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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Etude de stratégies de ventilation pour améliorer la qualité environnementale intérieure et le confort des occupants en milieu scolaire / Study of ventilation strategies improving indoor environmental quality and comfort in scholar buildings

Dhalluin, Adrien 19 June 2012 (has links)
La ventilation est un secteur clé du bâtiment, dont le rôle est d’assurer un air sain et confortable toute l’année, ce qui est rarement le cas dans les bâtiments scolaires, tout en minimisant les consommations énergétiques. Nos travaux consistent à apporter des éléments de réponses et des pistes d’amélioration pour l’élaboration de stratégies de ventilation appropriées au milieu scolaire, à partir de travaux expérimentaux et numériques. Pour ce faire, quatre modes de ventilation (naturelle et mixte) ont été testés dans des salles de classes de l’Université de La Rochelle, et leurs performances ont été comparées via une évaluation multicritère basée sur les paramètres physiques caractérisant l’environnement intérieur, les indices de confort (subjectif, analytique et adaptatif) et des critères énergétiques. Des méthodes normatives de classification et des estimations de consommations énergétiques nous ont permis de conclure, que le système de ventilation naturelle par ouverture automatisée des fenêtres, contrôlé par la détection de présence et des paramètres thermiques (système SOS), est le meilleur compromis. Nous soumettons toutefois dans ce manuscrit, un certain nombre d’améliorations à apporter à ce système.Notre contribution porte également sur la connaissance des mécanismes du confort humain et en particulier ses réactions adaptatives, en définissant les conditions favorables au confort et en proposant des modèles prédictifs du confort global, de l’ajustement personnel ainsi que du contrôle individuel de l’ambiance par les occupants. Ces résultats ont notamment pour vocation d’améliorer la prise en compte des interactions entre les occupants et leur environnement dans les simulations numériques et pourraient également servir de base au développement d’une stratégie de ventilation optimisée. Au niveau numérique, nous proposons des simulations annuelles de quatre stratégies de ventilation, très proches de celles testées sur site, à l’aide d’un code thermo-aéraulique multizone (couplage Trnsys/Contam), que nous avons validé à partir de certaines séquences de mesures. En tenant compte d’un scénario d’occupation scolaire standard et du fichier météorologique correspondant à la station de La Rochelle, nous avons notamment montré qu’il est primordial de pré-chauffer l’air d’un système de ventilation mécanique, sous peine d’être confronté à des besoins de chauffage insurmontables. En introduisant une puissance de chauffage illimitée, permettant de maintenir une température minimale acceptable et ainsi de simuler des conditions d’enseignement réalistes, il apparaît que la meilleure qualité environnementale intérieure est à nouveau obtenue avec le système SOS. Notre modèle nous donne désormais la possibilité de multiplier les stratégies de ventilation, ainsi que les scénarios d’occupation, les conditions climatiques ou tout autre étude paramétrique, afin d’élaborer les meilleures stratégies de ventilation dans chaque configuration. / Ventilation is a key sector of building, whose role is to ensure healthy and comfortable air all over the year, which is rarely the case in school buildings, while minimizing energy consumption. Our work provides some answers and possible improvements for the development of appropriate ventilation strategies for schools, from experimental and numerical work.To achieve this, four modes of ventilation (natural and mixed ventilation modes) were tested in classrooms of the University of La Rochelle, and their performances were compared via a multicriteria evaluation based on the physical parameters characterizing the indoor environment, comfort indices (subjective, analytical and adaptive) and energy criteria. Normative methods of classification and estimates of energy consumption enabled us to conclude that the natural ventilation system by automated opening windows, controlled by the presence detection and thermal parameters (SOS), is the best compromise. However, we submit in this manuscript, some improvements to this system.Our contribution concerns also the understanding of the human comfort mechanisms and in particular its adaptive reactions, by defining the favorable conditions for a state of comfort and providing predictive models concerning overall comfort, personal adjustments and the individual control of the indoor environment by the occupants. These results aim to improve the consideration of the interactions between occupants and their environment in numerical simulations, and may serve as a basis for developing an optimized ventilation strategy.Numerically, we propose annual simulations of four ventilation strategies, very similar to those tested in situ, by using a combined heat and mass transfer multizone model (coupling Trnsys / CONTAM), that we have validated from selected experimental sequences. Taking into account a standard scenario of occupation and the annual weather conditions for La Rochelle, we have shown the importance to pre-heat the supplied air of a mechanical ventilation system, because of insurmountable heating demand consequences. By introducing an unlimited heating power, in order to maintain a minimum acceptable temperature and thus to simulate realistic learning conditions, it appears that the best indoor environmental quality is again obtained with the SOS system. Our model now gives us the possibility to increase the number of ventilation strategies, as well as the occupation scenarios, the weather conditions or any other parametric study in order to design the best ventilation strategies for each configuration.
2

