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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.
71

Utveckling av en mindre borrigg

Skog, Axel January 2019 (has links)
This report is a bachelor thesis at Mälardalens University in Eskilstuna on the behalf of Scandinavian pile Driving AB in Sala.Scandinavian pile Driving AB is a relatively small company with high competitiveness that develops and manufactures drilling rigs and foundation mast in its factory in Sala.This report has investigated the development possibilities of Scandinavian Pile Driving AB's machine MD40, which is a smaller drilling rig which is usually used in smaller and special drilling operations. Where the company asks to find out what requirements the market demands and design suggestions on how their new machine can be designed.The work process in this report has strived to follow the six phases of the product development process presented in the book "Product Design and Development" by Karl T. Ulrich and Steven D. Eppinger up to and including Phase 3. Thereby, the work has completed market research in the form of benchmarking of competing companies drilling rigs and interviewing users of the MD40 drilling rig.With this reason, the work could have resulted in 11 concepts where one of the concepts has been transferred to a 3D CAD model with associated drawings. The goal of development has been to minimize the total volumes of the machine, maximize mobility and space controlsystem and make it as stable as possible. / Den här rapportenär ett examensarbete för högskoleexamen på grundnivå, det vill säga 15 hp på 50 procent arbetstakt. Arbetet görs vidMälardalens högskola i Eskilstuna mot Scandinavian pile Driving AB i Sala. Scandinavianpile Driving AB är relativt litet företag med hög konkurrenskraftighetsom utvecklar och tillverkar borriggar och borrmaster i sin fabrik i Sala. Denna rapport har undersök utvecklingsmöjligheter av Scandinavian pile Driving AB ́s maskin MD40 somär mindre borriggsomvanligen används vid mindre och speciella borrningsarbeten. Därföretaget efterfrågaratt ta reda på vilkakrav som marknaden efterfrågar och designförslag på hur deras nya maskin kan vara utformad.Arbetsprocessen hos denna rapport har strävat att följa den produktutvecklingsprocessens sex faser som presenteras i boken ”Product Design and Develepmonent” av Karl T. Ulrich och Steven D. Eppingersfram till och med fas 3. Där med har arbetet fullföljt en marknadsundersökningi form av benchmarking av konkurrerande företags borriggar och intervju med användare av MD40 borrigg.Med den grunden kunde arbetet resulterat i 11 stycket konceptdär ett av de koncepten har blivit överfört till en 3D CAD-modell med till hörande ritningar. Där målet av utvecklingen har varit att minimeraden totala volymen hos maskinen,maximera mobilitetochutrymme regleringssystemoch göra den så stabil som möjligt.
72

Konstruktion av lyftverktyg : Lyftverktyg till L-stöd för enklare hantering / Desing of Liftingtool : Liftingtool for L-support for easier handling

Jonsson, Emil January 2019 (has links)
The company Falcken Forshaga are manufacturing lifting tools for the steel, paper and concrete industry. The company wants a lifting tool for L-supports which they want to be able to sell to the concrete industry. The reason for this is that todays ways of lifting and rotation of the supports are done by slings which are time consuming to use because the process is done in multiple steps. The reason why the supports are rotated is because they are casted lying down and are transported standing up which means that the supports needs to be lifted and then rotated. The purpose of this project is to simplify the process between casting and transport as well as learn to work on a project at a company. The goal of the work is to design a lifting tool which follows the requirements set by Falcken for the lifting tool and so it can gain CE-mark in the future. To design a lifting tool the product development process was used as it best fits this project. The work started with status analysis to be able to study the steps which occur in the process today from casting to transport. This is today made possible in three steps lift, rotation and movement to make it ready for transportation. A project plan was developed where the project was divided into different parts with goals to always have something to work against which brings the work forward. A risk analysis over the project was constructed at the beginning to analyze potential risks with the aim to minimize them. The biggest risk that was analyzed was that the project will become delayed, to counter this the project plan needs to be up to date as well as to get help if in need. The next step in the process is to list all the specifications and requests from Falcken and summarize them to be able to generate concepts. A second risk analysis was made to analyze the potential risks with or around the lifting tool during lift where the biggest risks is those who involve people getting injured and are the most important to minimize. To generate the concepts the 6-3-5-method was used and resulted in five different concepts which was analyzed further and filtered through an elimination matrix where the best concept was selected. The concept that was chosen and was designed in Autodesk Inventor was a support arm lift which locks in the sides of the L-support and has beams which run along the sides of the support and in underneath the lower edge of the support with plates. The tool is designed to lift in front of the center of gravity of the support which means that when the support is lifted the whole thing will rotate by itself which means that the steps from casting to transport will be done in one step instead of three. To ensure the strength of the construction it is calculated against safety factor of three as well as it is controlled with a FEM-analyze in Creo parametric 5 and inventor 2019 on details with are too complicated to calculate by hand. The tool which was designed meets all the requirement that was set but to achieve a tool which is sellable and is CE-marked more risks must be analyzed according to SS-EN ISO 12100:2010 and its life span has to be calculated via fatigue calculations as well as it must be manufactured and tested.
73

