Log in

Relevant bibliographies by topics / Numerical modes / Dissertations / Theses

To see the other types of publications on this topic, follow the link: Numerical modes.

Dissertations / Theses on the topic 'Numerical modes'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Numerical modes.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Postnova, Julia A. "Trapped modes in non-uniform elastic waveguides : asymptotic and numerical methods." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/4384.

Full text

Abstract:

Trapped modes within elastic waveguides are investigated employing asymptotic and numericalmethods. The problems considered in this thesis concentrate on linear elastic wavesin thickened/thinned and curved waveguides. The localised modes are propagating withinsome region that is characterized by a small parameter but are cut-off for geometric reasonsexterior to that region, and thereafter exponentially decay with distance along the waveguide. Given this physical interpretation long wave theories become appropriate. The generalapproach is as follows: an asymptotic scheme is developed to analyse

APA, Harvard, Vancouver, ISO, and other styles

2

Adamou, Alexander Theodosis Ionas. "Asymptotic and numerical methods for trapped and propagating modes in slowly-varying waveguides." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438976.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Adams, Samuel David Matthew. "Asymptotic and Numerical Methods for Surface Waves and Modes in Elastic Guiding Structures." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511859.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Chen, Yi. "Propagation and Excitation of Electromagnetic Modes for Travelling-wave MRI Applications." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1449158025.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Sarkar, Mitradeep. "Hybrid surface plasmon modes in metallic nanostructures : Theory, numerical analysis and application to bio-sensing." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS251/document.

Full text

Abstract:

Les Plasmons de surface à l’interface d’un métal et d’un diélectrique sont des oscillations collectives des électrons libres. Pour une interface plane, les plasmons se manifestent comme des champs électromagnétiques évanescents, confinée à quelques centaines de nanomètres de la surface métallique et se propagent le long de l'interface. Ce mode plasmonique, appelé plasmon propagatif de surface (PSP), est un mode fondamental. D’autres modes fondamentaux, non-propagatifs, sont appelé plasmons localisés (LSP) et apparaissent dans les nano-particules métalliques. Dans ce travail, nous avons calculé

APA, Harvard, Vancouver, ISO, and other styles

6

Adamčík, Martin. "Limit Modes of Particulate Materials Classifiers." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-367539.

Full text

Abstract:

S požadavky materiálových věd na stále menší částice jsou potřebné i nové přístupy a metody jejich klasifikace. V disertační práci jsou zkoumány struktury turbulentního proudění a trajektorie částic uvnitř dynamického větrného třídiče. Zvyšující se výpočtový výkon a nové modely turbulence a přístupy modelování komplexních plně turbulentních problémů řešením Navier-Stokesových rovnic umožňují zkoumání stále menších lokálních proudových struktur a vlastností proudění s větší přesností. Částice menší než 10 mikronů jsou více ovlivnitelné a jejich klasifikace do hrubé nebo jemné frakce závisí na m

APA, Harvard, Vancouver, ISO, and other styles

7

Baselt, Tobias, Christopher Taudt, Bryan Nelsen, Andrés Fabián Lasagni, and Peter Hartmann. "Experimental measurement and numerical analysis of group velocity dispersion in cladding modes of an endlessly single-mode photonic crystal fiber." SPIE, 2017. https://tud.qucosa.de/id/qucosa%3A35152.

Full text

Abstract:

The optical properties of the guided modes in the core of photonic crystal fibers (PCFs) can be easily manipulated by changing the air-hole structure in the cladding. Special properties can be achieved in this case such as endless singlemode operation. Endlessly single-mode fibers, which enable single-mode guidance over a wide spectral range, are indispensable in the field of fiber technology. A two-dimensional photonic crystal with a silica central core and a micrometer-spaced hexagonal array of air holes is an established method to achieve endless single-mode properties. In addition to the g

APA, Harvard, Vancouver, ISO, and other styles

8

Streckienė, Giedrė. "Research of Heat Storage Tank Operation Modes in Cogeneration Plant." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110621_170138-31454.

