This thesis reports the development, testing, and application of computer programs for simulating Lagrangian-Stochastic particle dispersion in coastal seas, with particular application to tide and storm induced dispersion in South Australian seas. The three-dimensional tidal equations are briefly discussed for the two types of surge models used, and finite-difference methods for numerically solving these equations are considered. Different methods of simulating flows at open sea boundaries are investigated. The method of particle tracking and the development of the particle tracking model is also described. Various tests are conducted to investigate both the advective and diffusive aspects of dispersion, and a number of scenarios for the simulation of open (ocean) and closed (coastal) boundaries are considered. Various aspects of the particle tracking routine are given specific characteristics according to the nature of the particle being considered. Application of the tide and storm surge model to the Great Australian Bight is described. This uses spherical polar co-ordinates to account for the curvature of the earth, and an oblique boundary element to increase accuracy of the coastline representation. The effect of a low pressure system moving from west to east across the Bight and the resulting significant observed surge at Thevenard during the storm of April 1996 is simulated. This storm resulted in a significant number of deaths in aquaculture farms containing southern bluefin tuna (Thunnas maccoyii) within the Boston Bay region to the extreme east of the Bight due to the agitation of almost neutrally buoyant organic sediments at the sea floor. The effects of this storm are further considered using a Cartesian co-ordinate fine-grid local model of Boston Bay, in Spencer Gulf, South Australia, where both tidal and storm (wind and outside surge) induced flows are simulated. The dispersion of suspended neutrally buoyant sediment throughout the region is considered, and compared with the mortalities of tuna at various farms within the region. Tidal and storm induced currents in the Gulf St. Vincent region, South Australia, have also been modelled using Cartesian co-ordinates. Detailed consideration has been given to the modelling of tides, winds, atmospheric pressures and outside surges from the two open boundaries in Investigator Strait and Backstairs Passage. The information obtained has enabled the modelling of a number of storm surge scenarios. Further to this, various simulations of the dispersion of the larvae of the western king prawn (Penaeus latisulcatus) have been driven using the storm surge model developed. These incorporate currents near the surface and the sea floor, as well as the consideration of changes in behaviour during the life history of the larvae. / Thesis (Ph.D.)--Engineering, Computer and Mathematical Sciences, 2000.

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.

Esta tesis explora la precisión de dos métodos de estimación de precipitación, Auto-Estimator y CRR (Convective Rainfall Rate), generados a partir de imágenes infrarrojas y visibles del Meteosat. Ambos métodos junto con una serie de correcciones de la intensidad de lluvia estimada se aplican y se verifican en dos casos de inundaciones acaecidas en zonas mediterráneas. El primer caso ocurrió en Albania del 21 al 23 de septiembre de 2002 y el segundo, conocido como caso Montserrat, ocurrió en Cataluña la noche del 9 al 10 se junio de 2000. Por otro lado se investiga la posibilidad de realizar calibraciones de ambos métodos directamente con datos de estaciones pluviométricas cuando lo común es calibrar con datos de radares meteorológicos. También se propone cambios en algunas de las correcciones ya que parecen mejorar los resultados y se propone una nueva corrección muy eficiente que utiliza las descargas eléctricas para determinar la zonas más convectivas y de mayor precipitación de los sistemas nubosos. / This Thesis work explores the precision of two methods to estimate rainfall called Auto-Estimator and CRR (Convective Rainfall Rate). They are obtained by using infrared and visible images from Meteosat. Both Algorithms within a set of correction factors are applied and verified in two severe flood cases that took place in Mediterranean regions. The first case has occurred in Albania from 21 to 23 September 2002 and the second, known as the Montserrat case, has occurred in Catalonia the night from the 9 to 10 of June 2000. On the other hand it is explored new methods to perform calibrations to both satellite algorithms using direct rain rates from rain gauges. These kinds of adjustments are usually done using rain rates from meteorological radars. In addition it is proposed changes on some correction factors that seem to improve the results on estimations and it is defined an efficient correction factor that employ electrical discharges to detect the most convective and rainy areas in cloud systems.

