The Late Archean Magmatic Event (LAME), ca. 2.7 Ga, was the greatest crustal addition event in Earth history. My focus is the Superior Province of Canada, where LAME occurred ca. 2.75 – 2.65 Ga. Mantle plumes impinged on the Abitibi subprovince, where ~ 16 km regional thickness of tonalite-trondhjemite-granodiorite (TTG) melt was produced. Granites (sensu stricto) were the last magmatic phase of LAME, with a Superior-wide regional thickness of ~ 1 – 3 km. Assuming a crustal source for both TTG and granites, I use 1-D thermal models to investigate the origin of TTG in the Abitibi subprovince and that of late granites in the Superior Province. Melting curves appropriate to the source of TTG and granites are used to determine the thickness of melt produced in the models. I show that the incorporation of upward melt transfer into a standard model of lower crustal melting may increase the amount of predicted melt by ~ 1/(1-f), where f denotes the fraction of melt that is on average being extracted from the source rocks. Partitioning of heat producing elements between melt and restite reduces the amount of melt produced, but the effect is secondary compared to the increase in melt production through upward melt transfer. For the Abitibi subprovince, I show that the emplacement of a single plume coupled with the emplacement of a 12-km-thick greenstone cover can generate a maximum of ~ 9-km-thickness of TTG melt. However, the emplacement of a series of plumes, each coupled with the emplacement of a 3-km-thick greenstone cover and a 10-km-thick sill results in ~ 20-km-thickness of TTG melt. My model incorporates delamination of restitic eclogite. Finally, I show that late granites in the Superior Province may have resulted from thickening of a crust that had been “pre-heated” during earlier arc activity and that prolonged granitic magmatism observed in some areas of the Superior Province may be explained by late underthrusting of fertile source rocks into deeper and hotter regions of the crust.

The Late Archean Magmatic Event (LAME), ca. 2.7 Ga, was the greatest crustal addition event in Earth history. My focus is the Superior Province of Canada, where LAME occurred ca. 2.75 – 2.65 Ga. Mantle plumes impinged on the Abitibi subprovince, where ~ 16 km regional thickness of tonalite-trondhjemite-granodiorite (TTG) melt was produced. Granites (sensu stricto) were the last magmatic phase of LAME, with a Superior-wide regional thickness of ~ 1 – 3 km. Assuming a crustal source for both TTG and granites, I use 1-D thermal models to investigate the origin of TTG in the Abitibi subprovince and that of late granites in the Superior Province. Melting curves appropriate to the source of TTG and granites are used to determine the thickness of melt produced in the models. I show that the incorporation of upward melt transfer into a standard model of lower crustal melting may increase the amount of predicted melt by ~ 1/(1-f), where f denotes the fraction of melt that is on average being extracted from the source rocks. Partitioning of heat producing elements between melt and restite reduces the amount of melt produced, but the effect is secondary compared to the increase in melt production through upward melt transfer. For the Abitibi subprovince, I show that the emplacement of a single plume coupled with the emplacement of a 12-km-thick greenstone cover can generate a maximum of ~ 9-km-thickness of TTG melt. However, the emplacement of a series of plumes, each coupled with the emplacement of a 3-km-thick greenstone cover and a 10-km-thick sill results in ~ 20-km-thickness of TTG melt. My model incorporates delamination of restitic eclogite. Finally, I show that late granites in the Superior Province may have resulted from thickening of a crust that had been “pre-heated” during earlier arc activity and that prolonged granitic magmatism observed in some areas of the Superior Province may be explained by late underthrusting of fertile source rocks into deeper and hotter regions of the crust.

