Дисертації з теми "Wall models"
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Lamarche, Louis. "Reduction of wall interference for three dimensional models with two dimensional wall adaptation." Doctoral thesis, Universite Libre de Bruxelles, 1986. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213544.
Повний текст джерелаIssa, Camille Amine. "Nonlinear earthquake analysis of wall pier bridges." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54297.
Повний текст джерелаPh. D.
SACCO, FRANCESCO. "Mathematical models and analysis of turbulent, wall-bounded, complex flows." Doctoral thesis, Gran Sasso Science Institute, 2020. http://hdl.handle.net/20.500.12571/15321.
Повний текст джерелаIn many shear- and pressure-driven wall-bounded turbulent flows secondary motions spontaneously develop and their interaction with the main flow alters the overall large-scale features and transfer properties. Taylor–Couette flow, the fluid motion developing in the gap between two concentric cylinders rotating at different angular velocities, is not an exception, and toroidal Taylor rolls have been observed from the early development of the flow up to the fully turbulent regime. In this manuscript we show that under the generic name of ‘Taylor rolls’ there is a wide variety of structures that differ in the vorticity distribution within the cores, the way they are driven and their effects on the mean flow. We relate the rolls at high Reynolds numbers not to centrifugal instabilities, but to a combination of shear and anti-cyclonic rotation, showing that they are preserved in the limit of vanishing curvature and can be better understood as a pinned cycle which shows similar characteristics as the self-sustained process of shear flows. By analysing the effect of the computational domain size, we show that this pinning is not a product of numerics, and that the position of the rolls is governed by a random process with the space and time variations depending on domain size.
We use experiments and direct numerical simulations to probe the phase space of low-curvature Taylor–Couette flow in the vicinity of the ultimate regime. The cylinder radius ratio is fixed at η = r_i /r_o = 0.91, where r_i (r_o ) is the inner (outer) cylinder radius. Non-dimensional shear drivings (Taylor numbers Ta) in the range 10^7 ≤ Ta ≤ 10^11 are explored for both co- and counter-rotating configurations. In the Ta range 10^8 ≤ Ta ≤ 10^10 , we observe two local maxima of the angular momentum transport as a function of the cylinder rotation ratio, which can be described as either ‘co-’ or ‘counter-rotating’ due to their location or as ‘broad’ or ‘narrow’ due to their shape. We confirm that the broad peak is accompanied by the strengthening of the large-scale structures, and that the narrow peak appears once the driving (Ta) is strong enough. As first evidenced in numerical simulations by Brauckmann et al. (J. Fluid Mech., vol. 790, 2016, pp. 419–452), the broad peak is produced by centrifugal instabilities and that the narrow peak is a consequence of shear instabilities. We describe how the peaks change with Ta as the flow becomes more turbulent. Close to the transition to the ultimate regime when the boundary layers (BLs) become turbulent, the usual structure of counter-rotating Taylor vortex pairs breaks down and stable unpaired rolls appear locally. We attribute this state to changes in the underlying roll characteristics during the transition to the ultimate regime. Further changes in the flow structure around Ta ≈ 10^10 cause the broad peak to disappear completely and the narrow peak to move. This second transition is caused when the regions inside the BLs which are locally smooth regions disappear and the whole boundary layer becomes active.
Large scale structures have been observed in many turbulent wall bounded flows, such as pipe, Couette or square duct flows. Many efforts have been made in order to capture such structures to understand and model them. However, commonly used methods have their limitations, such as arbitrariness in parameter choice or specificity to certain setups. In this manuscript we attempt to overcome these limitations by using two variants of Dynamic Mode Decomposition (DMD). We apply these methods to (rotating) Plane Couette flow, and verify that DMD-based methods are adequate to detect the coherent structures and to extract the distinct properties arising from different control parameters. In particular, these DMD variants are able to capture the influence of rotation on large-scale structures by coupling velocity components. We also show how high-order DMD methods are able to capture some complex temporal dynamics of the large-scale structures. These results show that DMD-based methods are a promising way of filtering and analysing wall bounded flows.
Diaz, Ricardo H. "Critical evaluation and development of one-equation near-wall turbulence models." College Park, Md. : University of Maryland, 2003. http://hdl.handle.net/1903/2170.
Повний текст джерелаThesis research directed by: Aerospace Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Prinsloo, Wilma. "Computational models for conformations of cell wall mycolates from Mycobacterium tuberculosis." Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-06122009-114802/.
Повний текст джерелаGunawan, Leonardus. "Numerical models to simulate the thermal performance of LSF wall panels." Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/49856/1/Leonardus_Gunawan_Thesis.pdf.
Повний текст джерелаVisonà, Nicolò. "Study of plasma-wall interaction by fast cameras and numerical models." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3427219.
Повний текст джерелаLa tesi presentata è il risultato di tre anni di ricerca nel settore della fusione nucleare a confinamento magnetico, che ha come obiettivo di dimostrare la possibilità di ottenere energia pulita dalla fusione di atomi leggeri. Uno dei problemi attuali in questo campo riguarda l'interazione tra il plasma e la parete del dispositivo che lo contiene. Infatti i carichi termici e i flussi di particelle che incidono sulla prima parete possono danneggiare la struttura della macchina e, d'altra parte, le particelle rilasciate dai materiali che si affacciano al plasma possono influire negativamente sulle prestazioni e sul raggiungimento stesso dell'obiettivo della fusione controllata. L'attività svolta durante il periodo del dottorato di ricerca si è concentrata sullo studio dell'interazione plasma-parete, focalizzandosi su tre argomenti principali. Il primo è stato uno studio numerico di configurazioni magnetiche avanzate per ridurre sia l'intensità che la densità del flusso di calore incidente sul divertore di FAST, un tokamak proposto come esperimento satellite di ITER. Successivamente l'attività è stata svolta su RFX-mod, un'esperimento situato a Padova di confinamento magnetico in configurazione Reversed-Field Pinch. Si è studiata sperimentalmente l'interazione del plasma con dei provini ricoperti di tungsteno per analizzare le proprietà di questo materiale e valu-tarne il possibile impiego per future modifiche dell'esperimento. Come ultima attività sono stati misurati i flussi termici nel bordo del plasma tramite l'inserimento di campioni di grafite in configurazione limiter, misurando la lunghezza di decadimento del calore per la prima volta in un RFP. Il lavoro è presentato come segue. Il Capitolo 1 dà un'introduzione generale ai plasmi da fusione, al confinamento magnetico e alle principali configurazioni toroidali studiate. Viene fatta una breve introduzione a RFX-mod insieme ad uno sguardo a ITER. Il Capitolo 2 fornisce un'introduzione all'argomento del bordo plasma, introducendo concetti che sono alla base del lavoro presentato di seguito, come le configurazioni di divertore e limiter. Sono anche introdotti fenomeni fisici come il riciclaggio e gli elettroni sopratermici. Il Capitolo 3 descrive le simulazioni numeriche fatte nel contesto di studi preliminari per il tokamak proposto FAST. Una configurazione quasi-snowflake è stata studiata e confrontata a una di divertore standard usando il codice EDGE2D/EIRENE. Il Capitolo 4 presenta misure sperimentali di proprietà superficiali di provini ricoperti di tungsteno e di pura grafite. L'attività è stata svolta a RFX-mod con una telecamera veloce nel visibile che ha misurato le interazioni con il plasma ed è stata svolta un'analisi comparativa. Il Capitolo 5 descrive l'indagine sulle proprietà del flusso di calore del bordo del plasma di un RFP attraverso l'inserimento di campioni di grafite in configurazione limiter nel plasma di RFX-mod. La temperatura misurata è stata convertita in flusso termico da due software che sono stati standardizzati. I flussi termici e la lunghezza di decadimento del calore misurata sono stati analizzati e correlati con i parametri di plasma. Le Conclusioni sono presentate nell'ultimo capitolo insieme ad una panoramica sui possibili sviluppi futuri.
Gupta, Vikrant. "Linear amplification analysis for extraction of coherent structures in wall-bounded turbulent flows." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708610.
Повний текст джерелаSánchez, Rocha Martín. "Wall-models for large eddy simulation based on a generic additive-filter formulation." Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/28086.
Повний текст джерелаCommittee Chair: Menon, Suresh; Committee Member: Cvitanović, Predrag; Committee Member: Sankar, Lakshmi N.; Committee Member: Smith, Marilyn J.; Committee Member: Yeung, Pui-Kuen
Chin, David 1982. "Wall shear patterns of a 50% asymmetric stenosis model using photochromic molecular flow visualization." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111613.
Повний текст джерелаLau, Mei-wan, and 劉美雲. "On the early development of dispersion in flow through a tube with wall reactions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38994859.
Повний текст джерелаSánchez, Rocha Martín. "Wall-models for large eddy simulation based on a generic additive-filter formulation." Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/28086.
Повний текст джерелаKabiri, Ali. "Wall St. 1929 : Contemporary valuation models, money market arbitrage and liquidity Black Holes." Thesis, City University London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509120.