Full text

Abstract:

The dissertation investigates typical operation modes of the heat storage tank in the small-scale cogeneration (CHP) plant, analyses formation of thermal stratifi-cation in such storage tank and presents the simulation of the stratification. The main aim of the dissertation is to investigate peculiarities of operation modes of heat storage tank in small-scale CHP plant, develop an algorithm allowing to choose the storage tank volume and present a model allowing determination of thermal stratification in the storage tank at any time of its operation.<br>Disertacijoje nagrinėjami būdingi šilumos

APA, Harvard, Vancouver, ISO, and other styles

9

Mirza, Ahmed Akram. "Pressure driven instabilities in the reversed-field pinch : numerical and theoretical studies." Doctoral thesis, KTH, Fusionsplasmafysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121345.

Full text

Abstract:

According to classical linearized resistive magnetohydrodynamics theory, pressuredriven modes are unstable in the reversed-field pinch (RFP) due to unfavorable magnetic field line curvature. The result is based on the assumption of an adiabatic energy equation where anisotropic thermal conduction effects are ignored as compared to convection and compression. In this thesis the effects of heat conduction in the energy equation have been studied. We have examined these effects on the linear stability of pressure-driven resistive modes using boundary value theory (Δ´ ) and a novel initial-value f

APA, Harvard, Vancouver, ISO, and other styles

10

Khan, Mohammad Arsalan. "FE investigation of failure modes at the soffit of a steel plated RC beam." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/16319.

Full text

Abstract:

In recent decades, a significant research has been carried out towards understanding the behaviour of plated beam. Initially designed to achieve a desired capacity, the plated beams prematurely fail in undesirable modes of failure, such as debonding and peeling. The uncertainty related with such modes of failure poses a real challenge towards quantifying them. This field is far from being clearly understood. Therefore, an attempt is made in this thesis to accurately predict the behaviour of adhesively plated beams.

APA, Harvard, Vancouver, ISO, and other styles

11

Calderon, F. A. "Non-linear instabilities in the edge of tokamak plasmas : characterization of edge localized modes and numerical simulation of blob dynamics using a hybrid model." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/77687/.

Full text

Abstract:

Characterization of edge tokamak plasma instabilities by measuring emergent phenomena within a range of frequencies above the ion cyclotron frequency have been explored in two ways: using the inter-event waiting times of Edge Localized Modes (ELMs) occurrences in measured time series of JET plasmas and by performing 2D/3D simulations of filamentary structures dynamics using a hybrid model plasma description, i.e. kinetic ion particles and massless charge neutralizing electron fluid. The analysis of ELMs time series using characteristic emission lines Da of JET tokamak in otherwise similar plas

APA, Harvard, Vancouver, ISO, and other styles

12

Haque, Amil. "Modeling of the excited modes in inverted embedded microstrip lines using the finite-difference time-domain (FDTD) technique." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26582.

Full text

Abstract:

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.<br>Committee Chair: Tentzeris, Emmanouil; Committee Member: Andrew Peterson; Committee Member: Laskar, Joy; Committee Member: Papapolymerou, Ioannis. Part of the SMARTech Electronic Thesis and Dissertation Collection.

APA, Harvard, Vancouver, ISO, and other styles

13

Zhydenko, Olexandr. "Perturbações lineares de buracos negros: estabilidade, modos quase-normais e caudas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-17082009-092359/.

Full text

Abstract:

Buracos negros têm as suas oscilações próprias, que são chamadas modos quase-normais. As oscilações próprias de buracos negros astrofísicos podem ser observadas no futuro mais próximo com a ajuda de detectores de ondas gravitacionais. Os modos quase-normais são também muito importantes no contexto de teste da estabilidade de objetos negros, da correspondência anti-deSitter/ Teoria Campos Conformes (AdS/CFT) e nas teorias em dimensões mais altas, como os cenários de mundo-brana e teoria das cordas. Esta tese revê um numero de trabalhos, que fornecem um estudo completo do espectro quase normal d

APA, Harvard, Vancouver, ISO, and other styles

14

Issa, Nader. "Modes and propagation in microstructured optical fibres." University of Sydney. Physics and Optical Fibre Technology Centre, 2005. http://hdl.handle.net/2123/613.