Confined supersonic mixing layers: A computational investigation of instability and mixing enhancement

Unknown Date (has links)
Hydrodynamic instability of a compressible shear mixing layer plays a very important role in controlling and promoting the mixing processes in supersonic combustion problems. At supersonic convective Mach numbers the natural mixing rates of the shear layer are observed to be very small. The current research interest is in the mixing enhancement. In the first part of the present study, the linear spatial instability problem of a supersonic shear mixing layer inside a rectangular channel is solved. A systematic way of calculating and classifying all the normal modes is developed. It is demonstrated that a vortex sheet at high supersonic convective Mach number, neutrally stable when unconfined, becomes unstable when confined. Extensive numerical computations indicate that two classes of unstable waves, named as class A and class B supersonic instability waves, can be identified. In addition to unstable waves, two families of neutral waves, named as class C and class D neutral acoustic waves, can also be identified. The characteristics of the unstable waves as well as the neutral waves are determined. It is concluded that the new supersonic instabilities found in this study are the dominant instabilities of a confined mixing layer at high supersonic convective Mach numbers. As such they are very relevant to the supersonic combustion problem. The second part of the study explores the possibility of enhancing the rate of supersonic mixing by means of a periodic Mach wave system. The Mach wave system may be generated by small amplitude waviness of the confining channel walls. The stability of the periodic basic flow is analyzed numerically by the Floquet theory and the spectral-collocation method. The convergence of the numerical solutions is discussed. New secondary instabilities of the shear layer induced by the periodic Mach waves are found computationally. The / growth rate of the new instabilities is found to vary nearly linearly with the ratio of the wavy wall amplitude to the wave length. Therefore it is a potentially promising scheme for the enhancement of supersonic mixing. / Source: Dissertation Abstracts International, Volume: 51-05, Section: B, page: 2446. / Major Professor: Christopher K. W. Tam. / Thesis (Ph.D.)--The Florida State University, 1990.
74

Eficiência Energética num Mercado Restruturado: O Caso da Iluminação Pública em Cipolletti, Argentina / Energy Efficiency in a Restructured Market: The Case of Public Lighting in Cipolletti, Argentina

