A conversão da energia das ondas dos oceanos em energia elétrica é uma alternativa para o problema da falta de combustíveis fósseis. Uma das possibilidades de aproveitamento é através de dispositivos cujo princípio de funcionamento é o de Coluna de Água Oscilante (CAO). No presente trabalho o objetivo é, através da modelagem computacional e do emprego do Design Construtal, maximizar a potência hidropneumática de um dispositivo conversor de energia das ondas do mar do tipo CAO. São analisados diferentes eixos da restrição física, no formato elíptico, que representa a turbina, e duas formas geométricas na região de transição entre a câmara hidropneumática e a chaminé do dispositivo CAO: trapezoidal e semicircular. Considerando um domínio bidimensional, as restrições para estes problemas são: Área da restrição elíptica (AR), Área total do dispositivo (AT) e razão entre a área da restrição elíptica e a área total (ϕn). Os graus de liberdade analisados são: a razão entre os comprimentos dos eixos da restrição elíptica (d1/d2) para o caso da restrição física da turbina, o ângulo de inclinação da parede (α) para o caso com região de transição trapezoidal, o raio (r) e H2/l (razão entre altura e comprimento da chaminé de saída da câmara CAO) para o caso com região de transição semicircular. Para a solução numérica é empregado um código de dinâmica dos fluidos computacional, FLUENT®, baseado no Método de Volumes Finitos (MVF). O modelo multifásico Volume of Fluid (VOF) é aplicado no tratamento da interação água-ar. O domínio computacional é representado por um tanque de ondas com um dispositivo CAO acoplado. Os resultados obtidos indicam que, para o estudo da região de transição trapezoidal o desempenho do conversor tem aproximadamente o mesmo desempenho para todas as geometrias estudadas. A região de transição semicircular, apresenta resultados para os quais foi possível otimizar a potência hidropneumática. O estudo da turbina indica que foi possível determinar uma geometria capaz de converter a energia da onda incidente ao dispositivo, sem que ocorresse a obstrução do escoamento de ar na chaminé do dispositivo CAO. Assim, mostra-se a relação entre o método Design Construtal e o clima de ondas na definição das dimensões que maximizam a potência hidropneumática. / The conversion of ocean’s wave energy into electrical energy is an alternative for the scarcity of fossil fuels. One of the possibilities of energy use is through devices, whose operating principle is the Oscillating Water Column (OWC). In this work the aim is, through computer modeling and the Constructal Design, to maximize hydropneumatic power of a power converter device type OWC. Different axes of physical constraint with elliptical shape, representing the effect of the turbine , are analyzed. Two geometric shapes in the transition region between the hydropneumatic chamber and the chimney OWC device, trapezoidal and semicircular, are also analyzed. Considering a two-dimensional domain the restrictions for this problem are: Elliptical restriction area (AR), Total area device (AT) and the ratio between the area of the elliptical restraint and the total area (ϕn). The considered degrees of freedom are: the ratio between the lengths of the axes (d1/d2) of the elliptical restraint, for the turbine’s physical constraint case, the inclination angle (α) of the wall for the trapezoidal transition case, and the radius (r) and H2/l (ratio between height and length of output chimney CAO) for the semicircular transition region case. For the numerical solution, a commercial code of computational fluid dynamics, FLUENT®, which is based on the Finite Volume Method (FVM), is employed. The multiphase model Volume of Fluid (VOF) is applied in the treatment of water-air interaction. The computational domain is represented by a wave tank with a fixed OWC device. The obtained results indicate that, for the study of the trapezoidal transition region, the performance of converter don’t seems to be compensatory only by changing the geometry of the trapezoidal area. However, for the semicircular transition region, it was possible to optimize a hydropneumatic power. The study of turbine effect indicates a geometry capable of converting the energy of the incident wave to the device, without obstructing the air flow in the chimney of de OWC, showing the relationship between the Constructal Design method and the wave climate in the definition of the dimensions that maximize the hydropneumatic power.

Across the State of Texas and many other areas of the world, relatively young concrete structures have developed signs of premature concrete deterioration. Large cracks form on the surface of the concrete due to expansive forces from alkali-silica reaction (ASR) and delayed-ettringite formation (DEF). The goal of this project is to assess the effect of ASR/DEF on the trapezoidal box beam bridges in the US 59 corridor and Katy Central Business District (CBD) HOV lanes in Houston, TX. Five dapped-end beams were rejected during the casting process and have been in storage at a local precast yard for nearly fifteen years. These beams have been subject to accelerated deterioration and represent the potential severity of the ongoing ASR/DEF distress within the dapped end regions of the in-service trapezoidal box beams. The results from five load tests, corresponding strut-and-tie models, and forensic investigation are used to provide insights into the relationship between the severity of the deterioration and the capacity margin. / text

A conversão da energia das ondas dos oceanos em energia elétrica é uma alternativa para o problema da falta de combustíveis fósseis. Uma das possibilidades de aproveitamento é através de dispositivos cujo princípio de funcionamento é o de Coluna de Água Oscilante (CAO). No presente trabalho o objetivo é, através da modelagem computacional e do emprego do Design Construtal, maximizar a potência hidropneumática de um dispositivo conversor de energia das ondas do mar do tipo CAO. São analisados diferentes eixos da restrição física, no formato elíptico, que representa a turbina, e duas formas geométricas na região de transição entre a câmara hidropneumática e a chaminé do dispositivo CAO: trapezoidal e semicircular. Considerando um domínio bidimensional, as restrições para estes problemas são: Área da restrição elíptica (AR), Área total do dispositivo (AT) e razão entre a área da restrição elíptica e a área total (ϕn). Os graus de liberdade analisados são: a razão entre os comprimentos dos eixos da restrição elíptica (d1/d2) para o caso da restrição física da turbina, o ângulo de inclinação da parede (α) para o caso com região de transição trapezoidal, o raio (r) e H2/l (razão entre altura e comprimento da chaminé de saída da câmara CAO) para o caso com região de transição semicircular. Para a solução numérica é empregado um código de dinâmica dos fluidos computacional, FLUENT®, baseado no Método de Volumes Finitos (MVF). O modelo multifásico Volume of Fluid (VOF) é aplicado no tratamento da interação água-ar. O domínio computacional é representado por um tanque de ondas com um dispositivo CAO acoplado. Os resultados obtidos indicam que, para o estudo da região de transição trapezoidal o desempenho do conversor tem aproximadamente o mesmo desempenho para todas as geometrias estudadas. A região de transição semicircular, apresenta resultados para os quais foi possível otimizar a potência hidropneumática. O estudo da turbina indica que foi possível determinar uma geometria capaz de converter a energia da onda incidente ao dispositivo, sem que ocorresse a obstrução do escoamento de ar na chaminé do dispositivo CAO. Assim, mostra-se a relação entre o método Design Construtal e o clima de ondas na definição das dimensões que maximizam a potência hidropneumática. / The conversion of ocean’s wave energy into electrical energy is an alternative for the scarcity of fossil fuels. One of the possibilities of energy use is through devices, whose operating principle is the Oscillating Water Column (OWC). In this work the aim is, through computer modeling and the Constructal Design, to maximize hydropneumatic power of a power converter device type OWC. Different axes of physical constraint with elliptical shape, representing the effect of the turbine , are analyzed. Two geometric shapes in the transition region between the hydropneumatic chamber and the chimney OWC device, trapezoidal and semicircular, are also analyzed. Considering a two-dimensional domain the restrictions for this problem are: Elliptical restriction area (AR), Total area device (AT) and the ratio between the area of the elliptical restraint and the total area (ϕn). The considered degrees of freedom are: the ratio between the lengths of the axes (d1/d2) of the elliptical restraint, for the turbine’s physical constraint case, the inclination angle (α) of the wall for the trapezoidal transition case, and the radius (r) and H2/l (ratio between height and length of output chimney CAO) for the semicircular transition region case. For the numerical solution, a commercial code of computational fluid dynamics, FLUENT®, which is based on the Finite Volume Method (FVM), is employed. The multiphase model Volume of Fluid (VOF) is applied in the treatment of water-air interaction. The computational domain is represented by a wave tank with a fixed OWC device. The obtained results indicate that, for the study of the trapezoidal transition region, the performance of converter don’t seems to be compensatory only by changing the geometry of the trapezoidal area. However, for the semicircular transition region, it was possible to optimize a hydropneumatic power. The study of turbine effect indicates a geometry capable of converting the energy of the incident wave to the device, without obstructing the air flow in the chimney of de OWC, showing the relationship between the Constructal Design method and the wave climate in the definition of the dimensions that maximize the hydropneumatic power.

Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Mechanical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2014 / Open channels, flumes or launders are used in the mining industry to transport slurries during processing and to disposal sites. Water plays a major part in the makeup of these slurries, its usage and availability is critical in countries where there are strict water usage management programs. The optimisation of flume design involves the maximisation of solids transport efficiency whilst, at the same time reduces water usage. The design of open channels is complex as it is dependent on both the slurry rheology and the channel shape. Very little has been reported in the literature for predicting non-Newtonian laminar flow in open channels of arbitrary cross-section. The only method available was that proposed by Kozicki and Tiu (1967, 1986). The shape factors they used were those evaluated from analytical solutions for flow of Newtonian fluids in open channels of the same cross-section. However, they carried out no experimental work to validate their model. Few experimental studies have been made on the effect of shape on non-Newtonian flow in open channels. Naik (1983) tested kaolin in water suspensions in a rectangular channel. Coussot (1994) provided some data for the flow of a Herschel-Bulkley fluid in rectangular and trapezoidal channels. Fitton (2007; 2008) obtained data for flow of three different non-Newtonian fluids (carboxymethylcellulose, carbopol and thickened tailings) in a semi-circular channel. A large experimental database for non-Newtonian flow in rectangular open channels was published by Haldenwang (2003) at the Flow Process Research Centre, Cape Peninsula University of Technology. Guang et al. (2011) performed Direct Numerical Simulations of turbulent flow of a yield- pseudoplastic fluid in a semi-circular channel. They compared their simulations with actual field measurements and found them to over-predict the flow velocity by approximately 40%. The source for this discrepancy was difficult to ascertain. A comprehensive database was compiled during this research of the flow of three non–Newtonian fluids in rectangular, trapezoidal, semi-circular and triangular channels. The flow of carboxymethylcellulose solutions and aqueous kaolin and bentonite suspensions was investigated in a 10 meter long flume at angles ranging from 1° to 5° from the horizontal plane. The effect of channel shape on the friction factor-Reynolds number relationship for laminar and turbulent open channel flow of these three fluids was investigated. New models for the prediction of laminar and turbulent flow of non-Newtonian fluids in open channels of different cross-sectional shapes are proposed. The new laminar and turbulent velocity models are compared with three previously-published velocity models for laminar flow and five previously-published velocity models for turbulent flow using average velocity as comparison criteria. For each channel shape, the laminar flow data can be described by a general relationship, f = K/Re where f is the Fanning friction factor and Re is the appropriate Haldenwang et al. (2002) Reynolds number. The K values were found to be 14.6 for triangular channels with a vertex angle of 90°, 16.2 for semi-circular channels, 16.4 for rectangular channels and 17.6 for trapezoidal channels with 60 degree sides. These K values were found to be in line with those reported by Straub et al. (1958) and Chow (1969) for open channel laminar flow of Newtonian fluids as opposed to the assumption made by Haldenwang et al. (2002; 2004) of using a constant value of 16 based on the pipe flow paradigm for all channel shapes. This new laminar model gave a closer fit to the laminar flow data than those from the three previously-published models. However, the presence of the yield stress still presents a problem, which makes the flow prediction in laminar flow for such fluids not very accurate. The investigation on non-Newtonian turbulent flow of the three fluids in the four different shaped open channels revealed that the data was described by the modified Blasius equation f = a Re b where a and b are constant values determined for each channel shape and Re is the Haldenwang et al. (2002) Reynolds number. Values of a and b for a rectangular channel were found to be 0.12 and -0.330, for a semi- circular channel 0.048 and -0.205, for a trapezoidal channel with 60° sides, 0.085 and -0.266 and for a triangular channel with vertex angle of 90°, 0.042 and -0.202. New laminar and turbulent velocity models were derived from using the new laminar f = K/Re and turbulent f = a Re b, friction factor-Reynolds number relationship. The laminar velocity model did not always give the best result, but the majority of the time it did, compared to the three previously published models. The new turbulent velocity model yielded the best results when compared to the five previously published models using average velocity as comparison criteria. The composite power law modelling procedure of Garcia et al. (2003) used for pipe flow predictions was extended to the present work on non-Newtonian flow in open channels of various cross-sections. The results show that the modelling technique used by Garcia et al. (2003) for pipe flow can be used to adequately predict flow in an open channel of a given cross-sectional shape provided that an appropriate Reynolds number is used to take into account the non-Newtonian behaviour of the test fluid. It was found that the results using the Haldenwang et al. (2002) Reynolds number yielded better results than those based on the adapted Metzner-Reed Reynolds number. The correlations and models developed and experimentally validated during this research can be used to further improve the design of rectangular, semi-circular, trapezoidal and triangular open channels to transport non-Newtonian fluids.

A conversão da energia das ondas dos oceanos em energia elétrica é uma alternativa para o problema da falta de combustíveis fósseis. Uma das possibilidades de aproveitamento é através de dispositivos cujo princípio de funcionamento é o de Coluna de Água Oscilante (CAO). No presente trabalho o objetivo é, através da modelagem computacional e do emprego do Design Construtal, maximizar a potência hidropneumática de um dispositivo conversor de energia das ondas do mar do tipo CAO. São analisados diferentes eixos da restrição física, no formato elíptico, que representa a turbina, e duas formas geométricas na região de transição entre a câmara hidropneumática e a chaminé do dispositivo CAO: trapezoidal e semicircular. Considerando um domínio bidimensional, as restrições para estes problemas são: Área da restrição elíptica (AR), Área total do dispositivo (AT) e razão entre a área da restrição elíptica e a área total (ϕn). Os graus de liberdade analisados são: a razão entre os comprimentos dos eixos da restrição elíptica (d1/d2) para o caso da restrição física da turbina, o ângulo de inclinação da parede (α) para o caso com região de transição trapezoidal, o raio (r) e H2/l (razão entre altura e comprimento da chaminé de saída da câmara CAO) para o caso com região de transição semicircular. Para a solução numérica é empregado um código de dinâmica dos fluidos computacional, FLUENT®, baseado no Método de Volumes Finitos (MVF). O modelo multifásico Volume of Fluid (VOF) é aplicado no tratamento da interação água-ar. O domínio computacional é representado por um tanque de ondas com um dispositivo CAO acoplado. Os resultados obtidos indicam que, para o estudo da região de transição trapezoidal o desempenho do conversor tem aproximadamente o mesmo desempenho para todas as geometrias estudadas. A região de transição semicircular, apresenta resultados para os quais foi possível otimizar a potência hidropneumática. O estudo da turbina indica que foi possível determinar uma geometria capaz de converter a energia da onda incidente ao dispositivo, sem que ocorresse a obstrução do escoamento de ar na chaminé do dispositivo CAO. Assim, mostra-se a relação entre o método Design Construtal e o clima de ondas na definição das dimensões que maximizam a potência hidropneumática. / The conversion of ocean’s wave energy into electrical energy is an alternative for the scarcity of fossil fuels. One of the possibilities of energy use is through devices, whose operating principle is the Oscillating Water Column (OWC). In this work the aim is, through computer modeling and the Constructal Design, to maximize hydropneumatic power of a power converter device type OWC. Different axes of physical constraint with elliptical shape, representing the effect of the turbine , are analyzed. Two geometric shapes in the transition region between the hydropneumatic chamber and the chimney OWC device, trapezoidal and semicircular, are also analyzed. Considering a two-dimensional domain the restrictions for this problem are: Elliptical restriction area (AR), Total area device (AT) and the ratio between the area of the elliptical restraint and the total area (ϕn). The considered degrees of freedom are: the ratio between the lengths of the axes (d1/d2) of the elliptical restraint, for the turbine’s physical constraint case, the inclination angle (α) of the wall for the trapezoidal transition case, and the radius (r) and H2/l (ratio between height and length of output chimney CAO) for the semicircular transition region case. For the numerical solution, a commercial code of computational fluid dynamics, FLUENT®, which is based on the Finite Volume Method (FVM), is employed. The multiphase model Volume of Fluid (VOF) is applied in the treatment of water-air interaction. The computational domain is represented by a wave tank with a fixed OWC device. The obtained results indicate that, for the study of the trapezoidal transition region, the performance of converter don’t seems to be compensatory only by changing the geometry of the trapezoidal area. However, for the semicircular transition region, it was possible to optimize a hydropneumatic power. The study of turbine effect indicates a geometry capable of converting the energy of the incident wave to the device, without obstructing the air flow in the chimney of de OWC, showing the relationship between the Constructal Design method and the wave climate in the definition of the dimensions that maximize the hydropneumatic power.