Full text

Abstract:

Microstructured optical fibres (MOFs), also commonly called photonic crystal fibres or holey fibres, describe a type of optical fibre in which continuous channels of (typically) air run their entire length. These `holes' serve to both confine electromagnetic waves within the core of the fibre and to tailor its transmission properties. In order to understand and quantify both of these functions, a new computational algorithm was developed and implemented. It solves for the eigenvalues of Maxwell's wave equations in the two-dimensional waveguide cross-section, with radiating boundary conditions

APA, Harvard, Vancouver, ISO, and other styles

15

Bolibrzuch, Milosz. "Introduction to some modes of convergence : Theory and applications." Thesis, Mälardalens högskola, Akademin för utbildning, kultur och kommunikation, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-44563.

Full text

Abstract:

This thesis aims to provide a brief exposition of some chosen modes of convergence; namely uniform convergence, pointwise convergence and L1 convergence. Theoretical discussion is complemented by simple applications to scientific computing. The latter include solving differential equations with various methods and estimating the convergence, as well as modelling problematic situations to investigate odd behaviors of usually convergent methods.

APA, Harvard, Vancouver, ISO, and other styles

16

Bagheri, Shervin. "Analysis and control of transitional shear flows using global modes." Doctoral thesis, Stockholm : Department of Mechanics, Royal Institute of Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11894.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

London, Lionel. "On gravitational wave modeling: numerical relativity data analysis, the excitation of kerr quasinormal modes, and the unsupervised machine learning of waveform morphology." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53973.

Full text

Abstract:

The expectation that light waves are the only way to gather information about the distant universe dominated scientific thought, without serious alternative, until Einstein’s 1916 proposal that gravitational waves are generated by the dynamics of massive objects. Now, after nearly a century of speculation, theoretical development, observational support, and finally, tremendous experimental preparation, there are good reasons to believe that we will soon directly detect gravitational waves. One of the most important of these good reasons is the fact that matched filtering enables us to dig grav

APA, Harvard, Vancouver, ISO, and other styles

18

Ruan, Kangping. "NUMERICAL AND EXPERIMENTAL TECHNIQUES FOR ASSESSING THE ACOUSTIC PERFORMANCE OF DUCT SYSTEMS ABOVE THE PLANE WAVE CUTOFF FREQUENCY." UKnowledge, 2018. https://uknowledge.uky.edu/me_etds/120.

Full text

Abstract:

This research deals with determining the acoustic attenuation of heating, ventilation, and air conditioning (HVAC) ductwork. A finite element approach was developed for calculating insertion loss and breakout transmission loss. Procedures for simulating the source and receiving rooms were developed and the effect of structureborne flanking was included. Simulation results have been compared with measurements from the literature and the agreement is very good. With a good model in place, the work was extended in three ways. 1) Since measurements on full-scale equipment are difficult, scale mode

APA, Harvard, Vancouver, ISO, and other styles

19

Jrad, Wassim. "Dynamic behavior of thin-walled beams : Analytical, numerical and experimental approaches." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0271.

Full text

Abstract:

Les poutres à parois minces à sections ouvertes sont des éléments de base des ouvrages courants en génie civil, de l'automobile et de l'aéronautique. En raison de leur élancement et la forme des sections, elles sont très sensibles à la torsion et aux instabilités aussi bien en statique qu’en dynamique. En dynamique, les modes de vibration en torsion sont plus dominants par rapport au modes de flexion classiques. Pour ces raisons, les défaillances planaires de telles structures sont connues pour être une exception plutôt qu'une règle. Dans ce travail de thèse, on s’intéresse au comportement dyn

APA, Harvard, Vancouver, ISO, and other styles

20

Romero, García Vicente. "On the control of propagating acoustic waves in sonic crystals: analytical, numerical and optimization techniques." Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8982.

