he recent development of the power electronic and high-energy permanent magnets enables developing synchronous machines excited by permanent magnets, that are able to meet very gradual and exact control demands. Due to high torque density, that permanent magnet machines reach, the synchronous motors may be used even in direct (gearless) drives. One of the branches, in which direct drives can be used, is material handling. The most propelling drives in this branch consist of induction motor, simple gearbox with invariable gear ratio mounted to the drive wheel. Main aim of this thesis is designing the direct drive motor for low-lift truck. Motor is built-in the driven wheel, therefore outer rotor design appears to be more suitable. Two types of motors – permanent magnet synchronous motor and transverse flux motor have been chosen on the basis of technical paper study, many years lasting experience and verification computations. Both motor types are described in great details in this thesis. Both synchronous motor with PM and transverse flux motor have been designed for direct drive of the given low-lift truck. The proposals of both motors have been optimized by means of finite element method. Based on these design optimizing computations, both motors have been designed, produced and design accuracy has been verified by laboratory testing. Synchronous motor with PM achieves better electromagnetic parameters and its production is also simpler, therefore this motor is more suitable for this application. The solution with transverse flux motor may save substantial amount of active materials. Results of the detailed optimization and comparison of both motor types are the main benefits of this thesis.

The railway infrastructure needs to be safe, reliable and efficient in order to meet the growing demand of sustainable transportation methods. One of the main problems the railway industry faces today is that a higher traffic load increases the need for maintenance, at the same time as it reduces the availability of gaps in the timetables to perform maintenance activities. Unmanned Aerial Vehicles, UAVs, have in recent years been adopted commercially due to their potential of increasing work efficiency and productivity. Different actors in the railway industry have recently started to explore and test the possibilities of implementing UAVs. The objective of this master thesis was to investigate and define use case scenarios where the use of UAVs would create value for railway infrastructure operations and maintenance activities. It is meant for both stakeholders in the railway industry to gain better understanding of capabilities and limitations of UAV technology but also provide recommendations to UAV manufacturers to understand the railway industry and potential UAV applications. Theoretical research and qualitative user studies with UAV professionals and relevant stakeholders within the railway industry were conducted in order to gain insight in the railway industry and to identify potential use case scenarios. The research showed that maintenance activities to a large extent are performed either manually by walking along the tracks which is inefficient, physically demanding and dangerous or by using test/measurement vehicles which require track occupancy. It was concluded that the use of UAVs would mainly create value by; enabling remote inspection and operation, accessing the infrastructure without track occupancy or the need of roads. At the same time, improve the working conditions, efficiency and quality of maintenance activities. The thesis resulted in 15 potential use case scenarios for UAVs in the railway industry and proposals for common UAV solutions based on functional requirements. / Järnvägssystemet måste vara säkert, pålitligt och effektivt för att möta den växande efterfrågan på hållbara transportmetoder. Ett av de största problemen som den svenska järnvägsindustrin står inför idag är att ökad trafikbelastning ökar behovet av underhåll, samtidigt som det minskar tillgängligheten för att utföra underhållsaktiviteter. Obemannade flygfordon, även kallade drönare, har under de senaste åren tillämpats mer frekvent i kommersiella syften för att bland annat uppnå ökad effektivitet och produktivitet. Aktörer inom järnvägsindustrin har nyligen börjat utforska och testa möjligheterna att använda drönare. Syftet med detta examensarbete var att undersöka och definiera potentiella tillämpningar av drönare med syfte att skapa värde för drift- och underhållsarbete inom järnvägen. Denna rapport är avsedd för intressenter inom järnvägsindustrin att få bättre förståelse för kapaciteten och begränsningar av drönarteknik samt ge rekommendationer till drönartillverkare för att bättre förstå järnvägsindustrin och potentiella användningsområden. Teoretisk undersökning och kvalitativa användarstudier med drönarexperter och relevanta intressenter inom järnvägsindustrin genomfördes för att få insikt i järnvägsindustrin samt för att identifiera problemområden. Studien visade att underhållsverksamheten i stor utsträckning utförs antingen manuellt genom att gå längs spåren vilket är ineffektivt, fysiskt krävande och farligt eller genom att använda test/mätfordon som kräver tillgång till spår. Arbetet resulterade i 15 potentiella tillämpningar av drönare i järnvägsindustrin samt förslag på gemensamma drönarlösningar baserade på funktionella krav. Slutsatsen drogs att tillämpningen av drönare i järnvägsindustrin främst kan skapa värde genom att; på distans utföra underhållsaktiviteter och inspektioner, få tillgång till infrastrukturen utan behov av spår eller vägar. Detta resulterar i förbättrade arbetsförhållanden samt ökad effektivitet och kvalitet på underhållsarbetet.

