Thermische Gehäuseverkrümmungen spielen bei der Dimensionierung von radialen Spielen in Industriedampfturbinen eine große Rolle. Die zuverlässige Vorausberechnung der Gehäuseverkrümmung ist wichtig, um einerseits möglichst kleine Spiele und damit hohe innere Wirkungsgrade erzielen zu können und andererseits Schäden in Folge von Spielüberbrückungen auszuschließen. In der vorliegenden Arbeit wurde die Gehäuseverkrümmung mit analytischen Methoden und mit Hilfe von 3D-FE-Analysen untersucht. Eine neue semi-analytische Berechnungsmethode auf Basis eines Stufenkörpermodells wurde entwickelt. Damit lassen sich komplexe Geometrien und unterschiedliche thermische Randbedingungen berücksichtigen. Der Einfluss von Rotationsasymmetrien auf die Verkrümmung wurde mit Hilfe einer FE-Parameterstudie untersucht und in Form von Einflussfaktoren in das Modell integriert. Im Vergleich zu vereinfachten FE-Modellen und zu gemessenen Verkrümmungen an realen Turbinengehäusen zeigt das semi-analytische Modell eine gute Übereinstimmung. Weiterhin wurde das Verkrümmungsverhalten von Industriedampfturbinengehäusen mit Hilfe von 3D-FE-Analysen untersucht. Durch Abgleich von gemessenen und simulierten Temperaturen und Verformungen konnten Erkenntnisse zum Modellaufbau gesammelt werden. Da die thermischen Randbedingungen bei der Simulation von Gehäuseverkrümmungen von größter Bedeutung sind und Defizite beim Wissensstand zum Wärmeübergang erkannt wurden, sind umfangreiche Messungen des Wärmeübergangskoeffizienten durchgeführt worden. Damit wurde ein Beitrag geleistet, FE-Analysen zukünftig auch bei Dimensionierungs- und Auslegungsfragen einsetzen zu können.

The first main goal of this research is to develop comprehensive analytical and numerical models for the stress distribution around an inclined cased wellbore by considering all wellbore processes and to amend erroneous models of most previous work. The second main goal is to apply the developed models to explain near wellbore phenomena such as cement failure and sand production. To achieve these goals, this work checked the eligibility of using simple elastic approaches for the system by using a poroelastic undrained condition and a steady state condition for stresses induced by wellbore temperature variation. It utilized the generalized plane strain to compensate for the limitation of the plane strain which most previous work had used. In addition, this research developed comprehensive models to improve previous work by using superposing principles. For applying the developed models to cement failure, Mogi-Coulomb criterion for shear failure instead of Mohr-Coulomb and Drucker-Prager criteria was used to properly consider the intermediate stress. Additionally, ABAQUSr was utilized for numerical models with the "model change" option to simulate and combine all individual wellbore processes while MATLABr was used for analytical models. For predicting sand production, fully coupled poroelastic solutions for an inclined open wellbore were modified to obtain the stress distribution around a perforation tunnel after perforating. Then, modified Lade failure criterion was used to calculate the critical drawdown when sand production occurs, that is, when the perforation tunnel starts failure. This research obtained the following results. For developing models, the analytical models improved the previous research. However, the numerical results under a vertical tectonic stress showed discrepancies because of the difference between the generalized plane strain and numerical models. For cement failure, Young's modulus of cement, wellbore pressure and wellbore temperature variation could affect shear failure more significantly than the other factors. The numerical results showed closer to the failure envelopes than the analytical results. For predicting sand production, well completion affected sand production near wellbore and the critical drawdown converged to asymptotic values. In addition, perforating along the minimum horizontal stress direction was most preferable in a vertical cased wellbore under a normal stress regime. / text