Full text

Abstract:

El control de las propiedades acústicas de los cristales de sonido (CS) necesita del estudio de la distribución de dispersores en la propia estructura y de las propiedades acústicas intrínsecas de dichos dispersores. En este trabajo se presenta un estudio exhaustivo de diferentes distribuciones, así como el estudio de la mejora de las propiedades acústicas de CS constituidos por dispersores con propiedades absorbentes y/o resonantes. Estos dos procedimientos, tanto independientemente como conjuntamente, introducen posibilidades reales para el control de la propagación de ondas acústicas a trav

APA, Harvard, Vancouver, ISO, and other styles

21

Huang, Zhanyu. "Lateral Spreading Mechanics of Column-Supported Embankments." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/95325.

Full text

Abstract:

Column-supported embankments (CSE) enable accelerated construction on soft soils, high performance, and protection of adjacent facilities. The foundation columns transfer embankment and service loading to a competent stratum at depth such that loading on the soft soil can be reduced. This has the beneficial effects of reducing settlement and lateral displacement, and improving stability. Selection of column type depends on the design load, cost, constructability, etc., although unreinforced concrete columns are commonly used. A load transfer platform (LTP) is often included at the embankment b

APA, Harvard, Vancouver, ISO, and other styles

22

Legrand, Nicolas. "Numerical and modeling methods for multi-level large eddy simulations of turbulent flows in complex geometries." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR16/document.

Full text

Abstract:

La simulation aux grandes échelles est devenue un outil d’analyse incontournable pour l’étude des écoulements turbulents dans des géométries complexes. Cependant, à cause de l’augmentation constante des ressources de calcul, le traitement des grandes quantités de données générées par les simulations hautement résolues est devenu un véritable défi qu’il n’est plus possible de relever avec des outils traditionnels. En mécanique des fluides numérique, cette problématique émergente soulève les mêmes questions que celles communément rencontrées en informatique avec des données massives. A ce sujet,

APA, Harvard, Vancouver, ISO, and other styles

23

Williams, Paul David. "Nonlinear interactions of fast and slow modes in rotating, stratified fluid flows." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:5365c658-ab60-41e9-b07b-0f635909835e.

Full text

Abstract:

This thesis describes a combined model and laboratory investigation of the generation and mutual interactions of fluid waves whose characteristic scales differ by an order of magnitude or more. The principal aims are to study how waves on one scale can generate waves on another, much shorter scale, and to examine the subsequent nonlinear feedback of the short waves on the long waves. The underlying motive is to better understand such interactions in rotating, stratified, planetary fluids such as atmospheres and oceans. The first part of the thesis describes a laboratory investigation using a r

APA, Harvard, Vancouver, ISO, and other styles

24

Meyrand, Louis. "Modes non linéaires : approches réduites par PGD/HBM et applications aux réponses forcées." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0561.

Full text

Abstract:

Dans le domaine des vibrations de structures, les performances croissantes des calculateurs permettent de traiter des modèles de plus en plus complexes, conduisant immanquablement à la prise en compte de phénomènes non linéaires. Le contexte industriel mène par ailleurs à vouloir considérer des systèmes toujours plus gros. Ces travaux de thèse sont axés autour du développement de procédés algorithmiques permettant de résoudre efficacement, des problèmes de taille élevée en dynamique non linéaire. Le parti pris est pour cela de calculer les Modes Non Linéaires (MNLs) des structures, objets repr

APA, Harvard, Vancouver, ISO, and other styles

25

Botelho, Daniel Autran. "Em direção à determinação da circulação e transporte de constituintes no reservatório Billings." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-16072018-170112/.

Full text

Abstract:

A adoção de Modelos Numéricos se constitui numa das principais ferramentas para tomadas de decisões quanto à utilização dos Recursos Hídricos. No presente trabalho, é feita uma revisão de modelos matemáticos empregados no estudo do escoamento superficial de corpos d\'água, com atenção especial voltada aos reservatórios. Tendo em vista o reservatório Billings como um dos mais disputados recursos hídricos no pais, para o estudo do seu comportamento hidrodinâmico e consequente transporte de massa, implementou-se o Modelo Bidimensional Verticalmente Integrado IPH-A, v. 116. Foi feita uma análise d

APA, Harvard, Vancouver, ISO, and other styles

26

Arcot, Kiran. "ISSUES RELATED TO THE NUMERICAL IMPLEMENTATION OF A SPARSE METHOD FOR THE SOLUTION OF VOLUME INTEGRAL EQUATIONS AT LOW FREQUENCIES." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/53.

