Dissertations / Theses on the topic 'Conceptual design'
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Miller, Andrew Scott. "Compressor conceptual design optimization." Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53598.
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Gas turbine engines are conceptually designed using performance maps that describe the compressor’s effect on the cycle. During the traditional design process, the cycle designer selects a compressor design point based on criteria to meet cycle design point requirements, and performance maps are found or created for off-design analysis that meet this design point selection. Although the maps always have a pedigree to an existing compressor design, oftentimes these maps are scaled to account for design or technology changes. Scaling practices disconnect the maps from the geometry and flow associated with the reference compressor, or the design parameters which are needed for compressor preliminary design. A goal in gas turbine engine research is to bridge this disconnect in order to produce acceptable performance maps that are coupled with compressor design parameters.
A new compressor conceptual design and performance prediction method has been developed which will couple performance maps to conceptual design parameters. This method will adapt and combine the key elements of compressor conceptual design with multiple-meanline analysis, allowing for a map of optimal performance that is attached to reasonable design parameters to be defined for cycle design. This method is prompted by the development of multi-fidelity (zooming) analysis capabilities, which allow compressor analysis to be incorporated into cycle analysis. Integrating compressor conceptual design and map generation into cycle analysis will allow for more realistic decisions to be made sooner, which will reduce the time and cost used for design iterations.
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Karlsson, Albin, and Anton Lomaeus. "Transport Aircraft Conceptual Design." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210778.
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A conceptual design for a transport aircraft has been created, tailored for human-itarian missions along the equator with its home base in the European Union while optimizing for fuel eciency and speed. An initial estimate of the empty weight was made using historical data and Breguet equations, based on a required payload of 60 tonnes and range of 5 500 nautical miles. A constraint diagram consisting of require-ments for stall speed, takeo distance, climb rate and landing distance was used to determine wing loading and thrust to weight ratio, resulting in a main wing area of 387m 2 and thrust to weight ratio of 0:224, for which two Rolls Royce Trent 1000-H engines were selected. A high aspect ratio wing was designed with blended winglets to optimize against lift induced drag. Wing placement and tail volume were decided by iterative calculations, resulting in a centre of lift located aft of the centre of gravity during all stages of the mission. The resulting aircraft model has a high wing with a span of 62 m, length of 49m with a takeo gross weight of 221 tonnes, of which 83 tonnes are fuel.
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Morberg, Hampus. "Conceptual Speaker Study." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Maskinteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-25081.
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This thesis project is a stand-alone project with the goal to develop an optimized material suited for speaker cabinets, with the focus on acoustic abilities, production possibilities and environmental impact. And to further on design a high performance to price speaker, using the developed material properties and todays technology. The thesis is focused heavily on testing material, starting with research and thereafter creating and testing samples, to continue with find a material combination that would work for a product fit for the market. The final product should fulfill the demands of typical furniture handling, meaning it should be able to be moved around and withstand moderate abuse from daily events. The project results in a functional prototype for evaluation of material and the overall design. The project is based on design methods and design thinking.
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CHOOBINEH, JOOBIN. "FORM DRIVEN CONCEPTUAL DATA MODELING (DATABASE DESIGN, EXPERT SYSTEMS, CONCEPTUAL)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188043.
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Conceptual data schema is constructed from the analysis of the business forms which are used in an enterprise. In order to peform the analysis a data model, a forms model, and heuristics to map from the forms model to the data model are developed. The data model we use is an extended version of the Entity-Relationship Model. Extensions include the addition of the min-max cardinalities and generalization hierarchy. By extending the min-max cardinalities to attributes we capture a number of significant characteristics of the entities in a concise manner. We introduce a hierarchical model of forms. The model specifies various properties of each form field within the form such as their origin, hierarchical structure, and cardinalities. The inter-connection of the forms is expressed by specifying which form fields flow from one form to another. The Expert Database Design System creates a conceptual schema by incrementally integrating related collections of forms. The rules of the expert system are divided into six groups: (1) Form Selection, (2) Entity Identification, (3) Attribute Attachment, (4) Relationship Identification, (5) Cardinality Identification, and (6) Integrity Constraints. The rules of the first group use knowledge about the form flow to determine the order in which forms are analyzed. The rules in other groups are used in conjunction with a designer dialogue to identify entities, relationships, and attributes of a schema that represents the collection of forms.
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Karuppoor, Srinand Sreedharan. "Tools for innovation and conceptual design." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1260.