Повний текст джерелаCaillé, Jean. "New integral and differential computational procedures for incompressible wall-bounded turbulent flows." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/37425.
Повний текст джерелаPh. D.
Barrows, Richard James. "Two Dimensional Finite Element Modeling of Swift Delta Soil Nail Wall by "ABAQUS"." PDXScholar, 1994. https://pdxscholar.library.pdx.edu/open_access_etds/4741.
Повний текст джерелаBlackwell, Neal Elwood. "Wall jet model for ceiling fan applications in broiler houses." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54187.
Повний текст джерелаPh. D.
Lam, Sze Yue. "Ground movements due to excavation in clay : physical and analytical models." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/228701.
Повний текст джерелаHosseinpoor, Masoud. "Numerical simulation of fresh SCC flow in wall and beam elements using flow dynamics models." Thèse, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9808.
Повний текст джерелаRésumé : Récemment, il y a un grand intérêt à étudier les caractéristiques d'écoulement des suspensions dans différentes applications environnementales et industrielles, telles que les avalanches des neiges, les coulées de débris, les systèmes de transport et les processus d’écoulement des matériaux. En ce qui concerne les aspects rhéologiques, la plupart des suspensions, comme le béton frais, se comportent comme un fluide non-Newtonien. Le béton est le matériau de construction le plus largement utilisé dans le monde. En raison de limites qui caractérisent le béton normal en termes de maniabilité et de capacité de remplissage de coffrage, il était nécessaire de développer une nouvelle classe de béton qui peut couler sous son propre poids, en particulier à travers les zones congestionnées du coffrage. Par conséquent, le béton autoplaçant (BAP) est un nouveau matériau de construction qui est de plus en plus utilisé dans les différentes applications. Étant donné sa fluidité élevée de BAP peut être utilisé dans certaines applications particulières, notamment dans la section densément renforcée. Cependant, la fluidité élevée rend le béton plus sensible à la ségrégation des gros granulats pendant l'écoulement (la ségrégation dynamique) et ensuite au repos (ségrégation statique). La ségrégation dynamique peut augmenter lorsque le BAP est coulé sur une longue distance ou en présence d'obstacles. Par conséquent, il est toujours nécessaire d'établir un compromis entre la fluidité, la capacité de passage, et la stabilité du BAP. Ceci doit être pris en considération afin de concevoir le processus de coulée et dosage des mélanges du BAP. Ceci est appelé la conception d'ouvrabilité du BAP. Une conception de maniabilité efficace et non coûteuse peut être achevée à travers la e prévision et l'optimisation de l'ouvrabilité des mélanges de béton pour les procédés de construction sélectionnés, notamment le transport, le pompage, la mise en place, le compactage, la finition, etc. En effet, les formulations de mélange doivent se confirmer à la qualité de la construction demandée, par exemple les niveaux exigés de fluidité, la capacité de passage, la capacité de remplissage, et la stabilité (statique et dynamique). Celui est nécessaire pour développer des outils théoriques afin d’évaluer dans quelles conditions les exigences de qualité de la construction sont satisfaites. Cette thèse est consacrée à la réaliser des simulations analytiques et numériques pour prédire la performance d'écoulement du BAP dans différents procédés de la mise en place du béton. L'objectif spécifique de cette étude consiste à simuler l'écoulement du BAP dans essais empiriques, notamment la boite en L et la boite en T pour évaluer la performance du BAP pendent la mise en place (la fluidité, la capacité de passage, la capacité de remplissage, et la ségrégation dynamique induite par cisaillement ou par gravité). Par conséquent, le BAP est modélisé comme matériau hétérogène. En outre, un modèle analytique est proposé pour prédire la performance à l'écoulement du BAP dans la boite en L en utilisant la théorie de Dam Break. D'autre part, les résultats des simulations numériques de l’écoulement du BAP dans une poutre renforcée sont comparés aux résultats expérimentaux par des profils de surface libres. Les résultats des simulations numériques de BAP coulée (modélisée comme un fluide homogène unique), sont utilisés pour déterminer les zones critiques correspondant à des risques plus élevés de ségrégation et de blocage. Les effets des paramètres rhéologiques, la masse volumique, le contenu des particules, la distribution de barres d'armature, et les interactions particule-barres sur les performances d'écoulement du BAP sont évaluées à l'aide de simulations MFN d’écoulement du BAP par les essais des L-Box et T-box (modélisée comme une matériau hétérogène). Deux nouvelles approches sont proposées pour classifier les mélanges du BAP sur la base de la capacité de remplissage, et les propriétés de performabilité, en fonction de la fluidité, la capacité de passage et de la stabilité dynamique du BAP.