We propose a hypothesis and a numerical model for the formation of branching plagioclase textures visible at both macroscopic (∼cm to ∼m) and microscopic scale within melagabbro of the Isle of Rum, Scotland, based on macroscopic, microscopic observations and relevant geological history. The plagioclase crystals are typically linked as twins and form meshes of planar stellate structures (m-scale) with a large range in geometrical organization from patchy to radiating. Evidence of macroscopic crystal aggregation and alignment is attributed to interfacial free energy minimization at the microscopic scale during growth. Accordingly, a binary immiscible Lattice Boltzmann model was developed to simulate diffusion of simplified plagioclase in the melt phase. Isothermal phase transitions modelled via first order chemical reactions are subsequently coupled with stochastic dynamics at the crystal growth front to simulate energy minimization processes including twinning during crystallization in an igneous environment. The solid phase and the liquid phase are coupled with a temporal flexibility that sets the overall ratio between the rate of diffusion and chemical enrichment in the liquid state and the rate of crystallization. The parameter space of the model is explored extensively, followed by a reasonable transcription of physical parameters and an estimation of other parameters to construct realistic simulation scenarios yielding synthetic plagioclase stellates. The results are presented, analyzed and discussed. They appear to be in reasonable qualitative agreement with observations, and several aspects of the natural stellates such as the stellate spacing and long continuous stretches of plagioclase with epitaxial junctions seem to be in reasonable quantitative agreement with observations.

This thesis reports the development, testing, and application of computer programs for simulating Lagrangian-Stochastic particle dispersion in coastal seas, with particular application to tide and storm induced dispersion in South Australian seas. The three-dimensional tidal equations are briefly discussed for the two types of surge models used, and finite-difference methods for numerically solving these equations are considered. Different methods of simulating flows at open sea boundaries are investigated. The method of particle tracking and the development of the particle tracking model is also described. Various tests are conducted to investigate both the advective and diffusive aspects of dispersion, and a number of scenarios for the simulation of open (ocean) and closed (coastal) boundaries are considered. Various aspects of the particle tracking routine are given specific characteristics according to the nature of the particle being considered. Application of the tide and storm surge model to the Great Australian Bight is described. This uses spherical polar co-ordinates to account for the curvature of the earth, and an oblique boundary element to increase accuracy of the coastline representation. The effect of a low pressure system moving from west to east across the Bight and the resulting significant observed surge at Thevenard during the storm of April 1996 is simulated. This storm resulted in a significant number of deaths in aquaculture farms containing southern bluefin tuna (Thunnas maccoyii) within the Boston Bay region to the extreme east of the Bight due to the agitation of almost neutrally buoyant organic sediments at the sea floor. The effects of this storm are further considered using a Cartesian co-ordinate fine-grid local model of Boston Bay, in Spencer Gulf, South Australia, where both tidal and storm (wind and outside surge) induced flows are simulated. The dispersion of suspended neutrally buoyant sediment throughout the region is considered, and compared with the mortalities of tuna at various farms within the region. Tidal and storm induced currents in the Gulf St. Vincent region, South Australia, have also been modelled using Cartesian co-ordinates. Detailed consideration has been given to the modelling of tides, winds, atmospheric pressures and outside surges from the two open boundaries in Investigator Strait and Backstairs Passage. The information obtained has enabled the modelling of a number of storm surge scenarios. Further to this, various simulations of the dispersion of the larvae of the western king prawn (Penaeus latisulcatus) have been driven using the storm surge model developed. These incorporate currents near the surface and the sea floor, as well as the consideration of changes in behaviour during the life history of the larvae. / Thesis (Ph.D.)--Engineering, Computer and Mathematical Sciences, 2000.