Full text

Abstract:

Computational electromagnetic modeling involves generating system matrices by discretizing integral equations and solving the resulting system of linear equations. Many methods of solving the system of linear equations exist and one such method is the factorization of the matrix using the so called local-global solution (LOGOS) modes. Computer codes to perform the discretization of the integral equations, filling of the matrix, and the subsequent LOGOS factorization have previously been developed by others. However, these codes are limited to complex double precision arithmetic only. This thes

APA, Harvard, Vancouver, ISO, and other styles

27

Chalas, Jeffrey Michael. "Design and Location Optimization of Electrically Small Antennas Using Modal Techniques." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420798842.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Zeghuzi, Anissa. "Analysis of Spatio-Temporal Phenomena in High-Brightness Diode Lasers using Numerical Simulations." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/22016.

Full text

Abstract:

Breitstreifenlaser haben eine breite Emissionsapertur, die es ermöglicht eine hohe Ausgangsleistung zu erreichen. Gleichzeitig führt sie jedoch zu einer Verringerung der lateralen Strahlqualität und zu ihrem nicht-stationären Verhalten. Forschung in diesem Gebiet ist anwendungsgetrieben und somit ist das Hauptziel eine Erhöhung der Brillanz, die sowohl die Ausgangsleistung als auch die laterale Strahlqualität beinhaltet. Um die zugrunde liegenden raumzeitlichen Phänomene zu verstehen und dieses Wissen zu nutzen, um die Kosten der Brillanz-Optimierung zu minimieren, ist ein selbst-konsistentes

APA, Harvard, Vancouver, ISO, and other styles

29

Eigelaar, Lerika Susan. "Scale model validation of QUAYSIM and WAVESCAT numerical models of ship motions." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96758.

Full text

Abstract:

Thesis (MSc)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: Various numerical modelling software packages are available for predicting moored ship motions and forces. The focus of this study was to validate the numerical models QUAYSIM and WAVESCAT and how these models together form a procedure for predicting moored ship motions and forces under the impact of high and low frequency waves. The validation procedure applied in the study involved numerical modelling of a given physical model situation in which moored ship motions and forces were measured under both high and low frequen

APA, Harvard, Vancouver, ISO, and other styles

30

Ferria, Hakim. "Contribution to Numerical and Experimental Studies of Flutter in Space Turbines. Aerodynamic Analysis of Subsonic or Supersonic Flows in Response to a Prescribed Vibratory Mode of the Structure." Phd thesis, Ecole Centrale de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00677648.

Full text

Abstract:

Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. Although numerical tools are more and more reliable, flutter prediction still depends on a large degree on simplified models. In addition, the critical nature of flutter, resulting in poor welldocumented real cases in the open literature, and the lack of experimental database typical of engine flows make its apprehension even more challengin

APA, Harvard, Vancouver, ISO, and other styles

31

Moussi, El hadi. "Analyse de structures vibrantes dotées de non-linéarités localisées à jeu à l'aide des modes non-linéaires." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4792/document.

Full text

Abstract:

Le travail de cette thèse a été réalisé dans le cadre d'une collaboration entre EDF R&D et le LMA de Marseille (CNRS). Le but était de développer des outils théoriques et numériques pour le calcul de modes non-linéaires de structures industrielles possédant des non-linéarités localisées à jeu. La méthode de calcul utilisée est une combinaison de la méthode d'équilibrage harmonique (EH) et de la méthode asymptotique numérique (MAN), appelée EHMAN. Elle est réputée pour sa robustesse sur les problèmes réguliers. L'enjeu de ce travail de thèse est de l'appliquer sur des problèmes non-régulier

APA, Harvard, Vancouver, ISO, and other styles

32

Ruiz, Eduardo Alberto Pérez. "Comportamento mecânico de sistemas revestidos submetidos a esforços de contato normais e tangenciais." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3151/tde-30092016-100322/.

Full text

Abstract:

A deposição de filmes finos resistentes ao desgaste é uma prática realizada com bastante frequência para melhorar o comportamento tribológico (atrito, desgaste, lubrificação) de diferentes peças e componentes. Afim de se garantir o adequado funcionamento do sistema revestido (substrato+filme), é importante avaliar o comportamento mecânico do mesmo. Um método para avaliação e estudo do comportamento mecânico destes sistemas é o ensaio de riscamento. O ensaio é utilizado para analisar a fratura superficial do revestimento (falha chamada coesiva), ou a resistência à adesão (falha chamada adesiva)

APA, Harvard, Vancouver, ISO, and other styles

33

Latry, Olivier. "Théorie des modes locaux dans les guides perturbés application : couplage fibre optique - photodiode PIN." Rouen, 1995. http://www.theses.fr/1995ROUE5001.

Full text

Abstract:

La réduction des dimensions des composants optoélectroniques constitue une contrainte importante pour un couplage optimal avec la fibre optique. Le but recherché étant de focaliser le maximum de lumière à l'intérieur de la couche intrinsèque de la photodiode, il faudrait donc envisager de réduire le diamètre de la fibre optique. Une étude du bout de la fibre est également menée et montre que pour une forme lentillée appropriée, il est possible d'adapter la distribution d'énergie entre fibre optique et photodiode. Le calcul du champ le long de ce guide de dimensions lentement décroissantes util

APA, Harvard, Vancouver, ISO, and other styles

34

Zhang, Feng. "Instability in Settling Fibres : A Numerical Study." Doctoral thesis, KTH, Mekanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141037.

Full text

Abstract:

Sedimenting suspensions exist in a varity of natural phenomena and industrial applications. It is already observed in experiments that the dilute fibre suspensions experience a concentration instability under gravity at low Reynolds numbers. Initially well-mixed suspensions become inhomogeneous and anisotropic due to this instability. This project is focused on the development and validation of numerical models to understand the instability in a dilute fibre suspension by means of the mixture model and the point-particle model. For periodic boundary condition, we use a linear stability analysi

APA, Harvard, Vancouver, ISO, and other styles

35

Szubert, Damien. "Physics and modelling of unsteady turbulent flows around aerodynamic and hydrodynamic structures at high Reynold number by numerical simulation." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/15129/2/szubert_1.pdf.

Full text

Abstract:

This thesis aims at analysing the predictive capabilities of statistical URANS and hybrid RANS-LES methods to model complex flows at high Reynolds numbers and carrying out a physical analysis of the near-region turbulence and coherent structures. This study handles configurations included in the European research programmes ATAAC (Advanced Turbulent Simulation for Aerodynamics Application Challenges) and TFAST (Transition Location Effect on Shock Wave Boundary Layer Interaction). First, the detached flow in a configuration of a tandem of cylinders, positionned behind one another, is investigat

APA, Harvard, Vancouver, ISO, and other styles

36

Monette, Liza. "Numerical simulations of nucleation and growth phenomena." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=64053.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Djemal, Fathi. "Analyse et optimisation des batteurs dynamiques non linéaires." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2015. http://www.theses.fr/2015ECAP0007/document.

Full text

Abstract:

Les vibrations qui sont en général source de dérangement, d’usure et même destruction des machines et structures mécaniques doivent être contrôlées ou éliminées. Pour cette raison, la lutte contre les vibrations est devenue depuis des années un enjeu majeur pour les chercheurs de laboratoire et de développement dans l’industrie afin de développer des solutions efficaces contre ces problèmes. De nombreuses technologies ont donc été développées. Parmi ces technologies, les absorbeurs de vibration non linéaires présentent des performances importantes dans l’atténuation de vibration sur une large

APA, Harvard, Vancouver, ISO, and other styles

38

Bruciaferri, Diego. "Study of a wind-wave numerical model and its integration with ocean and oil-spill numerical models." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6757/.