Furbo, Eric. "Evaluation of RANS turbulence models for flow problems with signigicant impact of boundary layers." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-138757.
Повний текст джерелаHeazel, Thomas Edward. "Cell wall sulfur distribution in sulfonated southern pine latewood." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/5786.
Повний текст джерелаBiehler, Jonas [Verfasser], Wolfgang A. [Akademischer Betreuer] [Gutachter] Wall, and Phaedon-Stelios [Gutachter] Koutsourelakis. "Efficient Uncertainty Quantification for Large-Scale Biomechanical Models Using a Bayesian Multi-Fidelity Approach / Jonas Biehler ; Gutachter: Wolfgang A. Wall, Phaedon-Stelios Koutsourelakis ; Betreuer: Wolfgang A. Wall." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1123729220/34.
Повний текст джерелаPerry, Logan Andrew. "Sensitivity Study on Modification of Vertical Distribution of Strength and Stiffness in Wood Shear Wall Building Models." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/96023.
Повний текст джерелаMS
Grill, Maximilian Josef [Verfasser], Wolfgang A. [Akademischer Betreuer] Wall, Wolfgang A. [Gutachter] Wall, and Philipp J. [Gutachter] Thurner. "Computational Models and Methods for Molecular Interactions of Deformable Fibers in Complex Biophysical Systems / Maximilian Josef Grill ; Gutachter: Wolfgang A. Wall, Philipp J. Thurner ; Betreuer: Wolfgang A. Wall." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/122267274X/34.
Повний текст джерелаMumaw, James. "A comparison of analytical models and experimental results for the acoustic response in a non-rigid-wall enclosure." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-10022008-063326/.
Повний текст джерелаKarolyi, Daniel Roberts. "Hemodynamic wall shear stress in models of atherosclerotic plaques using phase contrast magnetic resonance velocimetry and computational fluid dynamics." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/20132.
Повний текст джерелаTassotti, Luca. "Seismic analysis and design of innovative steel and concrete hybrid coupled wall systems." Doctoral thesis, Università Politecnica delle Marche, 2015. http://hdl.handle.net/11566/242920.
Повний текст джерелаThe concept of structural fuse applied to earthquake resistant systems has led to the development of several seismic-resistant structural solutions, including interesting steel and concrete hybrid systems. These systems are obtained through a combination in series of steel elements and reinforced concrete elements with the aim of exploiting at their best the potentialities of each material. In this work the seismic behaviour of an innovative hybrid coupled shear wall (HCSW) system, developed in the European research project INNO-HYCO (INNOvative HYbrid and COmposite steel-concrete structural solutions for building in seismic area), is investigated. The earthquake resistant solution is composed by a reinforced concrete wall coupled to steel side columns by means of easily replaceable steel links with the objective to exploit both the stiffness of reinforced concrete wall, necessary to limit building damage under low-intensity earthquakes, and the ductility of steel links, necessary to dissipate energy under medium- and high-intensity earthquakes. The seismic behaviour of the system is assessed through nonlinear static (pushover) analysis and multi-record nonlinear incremental dynamic analysis (IDA). For this purpose, firstly a set of realistic case studies is designed, then a finite element model is developed into the platform Opensees and validated through comparisons against experimental tests including local and global responses quantities. A selection of results including global and local response quantities is shown in order to highlight the potentialities of the proposed innovative HCSW systems and the actual possibility to develop a ductile behaviour where plastic deformation are attained in the steel links before yielding in the reinforced concrete wall. The final results permit to provide a support for the identification of optimal solutions that could be competitive against existing seismic resistant structural systems.
Williams, Scott A. "Numerical Analysis of Reinforced Masonry Shear Walls Using the Nonlinear Truss Approach." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/25219.
Повний текст джерелаMaster of Science
Palombo, Carlo Loris. "Development and validation of an improved wall-function boundary condition for computational aerodynamics." Thesis, KTH, Strömningsmekanik och Teknisk Akustik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-293754.
