through the door seals into the interior. The sound transmission losses of different sealing conditions were measured which included well sealed and imperfectly sealed conditions; Sound pressure levels at passenger’s ear in three different types of vehicles were also compared, these comparison results indicated this laboratory was capable of distinguishing different sealing conditions. The installation procedure was compared with the one in reverberation room test. Numerical analysis showed that the latter method produced a different compression shape which would definitely influence the sound insulation abilities of the seals.</p><p>  The transmission mechanism of the acoustic waves through a vehicle seal was also discussed. Contact analysis showed high compression ratio leaded to tremendous inner stress intensity. But any further increase of the contact depth would not improve the effect of wind noise prevention. A vehicle seal with a complex shape was replaced by a simple model. The sound transmission theory of multiple partitions on the basis of mass law was applied. Whereas, compared with the experimental result, a different trend in the high frequency range was found. When taking the transmission though the side material and integration of incident angle into account, the result was quite similar to the experimental one. FEM analysis was also performed. The majority of sound power was believed to transmit along the seal wall into the interior instead of passing through the multiple partitions. A distorted circular duct model is believed to be close to the real geometry.</p><p> </p>

Escoamentos gás-líquido assim como escoamento líquido-líquido-gás em duto de geometria anular estão presentes em muitas aplicações industriais, por exemplo, em poços de petróleo direcionais. No entanto, até mesmo características globais de escoamento gás-líquido nessa geometria, como os padrões de escoamento ou gradiente de pressão, não são ainda totalmente compreendidas. E ainda, informações são escassas quando se refere a escoamento trifásico nessa geometria, cuja aplicação está relacionada ao fenômeno de inversão de fase, que é de extrema importância não apenas para ao setor petrolífero, como para a indústria alimentícia. O presente estudo experimental tem como objetivo avaliar o escoamento líquido-gás, apresentar dados inéditos de escoamento gás-líquido para três viscosidades de óleo, além de avaliar o fenômeno de inversão de fase em escoamento ascendente vertical em duto anular de grande diâmetro. Um aparato experimental inclinável com 10,5 m de comprimento foi projetado e construído para este trabalho. As dimensões radiais do duto anular estão em escala real, conforme se verifica em poços de petróleo e gás. A investigação em escoamento gás-líquido foi conduzida utilizando água, óleo e ar comprimido como fluidos de trabalho em escoamento ascendente vertical em duas geometrias: (i) um tubo com diâmetro de 95 mm e (ii) um duto de configuração anular e concêntrico, com diâmetro hidráulico de valor igual ao diâmetro do tubo. A avaliação do fenômeno de inversão de fase em escoamento trifásico foi conduzida em condições equivalentes em três geometrias: (i) tubo vertical menor com diâmetro de 50 mm, (ii) tubo com diâmetro de 95 mm e (iii) um duto anular concêntrico. Padrões de escoamento, queda de pressão e fração volumétrica de fase foram obtidos para ambos os escoamentos gás-líquido e líquido-líquido-gás. Os dados coletados nesse trabalho são de grande importância para o desenvolvimento de novas correlações de fechamento, que são essenciais para o projeto otimizado de poços de petróleo. Dados inéditos de escoamento bifásico óleo-gás são apresentados, bem como um estudo pioneiro em inversão de fase em escoamento trifásico com velocidade superficial de gás e viscosidade do óleo elevadas. / Two-phase flows as well as three-phase flow in annular geometry are present in many industrial applications, for example in oil directional wells. However, even global characteristics of gas-liquid flow in this geometry, such as flow patterns and pressure gradient are not fully understood. Moreover, information is scarce when it refers to three-phase flow in this geometry, which application is related to the phase inversion phenomenon, which is of extreme importance and not only for the oil industry. This experimental study aims to evaluate the liquid-gas flow, present new data from gas-liquid flow for three oil viscosities and evaluate the phase inversion phenomenon in vertical upward flow in large diameter annular duct. An experimental apparatus with 10.5 m length was designed and built for this work. The radial dimensions of the annular duct are similar to full scale, as observed in oil and gas wells. The investigation into gas-liquid flow was conducted using water, oil and compressed air as working fluids in an ascending vertical flow in two geometries: (i) a tube with 95 mm diameter and (ii) a concentric annular duct with hydraulic diameter equivalent to the tube internal diameter. The evaluation of the phase inversion phenomenon in three-phase flow was conducted under equivalent conditions for three geometries: (i) smaller vertical tube with 50 mm of internal diameter, (ii) tube with 95 mm of internal diameter and (iii) concentric annular duct with hydraulic diameter of 95 mm. Flow patterns, pressure drop and volumetric phase fraction were obtained for both gas-liquid and gas-liquid-liquid flows. The data collected in this study are of great importance for the development of new closing correlations, which are essential for the optimized design of oil wells. New two-phase flow data for three oil viscosities, not found in the literature, are presented as well as a pioneer study in three-phase-flow phase inversion with high oil viscosity and high superficial gas velocity.

