<p>Abstract</p><p>This thesis is studying the heatsinks new designs for copper heatsinks which utilizes modelling and simulation by CFD, construction of prototypes and experimental works. Challenges and complications in manufacturing of copper heatsinks are expressed and finding the solutions to these hindrances involve in this work. Numerical efforts supported by fluent are made to promote investigation and approaching the goal in which serves the new opportunities for wider application of copper material in heat sinks.</p><p>However the thermal conductivity of copper is about double as aluminium but still aluminium heatsinks are commonly used for heat dissipation in computers.</p><p>Comparing of heat performance of two analogous heatsink of different materials, aluminium and copper, is conducted by numerical analysis in the CFD environment.</p><p>In addition to larger surface area and airflow velocity another solution for enhancement of heat dissipation is suggested.</p><p>Manufacturing solutions of copper heatsinks are proposed which will facilitate fabrication of more high performance copper heatsinks than the current heavy and expensive models.</p><p>Our first copper heat sink model is designed exclusively based on the technical observations and analyses of numerical simulation of two identical copper and aluminium heatsinks by CFD and as well as manufacturability concerns.</p><p>This heat sink is fabricated mechanically and is tested by a number of heat sources and high sensitive devices such as adhesive K type thermocouple, data acquisition 34970A in associated with HP Bench Link program.</p><p>An extent experimental work on aluminium heatsinks, integrated with forced convection, is performed in order to measure their thermal capacities.</p><p>Comparison of the heat performance of a typical aluminium heatsink, which was the best among the all aluminium heat sinks and proposed copper heatsink under identical experimental conditions, is performed.</p><p>Also in some numerical efforts, optimizing and predicting of the thermal characterization of the proposed heatsink with inclined free fins is developed. The model is scaled up in the fluent environment to predict its application in the cooling of larger heat generated electronic devices.</p><p>Impingement air-cooling mode of force-convection is adopted for heat dissipation from high power electronic devices in associated with the proposed inclined fin model.</p><p>Components of airflow velocity in the hollow spaces of the heatsink are discussed. Pressure drop and other thermal variables are analyzed analytical and by CFD code.</p><p>Another mechanical manufactured copper heat sink is investigated. A new design of the base and fins is optimized.</p><p>A three-dimensional finite volume method is developed to determine the performance of the proposed heatsink.</p><p>Thermal and hydraulic characterization of the heat sink under air-forced convection cooling condition is studied. The flow behavior around the fins and some other parts of the heat sink is analyzed by utilizing CFD code.</p><p>The hydraulic parameters including velocity profiles, distribution of static pressure, dynamic pressure, boundary layer and fluid temperature between the fins and in the passageway at the middle of the heat sink are analyzed and presented schematically.</p><p>Furthermore the thermal characteristic of the proposed heatsink is studied by contouring the three dimensional temperature distributions through the fins and temperature of the heat source by CFD code.</p>

Abstract This thesis is studying the heatsinks new designs for copper heatsinks which utilizes modelling and simulation by CFD, construction of prototypes and experimental works. Challenges and complications in manufacturing of copper heatsinks are expressed and finding the solutions to these hindrances involve in this work. Numerical efforts supported by fluent are made to promote investigation and approaching the goal in which serves the new opportunities for wider application of copper material in heat sinks. However the thermal conductivity of copper is about double as aluminium but still aluminium heatsinks are commonly used for heat dissipation in computers. Comparing of heat performance of two analogous heatsink of different materials, aluminium and copper, is conducted by numerical analysis in the CFD environment. In addition to larger surface area and airflow velocity another solution for enhancement of heat dissipation is suggested. Manufacturing solutions of copper heatsinks are proposed which will facilitate fabrication of more high performance copper heatsinks than the current heavy and expensive models. Our first copper heat sink model is designed exclusively based on the technical observations and analyses of numerical simulation of two identical copper and aluminium heatsinks by CFD and as well as manufacturability concerns. This heat sink is fabricated mechanically and is tested by a number of heat sources and high sensitive devices such as adhesive K type thermocouple, data acquisition 34970A in associated with HP Bench Link program. An extent experimental work on aluminium heatsinks, integrated with forced convection, is performed in order to measure their thermal capacities. Comparison of the heat performance of a typical aluminium heatsink, which was the best among the all aluminium heat sinks and proposed copper heatsink under identical experimental conditions, is performed. Also in some numerical efforts, optimizing and predicting of the thermal characterization of the proposed heatsink with inclined free fins is developed. The model is scaled up in the fluent environment to predict its application in the cooling of larger heat generated electronic devices. Impingement air-cooling mode of force-convection is adopted for heat dissipation from high power electronic devices in associated with the proposed inclined fin model. Components of airflow velocity in the hollow spaces of the heatsink are discussed. Pressure drop and other thermal variables are analyzed analytical and by CFD code. Another mechanical manufactured copper heat sink is investigated. A new design of the base and fins is optimized. A three-dimensional finite volume method is developed to determine the performance of the proposed heatsink. Thermal and hydraulic characterization of the heat sink under air-forced convection cooling condition is studied. The flow behavior around the fins and some other parts of the heat sink is analyzed by utilizing CFD code. The hydraulic parameters including velocity profiles, distribution of static pressure, dynamic pressure, boundary layer and fluid temperature between the fins and in the passageway at the middle of the heat sink are analyzed and presented schematically. Furthermore the thermal characteristic of the proposed heatsink is studied by contouring the three dimensional temperature distributions through the fins and temperature of the heat source by CFD code.