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The ability to design is the distinguishing characteristic of an engineer. Recent research has increased our understanding of both the engineering design process and effective means for teaching that process to neophyte design engineers. In that spirit, a design methodology was developed at the Institute for Innovation and Design in Engineering (IIDE), Texas A&M University. At the core of this approach is a design philosophy based on the cognitive skills of Abstraction, Critical Parameter Identification, and Questioning. This philosophy along with the design process is taught in the senior undergraduate design and graduate design courses. The goal of the methodology is not only to teach the design process to novice designers but also to instill in them the design philosophy that would enable them to perform design effectively and innovatively in any area of specialty.
In this dissertation the design philosophy along with its role in the design methodology is explained. The Need Analysis and the Conceptual Design stages of the IIDE methodology are elaborated. The weaknesses in these stages are identified and addressed, by developing and incorporating design methods and techniques that fit the spirit and framework of the IIDE design methodology. The Object Function Method was developed to address certain aspects at the Need Analysis stage. There was need for an effective concept searching method within the Concept Design stage of the IIDE design methodology. This is addressed by the development of new search techniques and methods for effective concept discovery during concept searching. The usage and application of these methods and techniques is explained in detail along with examples.
Additionally, this dissertation contains the results of a study conducted with two groups of senior design students, those who have been through the process and those who have not, to evaluate the effectiveness of applying the IIDE design philosophy and performing the Need Analysis and Conceptual Design stages for the given design challenge. The goal of the study was to investigate the relationship, if any, between the degree to which these aspects of the design methodology were followed and the quality of the resulting design solutions produced.
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Vangbo, Petter Olav. "CFD in conceptual ship design." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15480.
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Computational Fluid Dynamics (CFD) has been around for many years. It is a computer tool that can be used to find the hydrodynamic fluid performances. In ship design it is used in a wide area from smoke propagation to resistance estimations. It is however in resistance estimations that CFD have had most focus and research. There are many tools a designer can make use of nowadays. Most of the tools are computer based. This is optimization algorithms, computer aided design (CAD) and computational fluid dynamics (CFD). Using the tools should shorten the time of ship design and make better solutions. I have used a computer tool that mixes optimization with model variation (CAD) and verification (CFD). My conclusion is that it is a powerful tool to use, but should be handled with care. Few variables in the optimization process are important. Conceptual design methodology could be broken down to two outer ranges; point based design and set based design. The methods are quite different when approaching a complex design problem. There seems to be some favor in set based design when coming to a global ‘optimized’ solution to the design problem. More knowledge is gathered in set based design before deciding the final requirements and parameters. This is especially in new developing design where little knowledge is produced in the past. CFD is a broad term. There is many different methods and area of use. In this thesis I will break it down to two terms; potential codes and RANSE codes. Potential codes are easy, robust and well developed. RANSE codes are difficult, takes a lot of time and not so well developed. Potential codes are used in areas where turbulent flows are not present, while RANSE codes are used when it is present and important to the result. If designing new innovative hulls CFD should be used earlier in the design process and with a simulation driven design approach. Simulation driven design could be used with potential codes or RANSE codes. To have a high value rate of the modeling potential codes should be used when many sets of variation I needed and turbulence is not important to the answers. RANSE code should be used when turbulent flow is important to the answer, but must be done with few sets of variations because of high computational effort. If designing a more standard ship, CFD should be used in a modeling design approach to verify the performance estimations that have been done earlier in the process.
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Liu, Huimin. "Knowledge-based inventive conceptual design." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54627/.
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Conceptual design is the first phase of the design process. Most basic functions of a new product and the solutions for solving design problems are generated in this critical phase, which will affect the attributes in the later detailed design process. Conceptual design, especially the process of concept generation, is an innovation process that is achieved by human intelligence. The intuition and experience of designers play a significant role during the design process which is hard to be replaced by computer-aided tools or artificial intelligence technology. TR1Z is an inventive problem-solving tool to help people improve creativity. It is applied in this work to generate creative design concepts. The TRIZ inventive principles are extended by integrating other TRIZ tools and TRIZ-derived tools. These principles are also restructured by the inspiration of I-Ching. The Behaviour-Entity representation of inventive principles enables the generation of new and innovative solutions based on TRIZ. The TRIZ Contradiction Matrix (CM) and inventive principles are then used to develop the TRIZ-based concept generation approach by adding constraints to the standard Behaviour-Entity representation of TRIZ. This approach is developed to retrieve modified TRIZ inventive principles and to generate new solutions by re-organising the BEC (Behaviour-Entity-Constraint) representation of principles according to the conflicting design requirements. Finally, a negotiation-based approach is integrated with an existing no-compromise approach to develop a knowledge-based system for automatically detecting and resolving conflicts. The recommendation is given as an output arranged by weight to help the designer improve creativity and efficiency for concept generation and conflict resolution in conceptual design. The approach is implemented by using a rule-based language, JESS. A case study of aircraft fuselage layout design is presented to demonstrate the benefits of using this conflict resolution system.
