L’objectif de ces travaux est de prédire la stabilité dynamique d’un moteur d’avion de type turbofan, lors de contacts légers entre l’extrémité des aubes et le carter en regard. Une voix d’amélioration des performances des turboréacteurs d’avion consiste, en effet, à réduire les jeux entre les extrémités des aubes en rotation et le carter. Réduction qui s’accompagne d’une augmentation des possibilités de contact entre ces parties tournantes et fixes pouvant conduire à des phénomènes vibratoires instables. La démarche proposée s’appuie sur un modèle hybride qui introduit de manière simplifiée une roue aubagée et un carter flexible à un modèle de ligne d’arbres. Une formulation dite 3D du contact a également été implémentée, elle intègre la cinématique des différents organes du modèle et introduit de manière précise la géométrie locale de la zone de contact. Le comportement du modèle lors de contacts aubes-carter est alors étudié en distinguant les analyses menées en supposant un contact permanent et celles autorisant l’intermittence des contacts. Les résultats obtenus mettent en évidence l’importance des couplages introduits dans l’apparition des phénomènes instables et la pertinence de la formulation 3D dans la prédiction de la stabilité du système. / This work aims to predict the dynamic stability of a turbofan engine submitted to light contacts between blade tips and casing. Reducing the clearance between the rotating blades and the casing improves indeed the performances of turbomachines ; however, it also increases the possible contacts between rotating and stationary parts, which can cause unstable dynamic behavior. The approach is based on a hybrid model which introduces a simplified bladed wheel and a flexible casing to a rotor-shaft model. A 3D contact formulation has also been implemented ; it considers the model kinematic and introduces the local geometry of the contact area. The model behavior with blade-to-casing contacts is analyzed through two approaches : the first one assumes permanent contacts while the other one allows contact intermittence. The results highlight the importance of couplings in the outbreak of unstable phenomena and the relevance of the 3D contact formulation in predicting the stability of the system.

Design methods for side shear of drilled shafts, including the resistance factors that should be applied, do not account for any specific construction procedure. Instead, design often relies on analysis of case studies which include all construction methods used in each geomaterial type (e.g. clays, sands and rocks), or on parametric analysis. Nonetheless, literature suggests that different construction procedures result in varying side shear. This research investigated 2 types of construction: (1) slurry stabilization in sandy soils using bentonite and polymer products that are commonly used on the field, with exposure times from near 0h to 96h, and (2) temporary casing stabilization in simulated limestone using 3 different methods for installation and extraction of the casings which included: driven, coarse-tooth rotated and fine-tooth rotated. All specimens were 1/10th scale in relation to the most common shafts sizes constructed in the field. The results showed that bentonite slurry causes a significant reduction on the side shear within relatively short periods of time (between 2h and 4h of open excavation), whereas polymer slurry did not show appreciable variations up to 96h. The driven and coarse-tooth rotated temporary casing exhibited lower side shear resistance than the fine-tooth rotated casings, which can be attributed to the larger annulus outside the casing and the additional crumbled pieces of rock that degrades the contact interface with the socket concrete. Construction-based resistance factors are suggested for each construction procedure investigated in this study and clearly show the effects from different methods.

In this master’s thesis, I made a thermodynamic calculation of a steam turbine under the parameters given. In order to increase the efficiency of the low-pressure turbine section and to reduce axial length of the low-pressure rotor, a radial stage is designed in this section. The master’s thesis also includes a design of the low-pressure section. The thesis is divided into chapters, which contains a calculation of the single sections of the turbine. In the introductory chapters, the single sections of the turbine engineered are theoretically discussed. In the conclusion, assessments of the benefits of the use of radial stage are made.

My diploma work deals with the project and the construction of prototype machinery into food-processing industry which serves for knotting of frankfurther casings. This knot is make on uneatable frankfurther casing of which is shirring a peg. Diploma work I separated into several parst. In the firts part I inscribe to project of principle of knotting. In other part I prefer instrumentation components and automation function, algorithms of operating, solution to automation problems and realization of application program. This work is complete any program in Visilogic.

This thesis was commissioned by Volvo Construction Equipment (Volvo CE) to redesign the front axle casing of their L90 wheel loader to be more in line with their larger wheel loaders. The current L90 front axle casing consists of two parts bolted together in the middle. However, the current assembly process is cumbersome, and as such, Volvo CE wants to determine if a one-piece front axle casing can be implemented into their L90 wheel loaders. Volvo CE’s larger wheel loaders such as the L120 currently have a one-piece design for the front axle casing and can serve as template. This thesis aimed to determine if it was possible to create a one-piece axle casing for the L90 and provide an example of how it would look like. Additionally, the suggested design would need to meet all of Volvo CE’s performance requirements and be on par with the current L90 front axle casing.  The methodology used to develop the redesigned axle casing consisted of performing different finite element analyses (FEA) in Ansys Mechanical to evaluate the casing’s performance. The analysis was preformed using Volvo CE’s guideline and performance criteria in order to determine what areas in the redesigned axle required further adjustment. Additionally, the redesigned casing would be compared against the current L90 casing. This would determine if the redesigned axle could be realistically implemented into a L90 wheel loader.  Applying this methodology led to three different iterations of the axle casing design. Each design iteration following the first one led to improvements in the casing’s mechanical performance. The third and final iteration was able to meet all of Volvo CE’s static and fatigue requirements. The stresses for the redesigned axle casing are, on average, 13% lower than that of the current axle casing at key points around the casing’s ribs. However, the tolerances required to manufacture the redesigned axle casing where slightly higher than the current L90 casing. Nevertheless, the tolerances required to manufacture redesigned axle can be realistically met by a foundry. This thesis was able to provide a plausible redesign that can be implemented in Volvo CE’s current line of L90 wheel loaders.

Around the world the implementation of the 5G mobile network is under way. With this latest generation of mobile data transfer comes many advantages compared to the previous generations. One tradeoff however is the reduced range of the transmitting radios due to the higher frequencies of the signal. One way to solve this is to place smaller radios closer to where the user is. This work studies one such radio and since it is cooled by fans and meant to be placed close to where people live and reside it is favorable to be able to reduce the noise transmitted to its surrounding. This work has therefor developed a proof of concept for a noise suppressing casing that accommodates three radios in order to reduce the total A-weighted sound power level that reaches its surrounding. This was done by using ducts with micro-perforated plates (MPPs) as a sound dampening element. To assist in the design process as well as to verify that placing the radios inside the casing did not raise the temperature of the radio’s component beyond acceptable levels a CFD-simulation was performed. The results of the CFD-simulations were also verified using an experiment where the radio’s temperature was recorded during different fan speeds. When measured, the casing lowered the total A-weighted sound power level of three radios by between 11.6 dB(A) and 14.2 dB(A) depending on the fan speed. The result of the thermal experiment show that the temperature was raised by between 2.8 °C and 5.9 °C depending on the fan speed, with higher fan speeds showing less difference when compared to the radio’s standalone performance. The results are deemed to show promise for the future use of casings fitted with Micro-perforated plates being used to reduce the noise transmitted by telecom radios. / Runt om i världen pågår implementeringen av 5G-mobilnätet. Med den senaste generationens mobila dataöverföring kommer många nya fördelar jämfört med tidigare generationer. En nackdel är däremot den kortare räckvidden hos signalen på grund av den högre frekvens som sänds ut av radion. Ett sätt att kringgå detta är att placera mindre radior närmare där användaren befinner sig. Detta examensarbete utgår från en sådan radio och eftersom den kyls med fläktar och ska placeras nära där människor bor och vistas är det fördelaktigt att kunna sänka ljudet som når omgivningen. Därför har ett ljudisolerande hölje utvecklats med plats för tre telekomradior med syfte att sänka den totala A-vägda ljudeffektnivån som når dess omgivning. För att åstadkomma detta användes kanaler i kombination med mikroperforerade plåtar (MPPs) tillsammans som ett ljuddämpande element. Som ett verktyg i designprocessen och för att säkerställa att radions komponenter inte blev för varma gjordes en CFD-simulering. Resultatet av simuleringen verifierades även med ett experiment där temperaturen hos radions kylflänsar mättes under olika fläktvarvtal. När den totala A-vägda ljudeffektnivån mättes för höljet tillsammans med tre radior uppstod en sänkning med mellan 11,6 dB(A) och 14,2 dB(A) beroende på aktuellt fläktvarvtal. Resultatet från experimentet visade även att temperaturen på radions kylfläns höjdes med mellan 2,8 och 5,9 °C beroende på fläktvarvtal, med mindre skillnad för högre fläktvarvtal vid jämförelse med radions temperatur vid drift utan hölje. Resultaten anses visa på den goda potentialen av att använda höljen utrustade med mikroperforerade plåtar för att minska överfört ljud från telekomradior.