Rotating blades are considered to be the one of the most common cause of failures in rotating machinery. Blade failure modes normally occur as a result of cracks due to unexpected operating conditions, which are normally caused by accidents of foreign objects damage, high cycle fatigue, blade rubbing, blade root looseness, and degradation from erosion and corrosion. Thus, detection of blade faults has an important role in reducing blade related failures and allowing repairs to be scheduled for the machinery. This in turn will lead to reduction in maintenance costs and thus raise productivity and safety aspects of operation. To maintain vital components of rotating machines, such as blades, shafts, bearings and gear boxes, at optimal levels, detection of failures in such components is important, because this will prevent any serious damage that could affect performance. This research study involves laboratory tests on a small rig with a bladed disc rotor that applied vibration measurements and analysis for blade fault detection. Three measurements: shaft torsional vibration, on-bearing vibration (OBV) and on-casing vibration (OCV), are used. A small test rig of a single stage bladed disc holding 8-blades was designed and manufactured, to carry out this research study to assess the usefulness and capability of each vibration technique in detection of incipient defects within machine blades. A series of tests was conducted on a test rig for three different cases of blade health conditions: (a) healthy blade(s) with mistuned effects, (b) blade root looseness and (c) cracks in a blade on two different blade sizes (long and short blades) in order to discover changes in blades' dynamic behaviour during the machine running-up operation. The data were collected using the three measurements during machine run-up and then recorded. The measured vibration data were analysed by computing the blades' resonance at different engine orders (EOs) related to the blade(s) resonance frequencies and their higher harmonics, to understand the blade(s) dynamics behaviour for the cases of healthy and faulty blade(s). Data have been further processed using a polar plot presentation method which provides clear results that can be used for monitoring blade integrity. To validate the obtained experimental results, a simplified mathematical model was also developed. Finally, a comparative study between three methods was undertaken to understand the relative advantages and limitations in the blade heath monitoring.

Drilling operations in deepwater (DW) or ultra-deepwater areas, even more in exploratory frontiers, have been increasingly challenging due to the operational complexities and limited available data about the subsurface conditions. In this sense, enhancing safety and minimizing the likelihood of losing well integrity and damage to the environment is a currently essential objective relating to offshore drilling activities. Hence, deepwater well designs should advance to safely meet the challenges related to the progression of well and water depths. The safe construction of these wells requires the application of suitable well design considerations that include well integrity approaches to reduce the risk of an unintended release of formation fluids (oil, gas or water) to the environment during the deepwater drilling operations, in other words a \"Blowout\" occurrence. In this study it is proposed two deepwater well architectural designs, limited to drilling stage, that safely accomplish the well targets and facing several deepwater well complexities, e.g. narrow operating envelopes. Thus, well logging and geological data of two actual pioneer wells drilled in deep and ultradeep water zones in Ceará Basin are used as a basis to construct and assess the drilling operating envelopes, to define the casing shoe depths and well barrier envelope. Furthermore, it is introduced the application of at least two independent Barrier Integrated Sets (BISs) to ensure the well integrity during the 4th phase drilling of the proposed well architectures, as it has recently been required in Brazil by the National Petroleum Agency (ANP) through \"Well Integrity Management System\" (SGIP for its acronym in Portuguese). / As operações de perfuração em áreas de águas profundas ou ultra profundas, ainda mais nas fronteiras exploratórias, têm sido cada vez mais desafiadoras devido às complexidades operacionais e aos limitados dados disponíveis sobre as condições do subsolo. Nesse sentido, aumentar a segurança e minimizar a probabilidade de perder a integridade do poço e os danos ao meio ambiente são objetivos essenciais atualmente relacionados às atividades de perfuração offshore. Portanto, os projetos de poços em águas profundas devem avançar para enfrentar com segurança os desafios associados à progressão do poço e das profundidades da água. A construção segura desses poços requer a aplicação de considerações de projeto adequadas que incluam abordagens da integridade do poço para reduzir o risco de liberação não intencional de fluidos de formação (óleo, gás ou água) para o ambiente durante as operações de perfuração em águas profundas, em outras palavras a ocorrência de \"Blowout\". Neste estudo, são propostos dois projetos arquiteturais de poços em águas profundas, limitados à etapa de perfuração, que cumprem com segurança os objetivos do poço e enfrentam várias complexidades de poços em águas profundas, por exemplo janelas operacionais estreitas. Assim, dados geológicos e de perfilagem de dois poços pioneiros perfurados nas zonas de águas profundas e ultra profundas da Bacia do Ceará são usados como base para a construção e avaliação da janela operacional, para definir as profundidades da sapata do revestimento e do conjunto das barreiras do poço. Além disso, é introduzida a aplicação de pelo menos dois Conjuntos Solidários de Barreiras (CSBs) independentes para garantir a integridade do poço durante a perfuração da 4ª fase das arquiteturas dos poços propostos, como tem sido recentemente exigido no Brasil pela Agência Nacional do Petróleo (ANP), através do \"Sistema de Gerenciamento de integridade de Poços\" (SGIP).