Nasslaufende Lamellenkupplungen finden im Automobil immer mehr Anwendungen. Im Bezug auf die steigenden Motorleistungen, die Gewichtsoptimierungsmaßnamen und die hohen Ansprüche an Fahrdynamik nimmt die geforderte Leistungsdichte einer nasslaufenden Lamellenkupplung ständig zu. Die Lamellenkupplung wird oft nahe an ihrer Belastungsgrenze ausgelegt. Außerdem wachsen gleichzeitig die Anforderungen an ihre Schaltdynamik, das Komfortverhalten und die Lebensdauer. Schwerpunkt dieser Arbeit ist die Modellierung und Simulation von Reibung und Verschleiß nasslaufender Lamellenkupplungen, insbesondere der mit dem Papierreibbelag. Ein umfassendes Verständnis für die Reibungsvorgänge und Verschleißmechanismen stellt die Grundvoraussetzung für eine optimale Entwicklung der nasslaufenden Lamellenkupplung dar. Zur Lösung der gestellten Aufgabe werden die wichtigsten Einflussgrößen auf das tribolgische System der Lamellenkupplung charakterisiert und die Wirkungen der tribologischen Beanspruchungsgrößen identifiziert. Zudem werden verschiedene Simulationsmodelle mit unterschiedlicher Modellierungstiefe erstellt. Dazu gehören Reibmodelle, Wärmeflussmodelle sowie Lebensdauermodelle, wobei die Reib- und Wärmeflussmodelle für die Lebensdauermodelle benötigt werden. Die hergeleiteten Modelle werden in die Simulationsumgebung implementiert und mit Hilfe eines Prüfstandsversuches verifiziert. Die validierten Modelle können für die Systemoptimierung und die Lebensdauerabsicherung der nasslaufenden Lamellenkupplungen effizient eingesetzt werden. Dies kann eine deutliche Reduktion der Entwicklungszeit sowie der Versuchskosten ermöglichen.

L’intégration des supercondensateurs dans les applications de type véhicule hybride nécessite la connaissance de leur comportement au cours du vieillissement. Ainsi, l’objectif de cette thèse est l’évaluation du vieillissement et la définition d’un modèle permettant la prédiction de l’état de santé des supercondensateurs. Les résultats de vieillissement sont présentés en s’intéressant principalement à l’évolution des performances durant le vieillissement accéléré en fonction de la température, de la tension et de la durée des arrêts dans le cas du cyclage. Un modèle de vieillissement est défini pour décrire l’évolution des performances en s’attachant aux principaux mécanismes de vieillissement. / The integration of ultracapacitors in applications like hybrid requires knowledge of their behavior during aging. Thus, the objective of this thesis is the evaluation of aging and the definition of a model for predicting the health of supercapacitors. The aging results are presented focusing mainly on the evolution of performance during accelerated aging function of temperature, voltage and duration of stops in the case of cycling. An aging model is defined to describe the evolution of performance by focusing on the key mechanisms of aging.

Avec l’accroissement des exigences des avionneurs, les problématiques thermique interviennent de plus en plus tôt dans les phases de conception d’un équipement roue et frein. La première phase de conception, appelée pré-étude, doit permettre de définir les grands choix technologiques pour répondre aux spécifications. Cette phase se déroulant sur une période de l’ordre du mois, la prévision du comportement thermique induit par les différentes solutions doit être de l’ordre de quelques jours. Aussi, les outils de simulation (de type CFD) ne peuvent pas être utilisé, car le temps d’implémentation (maillage) et de calcul ne sont pas adaptés. En outre, compte tenu de la faible maturité du design, aucune CAO n’est disponible. En revanche, le degré de précision et de résolution exigé sur les résultats est plus faible. Dans cette thèse nous proposons un outil de modélisation simplifiée adapté aux contraintes de cette phase de conception, à savoir, un temps d’implémentation et de calcul de l’ordre de quelques heures, et, un très fort niveau de paramétrisation. Pour cela, nous avons tout d’abord établi une représentation géométrique simplifié de l’équipement dans une grille en coordonnées R,T,Z. La simplification géométrique se traduit par une adaptation de la forme des pièces à la grille. L’obtention de cette représentation devient alors automatisable pour réduire le temps d’implémentation. Le modèle thermique utilisé est basé sur l’association d’une approche nodale par l’utilisation de formulation RC et un maillage spatiale adaptable sur chaque pièce qui se rapproche du principe d’une méthode de type volume finis. La complexité du problème thermique (liée à la géométrie, aux transferts multi-modes instationnaires, aux hautes températures et aux non-linéarités) va nous imposer, à des fins d’analyses, la mise au point d’un outil de représentation spatiale et temporelle des grandeurs thermiques. Une décomposition géométrique, associée à une décomposition temporelle du refroidissement par rapport à des temps caractéristiques, a permis d’établir une représentation intelligible des informations sous formes de cartographies. Dans une première étape, des cartographies de températures ont été établies à partir de données d’essais. Ces cartographies ont permis d’énoncer quelques hypothèses sur le sens et l’intensité des transferts, en particulier, conductifs. Dans une seconde étape, les résultats d’un modèle thermo-aéraulique complet de l’équipement, recalés sur les températures d’essais, ont offert la possibilité d’obtenir des cartographies énergétiques par l’intermédiaire des flux et des décompositions spatiale et temporelle. Ces dernières mettent en évidence les lieux et l’intensité des transferts énergétiques, ainsi que, les pièces stockant la chaleur. Cet outil de représentation a pu être utilisé sur d’autres équipements roue et frein, et sur plusieurs énergies de freinage (16 à 64MJ). / For several years, expectations of aircraft manufacturers and airlines have risen as far as reduction of aircraft weight and turn-around time are concerned. Mass reduced wheel and brake equipments tend to reach higher maximal temperature and need to be cooled down more efficiently. Therefore, equipments need to be better designed in terms of heat transfer, especially from the early design phases (i.e. right from the request for proposal). Brake cooling is insured by transient and multi-modal heat transfer, involving particularly, surface-to-surface thermal radiation, natural convection and heat conduction. Furthermore, because of the geometric complexity of the system, three-dimensional heat transfer should be considered. The first aim of this work is to develop a simplified representation of the heat transfer, inside the equipment and with the outdoor, leading to a better acknowledgment of its thermal comportment. This would eventually provide to the engineers some guidelines to a way to help the decision forecast and improve the thermal design of wheel and brake equipments. Secondly, a simplified thermal model should be developed, in order to fill the lack of dedicated tools ,in the preliminary design stage, to predict the thermal comportment. To predict thermal fields, in such a complex system, modelisation approaches, such as finite volume or finite-element methods (the use of CFD in the case of coupled convection/conduction problems) are commonly used in industry. Despite their ability to provide suitable and accurate results, that kind of numerical methods don't fit with the preliminary design stage requirements, especially in term of implementation and calculation time. On the opposite, model based on RC thermal network seems to meet the requirements of fast calculation time and implementation time thanks to fully adapted parameterization.

