Directional control valves are widely used in hydraulic systems to control the flow direction and the flow rate. In order to design an actuator for such a valve a preliminary analysis of forces acting on the spool is necessary. The dominant axial force is the so called steady flow force, which is analysed within this study. For this purpose a 2/2-way spool valve with a sharp control edge was manufactured and investigated. CFD simulations were carried out to visualize the fluid flow inside the valve. The measured and simulated axial forces and pressure drops across the test valve are compared and show good qualitative correlation. However, the simulated values of axial forces are in average by 32 % lower compared with the measured ones. Therefore, the components of the axial force were scrutinized revealing a dominancy of the pressure force acting on ring areas in the spool chamber. Although CFD simulations are preferably used to save resources, the results of this study emphasise the importance of the experiments.

This research demonstrates technology for detection of pathogens and environmental monitoring using a handheld optofluidic immunosensor and CFD simulation. The current methods such as ELISA and PCR require few hours for identification which means it is unavailable for early-monitoring. The use of a near-real-time, handheld biosensor device in a real animal/human environment is the key to monitoring the spread of dangerous pathogens. A 3-D computational fluid dynamics (CFD) simulation is needed to track the pathogens within an environment.This dissertation has four papers that demonstrate technologies for the detection and monitoring of pathogens and the miniaturization of these detection systems for in field applications with a handheld immunosensor and CFD simulation.In the first paper, an environmental prediction model was developed for optimal ventilation in a mushroom house by using sensible heat balance and 3-D CFD method. It is shown that the models can be used for farmers to predict the environmental conditions over different locations in a mushroom house.In the second paper, a field lab-on-a-chip system was constructed to detect mouse immunoglobulin G and Escherichia coli by using light scattering detection of particle immunoagglutination. Antibody-conjugated particles were able to be stored in a 4°C refrigerator for at least 4 weeks and to be lyophilized as a powder form for the storage in room temperature.In the third paper, rapid monitoring of the spreads of porcine reproductive and respiratory syndrome virus (PRRSV) was attempted using samples collected from nasal swabs of pigs and air samplers within an experimental swine building. An optofluidic device containing liquid-core waveguides was used to detect. It is shown that the developed optofluidic device and 3-D CFD model can serve as a good model for monitoring the spread of airborne viruses within animal and human environments.In the fourth paper, a handheld optofluidic immunosensor was developed for rapid detection of H1N1/2009 virus inside a 1:10 scale mock classroom. Both miniature spectrometer and cell phone camera were used as detector. A 3-D computational fluid dynamics (CFD) model was developed to track the transport/distribution of H1N1/2009 viruses, and corresponded very well with immunosensor readings.

Aneurismas são dilatações permanentes iguais ou superiores a 50% do diâmetro original de uma artéria ou do diâmetro proximal da mesma, de acordo com consenso publicado pela Sociedade de Cirurgia Vascular da América do Norte e Sociedade Internacional de Cirurgia Cardiovascular em 1991 (Vliet e Boll, 1997). Aneurisma de aorta é uma doença vascular que afeta mais de 5% da população masculina com mais de 55 anos de idade (How et al., 2005). Desde 1991 um novo método vem sendo utilizado como tratamento deste quadro clínico. Este novo método é considerado menos invasivo e com menor comorbidade, uma vez que se trata da instalação de uma endoprótese por meio de catéter através da artéria femoral. Neste trabalho, será verificado o escoamento através de três aneurismas de aorta abdominal (AAA) e das endopróteses indicadas para o tratamento de cada um dos aneurismas. Foram feitas simulações computacionais afim de se obter as pressões, as velocidades do escoamento sanguíneo e as tensões de cisalhamento na parede das geometrias, usando pulsos de pressão e velocidade fisiológico de um individuo adulto, normotenso, em repouso. No modelo de escoamento simulado, foi adotado o sangue como fluido Newtoniano, incompressível e homogêneo. Foi usado um modelo de turbulência K-, com interpolador upwind de 2ª ordem e tratamento de parede nas geometrias, para que se fosse possível obter resultados satisfatórios (das camadas próximas à parede, e de todos os vórtices). Os resultados obtidos no trabalho foram satisfatórios, uma vez que eles expressaram de forma realista o comportamento do escoamento sanguíneo pelos aneurismas e endopróteses. Foi possível justificar com esse trabalho a instalação de endopróteses em pacientes, quando necessário, com o objetivo de diminuir significativamente a degradação do vaso, causando a ruptura do aneurisma. / Aneurisms are permanently dilatation higher than 50% of the original diameter of an artery or of the proximal diameter of them, according to the published consensus of the Vascular Surgery Society of North America and International Society of Cardiovascular Surgery on 1991 (Vliet and Boll, 1997). Aortas Aneurism is a vascular disease that affects more than 5% of the male population, with more than 55 years old (How et al, 2005). Since 1991, a new method is used in the treatment of these diseases. This new method is less invasive and has less comorbidity. This method is provided by the installation of an endoprosthesis through the catheter through the femoral artery. In this work, the flow will be verified through three abdominal aortic aneurysms (AAA) and the endoprosthesis indicated for the treatment of each of the aneurysms. Computational simulations were made in order to obtain the pressures, velocities of the blood flow and the shear stresses on the wall of geometries, using a pulse pressure and velocity of an individual physiological adult normotensive at rest. For the fluid simulations, it was adopted the blood as Newtonian fluid, incompressible and homogeneous. In simulations, it was used a K- model of turbulence, with 2nd order upwind interpolator and wall geometry treatment in order to obtain satisfied results (on the layers near the walls, and all the vortices). The results obtained in this work were satisfied, once they expressed the realistic behavior of the blood flow through the aneurysm and the endoprosthesis. It was possible to justify with this work the installation of an endoprosthesis inside patients, when it is necessary, in order to decrease significantly the vessels degradation, causing the aneurysm rupture.

The existing local fire code ¡§Standard for Installation of Fire Protection Facilities in Classified Areas¡¨ is prescriptive in nature and suitable for buildings, which can be well compartmented. It also described the minimum requirement for specific system designs such as fire and smoke compartmentation, mechanical smoke extraction rate, etc. on item 188. In this reserch, the concourse level encountered large spaces and is the vital part for passengers¡¦ movement, either under normal condition or in emergency cases. Therefore, a performance-based fire engineering design has been exercised which is also allowed in local fire code subject to approval from the authorities having jurisdiction. First, a comparative study of the code compliances should be addressed, with the alternative design options supported by 3D CFD simulation. The FDS (Fire Dynamic Simulation) program was utilized for this reserch for 3D CFD simulation. It is developed by the National Institute of Standards and Technology (NIST) of U.S.. FDS is a computational fluid dynamics (CFD) model of fire-driven fluid flow. The software solves numerically a form of the Navier-Stokes equations appropriate for thermally-driven flow with an emphasis on smoke and heat transport from fires. Secondly, it is decided that a full-scale hot smoke test should be conducted to validate the smoke management system performances under the as-built conditions. It can be summarized that, following the NFPA 92B N-percentage Criteria, both test 1 and test 2 results indicated that the hot smoke tests are successful, in validating that a sufficient smoke clear height can be maintained for safe evacuation should a 5 MW t-squared fast fire occurred at the concourse level. Finally, following the NFPA 130 and NFPA 92B as the design guides, the performance-based fire safety engineering design conducted in concourse level, is successful through 3D CFD simulations and full-scale hot smoke test. A smoke¡Vfree escape route can be maintained for a period of time much longer than needed for the worst case fire scenario which warrants a safe evacuation in case of a 5 MW fire occurred on concourse level.

The works aimed at the further development and validation of models for CFD codes. For this reason, the new thermal-hydraulic test facility TOPFLOW was erected and equipped with wire-mesh sensors with high spatial and time resolution. Vertical test sections with nominal diameters of DN50 and DN200 operating with air-water as well as steam-water two-phase flows provided results on the evaluation of flow patterns, on the be¬haviour of the interfacial area as well as on interfacial momentum and heat transfer. The validation of the CFD-code for complex geometries was carried out using 3D void fraction and velocity distributions obtained in an experiment with an asymmetric obstacle in the large DN200 test section. With respect to free surface flows, stratified co- and counter-current flows as well as slug flows were studied in two horizontal test channels made from acrylic glass. Post-test calculations of these experiments succeeded in predicting the slug formation process. Corresponding to the main goal of the project, the experimental data was used for the model development. For vertical flows, the emphasis was put on lateral bubble forces (e.g. lift force). Different constitutive laws were tested using a Multi Bubble Size Class Test Solver that has been developed for this purpose. Basing on the results a generalized inhomogeneous Multiple Size Group (MUSIG) Model has been proposed and implemented into the CFD code CFX (ANSYS). Validation calculations with the new code resulted in the conclusion that particularly the models for bubble coalescence and fragmentation need further optimisation. Studies of single effects, like the assessment of turbulent dissipation in a bubbly flow and the analysis of trajectories of single bubbles near the wall, supplied other important results of the project.

Ziel der Arbeiten war die Weiterentwicklung und Validierung von Modellen in CFD-Codes. Hierzu wurde am FZD die thermohydraulische Versuchsanlage TOPFLOW aufgebaut und mit räumlich und zeitlich hochauflösenden Gittersensoren ausgestattet. Vertikale Teststrecken mit Nenndurchmessern von DN50 bzw. DN200 für Luft/Wasser- sowie Dampf/Wasser-Strömungen lieferten Ergebnisse zur Entwicklung von Strömungsformen, zum Verhalten der Zwischenphasengrenzfläche sowie zum Wärme- und Impulsaustausch zwischen den Phasen. Die Validierung des CFD-Codes in komplexen Geometrien erfolgte anhand von 3D Gasgehalts- und Geschwindigkeitsfeldern, die bei Umströmung eines asymmetrischen Hindernisses auftreten, das in der Teststrecke DN200 eingebaut war. Im Hinblick auf Strömungen mit freier Oberfläche untersuchte das FZD in zwei horizontalen Acrylglas-Kanälen geschichtete Zweiphasenströmungen im Gleich- bzw. Gegenstrom sowie Schwallströmungen. Bei den Nachrechnungen dieser Versuche gelang die Simulation der Schwallentstehung. Entsprechend des Projektziels wurden die experimentellen Ergebnisse zur Modellentwicklung genutzt. Bei vertikalen Strömungen stand die Wirkung der lateralen Blasenkräfte (z.B. Liftkraft) im Vordergrund. Zum Test unterschiedlicher Modellansätze wurde hierzu ein Mehrblasenklassen-Testsolver entwickelt und genutzt. Darauf aufbauend wurde ein neues Konzept für ein Mehrblasenklassenmodell, das Inhomogene MUSIG Modell erarbeitet und in den kommerziellen CFD Code CFX (ANSYS) implementiert. Bei Validierungsrechnungen zeigte sich, dass vor allem die Blasenkoaleszenz- und -zerfallsmodelle weiter optimiert werden müssen. Untersuchungen zu Einzeleffekten, wie z.B. die Abschätzung von Turbulenzkoeffizienten und die Analyse der Trajektoren von Einzelblasen in unmittelbarer Wandnähe, lieferten weitere wichtige Ergebnisse des Projekts.

Two of the main safety and health issues recognized during deep cut coal mining are methane and dust hazards. Advances in continuous miner technology have improved safety and productivity. However, these advances have created some environmental problems, notably more dust and methane being generated at the face during coal extraction. Results of studies performed in the last three decades concerning the face ventilation for deep cut mining showed very complicated airflow behavior. The specifics of flow patterns developed by the face ventilation systems presents significant challenge for analytical description even for equipment-free entry. Fortunately, there are methods, such as numerical simulations that could be used to provide an engineering solution to the problem. Computational Fluid Dynamics (CFD) codes have been successfully applied during the last decade using the power of Supercomputers. Although significant progress has been made, a benchmark industry oriented CFD code dedicated to face ventilation is still not available. The goal of this project is to provide the mining industry a software for CFD analysis and design of face ventilation systems. A commercial CFD system SC/Tetra Thermofluid Analysis System with Unstructured Mesh Generator, copyright © Cradle Co, was selected for a development platform. A number of CFD models were developed for the needs of this study including methane release, dust generation, 3D models of commonly used continuous mining machines, scrubbers and water spray systems. The developed models and the used CFD code were successfully validated in the part for methane dilution, using available data from small scale and full scale experiments. The developed models for simulation of dust control systems need to be validated in the future. The developed code automates all necessary steps needed for simulation of face ventilation systems, starting with the construction of a 3D model, generation of the computational mesh, solving and monitoring the calculations, to post-processing and graphical representation of the obtained results. This code shall allow mining engineers to design better and safer face ventilation systems while providing the Mine Safety and Health Administration (MSHA) a tool to check and approve the industry’ proposed ventilation plans.

