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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.
491

Modelling, Simulation and Optimisation of Asymmetric Rotor Profiles in Twin-screw Superchargers

Ilie, Katherine-Rodica, Katherine.ilie@rmit.edu.au January 2007 (has links)
There is a growing recognition worldwide of the need for more powerful, smaller petrol engines, capable of delivering the higher picking power of larger engines, yet still being economical and environmentally friendly when used for day-to-day driving. An engineering solution for more efficient engines has been considered by research so far. It has been identified that superchargers can potentially improve the performance of automotive engines; therefore research has focused on developing superchargers and supercharger components with higher efficiency. Of particular interest to the research presented in this thesis has been the twin-screw supercharging compressor with design adapted for automotive use (the twin-screw supercharger). The performance of this supercharger type depends on the volume and total losses of the air flow through the supercharger rotors more than on any other aspects of its behaviour. To accurately predict the efficiency of the twin-screw su percharger for matching a particular engine system, accurate supercharger design is required. The main objective of this research was the investigation of the existing limitations of twin-screw superchargers, in particular leakage and reduced efficiency, leading to the development of optimal asymmetric rotor profiles. This research has been completed in four stages defining an innovative rotor design method. The parametric three-dimensional geometric model of twin-screw supercharger rotors of any aspect ratio was developed. For model validation through visualisation, CAD rotor models with scalable data were generated in commercial CAD software and calibrated experimentally by Laser Doppler Velocimetry (LDV) tests. Calibrated rotor profile data can be transferred into CAD-CFD interface for flow simulation and performance optimisation. Through the application of this new rotor design method, new opportunities are created for the twin-screw supercharger design practice, making it a part of the engineering solution for more efficient engines.
492

Konstruktion av hård- och mjukvara för uppdaterad valsklocka / Design of hardware and software for updated roller watch

Srbinovski, Slobodan January 2009 (has links)
<p>Detta examensarbete är framtaget av SSAB:s ingenjörer i fabriken SSAB Oxelösund. Uppdraget består i att konstruera en ny hård- och mjukvara för en befintlig valsningsklocka.</p><p>Examensarbetet består av flera delar, där den första delen är att konstruera och välja komponenter till en prototyp av ny hårdvara till klockan. När delarna är valda kommer dem att testas med ett laborationskort med den valda processorn för att utvärdera att delarna är kompatibla innan den slutliga hårdvaran beställs.</p><p>Den andra består i att programmera mjukvara till processorn som kommer att vara kärnan till klockan. Processorn kommer att styra samt beräkna alla in- och utsignaler till alla komponenter som finns i klockan.</p><p>Den tredje och avslutande delen består av konstruera den slutgiltiga produkten med hjälp av CAD-verktyg. En layout med alla valda komponenter produceras.</p><p>Tanken med projektet är att man ska uppdatera äldre komponenter till nyare som är lättillgängligare att införskaffa. Det ska vara lättare att felsöka med hjälp av en enkel meny genom att ansluta kortet mot en dator. Man ska kunna använda samma mjuk- och hårdvara oavsett vilken av de två klocktyper som används.</p><p>Jag har fått olika resultat av skapandet av det nya prototypskortet. Det har varit mycket laborerande att hitta komponenter till hårdvaran för att få en fungerande prototyp till klockorna. Programmeringen av mjukvaran har varit lite varierande beroende på vilken A/D-omvandlare som har använts. I övrigt har de mesta arbetet gått åt att skapa en väl fungerande meny som ska fungera för båda klockorna. Tillverkning av en slutversion av prototypen är beställd men inte levererad. Programmeringen av Ethernet-kontrollen har inte hunnits med.</p><p>Fördelarna med det nya systemet är att det är lättare att hitta ersättningskomponenter vid reparation samt att menystyrd felsökning är snabb och enkel. Till exempel kan man med menystyrd felsökning se om A/D-omvandlarna får något värde eller om det är dålig anslutning mellan komponenterna. Med det nya systemet är det också möjligt att implementera ny mjukvara.</p> / <p>This thesis has been developed by SSAB´s engineers in the fabric SSAB Oxelösund. The assignment is to design a new hardware and software for a roller clock.</p><p>The thesis has several parts, where the first part is to construct and choose components to a prototype of the hardware to the watch. When the parts are chosen, they will be tested with an elaboration card with the chosen processor to be evaluated that the parts are compatible before the final hardware is ordered.</p><p>The second part is to program software for the processor that will be the core for the watch. The processor will be controlling and calculate all in signals and out signals to all components there is in the watch.</p><p>The third and the ending part are to construct the final product with help of CAD tools. A layout with all the chosen components produced.</p><p>The thought with the project is to update older components to newer ones that are more easily accessible to get. It shall be easier to debug with help of one simple menu by connecting the card against a computer. It will be able to use the same software and hardware to any kind of the two clock types that is in use.</p><p>I have got different results by creating the new prototype card. It has been a lot of elaborations to find the components to the hardware to get a functional prototype for the watches. Programming of the software has been a bit varying depending on what kind of A/D-converter has been used. Otherwise the most work of programming has been to create a functional menu that is functional for the both watches. The production of the final product of the prototype has been ordered but not yet delivered. Programming of the Ethernet control has not yet been managed.</p><p>The advantages with the new systems are it´s easier to get replacement parts at reparation and with the menu controlled error seeking it gets easier and quicker to find the errors. For an example it's possible with menu controlling to see if the A/D-converters gets any values or if there is bad connections between the components. With the new system it is also possible to implement new software.</p>
493