Les fours de maintien à induction sous vide sont utilisés pour la fabrication d'aubes de turbine à l'aide du procédé de fonderie à cire perdue. La maîtrise de la thermique de ce dernier est primordiale afin d'assurer la qualité de la production. Ce travail est composé de 3 grandes parties : la modélisation détaillée du four, la modélisation réduite et l'expérience. Un four axisymétrique et sa charge ont été modélisés numériquement à l'aide des logiciels FlexPDE et COMSOL Multiphysics. Ces modèles utilisent en entrée la puissance consommée par les inducteurs et fournissent en sortie la température en tout point du module de chauffe et de la charge. Les modèles réduits étudiés sont des modèles physiques dit convolutifs (enthalpique (0D), analytique de dimension 1 (1D)) et paramétrique de type AutoRégressifs avec variables eXogènes (ARX). Les modèles ARX ont été comparés aux modèles convolutifs (procédures d'identification, puis de validation, de modèles). L'objectif est d'accéder à des températures en certains points du four sans présence d'un capteur physique local (capteur virtuel). Les modélisations détaillées et réduites ont été comparées à des expériences réalisées sur four de production. Cette dernière partie n'est pas décrite dans ce mémoire / Vacuum holding induction furnaces are used for the manufacturing of turbine blades by loss wax foundry process. Heat transfer control in a holding furnace is crucial to ensure the quality of manufacturing. This work has 3 major parts, which are the detailed modelling, reduced modelling and experiments. An axyisymmetric furnace and its load have been numerically modelled using FlexPDE and COMSOL Multiphysics, finite element codes. Modelling takes as inputs the electric power consumed by inductors and gives the temperature field in the heating module. The studied reduced models are phyisical convolutive models (enthalpic (0D), 1 dimension analytical (1D)) and parametric like AutoRegressive with eXogeneous inputs (ARX). ARX models have been compared to convolutive models (identification, validation). The goal is to get temperatures in the heating module without local presence of physical sensors (virtual sensor). Detailed and reduced models have been compared to experiments on the furnace. This last part is not described in this document

La suffusion est un cas particulier d'érosion interne qui apparait dans les ouvrages hydrauliques. Elle se caractérise par le détachement et le transport des particules fines à travers les gros grains sous l'action d'un écoulement hydraulique en laissant derrière un squelette granulaire dont les caractéristiques en termes de densité et d'arrangement géométrique granulaire ont été changées. De telles modifications dans la micro-structure du sol peuvent conduire à des déformations à l'échelle macroscopique et peuvent influencer le comportement mécanique du sol. Ce travail a été consacré à l'étude du mécanisme de suffusion et à son impact sur les propriétés mécaniques des sols non-cohésifs. Pour atteindre cet objectif, deux approches ont été suivies dans ce travail: l'une numérique et l'autre expérimentale. Un modèle numérique discret a été défini pour décrire quantitativement le comportement macroscopique du sol et analyser la micro-structure des assemblages granulaires. Il est basé sur l'utilisation de particules sphériques et la résistance au roulement aux contacts, ainsi que sur une nouvelle méthode de compactage des échantillons pour simuler celle utilisée au laboratoire, et atteindre une large gamme de densités initiales. Le modèle a été validé par comparaison de résultats numériques et de données expérimentales. Ce modèle a d'abord été appliqué sur des assemblages granulaires avec des teneur en fines différentes afin d'étudier le rôle des particules fines pour une micro-structure de sol donnée, sans tenir compte d'un processus d'érosion. Il a été montré qu'il existe un pourcentage de fines, en dessous de la teneur seuil, où des particules fines peuvent commencer à participer au transfert de force, et que, si la suffusion s'initie et mobilise ces particules, ceci pourra affecter le comportement macroscopique du sol. Par la suite, une cinétique simplifiée d'extraction du grain a été proposée pour décrire le processus de suffusion. Elle est basée sur une approche de couplage fluide-solide partielle. L'intérêt de cette procédure d'extraction est que, d'une part, elle tient en compte des critères géométriques et hydrauliques complexes; d'autre part, le modèle induit un coût de calcul raisonnable. Cette procédure a été validée sur la base d'essais expérimentaux de suffusion effectués avec un dispositif nouvellement développé. Les conséquences de cette érosion sur les propriétés mécaniques des sols ont été caractérisées par la réalisation en laboratoire et la simulation d'essais de compression triaxiale. Le développement de la suffusion et ses conséquences sur le comportement macroscopique sont discutés en terme de densité et granulométrie initiale du sol, de chargement hydraulique et du type de particules érodées (actives ou inactive vis-à-vis du transfert de force). / Suffusion is a particular case of internal erosion taking place in hydraulic earth structures. It is characterized by the detachment and migration of fine particles by interstitial flow leaving behind the granular skeleton. Such modifications in the soil microstructure may lead to deformations at the macroscopic scale and may influence the mechanical behavior of the soil. This research was devoted to investigate the suffusion mechanism and its impact on the mechanical properties of cohesionless soils. To achieve this objective, two approaches were followed in this work: numerical and experimental approaches. A discrete numerical model was defined to describe quantitatively the soil macroscopic behavior and to analyze the microstructure of granular assemblies. It is based on the use of spherical particles and contact rolling resistance, as well as a new method of compaction to mimic the one used in laboratory and to reach a wide range of initial densities. The model was validated through comparison of numerical results with experimental data. This model was first applied on granular assemblies with different fines contents to study the role of fine particles with respect to a given soil microstructure, without taking into account an erosion process. It was shown that there exists a fines content, below the threshold, where fine particles may start to participate in the force transfer that if suffusion initiates and mobilizes these particles, it may affect the macroscopic behavior of the soil. Thereafter, a simplified kinetics of grain extraction was proposed to describe the suffusion process. It was based on a one-way fluid-solid coupling approach. The importance of this extraction procedure is that, on one hand, it takes into account complex geometric and hydraulic criteria; on the other hand, the model involves an affordable computational cost. This procedure was validated based on experimental tests carried out using a newly developed suffusion apparatus. Consequences of this erosion on the mechanical properties of soils were characterized from experimental and simulated triaxial compression tests. Suffusion development and its consequences on the macroscopic behavior are discussed from the results obtained in terms of the initial soil density and gradation, the hydraulic loading and the type of eroded particles (active or inactive in the force transfer).