Face au changement climatique global, il est de plus en plus important de prêter attention à la performance thermique-hydro-mécanique des constructions géotechniques sous l'effet des conditions atmosphériques. L'objectif principal de cette étude est d'étudier le comportement hydro-thermique des sols soumis au effets du changement climatique par la modélisation numérique.Un modèle hydro-thermique couplé est tout d'abord développé pour décrire le comportement du sol hydro-thermique. La théorie utilisée pour décrire l'interaction sol-atmosphère est présentée sous forme des bilans de masse et d'énergie. Ensuite, une approche numérique pour analyser le comportement hydro-thermique du sol est proposée en combinant le modèle hydro-thermique couplé avec un modèle d'interaction sol-atmosphère. La validation de cette approche est réalisée par la comparaison entre les résultats numériques obtenus en utilisant le code FreeFem++ et les données des essais de la colonne de séchage qui sont trouvées dans la littérature. Cette approche est d'abord utilisée pour la modélisation numérique des essais à la chambre environnementale, réalisés par Song en 2014. Des résultats de simulation satisfaisants sont obtenus en termes de variations de la température et de la teneur en eau volumétrique du sol. Ensuite, cette approche est appliquée à deux remblais, à Héricourt et à Rouen. Pour le remblai d’Héricourt, une étude numérique a été menée pour une durée de 20 jours. La bonne concordance obtenue entre les résultats de simulation et les mesures montre que l'approche proposée est pertinente pour l'analyse du comportement hydro-thermique du sol dans le cas de remblais bidimensionnels. Elle prouve également que les conditions aux limites et les paramètres du sol adoptés sont appropriés. Dans le cas du remblai de Rouen, deux périodes différentes, 187 jours et 387 jours, sont prises en considération. On vérifie également la bonne performance de l'approche proposée pour estimer le comportement hydro-thermique du remblai sous l'effet du climat. La comparaison entre les calculs et les mesures révèle également l'importance d'adopter correctement les conditions aux limites thermiques et hydrauliques ainsi que les paramètres du sol. De plus, à partir des simulations numériques, plusieurs suggestions sont faites pour collecter des données d'entrée dans l'application de cette approche pour prédire les variations de la température et de la teneur en eau du sol à plus long terme / Facing the global climate change, it is more and more important to pay attention to the thermal-hydro-mechanical performance of geotechnical constructions under the effect of atmospheric conditions. The main objective of this study is to investigate the hydro-thermal behavior of soil subjected to climate change through numerical modelling.A coupled hydro-thermal model is developed for describing the coupled hydro-thermal soil behavior. The soil-atmosphere interaction is studied through the mass and energy balances. Afterwards, a numerical approach to estimate soil hydro-thermal behavior by integrating the coupled hydro-thermal model with a soil-atmosphere interaction model is proposed. The validation of this approach is performed through the comparison between the numerical results using FreeFem++ code and the experimental data available from column drying tests reported in literature. This approach is firstly used for the numerical modelling of the environmental chamber tests carried out by Song in 2014. Satisfactory simulation results are obtained in terms of variations of soil temperature and soil volumetric water content. Afterwards, this approach is further applied to two cases of embankments, in Héricourt and in Rouen respectively. For Héricourt embankment, a numerical investigation was conducted for 20 days, and a good agreement between simulation results and filed measurements is obtained, showing that the proposed approach is suitable for analyzing the soil hydro-thermal behavior in the case of two-dimensional embankments. It proves also that the boundary conditions and the soil parameters adopted are appropriate. In the case of Rouen embankment, two different periods, 187 days and 387 days, are considered. The good performance of the proposed approach in estimating the embankment hydro-thermal behavior under the climate effect is also verified. The comparison between calculations and measurements also reveals the importance of appropriately adopting the thermal and hydraulic boundary conditions as well as the soil parameters. Based on the numerical simulations, several suggestions are made in terms of collection of input data for the application of this approach to predict soil temperature and volumetric water content variations in longer term