Pedranti, Aquiles 15 August 1997 (has links)
Este trabalho apresenta uma descrição do funcionamento do atual mercado elétrico Argentino e o relacionamento entre os diferentes atores. Em particular, para a concessionária de distribuição Energia de Rio Negro S.A. (EdERSA) é feita uma caracterização mais aprofundada. Na área de abrangência dessa concessionária, depois de analisadas as oportunidades para as medidas de eciêncía energética, são revisadas as barreiras, com ênfase naquelas barreiras à conservação na iluminação pública. ldentificado o potencial de conservação na iluminação pública, é proposto um programa concreto de eficiência num estudo de caso para a cidade de Cipolletti, Província de Río Negro, Argentina. O programa contempla diferentes propostas de troca de equipamentos por outros mais ecientes, buscando melhorar a qualidade do serviço de iluminação, e criando uma outra iniciativa que alivie tanto a atual capacidade limitada de transformação, quanto a operação de todo sistema elétrico. Como parte do estudo de caso e feita a avaliação do programa proposto, quantificando os resultados obtidos para os diferentes participantes: consumidor (Município), concessionária (EdERSA) e sociedade. Conclui-se que as medidas de eficiência energética na iluminação pública representam uma oportunidade econômica factível de aproveitamento pelo Município, concessionária EdERSA, ESCO\'s ou Bancos com benefício resultantes para toda a sociedade, permitindo uma redução de 34% no consumo de energia e 2% em demanda da potência de ponta. / This work brifly describes the operation of the newly restructured Argentine electricity market and the relationship between actors involved. More detailed description es provided for Energía de Rio Negro S.A. \" (EdERSA) utiliy. After analyzing the opportunities for the energy efciency improvement in the EdERSA area the barriers are reviewed, with emphasis in those barriers to the conservation in the public illumination. Once identified the potential of energy conservation in the street lighthing, an efciency program based on technology sustitutions is proposed for the case Cipolletti city, province of Rio Negro, Argentina. These substitutions allow improvement of quality of the public lighting service, and additionally provide an initiative that helps to alleviate the currently limited transformation capacity as well as the operation of distribution system. The evaluations of the programs are carried out on the perspectives of the several participants: consumer (municipality), utility (EdERSA) and Society. It is concluded that the energy efficiency mesures in the public illumination represent an economically feasible opportunity to take advantage of by the municipality, EdERSA (utility), ESCOs or Banks, providing benefit to all Society, allowing a reduction of 34% in energy consumption and around 2% of power peak demand.
75

Análise do Aproveitamento Econômico e Energético do Óleo de Palma na Guiné-Bissau na Perspectiva do Desenvolvimento Susténtavel / Analysis of the Economic and Energy Utilization of Palm Oil in Guinea-Bissau in the perspective of sustainable development

Silva, Orlando Cristiano da 19 September 1997 (has links)
A oferta energética na Guiné-Bissau, centrada em combustíveis fósseis importados e recursos da biomassa florestal, engendra sérios problemas à economia e ao meio ambiente. Os altos custos de importação do óleo diesel aliados a problemas estruturais do setor elétrico guineense geram um dos mais precários padrões de atendimento às necessidades energéticas do mundo. A demanda energética a partir da biomassa, por outro lado, constitui um dos fatores de degradação dos recursos florestais. Este trabalho apresenta uma alternativa para a geração de energia elétrica que consiste na utilização do óleo de palma proveniente de plantações extensivas de dendezeiros geneticamente melhorados, em substituição ao óleo diesel. Esta alternativa contempla benefícios ambientais, sociais e econômicos e atende os princípios do desenvolvimento sustentável preconizados pelo Relatório Bruntland em 1987. Foram analisadas duas alternativas tecnológicas de geração de eletricidade a partir do óleo de palma. Uma a partir do óleo in natura na Ilha de Bubaque e outra a partir do óleo de palma transesterificado na região Cacheu. A análise dos custos envolvidos mostrou que os projetos são viáveis e competitivos, se comparados com o atual sistema de geração à base do óleo diesel importado. Face a valorização do óleo de palma e do caroço do palmiste no mercado internacional, analisou-se a alternativa da exportação destes dois produtos oriundos das duas localidades. Chegou-se a conclusão da oportunidade de geração de receitas que poderiam atenuar o peso da importação dos derivados de petróleo na balança comercial. / The supply of energy in Guinea-Bissau, based on imported fossil fuels and biomass brings serious problems to Economy and to the Environment of that country. High importation costs of diesel as well as structural problems faced by the power sector in Guinea-Bissau leads to one of the most precarious supply systems to meet demand in the world. On the other hand, the energy demand based on biomass is considered as being one of the principal causes of degradation of the environment resources. This dissertation discuss an alternative to generate power from palm oil as feedstock in substitution of diesel. This alternative includes an overview of the environmental, social and economical benefits based on the principles of the sustainable development stated by The Brundtland Report in 1987. It was also discussed other two technological alternatives to generate power from palm oil. One of them is concerned to the use of palm oil in natura\" in the Isle of Bubaque. The other one is concerned to the use of transesterified oil in the Cacheu region. The cost analysis showed that the projects are feasible and competitive it compared to the current power generation based on imported diesel. Moreover, it is included an analysis of the exportation of those product considering the increase of their prices in the international market. Finally, it is concluded that the revenues from the alternatives discussed above could minimize the impact of oil imports in the GuineaBissau international trade.
76