Повний текст джерелаBerör strömmande fluider inom mycket olika områden. Industriella CFD-lösare utvecklaskontinuerligt i syfte att förbättra noggrannheten och minska beräkningskostnaderna försimuleringarna. Turbulent strömning nära väggar är särskilt krävande eftersom närvaron avett fast ytgränssnitt genererar stora gradienter i närheten av väggen. Att lösa upp sådanagradienter kan vara avgörande för att få en konsistent lösning men också mycket beräkningskrävandepå grund av nödvändig nätförfining.Väggfunktioner används ofta och ger betydandereduktioner i beräkningstid när det gäller att lösa upp strömningen nära vägg. En tidigareväggfunktion implementerad i M-Edge-lösaren led av dåliga prestanda i komplexa flödenmed starka tryckgradienter, såsom separation. En ny formulering har utvecklats och valideratsför k − omega och Spalart-Allmaras turbulensmodeller. Den har testats för enkla generiska fall(2D-plan platta utan tryckgradient) och för mer avancerade och komplexa strömningsfall ochgeometrier (komplett 3D-stridsflygplan).Varje fall har körts med väggfunktionens randvillkorkopplat med tre olika turbulensmodeller: Menter SST, Menter BSL med EARSM och Spalart-Allmaras enekvationsmodell. De övergripande resultaten visar att nya väggfunktionen gerbetydande förbättringar i att beskriva strömningen tillsammans med reducerade krav pånätupplösning, snabbare och djupare konvergens av lösningen och en allmän minskning avberäkningstiden.
Ranasinghe, Chathura P. "Development of combustion models for RANS and LES applications in SI engines." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/12507.
Повний текст джерелаDick, Melissa. "The effect of statins on endothelial cell response to wall shear stress in three dimensional in vitro tissue culture models." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107919.
Повний текст джерелаL'hypercholestérolémie est un facteur de risque des maladies cardiovasculaires comme l'athérosclérose. L'athérosclérose est une maladie dans laquelle les globules blancs, des lipides (y compris le cholestérol), et d'autres débris cellulaires s'accumulent dans les parois des vaisseaux sanguins ce qui provoque l'inflammation et le rétrécissement des vaisseaux, menant finalement à une crise cardiaque. Les statines, des inhibiteurs de l'enzyme 3-hydroxy-3-méthylglutaryl coenzyme A (HMG-CoA) réductase, ont été conçus pour inhiber la synthèse du cholestérol en empêchant la conversion de l'HMG-CoA en mévalonate dans la voie de biosynthèse du cholestérol. Bien que efficace pour réduire les taux de cholestérol, les statines démontrent d'autres effets bénéfiques. Les scientifiques pensent que ces effets sont causés par l'influence positive des statines sur les cellules endothéliales, la couche interne de la vascularisation qui est constamment exposée aux forces de cisaillement du fluide vasculaire.Ce travail étudie l'effet des statines et la contrainte de cisaillement sur la fonction et la structure des cellules endothéliales en utilisant un modèle tridimensionnel, in vitro de culture tissulaire. Les cellules ont été cultivées dans le modèle, exposées à une contrainte de cisaillement de 12,5 dynes/cm2, et traités avec la statine simvastatine pendant 24 heures. La morphologie des cellules endothéliale, l'arrangement du cytosquelette d'actine et l'adhésion des neutrophiles aux cellules endothéliales ont été analysés.Les statines ont causé l'arrondissement des cellules endothéliales, un phénotype malsain, qui n'a pas été renversé par la présence des forces de cisaillement. Le cytosquelette d'actine a été perturbé par le traitement aux statines, un effet qui n'a également pas été renversé par les forces de cisaillement. Il n'y avait pas de preuve que la thérapie aux statines affecte l'adhésion des neutrophiles, même si les forces de cisaillement ont diminué l'adhérence. L'ajout de mévalonate a inversé tous les effets des statines, ce qui confirme la réglementation statine par la voie de biosynthèse du cholestérol. Comprendre comment les statines affectent les cellules endothéliales en présence de forces de cisaillement pourrait permettre de meilleures options de traitement dans l'avenir.
Guardigli, Sara. "Dynamic out-of-plane behaviour of Dutch cavity walls: validation of numerical models." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Знайти повний текст джерелаJohnson, Kevin Robert. "In Vivo Coronary Wall Shear Stress Determination Using CT, MRI, and Computational Fluid Dynamics." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14482.
Повний текст джерелаYanovskiy, Vadim. "Theoretical analysis of tokamak disruptions by simplified analytical models and numerical simulations." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3427140.