This thesis describes complex modeling of asynchronous motor by finite element method. Complex modeling concerns to making models based on different physical principles and their connection. Models are made in Ansys program components and their connection is made in program Ansys Workbench. This thesis includes creating electromagnetic model, thermal model, mechanical model and coupled model which connect partial models.

Nasslaufende Lamellenkupplungen finden im Automobil immer mehr Anwendungen. Im Bezug auf die steigenden Motorleistungen, die Gewichtsoptimierungsmaßnamen und die hohen Ansprüche an Fahrdynamik nimmt die geforderte Leistungsdichte einer nasslaufenden Lamellenkupplung ständig zu. Die Lamellenkupplung wird oft nahe an ihrer Belastungsgrenze ausgelegt. Außerdem wachsen gleichzeitig die Anforderungen an ihre Schaltdynamik, das Komfortverhalten und die Lebensdauer. Schwerpunkt dieser Arbeit ist die Modellierung und Simulation von Reibung und Verschleiß nasslaufender Lamellenkupplungen, insbesondere der mit dem Papierreibbelag. Ein umfassendes Verständnis für die Reibungsvorgänge und Verschleißmechanismen stellt die Grundvoraussetzung für eine optimale Entwicklung der nasslaufenden Lamellenkupplung dar. Zur Lösung der gestellten Aufgabe werden die wichtigsten Einflussgrößen auf das tribolgische System der Lamellenkupplung charakterisiert und die Wirkungen der tribologischen Beanspruchungsgrößen identifiziert. Zudem werden verschiedene Simulationsmodelle mit unterschiedlicher Modellierungstiefe erstellt. Dazu gehören Reibmodelle, Wärmeflussmodelle sowie Lebensdauermodelle, wobei die Reib- und Wärmeflussmodelle für die Lebensdauermodelle benötigt werden. Die hergeleiteten Modelle werden in die Simulationsumgebung implementiert und mit Hilfe eines Prüfstandsversuches verifiziert. Die validierten Modelle können für die Systemoptimierung und die Lebensdauerabsicherung der nasslaufenden Lamellenkupplungen effizient eingesetzt werden. Dies kann eine deutliche Reduktion der Entwicklungszeit sowie der Versuchskosten ermöglichen.

Indiana University-Purdue University Indianapolis (IUPUI) / Heat generation is a major safety concern in the design and development of Li ion batteries (LIBs) for large scale applications, such as electric vehicles. The total heat generation in LIBs includes entropic heat, enthalpy, reaction heat, and heat of mixing. The main objective of this study is to investigate the influence of heat of mixing on the LIBs and to understand whether it is necessary to consider the heat of mixing during the design and development of LIBs. In the previous research, Thomas and Newman derived methods to compute heat of mixing in LIB cells. Their results show that the heat of mixing cannot be neglected in comparison with the other heat sources at 2 C rate. In this study, the heat of mixing in different materials, porosity, particle sizes, and charging/discharging rate was investigated. A COMSOL mathematical model was built to simulate the heat generation of LIBs. The LIB model was based on Newman’s model. LiMn2O4 and LiCoO2 were applied as the cathode materials, and LiC6 was applied as the anode material. The results of heat of mixing were compared with the other heat sources to investigate the weight of heat of mixing in the total heat generation. The heat of mixing in cathode is smaller than the heat of mixing in anode, because of the diffusivity of LiCoO2 is 1 ×10-13 m2/s, which is larger than LiC6's diffusivity 2.52 × 10-14 m2/s. In the comparison, the heat of mixing is not as much as the irreversible heat and reversible heat, but it still cannot be neglected. Finally, a special situation will be discussed, which is the heat of mixing under the relaxation status. For instance, after the drivers turn off their vehicles, the entropy, ix enthalpy and reaction heat in LIBs will stop generating, but the heat will still be generated due to the release of heat of mixing. Therefore, it is meaningful to investigate to see if this process has significant influence on the safety and cycle life of LIBs.