The object of the diploma thesis is the design and the assessment of the steel structure for rally team base in Napajedla, which contains the space for the administration and the space for the service hall. The overall ground plan proportions of the structure are 30 x 26 metres. The structure for administration is the four-storey building. The ground plan proportions of this structure are 30 x 12 metres and the height is 14.5 metres. The ground floor grid of the main load-bearing structure is 6 x 6 metres. The height of the one floor of the structure is 3.5 metres. The structure of ceilings and roof is designed like composite steel and concrete structure. All joints of the steel structure for administration are designed like bolted joints. The spatial rigidity of the structure is ensured by vertical wall truss bracings and by the rigidity of composite steel and concrete structure of ceillings and roof. To the structure for the administration is connected structure for the service hall. The ground plan proportions of this structure are 30 x 14 metres and the height is 10.5 metres. The main structure of the structure for service hall is frame with the rigid joint in the corner of the frame. The axial distance of the main structures is 6 metres. All joints including the rigid joint in the corner of the frame of the steel structure for service hall are designed like bolted joints. The spatial rigidity of the structure is ensured by vertical wall truss bracings and horizontal roof truss bracings. The whole structure is designed of steel S355.

The text of this thesis deals with techniques of parallel processing calculations. It is an analysis of the most important libraries for parallelization including libraries for parallelization on GPU graphics cards and computing speed by comparing these libraries in Visual Studio 2010 based on a simple application searching primes on three different computer hardware configurations. With OpenCL library, that achieved the best result, there are formed two applications – an improved program for searching prime numbers using the sieve of Eratosthenes and a program for calculating the integral with the trapezoidal rule.

The aim of this thesis is going to concentrate on the issues associated with the technology of mechanically anchored coating waterproofing of roofs. Today the mechanical anchoring belongs to the most widespread way of how to stabilize the layers of roofing material against the effects of wind uplift particularly in indoor buildings. However some malfunctions occur more and more frequently which cause leaking into the constructions or even the destruction of the whole roof in the worse cases. The practical part of this thesis is going to concentrate on the fasterners which belong to the most important elements of the mechanical anchored system. The aim of the experimental measurement is to draw a comparison of the quality of fasteners which are distributed on the Czech market. Thereafter the obtained figures are going to be compared with the theoretical calculating procedures according to the valid designed standards.

Steel load-bearing structure of a museum will serve to exhibit the museum's exhibits and organizing exhibitions for the public. The structure is elliptical in shape with a length of 30 m in direction of the major axis and 22 m in the direction of the minor axis. Construction height is 9 m. There is located gallery structure in the inner part of the museum with access by an internal staircase. The main load-bearing elements of museum structure are designed from steel S235. The roof deck is made from Kingspan panels and cladding consists of laminated safety glass.

In diploma thesis i designed supporting strukture of roofing for riding hall located in Pardubice. Building height is 9,5m and the other two dimensions are 48,7x77,5m. The actual frame with elliptically shaped truss system. The actual structure is formed from a conventional timber of different cross-section. Roof is supported by trapezoidal sheet. wooden elements are connected by steel plates, pins and bolts. Chosing variants depends on material price and manufacturing cost. A goual of my diploma thesis is to make static calculations and drawings.