Повний текст джерелаUno dei principali ostacoli sulla via della realizzazione di un reattore a fusione commerciale che si basi sulla configurazione Tokamak è rappresentato dalle disruzioni, cioè dalle terminazioni veloci della scarica di plasma, che se non adeguatamente mitigate possono causare danni gravi al reattore. Per futuri grandi impianti come ITER o DEMO, i forti carichi elettromagnetici sul contenitore da vuoto (vessel) durante le disruzioni possono minacciarne l’integrità strutturale. Alcune stime per ITER prevedono forze di decine di MN, ma la mancanza di una teoria veramente predittiva e completa, che includa tutti gli effetti rilevanti, solleva anche preoccupazioni sull’accuratezza di queste previsioni. Le forze più elevate sono osservate sperimentalmente quando il plasma viene in contatto con la prima parete. L’ampiezza dipende dalle cosiddette correnti di halo, che rappresentano la parte di corrente di plasma che può fluire verso le strutture conduttive ed eventualmente richiudersi nuovamente sul plasma stesso. Incertezze sull’ampiezza e la distribuzione delle correnti di halo e sulla dinamica del processo rappresentano una sfida aperta ai modelli teorici. La prima parte del lavoro di tesi presenta il calcolo delle forze elettromagnetiche sul vessel esercitate da una perturbazione in approssimazione cilindrica e l’analisi e la relazione tra vari tipi di correnti: le correnti indotte (eddy), le correnti di superficie (surface) e le correnti di halo propriamente dette. La seconda parte della tesi è dedicate alle instabilità più pericolose che possono portare a disruzioni: I modi di parete detti Resistive Wall Modes (RWM) e i modi tearing o riconnettivi. In presenza di una parete resistiva entrambi possono essere soppressi o almeno mitigati dalla rotazione di plasma. Questo effetto viene studiato analiticamente per configurazioni con shear magnetico positive e negative. Si analizza l’effetto della rotazione nel caso specifico di uno scenario tokamak avanzato con profilo di corrente cavo. Rispetto al problema del frenamento di un’isola magnetica vengono considerati gli effetti di pareti resistive multiple (fino a 3) aventi diverse conducibilità elettriche. In particolare viene derivata una formula analitica semplice per il momento elettromagnetico esercitato dalla parete di ITER, comprendente vessel e blanket.
Šliaužytė, Brigita. "Kompiuterinio automatizuoto projektavimo posistemė pastato sienoms su angomis formuoti." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060605_094639-19992.
Повний текст джерелаDing, Yao. "Evaluation of New Seismic Performance Factors for Special Hybrid Coupled Core Wall Systems with Steel Coupling Beams." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573225104906633.
Повний текст джерелаPELA', Luca. "CONTINUUM DAMAGE MODEL FOR NONLINEAR ANALYSIS OF MASONRY STRUCTURES." Doctoral thesis, Università degli studi di Ferrara, 2009. http://hdl.handle.net/11392/2389195.
Повний текст джерелаNguyen, Van Vinh. "Direct Strength Method for the Design of Cold-Formed Steel Sections Under Localised Loading." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17069.
Повний текст джерелаSavio, Daniele. "Nanoscale phenomena in lubrication : From atomistic simulations to their integration into continuous models." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961197.
Повний текст джерелаKheirkhah, Gildeh Hossein. "Numerical Modeling of Thermal/Saline Discharges in Coastal Waters." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24230.
Повний текст джерелаVaa, Kristian Huustad. "Yttervägg av trä utan invändig diffusionsbarriär : En byggnadsfysikalisk studie av en stuga." Thesis, Mittuniversitetet, Avdelningen för ekoteknik och hållbart byggande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-35526.
Повний текст джерелаWood has physical properties that makes it different from most other materials that traditionally has been used as load bearing parts when constructing a building. The hygroscopic properties and low relative weight of wood makes room for a different field of application than what is the case with for instance concrete or steel. Its low relative weight also gives interesting constructional possibilities and can make it possible to build on sites otherwise inaccessible without advanced techniques and means of transport. In this report the lower part of an exterior wall in a mountain cabin has been studied. The purpose of the study has been to examine whether the cabin will have problems related to mould or fungus. The examined part of the wall lies three meters below ground level. It is constructed with a steam barrier towards the ground, and a one meter thick layer of foam glass fragments on the inside of this. Further towards the inside of the wall there is a geotextile, two layers of 100 mm wood fibre insulation and one layer of 93 mm thick laminated vertically timbered timber, which faces the inside of the cabin. The examination was performed as an analysis of a simulation made with the software WUFI® Pro 6.1. The results of the analysis were quantitative data in the form of graphs and diagrams that were easily assessed against relevant literature. The results from the simulation showed that the construction would not have any problems related mould or fungus. However, the moisture buffering properties of the wood are obvious, and it is generally considered important that materials have a built-in moisture that is below what is favourable for mould or fungus growth.
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Olander, Sahlén Simon. "Feature Analysis in Online Signature Verification on Digital Whiteboard : An analysis on the performance of handwritten signature authentication using local and global features with Hidden Markov models." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-224661.
Повний текст джерелаAnvändandet av signaturer för autentisering är allmänt accepterat, och är fortfarande den mest använda biometriken i vårt samhälle. Arbetet med att digitalisera och automatisera verifieringen av dessa signaturer är ett populärt ämne inom maskininlärning, och en uppsjö av olika verktyg och metoder har utvecklats och anpassats för detta ändamål. Avsikten med denna studie är att bestämma hur man mest framgångsrikt kan inrätta ett verifikationssystem för handskrivna signatures på digitala whiteboards baserat på dolda Markovmodeller (HMMs) och globalt aggregerade attribut. Syftet är att bedöma vilka features som är Lämpliga för att bestämma huruvida en signatur är äkta Lämpliga för att avvisa förfalskningar Olämpliga för att mäta äktheten hos en signatur över huvud taget Utöver detta studerar vi HMM-konfigurationen själv, i syfte att hitta bra konfigurationer för Antalet komponenter som används i modellen Vilken typ av kovarians som ger bäst resultat Det bästa tröskelvärdet vid vilken att dra gränsen för huruvida en signatur är äkta eller förfalskad För forskningen samlade vi totalt in 200 signaturer och 400 förfalskningar från 10 olika personer med hjälp av digitala whiteboards. Vi drog slutsatsen att de bästa konfigurationerna hade 11 komponenter, använde komplett kovarians, och använde cirka fem features, där tryck, vinkel och hastighet var det viktigaste. Bland våra globala features kastade vi 11 av 35 på grund av att de antingen korrelerade för starkt med andra features, eller på grund av att de innehöll för lite information för att utröna huruvida en signatur var äkta eller ej. Våra bästa globala features var de som hänförde sig till hastighet, acceleration, riktning och krökning. Genom att använda den kombinerade verifieraren fick vi en EER på 7 %, vilket är i linje med liknande studier. Vi drog även slutsatsen att det bästa sättet att kombinera global verifiering med lokal HMM-verifiering är att utföra dem separat och endast acceptera signaturer som godkänns av bägge två. Den bästa toleransnivån för den globala och lokala verifieraren var 1,2 och 2,5 standardavvikelser, respektive.
Stocca, Valentina. "Development of a predictive LES model for the study of the pollutant dispersion in urban areas." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3512.
Повний текст джерелаIn this thesis, a new large-eddy simulation solver, LES-AIR, has been developed, tested and applied to a practical situation of flow and pollutant dispersion in urban environments. The novelty of the present research resides in the application of a high resolution, accurate, CFD technique to the simulation of real-life flows. The code uses a body fitted curvilinear grid to account for the macro geometry such as terrain slopes, and is thus able to reproduce in detail the complex conditions typical of urban areas; by utilizing the technique of immersed boundaries, the code is also able to mimic the presence the micro complexities such as anthropic structures (i.e. buildings). The first part of the thesis presents a detailed description of the mathematical and numerical model on which the code is based. An extensive set of validation tests was performed in flow configurations having an increasing degree of complexity in terms of forcing and geometry. The numerical model thus validated is applied for obtaining flow and pollutant dispersion in the Servola-Valmaura suburban area of the city of Trieste in Italy. The pollutant was introduced into the domain from a line source near the ground, mimicking the emission from vehicular traffic. In spite of the idealizations inherent to the model, LES-AIR is able to predict the flow and dispersion patterns well, and has proven to be a reliable tool for adaptation in urban pollution studies.
Nella presente tesi è stato sviluppato, testato ed applicato ad un caso studio applicativo un nuovo solutore numerico, chiamato codice LES-AIR, capace di predire i campi di vento e la dispersione di nquinanti in ambienti urbani. La maggiore novità di questo lavoro risiede nell’utilizzo di una tecnica fluidodinamica molto accurata e ad alta risoluzione per la simulazione di flussi reali. Il codice LES-AIR è capace di riprodurre con grande dettaglio le geometrie complesse tipiche delle aree urbane tramite l’utilizzo congiunto di una griglia curvilinea, che si adatta all’ orografia del terreno, e della tecnica dei corpi immersi, con la quale vengono riprodotti gli ostacoli antropici, quali gli edifici. Nella prima parte della tesi viene fornita una descrizione dettagliata del modello matematico e numerico su cui si basa il codice. Il modello è stato validato per mezzo di un esteso set di casi test, aventi un grado crescente di complessit à in termini di forzanti e di configurazione geometriche. Il modello così validato è stato applicato alla riproduzione di un caso applicativo nel quale i campi di vento e la dispersione di un inquinante nella zona di Servola-Valmaura, situata nella periferia di Trieste, sono stati simulati. L’ inquinante è stato introdotto da una sorgente lineare posta in prosimità del terreno e rappresentante l’emissione derivante dal traffico cittadino. Nonostante le condizioni idealizzate di vento considerate, il codice LES-AIR si è dimostrato molto efficace nella predizione del flusso e della dispersione dell’inquinante e quindi si è attestato essere un valido strumento negli studi d’ inquinamento urbani.