[pt] Em face à crescente demanda por petróleo e gás e ao alto custo nos processos de exploração e explotação, é imprescindível que se garanta a segurança e a integridade das estruturas pertencentes ao poço. Neste contexto, existem reservatórios localizados em rochas pouco consolidadas ou com cimentação incompleta que presenciam um fo-nômeno conhecido como produção de sólidos, o qual consiste na desagregação de par-ticulas que ao serem carrcadas junto ao fluido de produção podem gerar problemas como a erosão de equipamentos e o entupimento do poço. Com o intuito de mitigar estes problemas é usual que se adotem técnicas de controle mocânicas, que fazem uso de estruturas filtrantes compostas por telas de aço e pacotes granulares. Essas estruturas têm o objetivo de impedir que as particulas produzidas adentrem no poço. O presente trabalho busca compreender o comportamento e a integridade de filtros de areia em situações de campo. Para isso, foi desenvolvida uma metodologia de modelagem numérica que incorpora a interação rocha - filtro. O modelo foi aplicado a um ensaio efetuado em célula cúbica, onde os resultados foram comparados a fim de avaliar se as considerações adotadas estavam de acordo com a realidade. Como resposta desta análise percebeu-se que as propriedades do pacote granular não possuem um valor definido na literatura e que seria necessário efetuar uma calibração de acordo com as caracteris-ticas do material. A calibração mostrou que o pacote granular tem um comportamento não-linear anisotrópico e gerou um conjunto de propriedades que levam a resultados em concordância com o ensaio. Por fim, foi simulado um poço em atividade com de-pleção, em que foram assumidas uma hipótese de propriedades para o pacote granular e três condições de interfaces entre os componentes, onde foi possível avaliar como essas considerações interferem na integridade mecânica das telas filtrantes e do conjunto de completação do poço. / [en] Due the growing demand for oil and gas and the high cost of exploration and exploitation processes, it is essential to guarantee the safety and the integrity of completion structures that compose a well. In this context, there are reservoir located in poorly consolidated or with incomplete cementation rocks, that experience a phenomenon known as Solid Production which consists in the desegregation of rock particle, that when carried with the production fluid can generate problems as equipment erosion and well plugging. In order to mitigate these problems, it is usual toadopt mechanical control techniques, with the use of sand control equipment as sand screen and gravel pack. These structures are intended to prevent the particles produced from entering the well. The present work seeks to understand the behavior and the mechanical integrity of sand control structures in field situations. With this purpose, a numerical modeling methodology was developed and incorporates the rock-screen interaction. The model was applied to a cubic cell test, where the results were compared in order to evaluate if the considerations were in accordance with reality. As a response to this analysis, it was noticed that the properties of the gravel pack do not have a literature defined value, and that it would be necessary to calibrate they properties in accordance to the characteristies of the material. The calibration showed that the gravel pack has an anisotropic non-linear behavior and, with this assumption, was generated a set of properties that lead to results in agreement with the test. Finally, an active well with depletion was simulated, where one hypothesis was assumed for gravel pack properties and three interface condition between the components were evaluate, as well as the mechanical integrity of the sand screen and the completion structures.

This thesis describes the design of a condensing steam turbine with reheating for fossil power plant. The turbine is a double parts. The first casing is formed by a simple HP casing. The second casing is combined MP-LP casing with axial outlet of steam into the water-cooled condenser. Feedwater regeneration system consists of two high-pressure heaters, the four low-pressure heaters and feed tank. In thesis is includes the calculation of heat balance and the draft of flow channel of HP and MP-LP casing. Next is a detailed calculation of MP-LP casing with includes calculation of flowing part, selection of blade´s profiles and its stress control. Rotor MP-LP casing is checked for torsion and computed size of the critical speed. Clutch is ispected by security check and draft radial bearings. Stress control casing is carried out according to the theory of thick shells. Work includes flow scheme for 100% and 75% performance. In the end is comparing the efficiency of the individual casing of the turbine with the work 3b together with the specific heat consumption. Work includes a longitudinal section of the MP-LP casing. This thesis has been developed in cooperation Škoda Power, Doosan.