This thesis explores the dynamics of a heteronuclear diatomic molecular ion, possessing a permanent electric dipole moment, µ, which is trapped in a linear Paul trap and can interact with an off-resonance laser field. To build our model we use the rigid-rotor approximation, where the dynamics of the molecular ion are limited to its translational and rotational motions of the center-of-mass. These dynamics are investigated by carrying out suitable numerical calculations. To introduce our numerical methods, we divide our research topic into two different subjects. First, we ignore the rotational dynamics of the ion by assuming µ = 0. By this assumption, the system resembles an atomic ion, which mainly exhibits translational motion for its center of the mass when exposed to an external trapping field. To study this translational behavior, we implement full-quantum numerical simulations, in which a wave function is attributed to the ion. Finally, we study the quantum dynamics of the mentioned wave packet and we compare our results with those obtained classically. In the latter case, we keep the permanent dipole moment of the ion and we study the probable effects of the interaction between the dipole moment and the trapping electric field, on both the translational and the rotational dynamics of the trapped molecular ion. In order to study these dynamics, we implement both classical and semi-classical numerical simulations. In the classical method, the rotational and the translational motions of the center of mass of the ion are obtained via classical equations of motion. On the other hand, in the semi-classical method, while the translational motion of the center-of-mass is still obtained classically, the rotation is treated full-quantum mechanically by considering the rotational wave function of the ion. In the semi-classical approach, we mainly study the probable couplings between the rotational states of the molecular ion, due to the interaction of the permanent dipole moment with the trapping electric field. In the end, we also present a semi-classical model, where the trapped molecular ion interacts with an off-resonance laser field.

Die Vorteile des Systems „Horn“ gegenüber dem Gangbahn-Flügelrad System liegen in der faserschonenden und lageparallelen Flechtfadenverlegung sowie in der gesteigerten Flechtgeschwindigkeit. Die Herausforderung um das Potential des Systems „Horn“ zur Herstellung von Preforms durch Überflechten zu erschließen, bestand in der Integration eines dritten Fadensystems in eine antriebstechnisch umsetzbare Verlegetechnik zur Fertigung einer triaxialen Flechtstruktur. Für die Synthese dieser Antriebstechnik zur kinematisch optimalen Verlegung der Flechtfäden wurde eine prozessorientierte Synthesemethodik, auf Basis einer Technologiesynthese, erarbeitet. / Advantages of the system “Horn” versus the horn gear motion system lie in a gentle and parallel processing of the braiding materials as well as in an increased speed of braiding. The challenge in extrapolating the potential of the system “Horn” for the production of preforms by over-braiding was to integrate a third yarn system into a laying technique that is technically feasible for processing a triaxial braided structure. For the synthesis of this drive technology and to guarantee an optimal kinematic transfer of threads, a process-oriented synthesizing method, based on a technology synthesis, was elaborated.