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Solomons, Stanley Nicholls. "Conceptual models in industrial design." Thesis, De Montfort University, 1988. http://hdl.handle.net/2086/4144.
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King, Martin Graham. "The hierarchy of conceptual design." Thesis, University of Salford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272688.
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Agnesi, Vittorio C. (Vittorio Carlos). "Conceptual design of membrane structures." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/49997.
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Serrano, David. "Constraint management in conceptual design." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14689.
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Sokolova, I. "Conceptual Design of Texts-Announcements." Thesis, Хмельницький державний університет, 2002. http://essuir.sumdu.edu.ua/handle/123456789/63474.
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The paper is dedicated to analysis of conceptual model of texts-announcements, which reflects a derivative character of this type of texts. It is defined that text-announcement as an informative-advertising and a derivative type of texts is pragmatically directed to preparation of addressees for a newly published text reception.
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Brown, Charles Wayne. "Interactive constraint based conceptual design /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487682558443493.
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Guroglu, Serkan. "An Evolutionary Methodology For Conceptual Design." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606422/index.pdf.
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The main goal of this thesis is the development of a novel methodology to generate creative solutions at functional level for design tasks without binding solution spaces with designers&rsquoindividual experiences and prejudices. For this purpose, an evolutionary methodology for the conceptual design of engineering products has been proposed. This methodology performs evaluation, combination and modification of the existing solutions repetitively to generate new solution alternatives. Therefore, initially a representation scheme, which is generic enough to cover all alternatives in solution domain, has been defined. Following that, the evolutionary operations have been defined and two evaluation metrics have been proposed. Finally, the computer implementation of the developed theory has been performed. The test-runs of developed software resulted in creative alternatives for the design task. Consequently, the evolutionary design methodology presents a systematic design approach for less experienced or inexperienced designers and establishes a base for experienced designers to conceive many other solution alternatives beyond their experiences.
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Kadir, Mohammad Razali bin Abdul. "Conceptual phase best practices." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/7241.
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Construction projects comprise holistic and organic processes of the conceptual, detailed engineering, construction and start-up phases. The conceptual phase is the most critical phase in a project's life-cycle where the main strategic decisions are made. The success of other phases depends upon the decisions made during the conceptual phase. Although the conceptual phase presents the greatest opportunity for productivity improvement during the construction phase, it has been given relatively little attention. The main aim of this research was to establish the conceptual phase tasks and associated best practices for major projects that ensure good site productivity through decisions made in the conceptual phase. The aim was realised through the following five objectives: define tasks performed in the conceptual phase; rank the impact of conceptual phase tasks on site productivity; determine the impact of conceptual phase tasks on productivity in terms the main site resources of time, labour, plant, material and finance; establish the sequence with which tasks are performed in the conceptual phase; and establish Best Practices associated with each of the conceptual phase tasks. The research findings were based upon literature, an industry-wide postal questionnaire survey and case studies. The survey comprised a substantial twenty-page questionnaire containing 184 questions. The questionnaire was posted to 144 companies including clients, consultants, contractors and financial institutions throughout the European Union. A return of 37 per cent was achieved. The industry-wide survey was then followed by detailed case studies of six projects: a power plant; a chemical plant; a sewerage treatment plant; an offshore-structure; a motor way; and, a substantial building project. These case studies underpinned the survey and specific differences and similarities were highlighted among the six projects and the processes adopted during the conceptual stages. The industry-wide survey and complementary case studies formed the basis of recommendations for conceptual phase tasks and associated best practices achieving enhanced site productivity. It was concluded that the conceptual phase of construction projects comprised ten tasks: Consents and Permits; Project Definition; Financial Strategy; Project Planning; Contract Strategy; Project Management Organisation; Construction Philosophy; Procurement Strategy; Design of Temporary Works; and, Design of Permanent Structures. Eighty-one best practices relating to the conceptual phase were accepted by the respondents. These best practices, when adopted in the conceptual phase, should held to enhance site productivity.
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McClain, Lewis R. "Design-build interoperability and conceptual design and development." Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-04062007-132656/.
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Schueller, Andreas. "Aspects of distributed conceptual design support." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52698.
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Thesis (PhD)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: The findings of an investigation into the requirements of a support system for distributed conceptual design in small and medium enterprises are presented. Distributed conceptual design refers to the collaboration of spacially distributed design teams during the early stages of the product development process. Three main elements of a support system were identified. The first element, 'Design Methodology', places a framework for specification development, functional analysis, concept generation and concept evaluation at the designers' disposal. It systematically guides the users through the different steps of the design process. These steps can be performed either alone, or together with other team members. The users are also aided in documenting their steps in order to allow the team members or designers of followup projects to understand the decisions made. The second element, 'Communication and Information Transfer', co-ordinates the communication between the distributed designers and provides a platform for the exchange of design-related data, e.g. customer requirements, ideas, sketches, comments, and decisions. A case study was carried out to assess the use of various tools for communication and information transfer during synchronous and asynchronous collaboration. The case study is described and the results are presented and discussed. Both elements make use of a support service providing various 'Input Devices for Conceptual Design', the third element of a support system. While standard tools such as mouse and keyboard meet the requirements of subsequent stages of the design process, they are often impractical in creating or annotating sketches. Various low-cost input devices were investigated. A framework was developed to integrate the three elements into one support system. The 'Distributed Design Assistant', abbreviated as 'DiDeas', is an Internet-based system that allows simultaneous multi-user collaboration. A relational database is located on a central web-server and stores all design information entered into the system. The user interface was realized in the form of a collection of Microsoft Active Server Pages, which can be accessed platform-independently via a standard webbrowser. The development of the database structure and of the user interface is described in detail. A second case study was carried out to evaluate the Distributed Design Assistant. The case study is described and the results are presented and discussed. The low-cost system has proven to be a very useful tool for distributed conceptual design. The Distributed Design Assistant systematically guides novice and experienced designers through the stages of specification development and conceptual design. It facilitates the easy collection and the fast exchange of a large amount of textual and graphical information during these stages. Although the system is relatively simple, compared to professional product data management systems used in later stages of the design process, it strongly enhances the productivity of designers and distributed design teams. Keywords: Distributed Design, Conceptual Design, Systematic Product Development
AFRIKAANSE OPSOMMING: Die bevindinge van 'n ondersoek na die behoeftes van 'n ondersteuningstelsel VIr verspreide konsepsionele ontwerp in klein en medium ondernemings word aangebied. Verspreide konsepsionele ontwerp is die saamwerk van ruimtelik verspreide ontwerp spanne gedurende die aanvanklike fases van die produk ontwikkelingsproses. Drie hoof elemente van 'n ondersteuningstelsel is geïdentifiseer. Die eerste element, 'Ontwerpmetodiek' stel 'n raamwerk vir spesifikasie ontwikkeling, funksionele analise, konsep generasie en konsep beoordeling tot beskikking van die ontwerpers. Dit lei die gebruikers stelselmatig deur die verskillende stappe van die ontwikkelingsproses. Die stappe kan of alleen of tesame met ander lede van die span uitgevoer word. Die gebruiker word ook ondersteun met die dokumentasie van die stappe sodat die lede of ontwerpers van opvolgprojekte die besluite wat gemaak is, kan begryp. Die tweede element, 'Kommunikasie en Informasie Oordrag', koordineer die kommunikasie tussen die verspreide ontwerpers en bied 'n platvorm vir die uitruil van ontwerpinformasie, byvoorbeeld kliënte behoeftes, idees, sketse, kommentaar en besluite. 'n Gevallestudie is uitgevoer om die gebruik van verskeie gereedskapstukke vir kommunikasie en informasie-oordrag gedurende sinchrone en asinchrone samewerking te beoordeel. Die gevalle studie is beskryf en die resultate is bespreek. Altwee elemente maak gebruik van 'n ondersteuningsdiens wat verskeie 'Invoergereedskap vir Konsepsionele Ontwerp' voorsien, die derde element van die ondersteuningstelsel. Terwyl standard gereedskap, byvoorbeeld 'n rekenaar muis en sleutelbord, die behoeftes van die latere ontwerpsfases bevredig, is hulle dikwels onprakties vir die maak van sketse en byskrifte. Verskeie laekoste invoergereedskap is ondersoek. 'n Raamwerk is ontwikkel om die drie elemente in een ondersteuningstelsel te integreer. Die 'Distributed Design Assistant', verkort 'DiDeas', is 'n Internet-gebaseerde stelsel wat sinchrone multi-gebruiker samewerking moontlik maak. 'n Gekoppelde databasis is op 'n sentrale webbediener geplaas en versamel al die ontwerpinformasie wat in die stelsel ingevoer is. Die gebruikerintervlak is geskep as 'n versameling van Microsoft Active Server Pages. Toegang tot die stelsel is onafhanklik van die rekenaar bedryfstelsel en kan verkry word met 'n standard webblaaier. Die ontwikkeling van die databasisstruktuur en van die gebruikerintervlak is in detail beskryf. 'n Tweede gevallestudie is uitgevoer om die Distributed Design Assistant te beoordeel. Die gevallestudie is beskryf en die resultate is bespreek. Die laekoste stelsel het homself bewys as 'n baie nuttige werktuig VIr verspreide konsepsionele ontwerp. Die Distributed Design Assistant lei nuweling en ervare ontwerpers stelselmatig deur die spesifikasie ontwikkeling en konsepsionele ontwerp stappe. Dit fasiliteer die maklike versameling en die vinnige uitruil van 'n groot hoeveelheid teks en grafiese informasie gedurende hierdie stappe. Ofskoon die stelsel relatief eenvoudig is in vergelyking met professionele produkdata-bestuurstelsels, verhoog dit die produktiwiteit van ontwerpers en verspreide ontwerp spanne aansienlik.
