Airflow into, out of, and within buildings is fundamental to their design and operation as it can affect occupant health and comfort, building durability, and energy consumption. This thesis works to develop the understanding of airflow patterns and pressure regimes in high-rise multi-unit residential buildings which are both unique and complex due to the combination of their height, typical inclusion of operable windows, and compartmentalized layout. Specific attention is directed towards the performance of corridor pressurization based ventilation systems which are used pervasively within industry to ventilate and control contaminant transfer in these buildings. Airflow is caused by pressure differences which for buildings are created by the driving forces of wind, stack effect, and mechanical ventilation systems. These airflows are resisted by the air permeance (i.e. airtightness) of building elements including the exterior enclosure and interior compartmentalizing elements. Using an experimental program at a case study building, this thesis assesses the interaction of these driving forces of airflow with the physical building to create the airflow patterns for a typical high-rise multi-unit residential building. Perflourocarbon tracer (PFT) testing was performed to measure in-service airflows into and out of the suites. This testing found that the air change rates of upper suites are significantly higher than that of lower suites and that most suites receive small fractions of modern ventilation rates or are over ventilated. Airflow measurements of the supply of ventilation air to each corridor indicate that these low flow rates are in part due to leakage of air from the supply duct. The PFT testing also found that significant airflow occurred from the parking garage below the building into the occupied building spaces indicating significant potential for transfer of harmful air contaminants. The air permeance of the exterior enclosure and interior compartmentalizing elements were measured using neutralized fan pressurization and depressurization techniques and found to be within typical ranges. In particular this testing found that only 20% of the flow paths out of the corridor were to the adjacent suites through the suite entrance doors and that flows to the elevator shaft and stairwells could create a significant inefficiency in the ventilation system. A long-term monitoring program was implemented at the case study building primarily to monitor exterior environmental conditions including wind and exterior temperature and to correlate these with measured pressure differences. A strong correlation was found between building pressure and exterior temperature. Nearly 70% of the theoretical stack effect pressure was measured to act across the corridor to suite pressure boundary which creates a significant pressure differences to be overcome by the ventilation system, likely contributing to the uneven distribution of ventilation rates. Both wind and stack effect pressures were found to often be of similar or greater magnitude than mechanically induced pressure differences and thus can overwhelm the ventilation system. Overall, the corridor pressurization based ventilation system at the case study building does not effectively or efficiently ventilate the building and also does not provide sufficient control of air contaminants. As the case study building was found to be relatively representative of a typical multi-unit residential building, the findings from this building can be extended to many other buildings. Effective ventilation and airflow control in multi-unit residential buildings likely requires suite compartmentalization and direct supply of ventilation via ducted or in-suite systems.
Caractérisation et modélisation des effets d'empilement des couches minces sous la résine photosensible pendant le procédé de photolithographie optique / Characterization and modeling of wafer stack effect during photolithography process stepMichel, Jean-Christophe 24 October 2014 (has links)
La photolithographie optique assure en partie à la microélectronique la miniaturisation des circuits électroniques. Afin de faire face à la limite de résolution de l'équipement de photolithographie, les industriels ont mis au point des techniques d'amélioration de la résolution dont certaines sont basées sur l'utilisation de la modélisation numérique. Jusqu'au nœud technologique 45 nm, cette modélisation ne prenait pas en compte la présence de plusieurs empilements de matériaux sous la résine photosensible négligeant ainsi les phénomènes de réflexion, de diffraction et d'ondes stationnaires. Pour les nœuds 32 nm et suivants, ces phénomènes rendent difficile le contrôle de la forme et des dimensions des motifs résine notamment pour les niveaux dont l'exposition s'effectue sans couche antireflet. Cette thèse CIFRE entre le laboratoire Hubert Curien de Saint- Etienne et l'industriel STMicroelectronique de Crolles traite de la caractérisation, de la modélisation et de la simulation numérique des effets d'empilement sous la résine photosensible. Le premier chapitre regroupe un ensemble de pensées sur la microélectronique, son histoire et définit les notions essentielles de ce domaine et de la modélisation numérique. Les chapitres deux et trois donnent respectivement l'état de l'art de la photolithographie optique et des techniques de correction des effets de proximité optique. Le chapitre quatre présente l'étude expérimentale, de la conception des structures test à la caractérisation des effets d'empilement en passant par le protocole de création des groupes de données. La prise en compte de ces effets est l'objet du chapitre cinq avec l'état de l'art des techniques existantes suivi de la description de l'algorithme de construction de modèles développé dans cette thèse. Enfin l'application de la méthode des sources généralisées à la photolithographie optique est évaluée dans le chapitre six / In IC manufacturing, optical photolithography is one of key actors of electronic circuit miniaturization. To work around the photolithography resolution limit, manufacturers developed resolution improvement techniques, including some based on numerical modeling. For nodes larger than 45 nm, this modeling didn't take into account several stacks under the photoresist and that caused optical reflection, diffraction, and standing wave phenomena to be neglected. For 32 nm and smaller nodes, these phenomena make it di cult to control the shape and dimensions of resist patterns, especially for layers without an anti-reflecting coating during exposure. The CIFRE thesis from Hubert Curien Laboratories in Saint-Etienne and industrial STMicroelectronics from Crolles deals with wafer stack effect characterization, modeling, and numerical simulation. The first chapter gives my philosophy and history of IC manufacturing, and defines concepts in this field and concepts about numerical modeling. Chapter Two discusses state-of-the-art optical photolithography and Chapter Three discusses state-of-the-art optical proximity correction. Chapter Four emphasizes an experimental study from test pattern conception to wafer stack effect characterization, including data set building protocol. Chapter Five covers wafer stack effect management, first describing the current status of the industry followed by a description of the model building algorithm developed during this thesis. Finally, Chapter Six assesses the generalized source method applied to the photolithography process simulation
Simulace vlivu teploty a proudění vzduchu v poli rozvaděče s frekvenčním měničem / Simulation of temperature and airflow in a field distributor with frequency converterMelechovský, Ondřej January 2016 (has links)
Presented work deals with heat transfer and its methods. At the beginning thesis describes the theory and the ways of heat transfer with connected quantities and equations. Then it explains the stack effect and impact of temperature on electro technical device. In work is also described ABB driver ACS line and calculation of heat transfer according to IEC 60890 standard. In the practical part there is the calculation of heat transfer in Flow Simulation simulating CFD program solved and finite element method is mentioned. Important part of work is devoted to setting and optimization of simulation. In conclusion are made some changes of construction of driver, dependence on heat transfer is inspected.
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