Os hidrocarbonetos são encontrados sob alta pressão em rochas porosas, denominadas rochas reservatório. A camada pré-sal apresenta rochas reservatório cobertas por uma camada impermeável de sal de grande espessura. Ocorrências de estruturas salinas são favoráveis para o aprisionamento dos hidrocarbonetos e aumentam a probabilidade de sucesso na prospecção de óleo e gás, pois são excelentes rochas capeadoras, de porosidade e permeabilidade praticamente nulas. As rochas salinas apresentam deformação lenta e contínua quando submetidas a tensões constantes, fenômeno conhecido como fluência. Durante a perfuração de poços através de espessas camadas de sal podem ocorrer problemas operacionais, como o aprisionamento da coluna de perfuração e o colapso do poço. Ainda, a fluência pode levar ao colapso os revestimentos de um poço de petróleo revestido. Estes contratempos geram grandes desafios e criam oportunidades de evolução na indústria do petróleo. Neste contexto, este trabalho consiste na análise numérica da escavação de poços em rochas salinas para exploração de petróleo, com o estudo do comportamento geomecânico do sal utilizando o programa de elementos finitos Abaqus®. O efeito da fluência do sal durante e após a perfuração e cimentação dos poços foi verificado utilizando diferentes pesos de fluido de perfuração, simulado como não penetrante. Análises dos deslocamentos, deformações e tensões na parede do poço e em sua vizinhança foram realizadas por meio de análises de deformação plana e análises axissimétricas. Após a instalação do revestimento e cimentação do poço que engloba tanto o processo de endurecimento do cimento, quanto a resposta de fluência da camada de sal, pôde-se analisar os deslocamentos, deformações e o comportamento das tensões na fronteira sal-cimento, evitando possíveis intervenções em poços que acarretam perdas econômicas. Sendo assim, este estudo auxilia no monitoramento e controle do fechamento de poços de petróleo em evaporito, após a escavação e cimentação do poço, evitando os diversos problemas decorrentes do comportamento de fluência do sal. / Hydrocarbons are found under high pressure in porous rocks, called reservoir rocks. The presalt layer shows reservoir rock covered by an impermeable salt thick layer. Occurrences of salt structures are favorable for trapping of hydrocarbons and increase the probability of success in oil and gas prospecting. They are excellent cap rocks with porosity and permeability practically nil. Salt rock present creep when subjected to continuous and constant stress. During well drilling through thick salt layers operational problems may occur like the imprisonment of the drill string and the collapse of the well. Also, creep may cause the collapse of the well casing. These setbacks create great challenges and opportunities for the evolution of the oil industry. In this context, this work proposes the numerical analysis of well excavation in salt rock for oil exploration with the study of the geomechanical behavior of salt using a finite element method (FEM) software Abaqus®. The effect of salt creep during and after drilling and cementing of wells was verified using different weights of the drilling fluid assumed to be non-penetrable with respect to the wellbore formation. Analysis of displacements, strains and stresses on the face of the wellbore and into the salt formation were performed with plane strain and axisymmetric techniques. After installation of the well casing, cementing is simulated encompassing cement hardening as well as salt creep. It was possible to analyze displacements, strains and the behavior of the stress interactions between the existing boundary cement-salt formation, avoiding possible unnecessary workover operations that cause economical losses. Thus, this study assists in the control and monitoring of closing oil wells in evaporite, after excavation and cementing the well, avoiding many problems stemming from the behavior creep of salt.

Diesel engines operating the rig pose the problems of low efficiency and large amount of emissions. In addition the rig power requirements vary a lot with time and ongoing operation. Therefore it is in the best interest of operators to research on alternate drilling energy sources which can make entire drilling process economic and environmentally friendly. One of the major ways to reduce the footprint of drilling operations is to provide more efficient power sources for drilling operations. There are various sources of alternate energy storage/reuse. A quantitative comparison of physical size and economics shows that rigs powered by the electrical grid can provide lower cost operations, emit fewer emissions, are quieter, and have a smaller surface footprint than conventional diesel powered drilling. This thesis describes a study to evaluate the feasibility of adopting technology to reduce the size of the power generating equipment on drilling rigs and to provide ?peak shaving? energy through the new energy generating and energy storage devices such as flywheels. An energy audit was conducted on a new generation light weight Huisman LOC 250 rig drilling in South Texas to gather comprehensive time stamped drilling data. A study of emissions while drilling operation was also conducted during the audit. The data was analyzed using MATLAB and compared to a theoretical energy audit. The study showed that it is possible to remove peaks of rig power requirement by a flywheel kinetic energy recovery and storage (KERS) system and that linking to the electrical grid would supply sufficient power to operate the rig normally. Both the link to the grid and the KERS system would fit within a standard ISO container. A cost benefit analysis of the containerized system to transfer grid power to a rig, coupled with the KERS indicated that such a design had the potential to save more than $10,000 per week of drilling operations with significantly lower emissions, quieter operation, and smaller size well pad.