Parmi tous les composants mécaniques présents dans un moteur d'avion, les roulements tiennent une place majeure puisqu'ils assurent la liaison entre les parties tournantes, les rotors, et les parties fixes, les stators. Pour assurer leur bon fonctionnement, un jeu radial interne est nécessaire. Les roulements présentent de ce fait une non-linéarité forte qui peut affecter le comportement vibratoire de la structure. L'objectif de cette thèse, réalisée en collaboration avec la société Snecma Moteurs, est d'étudier l'influence de ce jeu fonctionnel sur la dynamique rotor. A cette fin, un banc expérimental, dénommé banc Dynamique D'Ensemble, a été réalisé. Dans un premier temps, l'aspect modélisation des roulements sera traité. Le modèle proposé, qui prend en compte le jeu radial et considère le contact bille/bague comme hertzien, nécessite cependant des outils de calcul appropriés. Nous présenterons alors la méthode de tir multiple et la méthode des éléments finis en temps avant de montrer les résultats de calculs effectués sur divers exemples. Dans un second temps, nous présenterons le banc Dynamique D'Ensemble qui permettra de valider expérimentalement les modèles de roulements utilisés. Ce banc a été conçu pour être le plus simple possible, tout en restant le plus représentatif d'un moteur d'avion. Nous exposerons tout d'abord les aspects dimensionnement et recalage, puis les premiers résultats obtenus sur banc tournant.

Computational fluid dynamics (CFD) is used in this thesis to model wind and tidal stream turbines and to investigate tidal turbine fence performance. There are two primary objectives of this work. The first is to develop and validate an actuator line method for the simulation of wind and tidal turbines which applies the blade forces to the flow field without the need for a regularisation kernel. The second is to examine tidal fences using, in part, the newly developed actuator line method. A potential flow equivalence method for determining the relative velocity to the blade chord and flow angle at the rotor blades in the actuator line method is proposed and validated. Results for simulations using this method compare favourably with those from both experiments and alternative computational methods, although the present model’s results deviate from experimental results in the vicinity of the blade tips. A CFD-embedded blade element-momentum tool is used to design rotors for operation in infinitely wide tidal fences spanning a tidal channel. Rotors are designed for fences with several different blockage ratios, with those designed for high blockage flows having greater solidity than those designed for operation in fences with lower blockage. It is found that designing rotors for operational blockage conditions can significantly improve the power output achieved by a tidal fence. Improved power output for higher blockage conditions is achieved by the application of greater thrust to the flow. Actuator line simulations of short (up to 8 turbines) fences with varying intra-rotor spacing and number of rotors confirm that hydrodynamic performance of the rotors improves as the spacing is reduced and as rotors are added to a fence. The position of a rotor within the fence impacts its performance; rotors at the ends of a fence extract reduced power compared to those at the centre of the fence, particularly for tip speed ratios greater than the design tip speed ratio.