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Rottier, Johannes. "Conceptual design of an organisational capability." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-11092006-121921/.
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Uebel, Karl. "Conceptual Design of Complex Hydromechanical Transmissions." Doctoral thesis, Linköpings universitet, Fluida och mekatroniska system, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-142895.
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This thesis explores the conceptual design process of complex hydromechanical transmissions for mobile working machines. Efficient methods for design optimisation and controller development are presented to support the final concept selection. In the endeavour to develop new fuel-efficient driveline solutions for construction machines and off-road equipment new complex hydromechanical transmission concepts are being investigated. This pursuit is driven by stricter emission legislation, high fuel prices and a desire for a greener image both for customers and manufacturers. The trend towards more complex transmission architectures increases the need for more sophisticated product development methods. Complex multiple-mode transmissions are difficult to design and prototype and can be realised in a great number of architectures. By introducing a secondary energy storage in the machine the design space expands further for both hardware and software. There is accordingly a need for more reliable concept assessment in early design stages and the possibility to support concurrent engineering throughout the development process. Previous research on the design and development of hydromechanical transmissions has been limited to analysis of fixed concept designs or design optimization using very simple performance indicators. Existing methodologies for electrified on-road vehicles are not suitable for off-road working machines with hydromechanical transmissions and hydraulic energy storage. The proposed conceptual design process uses detailed quasi-static simulation models and targets to optimise the fuel efficiency of the specific machine specifications and operations. It is also shown how high-speed dynamic simulations can be used for controller development and hardware-in-the-loop simulations to support an efficient product design process. The methods are demonstrated for typical use cases targeting new transmission development for construction machines. Software control development is also treated using control optimisation and real-time simulation. Finally a novel hybrid hydromechanical motion system is presented for which an efficient design process is crucial to its end performance.In the printed verison the series name Linköping studies in Arts and Science is incorrect. The correct series name is Linköping studies in science and technology. Dissertations.
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Tanaka, Asterio Kiyoshi. "On conceptual design of active databases." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/8299.
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Steele, John. "The interdisciplinary conceptual design of buildings." Thesis, Loughborough University, 2000. https://dspace.lboro.ac.uk/2134/6867.
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The Interdisciplinary Conceptual Design of Buildings Design activity during the conceptual phase of building projects is dynamic, vibrant and as a result, chaotic in appearance. This problem is compounded by the fact that iterative, or cyclic, design progression is often criticised, with the concept of 'going round in circles' being one that is discouraged. However, designbis a learning activity and, owing to the complexity of contemporary building projects,it is often only by moving ahead to improve knowledge, before taking a step back to re-address a problem with improved understanding, that the design process can progress. Today's design professionals are being urged to undertake early design activity in a more programmable, and thus manageable fashion. As such, it is becoming increasingly apparent that designers have little, if any, shared understanding of what conceptual design actually involves, let alone a deeper knowledge of the structure of iterative progression. This can, and is, causing problems for the industry, as the lack of both common understanding and synchronisation in interdisciplinary thinking is resulting in design team fragmentation and adversarial relationships. By modelling design activity it is possible to simplify, and thus ease understanding of, its complexities. The development and trialling of a generic framework of design phases and activities has allowed a simple graphical means of recording and displaying patterns of design progression to be devised. The models produced have been used to study and analyse the patterns of iterative working, the output of which has enabled a clarification of conceptual design practice to be achieved. A web-based design system has been developed from the paper-based framework. This accords well with the richly iterative and often non-linear process which design typically follows and is intended to encourage creativity without imposing a rigid procedure. The tool offers alternative routes through conceptual design, and contains 'Team Thinking Tools' to help designers widen the solution space, set priorities and evaluate options. In addition, it promotes effective teamwork practices to help teams deal with social interactions. Also, at the user's option, the system can be used to capture, store and retrieve decisions made, and the reasoning behind them. This is of key importance in improving the performance of the industry as a whole, for it is only by understanding how the final product is influenced by early design activity, that the design process can be adapted to take account of these issues on future projects.