A Mitigação de Gases de Efeito Estufa Associados ao Consumo Energético do Equador: O Caso do Setor Residencial / Mitigation of greenhouse gases related to energy consumption in Ecuador: The Case of Residential Sector

Benavides, Alvaro Cesar Morales 19 September 1997 (has links)
O presente trabalho aborda temas especificamente relacionados com a conservação da energia e o aproveitamento das fontes energéticas alternativas, como opções viáveis para reduzir as emissões de gases de efeito estufa associadas ao consumo energético do setor residencial do Equador. Neste contexto, são apresentados alguns aspectos gerais da problemática do \"Aquecimento Global, considerado como uma possível grande crise do próximo século, para logo analisar questões especificas do setor energético equatoriano, que têm relação com a produção e consumo de energia e suas implicações sobre as emissões de gases de estufa. Numa fase inicial se realiza uma análise da situação atual do setor, suas características de funcionamento, aspectos institucionais e legais, com ênfase na situação da conservação a as fontes não convencionais de energia. Com ajuda de um modelo para a projeção da demanda com base nos usos finais da energia, se estabeleceu um cenário que considera diversas medidas de mitigação, realizando-se, após, uma avaliação dos efeitos que estas teriam sobre a diminuição dos níveis de consumo energético e, por conseguinte, das emissões de gases, calculando-se, também, os respectivos custos. Finalmente se propõe certas estratégias para a implantação das medidas selecionadas, através das quais seria possível superar os obstáculos para conseguir uma evolução do consumo energético do setor estudado, num âmbito de eficiência energética, buscando a preservação do meio ambiente. / The present work analyses energy conservation and use of energy altemartive Sources, as viable options to reduce the greenhouse gases emissions associated to energy consumption in the residential sector of the Equador. In this context, general aspects of the Global Warming problem are reviewed, considerating it as the possible great crisis of the next century. Then, specic questions of the Equadorian\'s Energy Sector are analysed, as they related to production and consumption of energy and their implications to greenhouse gas emissions. The current situation of the sector, characteristics of operation, institutional and legal frameworks, are reviewed, with emphasis on energy conservation and non-conventional energy sources. LEAP model is used for projection of energy demand based on end-uses. Base Case and Alternative Scenario are developed, considering mitigation measures based on energy conservation and substitution. Assesments of measures, costs and impacts on energy consuption and on greenhouse gases emissions are carried out. Finally, an implementation strategy for selected measures is proposed, aimed at overcoming barriers and attaing energy efciency and environmental preservation.
77

Materialanalys & optimering av hydrauliska högtryckskopplingar med hjälp av simuleringar / Material analysis & Optimization of High pressure hydraulic couplings with help of simulations