La simulation d'écoulements dans des cavités cylindriques en rotation présente une difficulté particulière en raison de l'apparition de singularités sur l'axe. Le présent travail propose une méthode collocative pseudospectrale suffisamment efficace et précise pour surmonter cette difficulté et résoudre les équations 3D de Navier-Stokes écrites en coordonnées cylindriques. Cette méthode a été développée dans le cadre des différentes études menées au laboratoire M2P2, utilisant une méthode collocative de type Chebychev dans les directions radiale et axiale et Fourier-Galerkin dans la direction azimutale [thêta]. Pour éviter de prescrire des conditions sur l'axe, une nouvelle approche a été développée. Le domaine de calcul est défini par (r,[thêta],z)∈[-1,1]×[0,2π]×[-1,1] avec un nombre N pair de points de collocation dans la direction radiale. Ainsi, r=0 n'est pas un point de collocation. La distribution de points de type Gauss-Lobatto selon r et z densifie le maillage seulement près des parois ce qui rend l'algorithme bien adapté pour simuler les écoulements dans des cavités cylindriques en rotation. Dans la direction azimutale, le chevauchement des points dû à la discrétisation est évitée par l'introduction d'un décalage égal à π/2K à [thêta]>π dans la transformée de Fourier. La méthode conserve la convergence spectrale. Des comparaisons avec des résultats expérimentaux et numériques de la littérature montrent un très bon accord pour des écoulements induits par la rotation d'un disque dans des cavités cylindriques fermées. / When simulating flows in cylindrical rotating cavities, a difficulty arises from the singularities appearing on the axis. In the same time, the flow field itself does not have any singularity on the axis and this singularity is only apparent. The present work proposes an efficient and accurate collocation pseudospectral method for solving the 3D Navier-Stokes equations using cylindrical coordinates. This method has been developed in the framework of different studies of rotor-stator flows, using Chebyshev collocation in the radial and axial directions and Fourier-Galerkin approximation in the azimuthal periodic direction [thêta]. To avoid the difficulty on the axis without prescribing any pole and parity conditions usually required, a new approach has been developed. The calculation domain is defined as (r,[thêta];,z)∈[-1,1]×[0,2π]×[-1,1] using an even number N of collocation points in the radial direction. Thus, r=0 is not a collocation point. The method keeps the spectral convergence. The grid-point distribution densifies the mesh only near the boundaries that makes the algorithm well-suited to simulate rotating cavity flows where thin layers develop along the walls. In the azimuthal direction, the overlap in the discretization is avoided by introducing a shift equal to π/2K for [thêta]>π in the Fourier transform. Comparisons with reliable experimental and numerical results of the literature show good quantitative agreements for flows driven by rotating discs in cylindrical cavities. Associated to a Spectral Vanishing Viscosity, the method provides very promising LES results of turbulent cavity flows with or without heat transfer.

Renewable energy is harnessed from continuously replenishing natural processes. Some commonly known are sunlight, water, wind, tides, geothermal heat and various forms of biomass. The focus on renewable energy has over the past few decades intensified greatly. This thesis contributes to the research on developing renewable energy technologies, within the wind power, wave power and marine current power projects at the division of Electricity, Uppsala University. In this thesis grid connection of permanent magnet generator based renewable energy sources is evaluated. A tap transformer based grid connection system has been constructed and experimentally evaluated for a vertical axis wind turbine. Full range variable speed operation of the turbine is enabled by using the different step-up ratios of a tap transformer. This removes the need for a DC/DC step or an active rectifier on the generator side of the full frequency converter and thereby reduces system complexity. Experiments and simulations of the system for variable speed operation are done and efficiency and harmonic content are evaluated.  The work presented in the thesis has also contributed to the design, construction and evaluation of a full-scale offshore marine substation for wave power intended to grid connect a farm of wave energy converters. The function of the marine substation has been experimentally tested and the substation is ready for deployment. Results from the system verification are presented. Special focus is on the transformer losses and transformer in-rush currents. A control and grid connection system for a vertical axis marine current energy converter has been designed and constructed. The grid connection is done with a back-to-back 2L-3L system with a three level cascaded H-bridge converter grid side. The system has been tested in the laboratory and is ready to be installed at the experimental site. Results from the laboratory testing of the system are presented. / Wind Power / Wave Power / Marine Currnet Power

Cette étude s'inscrit dans le domaine des moteurs à doublets d'hélices contrarotatives, aussi appelés open rotors. Elle a porté sur le développement des méthodologies à coût modéré pour la simulation aérodynamique des open rotors. Elle avait pour objectif, d'un côté, la mise en place et la validation de ces méthodologies rapides ; et d'un autre côté, l'approfondissement de la compréhension de l'origine des efforts dans le plan hélice, aussi appelés les efforts 1P. Pour le premier des objectifs, le code HOST-MINT, basé sur la méthode de la ligne portante a été adapté et amélioré pour la simulation de l'aérodynamique instationnaire des hélices et des open rotors. Des validations ont été réalisées avec succès par comparaison avec des données expérimentales et des simulations CFD plus avancées. Cette étude a ainsi ouvert des nombreuses perspectives d'application de ce type de méthodologies rapides dans la conception aérodynamique des futurs open rotors. En outre, cette méthode s'est révélée aussi adaptée pour d'autres domaines autour de l'aérodynamique, comme par exemple, pour les problèmes d'aéroélasticité ou pour les prédictions aéroacoustiques préliminaires. / This study is devoted to the development of moderate-cost methodologies for the aerodynamic simulation of open rotors. The main goals are, on one side, to develop and validate these rapid methodologies, and, on the other side, to better understand the mechanisms behind propeller in-plane loads, also called the 1P loads. To reach the first goal, the HOST-MINT code, based on the lifting-line theory, has been adapted and improved for the unsteady simulation of propellers and open rotors. The code has been assessed by comparison with experimental data and more complex and precise CFD simulations. Finally, the first developments and tests of a Lagrangian/Eulerian coupling strategy between HOST-MINT and the elsA CFD code have been performed. These studies enable to endeavor a number of applications of this type of rapid methodologies in the aerodynamic design of future open rotors. Moreover, these methodologies may be adapted for other domains linked to aerodynamics, such as aeroelastic problems or preliminary aeroacoustic predictions.