Full text

Abstract:

The ability to represent the transport and fate of an oil slick at the sea surface is a formidable task. By using an accurate numerical representation of oil evolution and movement in seawater, the possibility to asses and reduce the oil-spill pollution risk can be greatly improved. The blowing of the wind on the sea surface generates ocean waves, which give rise to transport of pollutants by wave-induced velocities that are known as Stokes’ Drift velocities. The Stokes’ Drift transport associated to a random gravity wave field is a function of the wave Energy Spectra that statistically fully

APA, Harvard, Vancouver, ISO, and other styles

39

Petit, Frédéric. "Reverberation Chamber Modeling Using Finite-Difference Time-Domain Method." Diss., University of Marne la Vallée, 2002. http://hdl.handle.net/10919/71555.

Full text

Abstract:

Since the last few years, the unprecedented growth of communication systems involving the propagation of electromagnetic waves is particularly due to developments in mobile phone technology. The reverberation chamber is a reliable bench-test, enabling the study of the effects of electromagnetic waves on a specific electronic appliance. However, the operating of a reverberation chamber being rather complicated, development of numerical models are of utmost importance to determine the crucial parameters to be considered.This thesis consists in the modelling and the simulation of the operating pr

APA, Harvard, Vancouver, ISO, and other styles

40

Demange, Jérémie. "Schémas numériques d'advection et de propagation d'ondes de gravité dans les modèles de circulation océanique." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENM096/document.

Full text

Abstract:

Les modèles numériques d'océans régionaux tridimensionnels sont basés sur la résolution des équations primitives et utilisent pour la plupart des méthodes de résolution eulérienne de type différences finies sur des grilles décalées. Ces modèles doivent représenter fidèlement les transports et transferts d'énergie. L'amélioration de ces modèles numériques exige donc (i) l'identification des processus prépondérants, notamment en terme de dissipation, dans ces transferts et (ii) la construction de méthodes numériques respectant un certain nombre d'équilibres. La première partie du travail se conc

APA, Harvard, Vancouver, ISO, and other styles

41

Kerber, Thierry. "Réponse à un impact localisé d'une structure coque composite multicouche rotationnelle : études théoriques et mise au point de méthodes numériques." Châtenay-Malabry, Ecole centrale de Paris, 1995. http://www.theses.fr/1995ECAP0383.

Full text

Abstract:

Résoudre des problèmes d'impacts localises sur des coques composites multicouches reste à l'heure actuelle un véritable défi. Les couts informatiques, en stockages et en calculs, s'avèrent en effet gigantesques des qu'on s'intéresse à des cas industriels. De plus, les problèmes de fiabilité des résultats se posent de façon cruciale. Parmi ces difficultés, dominent la modélisation des coques et la résolution des problèmes d'impacts, incluant les choix délicats des discrétisations spatio-temporelles. Lorsque les structures étudiées présentent des symétries, en particulier axiales, de nouvelles o

APA, Harvard, Vancouver, ISO, and other styles

42

CHEN, YIDI. "A Numerical Study of Multi-class Traffic Flow Models." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu158714737847054.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Ritsataki, Aliki. "A numerical model of Kerr-Lens mode-locking in solid-state lasers." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325064.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Arosemena, Arturo. "Numerical Model of MeltingProblems." Thesis, KTH, Mekanik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-221141.

Full text

Abstract:

In the present study, a finite volume method is employed to modelthe advection-diffusion phenomenon during a pure substance meltingprocess. The exercise is limited to a benchmark problem consisting ofthe 2D melting from a vertical wall of a PCM driven by natural convectionin the melt. Numerical results, mainly the temporal evolutionof average Nusselt number at the hot wall and the average liquid fraction,are validated by available literature data and the effect of thermalinertia in the heat transfer is considered as well. Finally, motivatedby recent publications and the model presented here, p

APA, Harvard, Vancouver, ISO, and other styles

45

Nekouee, Navid. "Dynamics and numerical modeling of river plumes in lakes." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41104.

