A deformação permanente em trilha de roda é uma patologia crítica de pavimentos asfálticos por afetar diretamente os custos de transporte, devido à redução de conforto ao rolamento, e a segurança dos usuários, dadas as dificuldades de dirigibilidade ou ainda o acúmulo de água nos períodos chuvosos comprometendo a aderência pneu-pavimento. Em pavimentos de rodovias concessionadas, onde existem limites máximos de afundamentos nas trilhas de roda bem rígidos para a aceitação da condição dos pavimentos, o monitoramento deve ser periódico por força contratual. Esta pesquisa tem como objetivo central propor uma metodologia para calibração de curvas de desempenho que prevejam a evolução dos afundamentos da trilha de roda de pavimentos asfálticos, com a utilização de resultados de deformação permanente obtidos de forma acelerada por meio de Simuladores de Tráfego em escala real, como contribuição aos projetos de pavimentação/restauração, aos programas de gerencia de pavimentos e ao planejamento rodoviário. Para tanto, foram dosadas e determinadas propriedades mecânicas de três diferentes misturas asfálticas a quente em laboratório, que foram aplicadas como revestimento asfáltico de três trechos consecutivos, em pista ascendente da BR 376/PR, na 3ª. faixa de tráfego, utilizada por veículos comerciais muito pesados e lentos. As três soluções diferentes para a camada de rolamento são compostas por: um concreto asfáltico com ligante modificado por SBS, um concreto asfáltico com ligante modificado por RET e um GAP-GRADED com ligante modificado por borracha de pneu moído. As pistas testes foram solicitadas de forma acelerada com um equipamento simulador de tráfego móvel, em tamanho real, que simulou 500 mil semiciclos de carga ou a quantidade de semiciclos necessários para atingir o limite de deformação em trilha de roda constante no contrato da Concessionária Autopista Litoral Sul, que administra o segmento onde se encontram as pistas testes, com o poder concedente. Com as medidas periódicas dos afundamentos em trilha de roda realizadas durante a aplicação de carga do simulador de tráfego em cada um dos três trechos, foram calibradas as equações de evolução de afundamentos em trilha de roda, empregando o modelo do HDM IV. Com base nos procedimentos adotados nesta pesquisa, foi proposto um método de calibração das curvas de desempenho para futuros estudos em que se empregam simuladores de tráfego em escala real. / Permanent deformation, or rutting, is a critical type of pavement distress given that it is directly associated with transportation costs, due to a reduction of the ride quality, and user safety, due to poor driving conditions or water build-up during rainy periods that affect the tire-pavement interaction. In the case of pavements of highways belonging to concessionaries, where strict limits are required by contract for acceptance of the pavement conditions, the pavement\'s monitoring must be frequent. The present study\'s main objective is to propose a methodology for calibration of performance curves that can predict the behavior of permanent deformation in asphalt pavements using results obtained from Full-Scale Accelerated Pavement Testing (APT) by means of a Traffic Simulator as a contribution to pavement design and rehabilitation projects, to pavement management software, and to highway planning. In order to do so, the mechanical properties of three different hot-mix asphalt (HMA) mixtures were determined in the laboratory and the mixtures were used as the surface course of three consecutive test sections in an ascending, slow lane on highway BR 376 used mainly by heavy commercial vehicles. The test sections were loaded using an HVS large scale mobile traffic simulator machine for up to 500 thousand loading cycles or until the permanent deformation limits defined in contract for the Concessionária Autopista Litoral Sul concession, which manages the highway sections where the test sections were built, were met. The results of the periodic monitoring of the permanent deformation of the three test sections under HVS loading were then used to calibrate the equations for predicting the pavement deformation behavior for each of the three types of mixtures tested using the HDM IV model. A method for future calibration of performance curves using full scale traffic simulators was proposed based on the procedures used in this study.

A need was identified for a set of basic design tools for Multi-Effect Distillation (MED) plant evaporators. This led to an investigation into the different types of evaporators as well as further research on horizontal falling film evaporators as used in the MED process. It also included the theory on these types of evaporators. In order not to duplicate existing design tools, an investigation was also performed on some of the tools that are currently available. The first set of tools that were developed were tools, programmed in EES (Engineering Equation Solver), for the vacuum system and the evaporator. These programs can be used to simulate different parameters (like different mass flows and temperatures). That enables the correct selection of components for the vacuum system and can be used to address sizing issues around the evaporator. It can also be used to plan the layout of the plant. The second of the design tools was developed by designing and building a flow pattern test section. From the flow pattern test section a set of curves for the wetted length under different conditions was obtained which can be used in order to design the sieve tray. This set of curves was found to be accurate for municipal as well as seawater and can be used in the design of the sieve tray of the evaporator. Further development can be done by implementing the figures of the wetted length into a simulation package like, for example, Flownex (a system CFD (Computational Fluid Dynamics) code that enables users to perform detail design, analysis and optimization of a wide range of thermal-fluid systems). The background gained from the study done on the evaporator can also be implemented into such a package. This could solve the problem of different design packages by creating a single design package with all of the above mentioned options included. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.