Werner, Elin January 2018 (has links)
Optimering av prestanda görs på FEM ½” koppling på Parker Hannifin AB med hjälp av finita element analyser (FEA). De kritiska komponenterna som är styrningen, kulhållaren och nippelhuset är i fokus. En noggrannare materialanalys genomförs för att få mer verklighetbaserande materialdata på kopplingen.  Hela nippelhuset antas härdas efter varit i kontakt med företaget som utför härdningen på komponenten. För att få mer information om materialdata utförs statiska trycktester på en koppling. De uppmätta töjningarna från testerna jämförs med töjningarna i simuleringarna. Sträckgränsen och hårdnadskoefficienten på styrningen och kulhållaren kan justeras något från testerna men resultatet har flera osäkerheter.  Antalet kulor i kopplingen mellan 15 och 12 kulor undersöks efter önskemål från företaget. Analyser om hur en härdning påverkar styrningen görs samt hur nippelhuset påverkas av en ythärdning i form av sätthärdning. Vid härdning av styrningen uppkom de minsta deformationerna och spänningarna. Kulhållaren visade tydligt på mindre deformationer och spänningar om antalet kulor minskas från 15 till 12 kulor i kopplingen. För att minska kulintrycket på nippelhuset rekommenderas att ythärda komponenten med en 27 % hårdare yta än den nuvarande. På grund av uppskattade värden på materialdata på ythärdningen behöver mer information införskaffas. Detta för att kunna avgöra vilken tjocklek på ytans härdning som krävs för 12 kulor i kopplingen. / Optimizing the burst pressure with finite element analysis is done on the FEM ½” coupling at Parker Hannifin AB. The critical components which is the ball cage, guide and plug housing are in focus. A more accurate material analysis is done to make a more real-based data of the material in the coupling.   After being in contact with the company that performs the hardening of the component, the entire plug housing is assumed to be hardened. For more information about material data, static pressure test is performed on a coupling. The measured strains from the tests are compared to the strains in the simulations. The tensile strength and hardness coefficient on the guide and ball cage can be adjusted slightly from the tests, but the result has several uncertainties.  The number of balls can be reduced, numbers of balls between 15 and 12 are investigated at request from the company. Analysis of how hardening of the material for the guide is done and hardening of the surface for the plug housing.  The smallest deformation occurs when hardening the guide. The ball cage clearly demonstrated minor deformations and stresses as the number of balls is reduced from 15 to 12 balls in the coupling. To reduce the burst pressure on the plug housing, it is recommended to harden the surface with a 27 % harder surface than the current. Due to estimated values of material data on hardened surface, more information is needed to determine the thickness needed on the surface of the hardening when having 12 balls in the coupling.
78

Tomography applied to Lamb wave contact scanning nondestructive evaluation

McKeon, James Christopher P. 01 January 1998 (has links)
The aging world-wide aviation fleet requires methods for accurately predicting the presence of structural flaws that compromise airworthiness in aircraft structures. Nondestructive Evaluation (NDE) provides the means to assess these structures quickly, quantitatively, and noninvasively. Ultrasonic guided waves, Lamb waves, are useful for evaluating the plate and shell structures common in aerospace applications. The amplitude and time-of-flight of Lamb waves depend on the material properties and thickness of a medium, and so they can be used to detect any areas of differing thickness or material properties which indicate flaws. By scanning sending and receiving transducers over an aircraft, large sections can be evaluated after a single pass. However, while this technique enables the detection of areas of structural deterioration, it does not allow for the quantification of the extent of that deterioration. Tomographic reconstruction with Lamb waves allows for the accurate reconstruction of the variation of quantities of interest, such as thickness, throughout the investigated region, and it presents the data as a quantitative map. The location, shape, and extent of any flaw region can then be easily extracted from this Tomographic image. Two Lamb wave tomography techniques using Parallel Projection tomography (PPT) and Cross Borehole tomography (CBT), are shown to accurately reconstruct flaws of interest to the aircraft industry. A comparison of the quality of reconstruction and practicality is then made between these two methods, and their limitations are discussed and shown experimentally. Higher order plate theory is used to derive analytical solutions for the scattering of the lowest order symmetric Lamb wave from a circular inclusion, and these solutions are used to explain the scattering effects seen in the Tomographic reconstructions. Finally, the means by which this scattering theory can be used to develop Lamb wave Tomographic algorithms that are more generally applicable in-the-field, is presented.
79

Konstruktion av plattform, montering och drivning av höghastighetskameror / Construction of platform, mounting and operation of high-speed cameras

Rath Olsen, Christoffer, Olsson, Kaspar January 2019 (has links)
No description available.
80

The Sally : Ett mekaniskt vattenreningssytem

Christian, sandberg, Hansson, Måns January 2019 (has links)
No description available.

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