Biomechanický model interakce ventilace a oběhu za podmínek umělé plicní ventilace / Biomechanical model of interaction between ventilation and hemodynamics induced by mechanical ventilation

Otáhal, Michal January 2019 (has links)
MUDr. Michal Otáhal Biomechanický model interakce oběhu a ventilace za podmínek UPV Abstract: Conventional mechanical ventilation provides gas exchange in conditions of respiratory failure by application positive airway pressure in the respiratory system. Due to the significant change in pressure conditions inside the thorax during conventional artificial ventilation the circulation can be significantly affected. Recruitment maneuver (RM) techniques can be a part of ventilation strategy in patients with the Acute Respiratory Distress Syndrome (ARDS), that are used to re-aerate collapsed parts of the lung parenchyma. During these RMs a significantly higher airway pressure is used than in protective ventilation strategy, which can limit the flow through the lung capillary network and can significantly affect the systemic hemodynamics of the patient. The aim of this work was to develop an optimized animation model of ARDS, then to compare the influence that has the application of different types of recruitment maneuvers on hemodynamics and to create a biomechanical simulation model of interaction and blood circulation and its verification with data obtained during the implementation of different types of RM in the experimental animal ARDS model. Results from the experimental animal model and simulations...
3

Regression models to assess the thermal performance of Brazilian low-cost houses: consideration of natural ventilation / Modelos de regressão para avaliação do desempenho térmico de habitações de interesse social brasileiras: consideração da ventilação natural

Rossi, Michele Marta 28 January 2016 (has links)
Building performance simulations [BPS] tools are important in all the design stages, mainly in the early ones. However, some barriers such as time, resources and expertise do not contribute to their implementation in architecture offices. This research aimed to develop regression models (meta-models) to assess the thermal discomfort in a Brazilian low-cost house [LCH] during early design. They predicted the degree-hours of discomfort by heat and/or by cold as function of the design parameters changes for three Brazilian cities: Curitiba/PR, São Paulo/SP, and Manaus/AM. This work focused on using the meta-models to evaluate the impact of the parameters related to natural ventilation strategies on thermal performance in LCH. The analyzed Brazilian LCH consisted in a naturally ventilated representative unit developed based on the collected data. The most influential parameters in thermal performance, namely as key design parameters, were building orientation, shading devices positions and sizes, thermal material properties of the walls and roof constructive systems as well as window-to-wall ratios (WWR) and effective window ventilation areas (EWVA). The methodology was divided into: (a) collecting projects of Brazilian LCH, and based on that a base model that was able to represent them was proposed, (b) defining the key design parameters and their ranges, in order to compose the design space to be considered, (c) simulating thermal performance using EnergyPlus coupled with a Monte Carlo framework to randomly sample the design space considered, (d) using the greater part of the simulation results to develop the meta-models, (e)using the remaining portion to validate them, and (f) applying the meta-models in a simple design configuration in order to test their potential as a support design tool. Overall, the meta-models showed R2 values higher than 0.95 for all climates. Except for the regression models to predict discomfort by heat for Curitiba (R2 =0.61) and São Paulo (R2 =0.74). In their application, the models showed consistent predictions for WWR variations, but unexpected patterns for EWVA. / Simulações do desempenho de edificações são ferramentas importantes em todo processo de desenvolvimento do projeto, especialmente nas etapas iniciais. No entanto, barreiras como tempo, custo e conhecimento especializado impedem a implementação de tais ferramentas nos escritórios de arquitetura. A presente pesquisa se propôs a desenvolver modelos de regressão (meta-modelos) para avaliar o desconforto térmico em uma habitação de interesse social [HIS] brasileira. Estes meta - modelos predizem os graus-hora de desconforto por calor ou por frio em função de alterações nos parâmetros de projeto para três cidades brasileiras: Curitiba/PR, São Paulo/SP e Manaus/AM. O foco deste trabalho é o uso dos meta-modelos para avaliar o impacto de parâmetros relacionados com estratégias de ventilação natural no conforto térmico em HIS. A HIS brasileira analisada consistiu em uma unidade representativa, naturalmente ventilada e desenvolvida baseada em dados coletados. Os parâmetros que mais influenciam o conforto térmico, nomeados parâmetroschave de projeto foram: orientação da edificação, posição e tamanho das proteções solares, propriedades térmicas dos sistemas construtivos das paredes e do telhado, assim como, áreas de janela nas fachadas e áreas efetiva de abertura. A metodologia foi dividida em: (a) coleta de projetos de HIS brasileiras que embasaram a proposição de um modelobase que os representassem, (b) definição dos parâmetros chave de projeto e suas faixas de variação, a fim de compor o universo de projeto a ser explorado, (c) simulações térmicas usando o EnergyPlus acoplado com uma ferramenta de Monte Carlo para variar randomicamente o universo de projeto considerado, (d) uso da maior parte dos resultados das simulações para o desenvolvimento dos meta-modelos,(e) uso da porção remanescente para a validação dos meta-modelos e (f) aplicação dos meta-modelos em uma simples configuração de projeto, visando testar o seu potencial como ferramenta de suporte de projeto. De modo geral, os meta-modelos apresentaram R2 superiores a 0,95 para todos os climas, exceto os meta-modelos para predizer desconforto por calor para Curitiba (R2 =0,61) e São Paulo (R2 =0,74). Na fase de aplicação, os modelos mostraram predições consistentes para variações na área de janela na fachada, mas incoerências para variações nas áreas efetiva de abertura.
4