Introdução: O sucesso da cateterização da via biliar é de importância para o diagnóstico e terapêutica nas afecções biliopancreáticas nos procedimentos de colangiopancreatografia retrógrada endoscópica (CPRE) e está associado a complicações graves e mortalidade. O objetivo do estudo foi comparar o sucesso, perfil laboratorial e as complicações da técnica de fistulotomia papilar direta com o acesso cateter e fio-guia. Métodos: No período de julho de 2010 a maio de 2017 foram selecionados e randomizados para CPRE em dois grupos: cateterização com cateter e fioguia (Grupo I) e a fistulotomia papilar (Grupo II). As curvas de amilase, lipase e proteína C reativa (T0, 12 e 24 horas) e as complicações (pancreatite, sangramento e perfuração) foram avaliadas após CPRE. Resultados: Foram incluídos 102 pacientes (66 do sexo feminino e 36 do masculino, com idade média de 59,11±18,7 anos) e divididos em 51 pacientes para Grupo I e 51 no Grupo II. Os sucessos das cateterizações dos Grupos I e II foram de 76,47% e 100%, respectivamente (p=0,0002). Doze pacientes (23,53%) do Grupo I foram considerados pacientes de cateterização difícil e submetidos à fistulotomia papilar com sucesso no acesso biliar. Foram observadas 13,7% (2 perfurações e 5 pancreatites leves) e 2 % (1 paciente com perfuração e pancreatite) complicações nos Grupos I e II, respectivamente (p=0,062). Conclusão: A fistulotomia papilar demonstrou maior eficácia na cateterização da via biliar e com menor índice de amilasemia e lipasemia em comparação a cateterização com papilótomo e fio guia. As complicações foram semelhantes entre as duas técnicas / Background: The success of biliary tract cannulation is important for the diagnosis and treatment of biliopancreatic diseases in endoscopic retrograde cholangiopancreatography (ERCP) procedures. ERCP is associated with severe complications and mortality. The aim of the study was to compare the success, laboratory profile and complications of the direct papillary fistulotomy technique with standard catheter and guidewire access. Methods: In the period from July 2010 to May 2017, two groups were selected and randomized for ERCP: cannulation with catheter and guidewire (Group I) and papillary fistulotomy (Group II). The curves of amylase, lipase and C-reactive protein (T0, 12 and 24 hours) and complications (pancreatitis, bleeding and perforation) were evaluated after ERCP. Results: A total of 102 patients (66 females and 36 males, mean age 59.11 ± 18.7 years) were divided into 51 patients for Group I and 51 for Group II. The success of cannulation was 76.47% and 100%, in Groups I and II, respectively (p = 0.0002). Twelve patients (23.53%) of Group I were considered to have difficult cannulation and were submitted to fistulotomy with successful biliary access. There were 13.73% (2 perforations and 5 mild pancreatitis) and 2% (1 patient with perforation and pancreatitis) complications in Groups I and II, respectively (p=0,062). Conclusion: Papillary fistulotomy demonstrated greater efficacy in the bile duct cannulation and presented lower serum amylase and lipase compared with standard catheter and guidewire cannulation. Complications were similar in the two techniques

Une onde acoustique plane propagée dans un guide couplée à des parois vibrantes, siège d'ondes transversale ou de flexion, donne un ensemble d'ondes dans le fluide et dans la structure. Les ondes dans le fluide sont évanescentes, propagatives, ou encore propagatives avec un amortissement. Il n'est pas besoin que l'ensemble soit dissipatif pour en arriver là car les résultats proviennent d'interférences destructives on constructives. Un amortissement dans la structure donne un système cette fois-ci dissipatif et ajoute ses effets à la dissipation mais pas de façon classique puisqu'il s'agit ici d'ondes couplées acoustique/structure. En présence d'un flux stationnaire et uniforme la capacité d'une paroi vibrante à produire de l'atténuation acoustique se réduit. Les opérateurs en jeu, les méthodes pour les résoudre dont celle des éléments finis donnent accès à des prédictions. Elles sont confrontées à des résultats expérimentaux. Sans écoulement, les prédictions font sens. En revanche, avec écoulement, il n'en est pas de même et le mémoire tentera d'analyser les raisons. En conclusion technologique, une atténuation d'une quinzaine de décibels en moyenne sur une gamme de fréquences de quelques centaines de Hz centrées dans les médiums (500Hz) est envisageable avec une paroi mince qui n'encombre pas le guide. / A plane acoustic wave propagated in a duct some walls of which are vibrating due to transversal or flexural waves gives rise to a set of various waves within the fluid and the structure. Within the fluid, the waves are evanescent, propagatives or propagatives with decreasing amplitudes. There is no need for the global operator to be dissipative for such a result since it is arising from destructive or constructive interferences. When the structural damping exists, as in the real life, it adds its effect to the coupling but not in a classical way as coupled acoustic/structure waves are at play rather than pure acoustic or structural waves. Now in presence of a convection of the fluid that bears the acoustic wave (a stationary and uniform flow), the attenuation is reduced sligtly at the very low Mach numbers, and significantly at higher Mach numbers. As far as technological conclusions are sought, an averaged acoustic attenuation of around fifteen dB in a frequency range of some hundreds Hz centered at 500Hz can be obtained with this system very light and needing almost no room.