O presente trabalho consiste no projeto de um modelo em elementos finitos de um absorvedor dinâmico rotativo utilizando-se um material viscoelástico como componente dissipador do sistema. O absorvedor é composto por um anel de material viscoelástico interposto entre dois anéis de aço, o qual é fixado na extremidade livre de um sistema rotativo representado por um eixo flexível, suportado por dois rolamentos, no qual estão fixos dois discos igualmente espaçados do centro entre os dois mancais. O modelo em elementos finitos do sistema rotativo é validado com os dados experimentais do modelo real e suas velocidades críticas são determinadas baseadas no diagrama de Campbell e na resposta ao desbalanço em um dos discos. O modelo inicial do absorvedor dinâmico rotativo é replicado de um modelo da literatura e as respostas a uma excitação na forma de impulso são comparadas. O modelo desenvolvido equipara-se ao da literatura para frequências até 600 Hz, intervalo que compreende as velocidades críticas a serem amortecidas. A otimização do absorvedor é realizada através de variações da geometria do mesmo e são traçadas curvas de influência de cada parâmetro sobre suas frequências naturais. Com base nestas curvas são realizadas análises de influência conjunta dos parâmetros geométricos sobre tais frequências. Pelos resultados obtidos verifica-se a possibilidade da obtenção de um modelo que atue sobre modos de flexão específicos do sistema rotativo, atenuando as amplitudes de vibração das velocidades críticas correspondentes a cada modo. Uma vez obtidos os modelos de absorvedores dinâmicos correspondentes aos dois primeiros modos de flexão do sistema rotativo, ambos são acoplados ao sistema e se observa grande redução dos picos de amplitude do primeiro modo de flexão, enquanto os picos do segundo modo sofrem baixa alteração. / The present work concerns the development, optimization and validation of a finite element model of a dynamic vibration absorber using a viscoelastic material as the damping component. The dynamic absorber consists of a ring of viscoelastic material interposed between two rings of steel, which is fixed to the free end of a rotary system represented by a flexible shaft supported by two bearings, on which are fixed two discs equally spaced in the center of both bearings. The finite element model of the rotating system is validated with experimental data from the actual model and its critical speeds are determined based on the Campbell diagram and in its response to the imbalance. The initial model of the dynamic absorber is replicated from a model of the literature and the responses to an impulse excitation are compared. The developed model matches the literature one for frequencies up to 600 Hz, range comprising the critical speeds to be damped. The absorber\'s optimization is accomplished through variations of its geometry and influence curves of each parameter over its natural frequencies are drawn. Based on these curves, combined influence analyzes of the geometrical parameters over such frequencies are performed. From the results obtained, it can be seen the possibility of achieving a model that acts on specific bending modes of the rotation system, reducing the vibration amplitudes of the critical speeds corresponding to each mode. Once obtained the dynamic absorbers models corresponding to the first two modes of vibration of the rotatative system, both models are coupled to the system and it is observed great reduction of the amplitude of the first bending mode peaks, while the second mode suffer low peaks reduction.