Ce travail de thèse, mené dans le cadre d’une convention CIFRE entre Snecma, le CERFACS et le LMFA, s’inscrit dans un contexte d’amélioration des performances et d’extension de la plage de fonctionnement des compresseurs de type axial équipant les turboréacteurs. L’une des principales difficultés rencontrée dans cette démarche concerne la maîtrise des écoulements dans la zone de jeu en tête des aubes rotors et qui peuvent entraîner une perte de stabilité du système (pompage et décollement tournant).Une solution technologique prometteuse pour améliorer la stabilité est le traitement de carter qui consiste en un dispositif passif complexe de fentes implantées au carter au droit des rotors. En vue d’en améliorer sa conception, les travaux de thèse visent plus particulièrement à approfondir la compréhension des mécanismes d’action grâce à une approche numérique CFD avec le code elsA développé par l’ONERA et le CERFACS, en modélisation stationnaire et instationnaire. Ces travaux s’articulent autour de trois axes principaux. Le premier a eu pour objectif de développer un outil numérique d’aide à la compréhension des mécanismes d’action des traitements de carter et de diagnostic de leur efficacité. Le principe de l’outil, qui est une extension du modèle initialement proposé par Shabbir et Adamczyk, repose sur une évaluation des contributions des termes des équations de Navier-Stokes stationnaires et instationnaires sur un volume de contrôle pris dans l’écoulement. Dans le cas pratique, cela revient à quantifier les efforts appliqués sur le fluide. Le second axe traite de l’analyse des mécanismes d’action des traitements de carter axisymétriques dans deux compresseurs axiaux : l’un subsonique à carter cylindrique (CREATE) et l’autre transsonique à carter conique (NASA Rotor 37). Les enseignements de cette étude indiquent que ce type de géométrie est marqué par son effet d’aspiration de fluide dans la veine. Ce mécanisme est d’autant plus amplifié par un phénomène d’interaction complexe des fentes avec l’écoulement de jeu et la proximité de l’intrados de l’aube adjacente. Cette partie s’est également attardé à la réponse des rainures à un phénomène instationnaire de type sillage de roue amont. Les résultats ont montré que les fentes amortissent les fluctuations de gradient de pression adverse. Le troisième axe porte sur l’analyse des mécanismes des traitements de carter non-axisymétriques à travers l’étude numérique d’un cas test transsonique à carter cylindrique (CBUUA). Le mécanisme d’action améliorant la stabilité de la machine tient en la capacité des fentes à limiter la migration dans la direction circonférentielle du vortex de jeu. Les résultats montrent que ce type de géométrie est caractérisé par son effet de réinjection d’air qui vient ré-énergétiser l’écoulement proche carter. / This thesis work, conducted as part of a CIFRE agreement between Snecma, CERFACS and LMFA, deals with the context of improving performance and extending the operating range of axial compressors fitted turbojets. One of the main difficulties in this approach is the flow control in the rotor tip region, which can cause the loss of the system stability (surge and rotating stall). A promising technology known to bring substantial stability is the casing treatment. This passive control device consists of slots of complex geometry within the rotor casing. In order to improve its design, the thesis aimed specifically at improving the understanding of their mechanisms through a numerical approach using the CFD code elsA developed by ONERA and CERFACS, with steady and unsteady approaches. This work focused on three main axes. The first concerns the development of a numerical tool to support the understanding of casing treatment mechanisms and the diagnosis of their efficiency. The principle of the tool, which is an extension of the model originally proposed by Shabbir and Adamczyk, is based on an assessment of the contributions of the terms of the steady and unsteady Navier-Stokes equations on a control volume taken in the flow. In practice, this permits to quantify the forces applied to the fluid. The second axis deals with the analysis of the flow mechanisms induced by axisymetric casing treatments in two axial compressors : one subsonic with a cylindrical casing (CREATE) and the other transonic with a conical casing (NASA Rotor 37). The findings of this study indicate that this type of geometry is characterized by its bleeding effect. This mechanism is further amplified by a complex phenomenon of interaction between grooves, tip leakage vortex and the proximity to the pressure side of the adjacent blade. This part has also dwelt on the groove’s response to unsteady upstream stator wakes. The results showed that the slots are able to damp fluctuations of adverse pressure gradient. The third area concerns the analysis of the flow mechanisms induced by non-axisymmetric casing treatment through the numerical study of a transonic compressor with cylindrical casing (CBUUA). The mechanism leading to an enhancement of the stability results in slots ability to limit the migration in the circumferential direction of the tip leakage vortex. The results show that this type of geometry is characterized by its effect of re-injection of fluid that comes re-energize the near casing flow.