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Wu, Zhichao. "Modelling collective learning in conceptual design." Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405494.
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Potter, Stephen. "Artificial intelligence and conceptual design synthesis." Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760733.
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Margelis, Georgios A. "Geometric abstractions for conceptual design support." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36487.
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Thesis (Ocean. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1994.Includes bibliographical references (leaves 151-154).
by Georgios A. Margelis.
M.S.
Ocean.E.
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Perez, De Rosso Santiago (Santiago Nicolas). "A conceptual design analysis of Git." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97817.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 75-77).
It is commonly asserted that the success of a software development project, and the usability of the final product, depend on the quality of the concepts that underlie its design. Yet this hypothesis has not been systematically explored by researchers, and conceptual design has not played the central role in the research and teaching of software engineering that one might expect. As part of a new research project to explore conceptual design, we are engaging in a series of case studies. This thesis reports on our case study on Git, a popular-yet sometimes puzzling-version control system. In an attempt to understand the root causes of its complexity, we analyze its conceptual model and identify some undesirable properties; we then present a reworking of the conceptual model that forms the basis of Gitless, our redesign of Git.
by Santiago Perez De Rosso.
S.M.
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Daniel, Guido. "Conceptual design of reactive distillation processes." Thesis, University of Manchester, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503083.
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Integrated processes such as reactive distillation offer the potential for reduced capital and operating costs compared to conventional flowsheets. In this work new tools for the identification of the optimal reactive distillation process with the optimal degree of integration are developed. A conceptual design method based on the boundary value method is used for a set of reactive distillation processes. The combination of a reactive distillation column with a pre-reactor is a valuable alternative to standalone reactive distillation columns. This thesis presents an approach to identify promising designs for such flowsheets and the optimum distribution of the reaction extent between the pre-reactor and the reactive distillation column. The methodology uses a boundary value method for the design of the column; chemical equilibrium is assumed. The column usually consists of a reactive `core', two rectifying sections and one stripping section. This work presents an approach to identify promising designs for standalone reactive distillation columns as well as for reactor - reactive distillation column flowsheets, when reaction kinetics are available. Reaction kinetics are considered and several near-optimal flowsheet designs are generated. A new approach for the conceptual design of double-feed reactive distillation columns is presented. One of the feed streams is situated at the boundary of the reactive section and the other one can be fed into the non-reactive section of the column. Thus the column consists of an additional separating section, which offers the opportunity to add an additional function to the column. The production of methyl acetate is an example for such a column structure. The additional section in that case acts as an extractive distillation zone. Here also chemical equilibrium is assumed. The integration of further separation steps with a reactive distillation column leads to a highly integrated process: a reactive dividing wall column. Within one apparatus, more than two products can be obtained and the capital cost can be reduced drastically. Furthermore, the well-known reduction in energy demand for dividing wall columns compared to a sequence of conventional distillation columns can lead to reduced operating costs. However, the simulation, design and operation of such complex columns is complicated. A novel approach for the conceptual design of reactive dividing wall columns is presented in this work. Chemical equilibrium is assumed on every reactive stage of the column. The use of the concept of product regions and composition manifolds during all proposed design procedures leads to an increased robustness when compared to conventional approaches based on BVMs. Furthermore, the approaches can be used for n-component systems. Several column designs with different design and operating' parameters are identified for each reactive distillation process, allowing the process engineer to compare and choose from a selection of designs. These tools can assist in identifying the optimal degree of integration for reactive distillation processes ranging from reactor - reactive distillation combinations via complex double feed reactive distillation columns with additional separating sections to the most integrated reactive distillation process: the reactive dividing wall column. The new methodology offers an easy to use tool for process engineers, which assists in identifying an economical integrated reaction-distillation process and could lead to increased industrial applications of technologies coupling unit operations.
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Suckow, Scott Jeffrey 1975. "Conceptual design of suspended structural systems." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47657.