Full text

Abstract:

Models of the fate and transport of river plumes and the bacteria they carry into lakes are developed. They are needed to enable informed decisions about beach closures to avoid economic losses, and to help design water intakes and operate combined sewer overflow schemes to obviate exposure of the public to potential pathogens. This study advances our understanding of river plumes dynamics in coastal waters by means of field studies and numerical techniques. Extensive field measurements were carried out in the swimming seasons of 2006 and 2007 on the Grand River plume as it enters Lake Michig

APA, Harvard, Vancouver, ISO, and other styles

46

Hu, Zhongbo. "Atmospheric artifacts correction for InSAR using empirical model and numerical weather prediction models." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/668264.

Full text

Abstract:

lnSAR has been proved its unprecedented ability and merits of monitoring ground deformation on large scale with centimeter to millimeter scale accuracy. However, several factors affect the reliability and accuracy of its applications. Among them, atmospheric artifacts due to spatial and temporal variations of atmosphere state often pose noise to interferograms. Therefore, atmospheric artifacts m itigalion remains one of the biggest challenges to be addressed in the In SAR community. State-of-the-art research works have revealed atmospheric artifacts can be partially compensated with empiri

APA, Harvard, Vancouver, ISO, and other styles

47

Brandão, Matheus Marcelino. "Modelagem numerica de sistemas de refrigeração por compressão de vapor." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263358.

Full text

Abstract:

Orientador: Luiz Felipe Mendes de Moura<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica<br>Made available in DSpace on 2018-08-12T21:08:34Z (GMT). No. of bitstreams: 1 Brandao_MatheusMarcelino_M.pdf: 452664 bytes, checksum: 124f6ab109716c77cffe6f192c006b30 (MD5) Previous issue date: 2005<br>Resumo: No presente trabalho se realiza o estudo e desenvolvimento de um modelo numérico computacional com a finalidade da simulação de sistemas de refrigeração por compressão de vapor. Em um primeiro momento, foram analisados e discutidos os principais tipo

APA, Harvard, Vancouver, ISO, and other styles

48

Londani, Mukhethwa. "Numerical Methods for Mathematical Models on Warrant Pricing." University of the Western Cape, 2010. http://hdl.handle.net/11394/8210.

Full text

Abstract:

>Magister Scientiae - MSc<br>Warrant pricing has become very crucial in the present market scenario. See, for example, M. Hanke and K. Potzelberger, Consistent pricing of warrants and traded options, Review Financial Economics 11(1) (2002) 63-77 where the authors indicate that warrants issuance affects the stock price process of the issuing company. This change in the stock price process leads to subsequent changes in the prices of options written on the issuing company's stocks. Another notable work is W.G. Zhang, W.L. Xiao and C.X. He, Equity warrant pricing model under Fractional Brownian m

APA, Harvard, Vancouver, ISO, and other styles

49

Deslandes, Pierre. "Développement d’oscillateurs lasers à fibre de forte puissance moyenne et à durée d’impulsion ajustable." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR14757/document.

Full text

Abstract:

Un nombre croissant d’applications telles que le micro-usinage ou le diagnostique de composants électroniques nécessitent de fortes puissances moyennes dans différentes gammes de longueurs d’onde (infra-rouge à 1030 nm, vert à 515 nm ou ultra-violet à 343 nm). Ces fortes puissances moyennes lasers ne sont généralement atteignables qu’à l’aide d’architecture laser de type MOPA (Master Oscillator Power Amplifier). C’est dans cette optique que la société Eolite Systems veut développer ses propres oscillateurs car elle maitrise déjà l’amplification à l’aide de fibres de type barreau à large aire m

APA, Harvard, Vancouver, ISO, and other styles

50

Jenkins, Siân. "Numerical model error in data assimilation." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665395.

Full text

Abstract:

In this thesis, we produce a rigorous and quantitative analysis of the errors introduced by finite difference schemes into strong constraint 4D-Variational (4D-Var) data assimilation. Strong constraint 4D-Var data assimilation is a method that solves a particular kind of inverse problem; given a set of observations and a numerical model for a physical system together with a priori information on the initial condition, estimate an improved initial condition for the numerical model, known as the analysis vector. This method has many forms of error affecting the accuracy of the analysis vector, a

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!