Pour les compresseurs axiaux et centrifuges, la minimisation du jeu, entre l’extrémité des aubes et le carter qui les entoure, augmente l’efficacité aérodynamique des turbomachines mais favorise également l’apparition de contacts structuraux. En présence du contact, les deux structures échangent de l’énergie et le système peut devenir instable lorsque ses fréquences propres, exprimées dans le même repère, sont égales. Nous verrons qu’il existe également la possibilité de créer des réponses forcées lorsque les harmoniques de la vitesse de rotation coïncident avec les fréquences propres de la structure fixe ou tournante. Dans les deux cas, les structures peuvent subir des endommagements assez importants. La maitrise de l’interaction aube-carter est donc logiquement un phénomène que les constructeurs de turbomachines doivent intégrer lors de la définition d’un moteur. Ainsi, dans l’étape de conception des compresseurs, il faut prévoir le comportement vibratoire du système en prenant en compte les phénomènes physiques les plus influents. Dans ce contexte, ce travail de recherche est focalise sur l’étude du comportement mécanique et thermomécanique résultant de l’interaction aube-carter entre un compresseur centrifuge (ou rouet) expérimental du premier étage de compression d’un moteur d’hélicoptère et son couvercle qui est recouvert d’un matériau abradable afin de réduire la sévérité du contact. L’objectif majeur des travaux présentes dans ce manuscrit est d’établir un scénario plausible pour expliquer les divers phénomènes présents lors du contact et de créer une base de données expérimentales, dans un environnement de laboratoire au travers d’un essai réaliste et maitrisé. Puis, il s’agit de confronter et valider les interprétations expérimentales sur un modèle numérique. Pour atteindre nos objectifs, nous avons utilisé un dispositif d’essai adapté afin de fournir des données fiables sur le comportement dynamique et thermomécanique en situation de contact aube-carter. L’analyse des résultats expérimentaux et numériques montre des évènements transitoires concomitants entre la structure fixe et tournante. Le contenu spectral des réponses est caractérise par la présence d’harmoniques de la vitesse de rotation et de sidebands, qui influencent le comportement dynamique du système lorsqu’ils coïncident avec les fréquences propres des structures. / In axial and centrifugal compressors, minimizing the clearance between the blade tips of the impeller and its surrounding casing increases the aerodynamic efficiency, but also the probability of contacts. An energy exchange is then produced between the two structures, leading to forced excitation of the natural modes and potentially to dynamical instabilities, such as interaction phenomena. In both cases, the structures suffer subsequent structural damages. Mastering blade-to-casing interactions is thus a phenomenon that turbomachinery manufacturers must incorporate into the design process of an engine. Compressor designers must predict the vibration behavior of the system, taking into account the predominant physical phenomena. In this context, this work focuses on the study of the dynamic and thermomecanichal behavior resulting from blade-to-casing interactions between a low-pressure centrifugal compressor (or impeller) and a casing lined with abradable coating. The main purpose of this work is to build a likely scenario to explain the various phenomena present when contact occurs, and the creation of a database for subsequent comparisons with numerical simulations. To achieve this, a test rig heavily instrumented has been used in order to better understand the influence of various physical phenomena (dynamic, wearing, heating). Analysis of experimental and numerical results shows transient events, characterized by a simultaneous increase in amplitude on both the rotating and stationary structures. The spectral content of the response highlights the presence of harmonics of the rotating speed and some sidebands aside from the main excited frequencies, which may cause the system to become unstable when they coincide with the natural frequencies of structures.