Full textAbstract:
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998.Includes bibliographical references.
This thesis investigates the use of suspended structural systems. This is done by performing a conceptual design for the proposed new Civil and Environmental Engineering building at the Massachusetts Institute of Technology. It begins with site considerations and owner requirements and progresses through the concept development and design development. Preliminary member sizes are determined. The majority of these are calculated using computer analysis, but hand calculations are included as well. In addition, a 3- dimensional model is created in SAP 2000. This model was used to analyze the impact of dynamic loading on suspended systems. AutoCAD is used to create 2- dimensional architectural and structural drawings. It is also used to create 3-dimensional architectural drawings. AutoVISION is used to apply materials to the surfaces of the drawings and render images. AutoVISION is also used to create a simulated 'fly-by' and 'walk-through.' The issue of constructibility is addressed and erection techniques are proposed. The topic of scheduling construction phases is briefly discussed as well. The thesis includes a rough cost analysis with suggested refinements to enhance the design and reduce the cost.
by Scott Jeffrey Suckow.
M.Eng.
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Carlson, Jesper, and Diyar Jazrawi. "Conceptual Design of a Transport Aircraft." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211549.
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When flooding or earthquakes hits a country the population in the area could suffer a lot and are in a big need of help quickly. In these situations heavy transport aircraft are used around the world to help and support the victims in the area by delivering supplies. In our operational mission scenario the country Papa New guinea has been hit by an earthquake and approximately 5000 people have lost their home and are in need of help. The only problem is that there are no heavy transport airplanes available to fly from EU to this country and return without refuelling. The problem here is that the country is in a big need of help and if an airplane needs to land to refuel a lot of time is wasted. Therefore, in this task we have designed a conceptual transport aircraft that is able to fly from EU to Papa New Guinea to deliver supplies in form of food, aid, water etc. Due to the horrific accident the airplane does not have access to a runway and will have to deliver the supplies by airdrop in parachutes. In this report we will generate a requirements specification, which will state the requirements of the aircraft and be vital for the design. There will be precise estimations and calculations presented and it will include important parameters used in the Design of the aircraft.
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Rabizadeh, Nadja, and Bahar Kasbi. "Conceptual Design of a Transport Aircraft." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211556.
Full textAbstract:
The mission of this project is to conceptually design a transport aircraft. A typical mission for a transport aircraft is to deliver supplies to countries in need of help. The given requirement is that the aircraft should be able to travel from a place within EU to a place along the equator in Africa, deliver the supplies, and return (to the takeoff location) without refueling. The operational mission will be to provide people in need with supplies such as food, water and tents. The aircraft will be able to carry necessities that will be able to provide 5000 persons during a week. Since a landing runway is not available at the destination, the payload will be airdropped in parachutes. First off, the desired requirements are defined, they are either already given or estimated. An analysis of´the mission and the desired performance of the aircraft is made by creating a mission profile. With the help of this a weight estimation is done, most importantly the takeoff weight of the aircraft is estimated. With the takeoff weight known and by the help of the desired performance requirements, a constraint diagram is made. By a constraint analysis the optimal wing loading and thrust-to-weight ratio is found. This makes it possible to choose an appropriate engine and to design the wings so that they are customized for the desired mission. Other parts of the aircraft such as the tail and fuselage are designed, and the center-of gravity of the aircraft is found. Throughout the project, different aerodynamic parameters are changed in order to optimize the aircraft and its performance to make it as adapted as possible to the desired mission.
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Morley, Jane. "Conceptual fashion : design, practice and process." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/62703/1/Jane_Morley_Thesis.pdf.
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While Conceptual fashion design practices have been a pervasive influence in fashion since the early 1980s, there is little academic analysis that might explain how they are distinct from conventional fashion design practices. In addition, fashion practitioners have not historically contributed to fashion research. As a result, contemporary fashion practitioners have difficulty setting critical contexts and expanding their creative work as there is little relevant literature available from practitioner perspectives. This project uses practice-led research to develop a discourse for understanding Conceptual fashion design process and how it relates to more conventional fashion design practices. In this exegesis I use Conceptual art as a lens to expand understandings of Conceptual fashion and my own creative practice. This analysis demonstrates that there are valuable connections to be drawn between Conceptual art and Conceptual fashion practice. In particular, these connections reveal the differences between the way Conceptual and more conventional fashion designers relate to the conceptual and the visual in their design process. This exploration demonstrates that while fashion is a visual field, Conceptual fashion designers produce a more ‘intellectual’ type of fashion that uses the visual to communicate ideas that question the nature of fashion. I explore the relevance of these ideas through application and experimentation in my creative practice projects by drawing from systems and rules identified in the work of early Conceptual artists and contemporary Conceptual fashion designers.