Regression models to assess the thermal performance of Brazilian low-cost houses: consideration of natural ventilation / Modelos de regressão para avaliação do desempenho térmico de habitações de interesse social brasileiras: consideração da ventilação natural

Michele Marta Rossi 28 January 2016 (has links)
Building performance simulations [BPS] tools are important in all the design stages, mainly in the early ones. However, some barriers such as time, resources and expertise do not contribute to their implementation in architecture offices. This research aimed to develop regression models (meta-models) to assess the thermal discomfort in a Brazilian low-cost house [LCH] during early design. They predicted the degree-hours of discomfort by heat and/or by cold as function of the design parameters changes for three Brazilian cities: Curitiba/PR, São Paulo/SP, and Manaus/AM. This work focused on using the meta-models to evaluate the impact of the parameters related to natural ventilation strategies on thermal performance in LCH. The analyzed Brazilian LCH consisted in a naturally ventilated representative unit developed based on the collected data. The most influential parameters in thermal performance, namely as key design parameters, were building orientation, shading devices positions and sizes, thermal material properties of the walls and roof constructive systems as well as window-to-wall ratios (WWR) and effective window ventilation areas (EWVA). The methodology was divided into: (a) collecting projects of Brazilian LCH, and based on that a base model that was able to represent them was proposed, (b) defining the key design parameters and their ranges, in order to compose the design space to be considered, (c) simulating thermal performance using EnergyPlus coupled with a Monte Carlo framework to randomly sample the design space considered, (d) using the greater part of the simulation results to develop the meta-models, (e)using the remaining portion to validate them, and (f) applying the meta-models in a simple design configuration in order to test their potential as a support design tool. Overall, the meta-models showed R2 values higher than 0.95 for all climates. Except for the regression models to predict discomfort by heat for Curitiba (R2 =0.61) and São Paulo (R2 =0.74). In their application, the models showed consistent predictions for WWR variations, but unexpected patterns for EWVA. / Simulações do desempenho de edificações são ferramentas importantes em todo processo de desenvolvimento do projeto, especialmente nas etapas iniciais. No entanto, barreiras como tempo, custo e conhecimento especializado impedem a implementação de tais ferramentas nos escritórios de arquitetura. A presente pesquisa se propôs a desenvolver modelos de regressão (meta-modelos) para avaliar o desconforto térmico em uma habitação de interesse social [HIS] brasileira. Estes meta - modelos predizem os graus-hora de desconforto por calor ou por frio em função de alterações nos parâmetros de projeto para três cidades brasileiras: Curitiba/PR, São Paulo/SP e Manaus/AM. O foco deste trabalho é o uso dos meta-modelos para avaliar o impacto de parâmetros relacionados com estratégias de ventilação natural no conforto térmico em HIS. A HIS brasileira analisada consistiu em uma unidade representativa, naturalmente ventilada e desenvolvida baseada em dados coletados. Os parâmetros que mais influenciam o conforto térmico, nomeados parâmetroschave de projeto foram: orientação da edificação, posição e tamanho das proteções solares, propriedades térmicas dos sistemas construtivos das paredes e do telhado, assim como, áreas de janela nas fachadas e áreas efetiva de abertura. A metodologia foi dividida em: (a) coleta de projetos de HIS brasileiras que embasaram a proposição de um modelobase que os representassem, (b) definição dos parâmetros chave de projeto e suas faixas de variação, a fim de compor o universo de projeto a ser explorado, (c) simulações térmicas usando o EnergyPlus acoplado com uma ferramenta de Monte Carlo para variar randomicamente o universo de projeto considerado, (d) uso da maior parte dos resultados das simulações para o desenvolvimento dos meta-modelos,(e) uso da porção remanescente para a validação dos meta-modelos e (f) aplicação dos meta-modelos em uma simples configuração de projeto, visando testar o seu potencial como ferramenta de suporte de projeto. De modo geral, os meta-modelos apresentaram R2 superiores a 0,95 para todos os climas, exceto os meta-modelos para predizer desconforto por calor para Curitiba (R2 =0,61) e São Paulo (R2 =0,74). Na fase de aplicação, os modelos mostraram predições consistentes para variações na área de janela na fachada, mas incoerências para variações nas áreas efetiva de abertura.

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