Cílem této diplomové práce je vytvořit 3D model horních dýchacích cest podle originálního modelu segmentovaného z CT dat, aplikovat různé podmínky na průtok vzduchu v modelu, a poté hodnotit změnu charakteristik rychlosti a tlaku. Model horních dýchacích cest byl vytvořen v prostředí softwaru ANSYS, který využívá výpočetní dynamiku tekutin, a byly použity Navier-Stokesovy rovnice pro modelování průtoku vzduchu v modelu. Nejprve byl vytvořen jednoduchý 2D model za účelem seznámení se s prostředím ANSYS. Dále byl zkonstruován 3D model horních dýchacích cest a byly modelovány charakteristiky rychlosti a tlaku za různých podmínek. Tyto podmínky zahrnují různé umístění a množství míst pro odběr vzorků v modelu a výběr různých kombinací vstupů. Nakonec byly prezentovány a hodnoceny výsledky spolu s ilustracemi modelů modelovaných za různých podmínek. 3D model lze považovat ze kompromis mezi výpočetní náročností a složitostí modelu a lze jej použít jako základ pro další výzkum.

Cette thèse expérimentale s’inscrit dans le domaine des sciences séparatives et se base sur la technique de SPLITT (SPLIT-flow Thin fractionation). Son objectif consiste en l’étude des mécanismes qui sont à l’origine de la séparation, en continu et sans membrane, d’objets de taille micrométrique dans des mini-séparateurs fluidiques (Step-SPLITT). Les expériences menées, en laboratoire et lors de vols paraboliques, ont révélé le couplage complexe comme l’influence des effets hydrodynamiques et du champ gravitationnel sur la migration transverse des espèces en écoulement. Des visualisations tridimensionnelles par holographie digitale ont corroboré nos résultats et dévoilé des comportements inattendus. Les capacités séparatives des Step-SPLITT ont rendu possible l’analyse et la séparation d’objets biologiques et biomimétiques. Enfin, cette étude complétée par une modélisation tridimensionnelle de l’écoulement nous a permis de mettre au point un nouveau prototype de séparateur. This experimental thesis belongs to the field of separative sciences and is based on the SPLITT technique (SPLIT-flow Thin fractionation). The objective is to study the mechanisms that are at the origin of continuous and membraneless separation of micron-size species in mini fluidic separators (Step-SPLITT). Experiments undertaken in laboratory and during parabolic flights revealed the complex coupling of the hydrodynamic effects and the gravitational field influencing the transverse migration of the flowing species. Three-dimensional visualizations performed by digital holography confirmed our results and disclosed unexpected behaviours. The separation capacities of Step-SPLITT made the analysis and the separation of biological and biomimetic species possible. In addition this study in conjunction with a three-dimensional flow modelling enabled us to develop a new prototype of separator.

Cette thèse expérimentale s’inscrit dans le domaine des sciences séparatives et se base sur la technique de SPLITT (SPLIT-flow Thin fractionation). Son objectif consiste en l’étude des mécanismes qui sont à l’origine de la séparation, en continu et sans membrane, d’objets de taille micrométrique dans des mini-séparateurs fluidiques (Step-SPLITT). Les expériences menées, en laboratoire et lors de vols paraboliques, ont révélé le couplage complexe comme l’influence des effets hydrodynamiques et du champ gravitationnel sur la migration transverse des espèces en écoulement. Des visualisations tridimensionnelles par holographie digitale ont corroboré nos résultats et dévoilé des comportements inattendus. Les capacités séparatives des Step-SPLITT ont rendu possible l’analyse et la séparation d’objets biologiques et biomimétiques. Enfin, cette étude complétée par une modélisation tridimensionnelle de l’écoulement nous a permis de mettre au point un nouveau prototype de séparateur.<p><p>This experimental thesis belongs to the field of separative sciences and is based on the SPLITT technique (SPLIT-flow Thin fractionation). The objective is to study the mechanisms that are at the origin of continuous and membraneless separation of micron-size species in mini fluidic separators (Step-SPLITT). Experiments undertaken in laboratory and during parabolic flights revealed the complex coupling of the hydrodynamic effects and the gravitational field influencing the transverse migration of the flowing species. Three-dimensional visualizations performed by digital holography confirmed our results and disclosed unexpected behaviours. The separation capacities of Step-SPLITT made the analysis and the separation of biological and biomimetic species possible. In addition this study in conjunction with a three-dimensional flow modelling enabled us to develop a new prototype of separator. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished