Στα πλαίσια αυτής της εργασίας θα εξετάσουμε την δυνατότητα αξιοποίησης της μονάδας επεξεργασίας γραφικών (GPU) για την εκτέλεση ενός αλγορίθμου πολλαπλασιασμού πίνακα-διανύσματος και τριών αλγορίθμων ταξινόμησης και το κατά πόσο είναι δυνατό να επιταχυνθεί η εκτέλεση του κώδικα αυτού. Η αρχιτεκτονική που μελετήθηκε και αναλύεται στην εργασία ονομάζεται Tesla και αναπτύχθηκε από την εταιρία Nvidia, το μοντέλο και το περιβάλλον ανάπτυξης ονομάζονται Cuda (Compute Unified Device Architecture). / In context of this diploma thesis the capability of exploiting the graphics processing unit (GPU) to execute and accelerate an algorithm for matrix vector multiplication and three sorting algorithms was examined. The architecture which was examined and described in this diploma thesis is Tesla and it was created by Nvidia. The CUDA (Compute Unified Device Architecture) programming environment was used to implement the algorithms.

Neste trabalho é realizada a concepção, projeto, construção e ensaio de turbinas de múltiplos discos para a verificação dos principais parâmetros e metodologias utilizadas para o projeto e análise do equipamento, além de estudar formas de otimização do equipamento. Assim, uma turbina de múltiplos discos é construída e testada com diferentes configurações de rotores, em uma bancada experimental construída e dimensionada especialmente para esse fim, além da implementação dos métodos analíticos pesquisados no software Engineering Equation Solver (EES). Assim, uma comparação entre os resultados experimentais obtidos por Rice e os modelos de analíticos disponíveis, mostra que o modelo do fator de atrito (FA) é o que melhor representa a operação do equipamento, além de ser o mais versátil dos métodos testados, permitindo que a turbina seja dimensionada e otimizada para várias configurações de construção. Já os resultados experimentais obtidos com um dos protótipos de turbina construído e operado com ar comprimido, mostram que, com modificações simples da geometria, configuração e acabamento superficial dos discos que compõem o rotor, é possível aumentar a eficiência isentrópica em até 35% em relação a turbina padrão montada com a configuração padrão de rotor (discos lisos), sem acarretar prejuízo em alguns dos principais benefícios da utilização deste tipo de equipamento. Os resultados experimentais obtidos mostram também que a eficiência diminui significativamente com o aumento da folga entre o raio externo do rotor e a parte interna da carcaça. / This work is performed conception, design, construction and testing of multiple-disks turbines (MDTs) for the verification of key parameters and methodologies used for the design and analysis of machine as well as consider ways to equipment optimization. Thus, a multiple-disk turbine is constructed and tested with different impeller configurations, in a test rig especially constructed and dimensioned for this purpose, besides the implementation of the analytical methods in software Engineering Equation Solver (ESS). Thus, a comparison between the experimental results obtained by Rice and analytical models available, shows that the friction factor model (FF) is what best represents the operation of the equipment, and is the most versatile of the tested methods, allowing the turbine is sized and optimized for various building configurations. Since the experimental results obtained with one of the turbine prototypes built and operated with compressed air, show that with simple modifications of geometry, configuration and surface finish of the disks that make up the rotor, it is possible to increase the isentropic efficiency by up to 35% compared the standard turbine rotor mounted with the default configuration (flat disks), without causing damage in some of the major benefits of using this type of equipment. The experimental results also show that efficiency decreases significantly with increasing clearance between the outer radius of the rotor and the internal part of the housing.

Neste trabalho é realizada a concepção, projeto, construção e ensaio de turbinas de múltiplos discos para a verificação dos principais parâmetros e metodologias utilizadas para o projeto e análise do equipamento, além de estudar formas de otimização do equipamento. Assim, uma turbina de múltiplos discos é construída e testada com diferentes configurações de rotores, em uma bancada experimental construída e dimensionada especialmente para esse fim, além da implementação dos métodos analíticos pesquisados no software Engineering Equation Solver (EES). Assim, uma comparação entre os resultados experimentais obtidos por Rice e os modelos de analíticos disponíveis, mostra que o modelo do fator de atrito (FA) é o que melhor representa a operação do equipamento, além de ser o mais versátil dos métodos testados, permitindo que a turbina seja dimensionada e otimizada para várias configurações de construção. Já os resultados experimentais obtidos com um dos protótipos de turbina construído e operado com ar comprimido, mostram que, com modificações simples da geometria, configuração e acabamento superficial dos discos que compõem o rotor, é possível aumentar a eficiência isentrópica em até 35% em relação a turbina padrão montada com a configuração padrão de rotor (discos lisos), sem acarretar prejuízo em alguns dos principais benefícios da utilização deste tipo de equipamento. Os resultados experimentais obtidos mostram também que a eficiência diminui significativamente com o aumento da folga entre o raio externo do rotor e a parte interna da carcaça. / This work is performed conception, design, construction and testing of multiple-disks turbines (MDTs) for the verification of key parameters and methodologies used for the design and analysis of machine as well as consider ways to equipment optimization. Thus, a multiple-disk turbine is constructed and tested with different impeller configurations, in a test rig especially constructed and dimensioned for this purpose, besides the implementation of the analytical methods in software Engineering Equation Solver (ESS). Thus, a comparison between the experimental results obtained by Rice and analytical models available, shows that the friction factor model (FF) is what best represents the operation of the equipment, and is the most versatile of the tested methods, allowing the turbine is sized and optimized for various building configurations. Since the experimental results obtained with one of the turbine prototypes built and operated with compressed air, show that with simple modifications of geometry, configuration and surface finish of the disks that make up the rotor, it is possible to increase the isentropic efficiency by up to 35% compared the standard turbine rotor mounted with the default configuration (flat disks), without causing damage in some of the major benefits of using this type of equipment. The experimental results also show that efficiency decreases significantly with increasing clearance between the outer radius of the rotor and the internal part of the housing.

Neste trabalho é realizada a concepção, projeto, construção e ensaio de turbinas de múltiplos discos para a verificação dos principais parâmetros e metodologias utilizadas para o projeto e análise do equipamento, além de estudar formas de otimização do equipamento. Assim, uma turbina de múltiplos discos é construída e testada com diferentes configurações de rotores, em uma bancada experimental construída e dimensionada especialmente para esse fim, além da implementação dos métodos analíticos pesquisados no software Engineering Equation Solver (EES). Assim, uma comparação entre os resultados experimentais obtidos por Rice e os modelos de analíticos disponíveis, mostra que o modelo do fator de atrito (FA) é o que melhor representa a operação do equipamento, além de ser o mais versátil dos métodos testados, permitindo que a turbina seja dimensionada e otimizada para várias configurações de construção. Já os resultados experimentais obtidos com um dos protótipos de turbina construído e operado com ar comprimido, mostram que, com modificações simples da geometria, configuração e acabamento superficial dos discos que compõem o rotor, é possível aumentar a eficiência isentrópica em até 35% em relação a turbina padrão montada com a configuração padrão de rotor (discos lisos), sem acarretar prejuízo em alguns dos principais benefícios da utilização deste tipo de equipamento. Os resultados experimentais obtidos mostram também que a eficiência diminui significativamente com o aumento da folga entre o raio externo do rotor e a parte interna da carcaça. / This work is performed conception, design, construction and testing of multiple-disks turbines (MDTs) for the verification of key parameters and methodologies used for the design and analysis of machine as well as consider ways to equipment optimization. Thus, a multiple-disk turbine is constructed and tested with different impeller configurations, in a test rig especially constructed and dimensioned for this purpose, besides the implementation of the analytical methods in software Engineering Equation Solver (ESS). Thus, a comparison between the experimental results obtained by Rice and analytical models available, shows that the friction factor model (FF) is what best represents the operation of the equipment, and is the most versatile of the tested methods, allowing the turbine is sized and optimized for various building configurations. Since the experimental results obtained with one of the turbine prototypes built and operated with compressed air, show that with simple modifications of geometry, configuration and surface finish of the disks that make up the rotor, it is possible to increase the isentropic efficiency by up to 35% compared the standard turbine rotor mounted with the default configuration (flat disks), without causing damage in some of the major benefits of using this type of equipment. The experimental results also show that efficiency decreases significantly with increasing clearance between the outer radius of the rotor and the internal part of the housing.

While conventional turbines have been extensively researched and tested, Tesla and boundary layer type turbines have not. In order to construct a dynamometer, thermodynamic flow apparatus and future turbines, we modeled the Tesla turbine using theoretical calculations and preliminary experiments. Thus a series of experiments were run to determine stall torque and maximum run speed for a known pressure range. This data was then applied to modeling formulas to estimate stall torque over an extended range of variables. The data were then used to design an appropriate dynamometer and airflow experiment. The model data also served to estimate various specifications and power output of the future turbine. An Obi Laser SSTG‐001 Tesla turbine was used in the experiments described. Experimental stall torque measurements were conducted in two stages. Shaft speed measurements were taken with an optical laser tachometer and Tesla turbine stall torque was measured using a spring force gauge. Two methods were chosen to model Tesla turbine stall torque: 1) flow over flat plate and 2) free vortex with a sink. A functional dynamometer and thermodynamic apparatus were constructed once the model was confirmed to be within the experimental uncertainty. Results of the experiments show that the experimental turbine at 65 PSI has a speed of approximately 27,000 RPM and a measured stall torque of 0.1279 N‐m. 65 PSI is an important data point because that data set is the cut‐off from laminar to turbulent flow. Thus at 65 PSI, a rejection of the null hypothesis for research question one with respect to the flow over flat plate method can be seen from the data, while the vortex model results in a failure to reject the null hypothesis. In conclusion, the experimental turbine was seen to have a laminar and a turbulent flow regime at different air pressures, rather than the assumed laminar flow regime. As a result of this model work, a new Tesla turbine of different dimensions was designed to adjust for flaws in the experimental turbine. The theoretical stall torque models were then applied to the new Tesla turbine design. Results of the models show that the vortex model sets the upper bound for theoretical stall torque for the new and the flat plate flow model sets the lower bound.

No description available.

This study examines the topic of open innovation in EVs. Initially a brief description of the concept of innovation and open innovation is carried out. Moreover, the three processes of open innovation are deployed while the coupled process is described in more detail. Furthermore, a short description is also given for corporate entrepreneurship, alliances, and the U.S. government policy. Also, this report considers Tesla Motors’ partnerships as a case study and it aims to give an insight of how the coupled process of open innovation is. Concluding, Tesla Motors follows the coupled innovation process by establishing strategic partnerships.

Research questions                How do different cultural perceptions of sustainability affect the consumer behavior towards EVs? Purpose:                                         To inductively explore some different perceptions of sustainability in comparison between Sweden, Germany, United Emirates, and Saudi Arabia, as well as to investigate how these perceptions influence consumer behavior towards the EV industry with Tesla leading the way. Method:                                           This research was conducted with an exploratory qualitative approach. The empirical data was obtained through online interviewing using WhatsApp. Findings were thematically analyzed.  Conclusion:                                 The focus of this exploratory study is to gain a deeper knowledge and understanding the different perceptions of sustainability and investigate the factors behind the related consumer behavior to be taken into consideration when perceiving sustainability development in business. The comparison between Sweden, Germany, United Emirates, and Saudi Arabia sheds light on how these differences contribute to a better understanding for the EV marketing in general and Tesla in particular.

The work presented in this thesis was conducted at Uppsala University and at Fraunhofer IKTS, Dresden. The thesis aims to study design optimizations for increasing the diodicity and thereby performance of a Tesla valve, a type of “no moving parts” (NMP) valve, through design freedoms offered by ceramic additive manufacturing. Tesla valves are capable of creating a pressure differential across them purely by virtue of mechanical design, and do not employ any moving parts. By geometry manipulation, Tesla valves enable fluid to flow in a way that hinders its own flow, thereby creating fluidic resistance and increasing pressure in one fluid direction, while allowing relatively unimpeded flow in the opposite direction. The manufacture of Tesla valves in the past has been restricted to simple geometries because conventional manufacturing processes such as CNC machining are unable to produce intricate geometries, something that Tesla valves require. With the recent innovations in additive manufacturing, design of these complex geometries has become feasible but still requires further research. Prior literature has only explored relatively simpler constructs of Tesla valves, not fully utilizing the design freedoms offered by additive manufacturing. In this thesis, ceramic additive manufacturing and stereolithography has been used to manufacture complex Tesla valves. In addition to just complex design, this thesis also presents design optimizations that can be utilized for simpler Tesla valves for increasing a metric known as diodicity. Diodicity refers to the ratio of reverse to forward pressure difference, and a high diodicity of a valve indicates that the valve is able to hinder fluid flow more effectively in one direction than the opposite. Additive manufacturing boasts an ability to construct complex geometries, due to the layer-by-layer process of building the final component. Stereolithography (in particular, ceramic stereolithography) is capable of producing parts that have high resolution and dimensional accuracy, while also maintaining desirable material properties, such as resistance to high temperatures and mechanical durability. Since the envisioned Tesla valve is to be used at elevated temperatures, this makes stereolithography a viable method of producing Tesla valves for aerospace applications. Design optimizations were carried out and subsequently verified for effectiveness through fluid flow simulations and practical evaluations. Certain design optimizations were shown to have drastic effects on the diodicity of the Tesla valve, and these have been subsequently incorporated into the designs of the Tesla valve in an effort to increase the diodicity of the designed Tesla valves. For practical evaluation, the optimized Tesla valves were 3D printed through ceramic stereolithography and stereolithography and extensively tested on a testing rig, with experimental parameters congruent to the fluid flow parameters applied during fluid flow simulations. It was found that the results of the fluid flow simulations and experimental testing were somewhat consistent with each other, and that it is feasible to produce optimized Tesla valves through ceramic stereolithography. However, it was found through practical evaluation that certain design optimizations were found to have little to no effect on the diodicity of the final Tesla valve, with some optimizations even reducing the diodicity.

No description available.