Utveckling av modulbaserad 11C-processutrustning inom PET : Presentation av idéer och koncept / Development of module-based 11C process equipment within PET : Presentation of ideas and concepts

Fredén, Emil, Johansson, Sebastian January 2010 (has links)
<p>This report describes the planning and the accomplishment of the final diploma workat the study program Mechanical Engineering, Department of Engineering Sciences, Uppsala University. Two students carried out the diploma work at GE HealthcareHusbyborg in Uppsala.</p><p>The aim of the diploma work was to develop and improve existing processequipment for 11C-radiochemistry in PET. The process equipment was to be dividedinto smaller independent modules to make it more flexible. Part of the existingprocess equipment is an oven that is supposed to perform a specific chemicalreaction. One of the main goals was to study and improve this oven.</p><p>The work could be divided into three main phases: 1.Present concepts for one module, and interface between different modules. 2. Analyze and choose components for the module mentioned above. 3. Present concepts for the oven, which is placed in the module mentioned above.</p><p>At the beginning, user requirements were listed in cooperation with the mentor. Later, components available on the market and the existing process equipment wereanalyzed. A product function analysis of the oven was made to show its function and design.</p><p>The concept phase was mainly about brainstorming to generate ideas. Later, hybridization was used as a method to combine different ideas. Then two prototypeswere built and tested. The test results showed which idea seemed to be the best.Different concepts were assessed and put into a concept selection matrix, after which the best was chosen and developed further.</p>
494

Ergo Mopp : Från koncept till produkt / Ergo Mop : From concept to product

Kamf, Tobias January 2010 (has links)
<p>This thesis describes the work process and the results for the development of a newkind of ergonomic cleaning mop, ranging from basic concept to a virtually productionready digital prototype. The project was made in cooperation with, Ömer Altun, whowas also the project supervisor, and whose plan it is to launch this new product onthe market in a foreseeable future. The mop is meant to be used by both professionalcleaning staff and ordinary home users. What makes this product unique is that it hasa movable center piece that simplifies the cleaning under low furniture.The work began with the establishment of a product requirements specification andlater a study of similar products and existing functional models was conducted. Afterthese surveys the work began with refining the existing concepts in order to makethem more complete. In consultation with Ömer, further refining of one of these newconcepts was conducted, but was split into seven smaller steps.After the initial refining process, effort shifted into the investigation and selection ofappropriate materials and manufacturing methods. At this stage, two experimentswere also conducted and subsequently used to support the final decisions concerningthe choice of materials and design.When the materials and methods were adopted, a detailed CAD model of the wholeproduct and related technical drawings was made and also a number of FEM-analyseson all critical details, to ensure that performance requirements were met, wasconducted. These CAD models are closer described in detail in the chapter“Detaljkonstruktion”.In the final sections of discussion and evaluation are suggestions for furtherimprovements. And also some evaluation of the work process and the problems andsolutions encountered during the project execution.</p>
495

Integrating product design and manufacturing process : a framework and implementation

Li, Yu-An 24 August 1994 (has links)
The importance of integrating design and manufacturing becomes apparent when the increase in the degree of difficulty of change is observed as the product development proceeds from concept to production in a serial engineering process. The greatest opportunity in design for manufacture occurs at the initial design stage before any commitments to tooling and equipment have been made. This research develops a framework and an implementation system dealing with integration of design, manufacturing and economic aspects in the development of a product. The objective is to evaluate process technology for a specified product design and to identify the best work/tool material combination and production conditions to optimize the production process. A commercial CAD/CAM package (SmartCAM) playing roles as a part design tool, a processing time simulator, and a NC code generator is integrated with a manufacturing database, and a machining cost model. This integrated system runs in Microsoft Windows environment under an external program which not only coordinates the activities of various modules but also enhances the capabilities of SmartCAM. This system allows product design evaluation for economic and technical criteria and recommends best manufacturing environment. An NC program containing recommended machining parameters is generated. Furthermore, the system reports on tool wear on each tool per part manufactured. This information is useful for cost analysis as well as for producing a tool replacement schedule. / Graduation date: 1995
496

Automation of Design and Drafting for Manufacturing of Panels for Wood Frames of Buildings