The Swedish municipalities of Gävle and Älvkarleby need new sources of drinking water as the population grows. Gästrike vatten AB has employed the consultant firm Midvatten AB to assess the possibility of a new groundwater extraction site on the Uppsala esker between Älvkarleby and Skutskär in northern Uppland county. It has been observed that the natural recharge to the aquifer in the Uppsala esker might be too low to compensate for a future groundwater extraction and that there is a risk of induced infiltration from the river Dalälven if the water table is lowered. River water might bring organic contaminants into the aquifer and negatively affect the groundwater quality.A solution proposed by Midvatten is to infiltrate the esker with river water free from organic contaminants at infiltration sites. This artificial infiltration is estimated to create new groundwater to compensate for the extraction and stop river water from reaching the extraction wells. There is however, a need to estimate the magnitude of infiltrating river water when the infiltration sites are active.The aim of this study was to estimate the flow of water between the river and a section of the Uppsala esker for a test period during 2017, specifically, the infiltration from the river. In addition to this, changes in flow depending on proposed pumping and infiltration scenarios were modelled.A MODFLOW model was developed in the graphical user interface Groundwater Modeling System (GMS) and its performance was validated against observed aquifer head. The model could accurately represent the head close to the river but was less accurate with increasing distance from the river. Average infiltration from the river varied from 3 to 25 l s-1. The calculated infiltration depended on which extraction well or artificial infiltration site was active and the rate of flow.It was concluded that the distribution of hydraulic conductivity in the aquifer was not sufficiently detailed. A solution could have been to use stratigraphic data from borehole logs instead of a general quaternary deposits map as basis for the distribution of hydraulic conductivity. Artificial infiltration close to the river prevented large volumes of induced infiltration. The accuracy of the model could have been improved if the results were compared to other methods such as particle-tracking, tracer tests and with measurements of the streambed such as seepage meters. / Gävle och Älvkarlebys kommuner är i behov av nya grundvattentäkter för att kunna försörja invånarna med dricksvatten i framtiden. Ett område som är av intresse för de två kommunerna är ett grundvattenmagasin i Uppsalaåsen intill Dalälven mellan Älvkarleby och Skutskär. Vid ett dricksvattenuttag kan vattenbalansen i magasinet ändras. I magasinet uppskattas grundvattenbildningen vara för låg för att pumpa upp nog mycket vatten och bibehålla en stabil dricksvattenförsörjning. När uttaget av grundvatten är högre än grundvattenbildningen sänks grundvattenytan och vatten flödar från andra delar av magasinet eller älven för att kompensera. Älvvattnet bedöms ha en stark hydraulisk koppling med grundvattnet, vilket innebär att det finns en risk att älvvattnet infiltrerar i magasinet och sänker kvalitén på framtida dricksvatten.Konsultföretaget Midvatten AB har i uppdrag att bedöma möjligheten till ett framtida dricksvattenuttag. Midvatten har som lösning anlagt stationer med sprinklerinfiltration för att i framtiden kunna infiltrera avhumifierat älvvatten som på sikt omvandlas till grundvatten. Denna konstgjorda infiltration är också tänkt att hindra älvvatten från att ta sig in i magasinet genom att förse magasinet med den mängd vatten som går förlorad av dricksvattenuttag. Hur mycket älvvatten som tar sig in till grundvattenmagasinet och når brunnarna vid ett framtida uttag och konstgjord infiltration, är dock oklart.Syftet med denna studie var att uppskatta flödet mellan åsens grundvattenmagasin och Dalälven och specifikt infiltrationen av älvvatten. Detta gjordes genom att utveckla en digital MODFLOW-flödesmodell i programmet GMS. Modellen kunde, med hjälp av uppmätta vattennivåer i grundvattenmagasinet och älven, räkna ut hur mycket vatten som flödade in från älven (infiltrerade). Den uträknade infiltrationen låg i genomsnitt på 3-25 l s-1. Infiltrationsmängden berodde på vilken brunn som vattnet pumpades ur, hur mycket som pumpades ut och hur mycket artificiell infiltration som tillfördes i de tre