<p>Positive displacement machines (PDMs) operate based on the principle of positive displacement, which necessitates a periodic alteration of volume. This volume variation is accomplished through relative motion between machine components. PDMs find extensive applications in diverse domains, encompassing fluid power systems, lubrication systems, fluid transport systems, fuel injection systems, and more. The primary distinction among PDMs lies in the geometric mechanisms employed for fluid displacement, as well as the flow distribution mechanisms they employ. PDMs can be broadly classified into piston machines, vane machines, screw machines, and gear machines. In fluid power systems, the most commonly used PDMs are the piston and gear machines. Piston machines can be further classified into radial piston machines, in-line piston machines, and axial piston machines. The most commonly used piston machines are the axial piston machine owing to their superior efficiency and compactness. Gear machines can be further classified into external gear machines, internal gear machines, and annular gear machines. The most commonly used gear machine is the external gear machine owing to its price.</p> <p><br></p> <p>PDMs typically involve multiple solid bodies in relative motion, with micron-level gaps between them. These gaps, known as lubricating interfaces, present a significant design challenge during the machine development process. They are a primary source of power losses and play a crucial role in determining the efficiency and durability of the machine. The lubricating interfaces must effectively balance loads and maintain a high-pressure fluid seal. Achieving this delicate balance necessitates a comprehensive understanding of the underlying physical phenomena. Lubricating interfaces generate substantial heat due to viscous dissipation, which directly impacts the operation of the entire machine. The viscosity of the working fluid rapidly decays with temperature, causing the warmer fluid within the lubricating interface to possess lower viscosity. Consequently, it can support lesser loads and is more prone to leakage. Moreover, as the solid bodies enclosing the warmer fluid heat up, they undergo thermal expansion, further changing the clearance and leading to a decline in performance. Additionally, the elevated temperature of the fluid within the lubricating interface affects the compressibility of the displacement chamber fluid, thereby influencing the pressurization characteristics of the entire unit. Thus, thermal effects play a critical role in the performance of PDMs.</p> <p><br></p> <p>  The ever-increasing market demand for more compact, efficient, and reliable designs requires a continuous process of design improvements over previous designs, and sometimes completely new designs. Sophisticated simulation tools are a necessity for such a design process. Additionally, these simulation tools also prove to be valuable in formulating design modifications in case of underperforming designs. Due to the complexity associated with the operation of such units, the simulation tools need to capture a wide variety of physical phenomena. Over the past few decades, owing to the increasing computing power of the desktop computer, several simulation tools have been proposed across the literature to aid the design process of such machines with each having limitations of their own.</p> <p><br></p> <p>  The objective of the present thesis is to propose a modeling approach that assists in the design process of positive displacement machines, addressing various limitations identified in the existing literature. The approach is intentionally designed to be generic, enabling its application across a diverse range of positive displacement machines. The modeling approach encompasses three distinct domains: the displacement chamber fluid domain, the lubricating interface fluid domain, and the solid domain. A novel thermal model that integrates all three domains is introduced. </p> <p><br></p> <p>  To validate the effectiveness of the proposed modeling approach, two separate validation studies are conducted. The first study focuses on a model for an isolated piston/cylinder interface of an axial piston machine, operating under the mixed lubrication regime. The model demonstrates a strong agreement with the measured data. The second study involves steady-state measurements of an entire axial piston machine. The model is validated by comparing the steady-state flow characteristics and temperature distribution on the valveplate, both of which are accurately captured by a single fully coupled model. The modeling approach developed in this study, specifically, the energy conservation in the lubricating interface, heat transfer in the solid bodies, and thermal deformation in the solid bodies are all generalized for applicability in different types of PDMs. However, the results presented in this thesis pertain to an axial piston machine.</p>