Work occupies computational modelling mechanical behavior elastomers and composits with rubber matrix and their utilization for compute model of tire creation. MATADOR tire 165/65 R13 Axisymetric 2D model was created in two geometric variants. For the computational modeling is applying the Finite element method (FEM). The model was in different variants distinctive grade of modeling material. At first was done inner pressure analyst impact on deformation of each of model. Then was count influence on tire load with angular velocity meanwhile with inner pressure. The impact thickness of tire protector layer on global deformation tyre casing was verified too.

For air cooling in aircrafts is used an air cycle machine. Recently, there is focusing on incresing efficiency of air cycle and due this are added another rotors. Design of machine with three rotors is performed in this thesis.

The aim of the master’s thesis is a design of double casing condensing steam turbine with gearbox, reheat and with power output 110 MW for solar power station. The steam turbine has an axial output to the air cooled condenser. The design of the turbine is developed on the basis of concept of Doosan Skoda Power company. It is the main reason this turbine has the impulse blading. There are heat calculation and calculation of heat balance diagram in the first part of the thesis. The system of regeneration consist of three Low Pressure Feedwater Heaters (L.P. FWH), deaerator, and two High Pressure Feedwater Heaters (H.P. FWH). The next part of the thesis is focused on a flow path section of turbine. There is a selection of profile of turbine blades at this part, too. The basic design and strength calculation are available only for high-speed high pressure (HP) part of turbine, as an assignment of the thesis says. There is heat balance diagram for 75 % of nominal power output at the end of thesis. The drawing of longitudinal section of HP part of turbine is the main appendix of this thesis.

Thermische Gehäuseverkrümmungen spielen bei der Dimensionierung von radialen Spielen in Industriedampfturbinen eine große Rolle. Die zuverlässige Vorausberechnung der Gehäuseverkrümmung ist wichtig, um einerseits möglichst kleine Spiele und damit hohe innere Wirkungsgrade erzielen zu können und andererseits Schäden in Folge von Spielüberbrückungen auszuschließen. In der vorliegenden Arbeit wurde die Gehäuseverkrümmung mit analytischen Methoden und mit Hilfe von 3D-FE-Analysen untersucht. Eine neue semi-analytische Berechnungsmethode auf Basis eines Stufenkörpermodells wurde entwickelt. Damit lassen sich komplexe Geometrien und unterschiedliche thermische Randbedingungen berücksichtigen. Der Einfluss von Rotationsasymmetrien auf die Verkrümmung wurde mit Hilfe einer FE-Parameterstudie untersucht und in Form von Einflussfaktoren in das Modell integriert. Im Vergleich zu vereinfachten FE-Modellen und zu gemessenen Verkrümmungen an realen Turbinengehäusen zeigt das semi-analytische Modell eine gute Übereinstimmung. Weiterhin wurde das Verkrümmungsverhalten von Industriedampfturbinengehäusen mit Hilfe von 3D-FE-Analysen untersucht. Durch Abgleich von gemessenen und simulierten Temperaturen und Verformungen konnten Erkenntnisse zum Modellaufbau gesammelt werden. Da die thermischen Randbedingungen bei der Simulation von Gehäuseverkrümmungen von größter Bedeutung sind und Defizite beim Wissensstand zum Wärmeübergang erkannt wurden, sind umfangreiche Messungen des Wärmeübergangskoeffizienten durchgeführt worden. Damit wurde ein Beitrag geleistet, FE-Analysen zukünftig auch bei Dimensionierungs- und Auslegungsfragen einsetzen zu können.