This thesis considers linear perturbations to the steady flow of a compressible inviscid perfect gas along a cylindrical or annular duct. Particular consideration is given to the model of the duct boundary, and to the effect of curvature of the duct centreline. For a duct with a straight centreline and a locally-reacting boundary, the acoustic duct modes can be segregated into ordinary duct modes and surface modes. Previously-known asymptotics for the surface modes are generalized, and the generalization is shown to provide a distinctly better approximation in aeroacoustically relevant situations. The stability of the surface modes is considered, and previous stability analyses are shown to be incorrect, as their boundary model is illposed. By considering a metal thin-shell boundary, this illposedness is explained, and stability analysed using the Briggs-Bers criterion. The stability of a cylindrical thin shell containing compressible fluid is shown to differ significantly from the stability for an incompressible fluid, even for parameters for which the fluid would otherwise be expected to behave incompressibly. The scattering of sound by a sudden hard-wall to thin-shell boundary change is considered, using the Wiener-Hopf technique. The causal acoustic field is derived analytically, without the need to apply a Kutta-like condition or to include an instability wave, as had previously been necessary. Attention is then turned to a cylindrical duct with a curved centreline and either hard or locally-reacting walls. The centreline curvature (which is not assumed small) and wall radii vary slowly along the duct, enabling an asymptotic multiple scales analysis. The duct modes are found numerically at each axial location, and interesting characteristics are explained using ray theory. This analysis is applied to a hard-walled RAE 2129 duct, and frequency-domain solutions are convolved to give a time-domain example of a pulse propagating along this duct. Finally, some numerical work on the nonlinear propagation of a large-amplitude pulse along a curved duct is presented. This is aimed at modelling a surge event in an aeroengine with a convoluted intake.

Because compressibility effects arise in real applications of propellers and turbines, the Actuator Disk Theory or Froude’s Momentum Theory was established for compressible, subsonic flow using the three laws of conservation and isentropic thermodynamics. The compressible Actuator Disk Theory was established for the unducted (bare) and ducted cases in which the disk was treated as the only assembly within the flow stream in the bare case and enclosed by a duct having a constant cross-sectional area equal to the disk area in the ducted case. The primary motivation of the current thesis was to predict the ideal performance of a small ram-air turbine (microRAT), operating at high subsonic Mach numbers, that would power an autonomous Boundary Layer Data System during test flights. The compressible-flow governing equations were applied to a propeller and a turbine for both the bare and ducted cases. The solutions to the resulting system of coupled, non-linear, algebraic equations were obtained using an iterative approach. The results showed that the power extraction efficiency and the total drag coefficient of the bare turbine are slightly higher for compressible flow than for incompressible flow. As the free-stream Mach increases, the Betz limit of the compressible bare turbine slightly increases from the incompressible value of 0.593 and occurs at a velocity ratio between the far downstream and the free-stream that is lower than the incompressible value of 0.333. From incompressible to a free-stream Mach number of 0.8, the Betz limit increases by 0.021 while its corresponding velocity ratio decreases by 0.036. The Betz limit and its corresponding velocity ratio for the ducted turbine are not affected by the free-stream Mach and are the same for both incompressible and compressible flow. The total drag coefficient of the ducted turbine is also the same regardless of the free-stream Mach number and the compressibility of the flow; but, the individual contributions of the turbine drag and the lip thrust to the total drag differs between compressible and incompressible flow and between varying free-stream Mach numbers. It was concluded that overall compressibility has little influence on the ideal performance of an actuator disk.

My diploma thesis focuses on design of air-conditioning system for chicken breeding spaces. In the background are considered general issues of air-conditioning, hatchery layout and microclimate for eggs incubation and chicken breeding. The research part is divided into two parts – Calculations and Design. The Calculations address the amount of incoming fresh air, heat loss, heat load and psychrometric calculations for summer and winter periods. The Design focuses on defining suitable diffusers and air-ducts, optimal air-conditioning unit with fans corresponding to hatchery requirements and pressure loss in ducts. The technical drawings and a list of used material are included.