Aneurismas são dilatações permanentes iguais ou superiores a 50% do diâmetro original de uma artéria ou do diâmetro proximal da mesma, de acordo com consenso publicado pela Sociedade de Cirurgia Vascular da América do Norte e Sociedade Internacional de Cirurgia Cardiovascular em 1991 (Vliet e Boll, 1997). Aneurisma de aorta é uma doença vascular que afeta mais de 5% da população masculina com mais de 55 anos de idade (How et al., 2005). Desde 1991 um novo método vem sendo utilizado como tratamento deste quadro clínico. Este novo método é considerado menos invasivo e com menor comorbidade, uma vez que se trata da instalação de uma endoprótese por meio de catéter através da artéria femoral. Neste trabalho, será verificado o escoamento através de três aneurismas de aorta abdominal (AAA) e das endopróteses indicadas para o tratamento de cada um dos aneurismas. Foram feitas simulações computacionais afim de se obter as pressões, as velocidades do escoamento sanguíneo e as tensões de cisalhamento na parede das geometrias, usando pulsos de pressão e velocidade fisiológico de um individuo adulto, normotenso, em repouso. No modelo de escoamento simulado, foi adotado o sangue como fluido Newtoniano, incompressível e homogêneo. Foi usado um modelo de turbulência K-, com interpolador upwind de 2ª ordem e tratamento de parede nas geometrias, para que se fosse possível obter resultados satisfatórios (das camadas próximas à parede, e de todos os vórtices). Os resultados obtidos no trabalho foram satisfatórios, uma vez que eles expressaram de forma realista o comportamento do escoamento sanguíneo pelos aneurismas e endopróteses. Foi possível justificar com esse trabalho a instalação de endopróteses em pacientes, quando necessário, com o objetivo de diminuir significativamente a degradação do vaso, causando a ruptura do aneurisma. / Aneurisms are permanently dilatation higher than 50% of the original diameter of an artery or of the proximal diameter of them, according to the published consensus of the Vascular Surgery Society of North America and International Society of Cardiovascular Surgery on 1991 (Vliet and Boll, 1997). Aortas Aneurism is a vascular disease that affects more than 5% of the male population, with more than 55 years old (How et al, 2005). Since 1991, a new method is used in the treatment of these diseases. This new method is less invasive and has less comorbidity. This method is provided by the installation of an endoprosthesis through the catheter through the femoral artery. In this work, the flow will be verified through three abdominal aortic aneurysms (AAA) and the endoprosthesis indicated for the treatment of each of the aneurysms. Computational simulations were made in order to obtain the pressures, velocities of the blood flow and the shear stresses on the wall of geometries, using a pulse pressure and velocity of an individual physiological adult normotensive at rest. For the fluid simulations, it was adopted the blood as Newtonian fluid, incompressible and homogeneous. In simulations, it was used a K- model of turbulence, with 2nd order upwind interpolator and wall geometry treatment in order to obtain satisfied results (on the layers near the walls, and all the vortices). The results obtained in this work were satisfied, once they expressed the realistic behavior of the blood flow through the aneurysm and the endoprosthesis. It was possible to justify with this work the installation of an endoprosthesis inside patients, when it is necessary, in order to decrease significantly the vessels degradation, causing the aneurysm rupture.

The thesis pursues a design of mechanism for controlling the amount of air sucked by a turbocharger compressor. In the first part, there is a brief description of a turbocharger and its characteristics, in the second part the usual regulation methodologies are presented. Third, the main part describes the creation of the mechanism from concept drafts and their comparison, through the kinematic and force analysis of control parts, to the complete packaging a connection to the compressor housing. The fourth part is dedicated to the mechanism analysis in the terms of ability to perform as required.

Diploma thesis is divided into two parts. The theoretical part deals with natural ventilation and the practical part focuses on the optimization of the ventilation in the original hall using CFD simulation. One of the solutions is proposed in the design part of the diploma thesis.