infiltrationsområdena under en period av 2017. Modellen användes även till att uppskatta flödet från älven för 28 tilltänkta scenarier under 2017 med konstant pumpning och konstgjord infiltration i de olika brunnarna och infiltrationsstationerna.Resultaten visade att modellen kunde uppskatta grundvattenmagasinets vattennivåer nära älven men inte på längre avstånd ifrån älven. Detta berodde på att magasinets hydrauliska parametrar inte var korrekt fördelade. Fördelningen kunde ha förbättrats om de baserats på jordarter från borrprotokoll istället för en jordartskarta. Modellen visade att mycket lite älvvatten flödar in i akviferen om vatten artificiellt infiltreras nära älven. För att resultaten av den här studien ska bli tillförlitliga krävs det att resultaten jämförs med andra metoder som använder sig av förslagsvis partikelspårningsmodeller, spårämnesstudier eller flödesmätningar av flodbädden.

Le travail présenté dans cette thèse s’inscrit dans le cadre de différents programmes de recherches sur la modélisation et la conception des machines synchrones à aimants permanents, pour des applications de transports terrestres. En effet, la tendance actuelle, que ce soit dans la traction ferroviaire, ou dans les véhicules électriques et/ou hybrides électriques, est d’utiliser de tels moteurs pour leurs grandes performances massiques et leur bon rendement. Cette tendance est également observable dans les grandes éoliennes à attaque directe. Toutefois, un inconvénient de ces machines est l’existence de pertes pouvant être importantes dans les aimants permanents. Ces pertes sont d’une part à l’origine d’une dégradation du rendement, mais elles peuvent aussi être à l’origine d’échauffements excessifs des aimants, avec des risques de désaimantation d’une part et des risques de décollement d’autre part. Dans ce contexte, l’objectif de notre travail de thèse a été d’établir de nouveaux modèles, plus précis, des pertes par courants de Foucault dans les aimants. Les modèles utilisés actuellement sont généralement des modèles bidimensionnels qui ignorent donc le fait que les courants de Foucault ont une répartition tridimensionnelle dans les aimants. Afin de valider le modèle développé, une maquette expérimentale a été mise en place. Dans un premier temps, le modèle de calcul des pertes par courants induits dans les pièces massives a été validé en utilisant une approche qui combine les résultats expérimentaux et ceux calculés analytiquement et numériquement. Ensuite différentes grandeurs globales et locales issues du modèle analytique ont été comparées aux éléments finis aussi bien en 2D qu'en 3D de même qu'aux mesures expérimentales. Les modèles et méthodes de calcul et de mesures proposés pourront être efficacement utilisés ultérieurement pour estimer les pertes par courants induits dans les aimants permanents de moteurs synchrone à aimants. / The work presented in this thesis is part of various research programs on the modeling and design of permanent magnet synchronous machines for land transport applications. Indeed, the current trend, whether in railway traction, or in electric and / or hybrid electric vehicles, is to use such engines for their high mass performance and good efficiency. This trend is also observable in large direct-attack wind turbines. However, one disadvantage of these machines is the existence of significant losses in the permanent magnets. These losses can cause a deterioration in efficiency, and also be the cause of excessive heating of the magnets, with risks of demagnetization and risks of. In this context, the aim of our thesis work was to establish new, more accurate models of eddy current losses in magnets. The models currently used are generally two-dimensional models which therefore ignore the three-dimensional distribution of eddy currents in the magnets. In order to validate the model developed, we set up an experimental test bench. In a first step, the calculation of induced current losses in massive pieces was validated using an approach that combines the experimental results with those calculated analytically and numerically. Then, different global and local quantities from the analytical model were compared to the finite elements in both 2D and 3D as well as experimental measurements. The models and methods of computation and measurements proposed can be effectively used later to estimate eddy current losses in the permanent magnets of synchronous magnet motors.