A need was identified for a set of basic design tools for Multi-Effect Distillation (MED) plant evaporators. This led to an investigation into the different types of evaporators as well as further research on horizontal falling film evaporators as used in the MED process. It also included the theory on these types of evaporators. In order not to duplicate existing design tools, an investigation was also performed on some of the tools that are currently available. The first set of tools that were developed were tools, programmed in EES (Engineering Equation Solver), for the vacuum system and the evaporator. These programs can be used to simulate different parameters (like different mass flows and temperatures). That enables the correct selection of components for the vacuum system and can be used to address sizing issues around the evaporator. It can also be used to plan the layout of the plant. The second of the design tools was developed by designing and building a flow pattern test section. From the flow pattern test section a set of curves for the wetted length under different conditions was obtained which can be used in order to design the sieve tray. This set of curves was found to be accurate for municipal as well as seawater and can be used in the design of the sieve tray of the evaporator. Further development can be done by implementing the figures of the wetted length into a simulation package like, for example, Flownex (a system CFD (Computational Fluid Dynamics) code that enables users to perform detail design, analysis and optimization of a wide range of thermal-fluid systems). The background gained from the study done on the evaporator can also be implemented into such a package. This could solve the problem of different design packages by creating a single design package with all of the above mentioned options included. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.

A deformação permanente em trilha de roda é uma patologia crítica de pavimentos asfálticos por afetar diretamente os custos de transporte, devido à redução de conforto ao rolamento, e a segurança dos usuários, dadas as dificuldades de dirigibilidade ou ainda o acúmulo de água nos períodos chuvosos comprometendo a aderência pneu-pavimento. Em pavimentos de rodovias concessionadas, onde existem limites máximos de afundamentos nas trilhas de roda bem rígidos para a aceitação da condição dos pavimentos, o monitoramento deve ser periódico por força contratual. Esta pesquisa tem como objetivo central propor uma metodologia para calibração de curvas de desempenho que prevejam a evolução dos afundamentos da trilha de roda de pavimentos asfálticos, com a utilização de resultados de deformação permanente obtidos de forma acelerada por meio de Simuladores de Tráfego em escala real, como contribuição aos projetos de pavimentação/restauração, aos programas de gerencia de pavimentos e ao planejamento rodoviário. Para tanto, foram dosadas e determinadas propriedades mecânicas de três diferentes misturas asfálticas a quente em laboratório, que foram aplicadas como revestimento asfáltico de três trechos consecutivos, em pista ascendente da BR 376/PR, na 3ª. faixa de tráfego, utilizada por veículos comerciais muito pesados e lentos. As três soluções diferentes para a camada de rolamento são compostas por: um concreto asfáltico com ligante modificado por SBS, um concreto asfáltico com ligante modificado por RET e um GAP-GRADED com ligante modificado por borracha de pneu moído. As pistas testes foram solicitadas de forma acelerada com um equipamento simulador de tráfego móvel, em tamanho real, que simulou 500 mil semiciclos de carga ou a quantidade de semiciclos necessários para atingir o limite de deformação em trilha de roda constante no contrato da Concessionária Autopista Litoral Sul, que administra o segmento onde se encontram as pistas testes, com o poder concedente. Com as medidas periódicas dos afundamentos em trilha de roda realizadas durante a aplicação de carga do simulador de tráfego em cada um dos três trechos, foram calibradas as equações de evolução de afundamentos em trilha de roda, empregando o modelo do HDM IV. Com base nos procedimentos adotados nesta pesquisa, foi proposto um método de calibração das curvas de desempenho para futuros estudos em que se empregam simuladores de tráfego em escala real. / Permanent deformation, or rutting, is a critical type of pavement distress given that it is directly associated with transportation costs, due to a reduction of the ride quality, and user safety, due to poor driving conditions or water build-up during rainy periods that affect the tire-pavement interaction. In the case of pavements of highways belonging to concessionaries, where strict limits are required by contract for acceptance of the pavement conditions, the pavement\'s monitoring must be frequent. The present study\'s main objective is to propose a methodology for calibration of performance curves that can predict the behavior of permanent deformation in asphalt pavements using results obtained from Full-Scale Accelerated Pavement Testing (APT) by means of a Traffic Simulator as a contribution to pavement design and rehabilitation projects, to pavement management software, and to highway planning. In order to do so, the mechanical properties of three different hot-mix asphalt (HMA) mixtures were determined in the laboratory and the mixtures were used as the surface course of three consecutive test sections in an ascending, slow lane on highway BR 376 used mainly by heavy commercial vehicles. The test sections were loaded using an HVS large scale mobile traffic simulator machine for up to 500 thousand loading cycles or until the permanent deformation limits defined in contract for the Concessionária Autopista Litoral Sul concession, which manages the highway sections where the test sections were built, were met. The results of the periodic monitoring of the permanent deformation of the three test sections under HVS loading were then used to calibrate the equations for predicting the pavement deformation behavior for each of the three types of mixtures tested using the HDM IV model. A method for future calibration of performance curves using full scale traffic simulators was proposed based on the procedures used in this study.

