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Aerodynamická analýza a návrh úprav podvozkové gondoly letounu L 410 NG / Aerodynamic analysis and design modifications of L 410 NG aircraft landing gear nacellePukl, Marek January 2013 (has links)
This diploma thesis deals with the flow analysis around the landing gear nacelle of L 410 and with its following aerodynamical optimalization. In the first part the calibration is performed on the known geometry which was tested in wind tunnel. The following parts contain own design of the optimal geometry, design of the computional mesh with its numerical solution and results evaluation.
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オンチップ電源電圧変動を考慮したLSI-coreマクロモデルに関する研究田中, 広志 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第24619号 / 工博第5125号 / 新制||工||1980(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 和田 修己, 教授 佐藤 高史, 准教授 久門 尚史, 教授 松尾 哲司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Active Flow Control Schemes for Bluff Body Drag ReductionWhiteman, Jacob T. 08 June 2016 (has links)
No description available.
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Development and validation of a predictive model to ensure the long-term electromagnetic compatibility of embedded electronic systems / Développement et validation de modèle prédictif pour assurer la compatibilité électromagnétique à long terme des systèmes électroniques embarqués.Ghfiri, Chaimae 13 December 2017 (has links)
Avec l’avancement technologique des circuits intégrés à travers la miniaturisation des tailles des transistors et leur multiplication au sein d’une même puce, l’intégration des circuits dans des systèmes embarqués complexes, principalement dans l’industrie aéronautique, spatiale et automobile, rencontre de plus en plus d’exigences en termes de respect des niveaux d’émission et d’immunité. De plus, étant donné que l’évolution des niveaux de Compatibilité Electromagnétique (CEM) des équipements électroniques doit respecter ces exigences à long terme, les marges définis par les industriels sont souvent surestimés et les systèmes de filtrages établis par les équipementiers peuvent être surdimensionnés. De ce fait, pour les circuits intégrés dédiés aux applications embarquées, il est nécessaire d’étudier les deux aspects qui concernent la modélisation CEM ainsi que la modélisation de la fiabilité. Ces dernières années, des standards ont été proposés et permettent la construction de modèles CEM prédictifs tel que ICEM-CE/RE (Integrated Circuit Emission Model for Conducted and Radiated Emission) et ICIM-CI (Integrated Circuit Immunity Model for Conducted Immunity). De plus, pour intégrer l’effet du vieillissement dans les modèles CEM, il faut étudier les principaux mécanismes de dégradation intrinsèques aux circuits intégrés qui accélèrent leur vieillissement tels que le HCI (Hot Carrier Injection), TDDB (Time Dependent Dielectric Breakdown), EM (Electromigration) et NBTI (Negative Bias Temperature Instability). Des modèles standardisés sont utilisés dans les différents domaines industriels qui permettent la construction de modèle de fiabilité tels que le standard MIL-HDBK-217 et le standard FIDES. Cependant, ils ne permettent de prendre en compte qu’un seul mécanisme de dégradation à la fois. Ce manuscrit de thèse introduit ces aspects de modélisation CEM et de fiabilité. Il traite également la construction d’un modèle d’émission conduite d’un FPGA avec la proposition de nouvelle méthodologie de modélisation. Ensuite, l’étude de la fiabilité du FPGA est décrite à travers l’utilisation d’un nouveau modèle permettant la prise en compte des différents mécanismes de dégradations et a été combiné au modèle CEM pour la prédiction des niveaux d’émissions conduite à long terme. / With the technological evolution of integrated circuits (ICs) through the transistors scaling, which leads to the multiplication of the number of transistors within a chip, the requirements in terms of emission and immunity levels become more restrictive in the aeronautic, space and automotive industries. Moreover, since the evolution of Electromagnetic Compatibility (EMC) levels of electronic equipment after aging must meet the EMC long-term requirements, the EMC margins defined by the manufacturers are often overestimated and the filtering systems designed by the equipment manufacturer could be oversized.Therefore, for the integrated circuits dedicated to embedded applications, it is necessary to study the different aspects of EMC modeling as well as the reliability the modeling. These last years, several standards have been proposed for the construction of predictive EMC models such as ICEM-CE/RE (Integrated Circuit Emission Model for Conducted and Radiated Emission) and ICIM-CI (Integrated Circuit Immunity Model for Conducted Immunity). On the other hand, to integrate the effect of aging in EMC models, it is important to study the main intrinsic degradation mechanisms that accelerate the aging of ICs, such as HCI (Hot Carrier Injection), TDDB (Time Dependent Dielectric Breakdown), EM (Electromigration) and NBTI (Negative Bias Temperature Instability). For this purpose, there are existing models for the reliability prediction, such as the MIL-HDBK-217 standard and the FIDES standard. However, these models could take into account only the activation of one degradation mechanism. The combination of several degradation mechanisms could be critical for the IC performances and could contribute in the evolution of EMC level.This thesis introduces the different aspects of EMC and reliability modeling. This work deals with the construction of a conducted emission model of an FPGA and the proposition of new modeling methodologies. Furthermore, the reliability of the tested FPGA is described using a new predictive model, which takes into account the activation of the different degradation mechanisms. The reliability model has been combined with the EMC model for the long-term conducted emission level prediction.
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Method development for investigation of real effects on flow around vanesMårtensson, Jonathan January 2010 (has links)
<p>In the development of turbo machinery components it's desirable to not spend more time than necessary when setting up aero-thermal calculations to investigate uncertainties in the design. This report aims to describe general thoughts used in the development of an ICEM-mesh script and the possible configurations in the script file which enables the user to build mesh-grids with/without clearance gap at the hub and/or shroud for different blade geometries. It also aims to illustrate the performance analysis made on the Vinci LH2 turbine, a next generation upper stage engine to the Ariane 5 rocket, in which the effect of the tip gap size on the efficiency has been studied.</p><p>The calculations made have shown good agreement with experimental data. The efficiency loss due to the mixing of fluid where leakage flow passes the tip gap, which results in growth of a strong vortex, and the fluid passing the blade tip, with almost no work extracted from it, has shown a quite linear efficiency dependence depending on the tip gap size.</p>
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Method development for investigation of real effects on flow around vanesMårtensson, Jonathan January 2010 (has links)
In the development of turbo machinery components it's desirable to not spend more time than necessary when setting up aero-thermal calculations to investigate uncertainties in the design. This report aims to describe general thoughts used in the development of an ICEM-mesh script and the possible configurations in the script file which enables the user to build mesh-grids with/without clearance gap at the hub and/or shroud for different blade geometries. It also aims to illustrate the performance analysis made on the Vinci LH2 turbine, a next generation upper stage engine to the Ariane 5 rocket, in which the effect of the tip gap size on the efficiency has been studied. The calculations made have shown good agreement with experimental data. The efficiency loss due to the mixing of fluid where leakage flow passes the tip gap, which results in growth of a strong vortex, and the fluid passing the blade tip, with almost no work extracted from it, has shown a quite linear efficiency dependence depending on the tip gap size.
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Aerodynamická analýza a optimalizace konfigurace letounu ARES / Aerodynamic analysis and shape optimization of ARES aircraftFoltýn, Pavel January 2015 (has links)
This thesis deals with the aerodynamic analysis and shape modifications of the ARES aircraft. The analysis focuses on the evaluation lift, drag, and pitching moment coefficient, and further to identify the locations of stripping stream which is characterized by high drag. Before the analysis calibration of the CFD solver is done with the model, which has been measured in the wind tunnel. The aim of calibration is to verify the accuracy and veracity of the methodology used in mesh creation and calculated values. Calculated values are compared with measured data. The shape modifications of the aircraft are focused on conceptual design of the suction inlets for cooling radiators and engine aircraft. Aerodynamic analysis is performed with the modified model in order to determine the variation of lift, drag and pitching moment coefficient from its original configuration.
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Méthodologie de prédiction des niveaux d'émission conduite dans les circuits intégrés, à l'aide de VHDL-AMS / A VHDL-AMS based prediction methodology of conducted emission in integrated circuitsPerdriau, Richard 25 March 2004 (has links)
Depuis de nombreuses années, la prise en compte des critères de compatibilité électromagnétique (CEM) constitue une étape capitale dans la
conception des systèmes électroniques. Or, l'augmentation de la complexité des circuits intégrés rend indispensable l'étude du comportement électromagnétique directement au niveau du silicium.
L'objectif de ces travaux est la définition d'une méthodologie de prédiction, avant fonderie, de l'émission conduite des circuits intégrés. Celle-ci s'appuie sur le langage VHDL-AMS et le modèle ICEM (Integrated Circuit Electromagnetic Model), et peut s'intégrer dans un flot de
conception industriel.
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For many years, taking into account electromagnetic compatibility (EMC) constraints has been a fundamental requirement in electronic system design. However, the increase in complexity of integrated circuits now demands the study of their electromagnetic behavior at chip level.
The objective of this work is the definition of a methodology aimed at predicting conducted emission in integrated circuits. This methodology is based on the VHDL-AMS language and the ICEM (Integrated Circuit Electromagnetic Model) model, and can be integrated into an industrial design flow.
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Etude et réalisation d'une nouvelle cellule TEM à support rotatif pour des mesures CEM des circuits intégrés :<br />Application du modèle ICEMEl Abbazi, Adil 14 June 2006 (has links) (PDF)
L'essor des applications microélectroniques, qui fonctionnent de plus en plus à des fréquences<br />élevées, nécessite le développement de nouveaux modèles ainsi que des méthodes de mesures adéquates<br />en CEM des circuits intégrés. Les travaux de cette thèse sont consacrés à l'étude, l'optimisation et de la<br />réalisation d'une nouvelle cellule TEM (Transverse ElectroMagnetic) ainsi qu'à l'application du modèle ICEM<br />(I ntegrated Circuit Electromagnetic Model). Après une première partie consacrée à l'introduction des différentes méthodes de mesures CEM des composants électroniques et des différents modèles de circuits intégrés, nous présentons les outils théoriques et expérimentaux utilisés pour nos travaux. Ces derniers contribuent, d'une part, à la mise au point technologique et, d'autre part, à l'optimisation de la structure de la cellule.<br />Les principales contributions concernent l'optimisation électromagnétique d'une cellule TEM à support rotatif, présentant notamment une fréquence de coupure proche de 3 GHz et une impédance caractéristique de 50Ω.<br />La technique développée dans la thèse constitue une amélioration de solutions existantes visant à élargir la bande de fréquence couverte par les cellules TEM. Un aménagement particulier de la cellule est également imaginé en vue de détecter l'orientation du circuit offrant le couplage maximum. Les phénomènes parasites de l'environnement de mesures ont été affranchis grâce au développement d'une cloche de protection associée au support rotatif lequel permet ainsi d'améliorer la précision lors de la localisation des sources rayonnantes du composant sous test.<br />Les performances de la nouvelle cellule TEM validées par la mesure expérimentale confirment la pertinence des solutions proposées pour à la fois caractériser et localiser les sources d'émission des circuits intégrés.
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Energy audit methodology for belt conveyorsMarx, Dirk Johannes, Lewies 11 April 2007 (has links)
The electricity cost is one of the largest components of operating costs on a belt conveyor system. This dissertation introduces a unique Conveyor Electricity Cost Efficiency Audit Methodology (CECEAM). In the CECEAM the conveyor system is evaluated from a high to detail level in order to identify opportunities to improve electricity costs. The CECEAM includes methodologies and tools developed to analyze not only the conveyor belt alone, but also the materials handling system as a whole. The outline of the dissertation is structured as follows: Chapter 1 includes the background and problem identification by means of a literature study. The main objective, as well as specific objectives, is defined in this chapter. In chapter 2, the CECEAM is introduced and an overview of the total methodology is discussed. The data acquisition part of the CECEAM; documentation, personnel, walk, technical audit as well as the conveyor database is discussed in chapter 3. Chapter 4 concentrates on the Conveyor Energy Conversion Model (CECM) and the verification thereof. The Integrated Conveyor Energy Model (ICEM) methodology is introduced (in chapter 5) and the economic evaluation concepts and energy management basics needed in the CECEAM are covered. Chapter 6 covers a CECEAM case study where the practical application of the CECEAM is illustrated with ICEM simulations, opportunity identification and recommendations. The conclusion and recommendations for further studies is proposed in chapter 7. / Dissertation (MSc (Electrical Engineering))--University of Pretoria, 2007. / Electrical, Electronic and Computer Engineering / unrestricted
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