Alwisy, Aladdin 11 1900 (has links)
Industrialization creates new requirements for design. Designers need to consider not only building performance, but also production plan needs. This requires a well-structured Building Information Model (BIM) to support the manufacturing needs for design and drafting. BIM, in combination with CAD tools such as AutoCAD and ArchiCAD, can be used for this purpose. These, however, are not sufficient to support the level of detail needed for the manufacturing process. The proposed research establishes a methodology for the automation of design and drafting for the building manufacturing of residential facilities based on the platform construction framing method. The proposed methodology has been incorporated into a computer model called MCMPro, which was developed using Visual Essential for Applications (VBA) as an add-on to a CAD model. MCMPro incorporates BIM technology based on CAD parametric modelling and manufacturing requirements in a 3D-model, in order to generate sets of shop and fabrication drawings. / Construction Engineering and Management
497

Enhanced Design Process with CAD/CAE Integration and Smart Knowledge Capturing Method

Gujarathi, Ganesh 06 1900 (has links)
Generally, a design process involves multiple modeling and analysis interaction iterations accommodating changes and verifications. It is convenient to develop generative programs to automate some tedious and repetitive processes in order to minimize cycle times and the engineer’s routine efforts associated with various design stages. The proposed process model incorporates embedded engineering knowledge and generative Computer Aided Design (CAD) and Computer Aided Engineering (CAE) analysis for partial automation of product development. For improved efficiency and ease of operation, the process used a CAD/CAE integration approach with smart program development mechanism for automated modeling and analysis. A CAD/CAE integration method using a Common Data Model (CDM) containing all the required parametric information for both CAD modelling and CAE analysis is implemented. The CDM is used as a parametric data model repository and the supply source of input for those associative entities of CAD and CAE models and thus maintaining the associative dependencies among them. The pro-recorded journal file from the modeling and analysis software tool are used for rapid and easy program development of generative CAD and CAE. / Engineering Design
498

Nesting automated design modules in an interconnected framework /

Young, Jared M. January 2005 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 131-139).
499

Zirconia as a biomaterial for odontological applications : effects of composition and manufacturing processes on fracture resistance

Sundh, Anders January 2010 (has links)
Background: Ceramics have long been amongst the most biocompatible materials known but their mechanical properties have limited their use. During the past few decades zirconia has aroused particular interest as a biomaterial because of its greater flexural strength, fracture resistance and toughness compared to other bioceramics. Technological inventions and developments have made the processing of zirconia-based ceramics possible and thus also the successful processing of dental restorations constructed from this type of material. The properties of zirconia-based ceramics can, however, be affected by, for example, shape, composition, manufacturing processes and subsequent handling. It was, therefore, of particular interest to study in what way recently introduced zirconia-based ceramics intended for odontological applications could be affected by the shape, manufacturing process, composition, grinding and veneering. Methods: By means of newly invented and developed CAM-Software systems with improvements in grinding technology and strategy and hardware technology, cores for single crowns, fixed partial denture (FPD) frameworks and implant-supported abutments and copies were manufactured from a hot isostatic-pressed (HIPed) yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. In addition, zirconia-based ceramics intended for odontological applications but made from other compositions and/or using different manufacturing techniques were studied. The effects were determined of shape, composition, manufacturing process, heat treatment and veneering of the cores/frameworks on the fracture or bending resistance of various types of ceramic single crowns, FPD frameworks and implant-supported abutments and copies. Results: Different thicknesses in different parts of HIPed Y-TZP cores improved the fracture resistance compared with cores of a uniform thickness resulting in a thicker veneer layer. Machining, heat treatment and veneering affected the fracture resistance of the zirconia-based ceramics studied. In addition, the quality of sintering and composition and type of veneering porcelain used influenced the fracture resistance of zirconia-based ceramics. Conclusion: The results obtained indicate that zirconia-based ceramics have the potential for use as a material in odontological applications. The mechanical properties of zirconia ceramics are, however, affected by, among other things, the shape, composition, manufacturing processes and subsequent handling of the material. These findings have to be taken in consideration in the production processes of zirconia-based ceramic restorations. To further improve their function more studies are needed to elucidate the effects of various manufacturing and handling techniques on the properties of zirconia-based ceramics.
500

Simulation und Analyse zur Ermittlung kinematischer Parameter für die CAE-gestützte Mechanismensynthese

Denninger, Daniel, Berger, Maik, Meyer, Torsten, Wallasch, Rainer 26 June 2013 (has links) (PDF)
Charakterisierung eines textilen Halbzeuges aus Maschenstruktur Technologiedefinition zu einem ausgewählten Verfahren zum Erzeugen der Maschenstruktur Analyse und Simulation des Antriebskonzeptes einer Flachraschelmaschine Synchronisation technologiebedingter Fertigungsschritte und Ableiten von Randbedingungen für die Mechanismensynthese

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