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Dilip, Deepu. "Wall Modeled Large Eddy Simulation of Flow over a Wall Mounted Hump." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64356.
Повний текст джерелаMaster of Science
Yang, Jin Rong. "The Application of Fuzzy Logic and Virtual Reality in the Study of Ancient Methods and Materials Used for the Construction of the Great Wall of China in Jinshanling." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu152410262072719.
Повний текст джерелаSincos, Igor Rafael. "Determinação do impacto do oversizing da endoprótese sobre a aorta torácica. Estudo experimental em porcos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5132/tde-22012013-160615/.
Повний текст джерелаIntroduction: The use of endovascular techniques to treat the various disorders of the aorta has supplanted traditional open techniques, and is particularly promising in trauma1. The traumatic rupture of the aorta is the second leading cause of death by traffic accident2, 3, and repair of these lesions with endoluminal stents has showed lower mortality and paraplegia when compared to open surgery, however the long-term results are not yet available2-7. The endoprosthesis approved and commercially available during this study were designed to aneurysmal disease, with a diameter greater than the diameter of the aorta of young people ( ) \" z \" prosthesis with the aortic wall, affecting the vascularization and raising the risk of complications related to stent-graft implantation8-12. Purpose: Analyze, from an experimental animal model, the biomechanical and histological effects of four different levels of stents-graft oversizing in non-atherosclerotic aortas; such as those aorta found in young individuals who undergo stent-graft repair for traumatic aortic injuries. Methods: The diameter of the porcine thoracic aorta is similar to the aorta of young adults (18-20 mm), so 25 pigs were randomized into 5 groups: 1 control (without stent-graft) and 4 oversizing groups (A: 10%-19%, B: 20%-29%, C: 30%-39%, and D: .40%). Two types of biomechanical tests were performed on all aortas 4 weeks after endoprosthesis deployment: The \"detachment\" of the stent, and the biomechanics test of aortic fragments collected. The fragments were submitted to a histological and an immunohistochemistry analysis. Results: The results of the detachment test, which analyzed the strength necessary to remove the stent-graft from the aorta, were similar in the 4 groups (A: 42 N, B: 41 N, C: 46 N e D: 46 N, p= 0,881204). The second test was performed in 3 aortic segments. Maximum strength, maximum stress, and maximum tension supported by the aortic wall had a negative and linear correlation with oversizing. There were significant differences in all 4 groups when compared with the control group. The maximum deformation and strain, which reflect the elastic properties of the aortic wall, were very similar in all 4 groups. But a significant decrease in elasticity was found when compared each group with the control group (p = 0.0000001). Histological and immunohistochemistry analysis supported that the aortic wall has a signifi-?-actin by increasing the oversize (p = 0.000198 p = 0.002031, respectively). The amount of elastic fiber showed a significant drop regardless of the oversizing (p = 0.0000001). Conclusion: The four levels of oversizing studied did not show significant differences in the detachment test. Biomechanical tests of the fragments of the aorta showed a decrease in resistance of the aortic wall with increase in oversize. The elasticity of the aortic wall undergoes significant change independent of the oversizing used. The histopathological and immunohistochemical examinations confirmed the breakdown in the structure of the aortic wall with the use of stents-graft, resulting in decreased amount of elastic and muscle fibers.
Koudela, Pavel. "Stanovení hodnot vstupních parametrů pokročilých materiálových modelů s využitím optimalizačních metod." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372248.
Повний текст джерелаWong, Thomas. "Enumeration problems in directed walk models." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54483.
Повний текст джерелаScience, Faculty of
Mathematics, Department of
Graduate
Mehta, A. "Scaling approaches to interacting walk models." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370291.
Повний текст джерелаThomson, D. J. "Random walk models of turbulent dispersion." Thesis, Brunel University, 1988. http://bura.brunel.ac.uk/handle/2438/5549.
Повний текст джерелаBall, Stephen. "Near wall flow characteristics in jet impingement heat transfer." Thesis, Nottingham Trent University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388866.
Повний текст джерела