No description available.

Shear layer development over a NACA 0018 airfoil at a chord Reynolds number of 100,000 was investigated experimentally. The effects of experimental setup and analysis tools on the results were also examined. The sensitivity of linear stability predictions for measured separated shear layer velocity profiles to both the analysis approach and experimental data scatter was evaluated. Analysis approaches that are relatively insensitive to experimental data scatter were identified. Stability predictions were shown to be more sensitive to the analysis approach than to experimental data scatter, with differences in the predicted maximum disturbance growth rate and corresponding frequency of approximately 35% between approaches. A parametric study on the effects of experimental setup on low Reynolds number airfoil experiments was completed. It was found that measured lift forces and vortex shedding frequencies were affected by the end plate configuration. It was concluded that the ratio of end plate spacing to projected model height should be at least seven, consistent with the guideline for circular cylinders. Measurements before and after test section wall streamlining revealed errors in lift coefficients due to blockage as high as 9% and errors in the wake vortex shedding frequency of 3.5%. Shear layer development over the model was investigated in detail. Flow visualization images linked an observed asymmetry in wake velocity profiles to pronounced vortex roll-up below the wake centerline. Linear stability predictions based on the mean hot-wire profiles were found to agree with measured disturbance growth rates, wave numbers, and streamwise velocity fluctuation profiles. Embedded surface pressure sensors were shown to provide reasonable estimates of disturbance growth rate, wave number, and convection speed for conditions at which a separation bubble formed on the airfoil surface. Convection speeds of between 30 and 50% of the edge velocity were measured, consistent with phase speed estimates from linear stability theory.

Shear layer development over a NACA 0018 airfoil at a chord Reynolds number of 100,000 was investigated experimentally. The effects of experimental setup and analysis tools on the results were also examined. The sensitivity of linear stability predictions for measured separated shear layer velocity profiles to both the analysis approach and experimental data scatter was evaluated. Analysis approaches that are relatively insensitive to experimental data scatter were identified. Stability predictions were shown to be more sensitive to the analysis approach than to experimental data scatter, with differences in the predicted maximum disturbance growth rate and corresponding frequency of approximately 35% between approaches. A parametric study on the effects of experimental setup on low Reynolds number airfoil experiments was completed. It was found that measured lift forces and vortex shedding frequencies were affected by the end plate configuration. It was concluded that the ratio of end plate spacing to projected model height should be at least seven, consistent with the guideline for circular cylinders. Measurements before and after test section wall streamlining revealed errors in lift coefficients due to blockage as high as 9% and errors in the wake vortex shedding frequency of 3.5%. Shear layer development over the model was investigated in detail. Flow visualization images linked an observed asymmetry in wake velocity profiles to pronounced vortex roll-up below the wake centerline. Linear stability predictions based on the mean hot-wire profiles were found to agree with measured disturbance growth rates, wave numbers, and streamwise velocity fluctuation profiles. Embedded surface pressure sensors were shown to provide reasonable estimates of disturbance growth rate, wave number, and convection speed for conditions at which a separation bubble formed on the airfoil surface. Convection speeds of between 30 and 50% of the edge velocity were measured, consistent with phase speed estimates from linear stability theory.

This master thesis focuses on designing of an external six-component balance. This universal concept would provide access of results from different models of wings, aircraft and automobiles with relatively small scales. This work also includes theoretical background needed in aerodynamic testing, analysis of 1D beam element model of scale and explanation of components used in scale. Lastly methods of calibration and measurement in aerodynamic tunnel are described, which can be adopted for this design to achieve the adequate level of accuracy.

The masters thesis is focused on design of the device for measurement of the aerodynamic forces and moments acting on radiators mounted in the wind tunnel test section. The thesis also includes the analysis of the aerodynamic drag which is produced by radiators and the LabView application software development.

No description available.