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Schrock, Eric V. "A PHIGS-based spreadsheet for conceptual design." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10242009-020217/.
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Abreu, Michael N. "Conceptual design tools for the NPS spacecraft design center." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA397230.
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Mueller, Caitlin T. "High-dimensional design space visualization for conceptual structural design." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90083.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 63-66).
This thesis focuses on visualizing high-dimensional design spaces for early-stage design problems in structural engineering and related disciplines. The design space, which is defined as the n + 1-dimensional surface that relates n design variables to a performance metric, contains all possible solutions to a formulated design problem. Graphical views of the design space are highly useful for designers because they organize a wide range of design possibilities in a compact, intuitive, and logical manner, illuminating global patterns, variable behaviors and relationships, and the nature of paths taken during iterative design processes. Design problems with two or fewer variables can easily be visualized in Euclidian space, through a curve or surface, but high-dimensional problems are difficult to display graphically. This is the key challenge addressed in this thesis. The thesis includes a critical review of existing methods for high-dimensional design space visualization, highlighting the unmet needs across a range of approaches. In response to these needs, the thesis makes a key contribution in the form of a new design space visualization method, called isoperforming parallel coordinate clusters (IPC clusters), that overcomes the issues of previous techniques. The IPC cluster approach is demonstrated on several conceptual structural design problems, and its application in optimization, directed exploration, and related design strategies is illustrated. Finally, the thesis concludes with a discussion of applications, impact, and future research directions. Key words: design space visualization, conceptual design, structural design, structural optimization
by Caitlin T. Mueller.
S.M.
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Jiang, Pingfei. "Development of a conceptual design tool for mechanism design." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/31370.
Full textAbstract:
Engineering design can be seen as a problem solving process in which engineers and designers convert their thoughts and ideas into real-life designs satisfying market and customer needs. The conceptual design process is crucial in engineering product design since it determines fundamental design features with respect to design requirements. Any decisions made at this stage have a significant impact on later stages of design. However, connection between system functional requirements and selection of actual mechanical components in mechanism designs is severely lacking. With the purpose filling this gap and assisting engineers and designers to obtain in-depth understanding on commonly seen mechanisms and machine elements a database (MMET) was established and programmed containing detail information of these components including technical functional attributes, movement attributes, pictures/drawings and merit analysis. A conceptual design tool built on MMET was then developed aiming to help the user to explore a broad range of mechanical components regarding system requirements. The database and conceptual design tool were validated and improved through industrial case studies which suggest the addition of Function Means tree and Functional Analysis Diagram. The value of MMET and the new conceptual design tool are indicated via positive outcomes of case studies, asserting their capability of offering assistance in understanding engineering product functions and how these functions are achieved, enabling comparisons regarding same functional requirements and finally providing opportunities for conceptual design improvements based on a cyclic process containing detail functional analysis, function-means tree construction and design optimisation.
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Ledendal, Marie. "Chromatic chlorophyll : Conceptual hospital textiles with chromatic Smart Materials." Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19626.
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THIS PROJECT AIMS TO look at how Smart Textiles can change today’s view and useof the interiors of the healthcare environment, through conceptual examples of the usabilityof the Photochromics and Thermochromics working as an information bridge for moreisolated patients. The thesis has a practical experimental approach and points out some of thechromatic materials possibilities in relation to present research of the two chromatic materials.The thesis discusses the relation between healing environment and the importance of aesthetics,with a purpose to meet Emotional and Social needs of feeling “alive”, “well” and“included”. Research indicate that nature has a calming affect on patients, therefore flowersand leaves have been inspiration for the expression of the textiles. The colour changecreates a subtle communicative bridge between patient and movement in the hospital - “theRhythm of the House” and the outdoor -“the Rhythm of the Sun”. The conceptual proposalpresents a design solution where the colour changeability stands for a communicativelevel, as well as a decorative and a dynamic level. The textile samples communicate thevisual and hepatic expression, as well as the integration of the electronics. The scenariofor the thesis is set to the 2015-20, due to reasonability for Smart Textiles to be developedto be used as interior textile products for the healthcare environment.
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Jackson, David Wayne. "Robust aircraft subsystem conceptual architecting." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50202.
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Aircraft subsystems are key components in modern aircraft, the impact and significance of which have been constantly increasing. Furthermore, the architecture selection of these subsystems has overall system-level effects. Despite the significant effects of architecture selections, existing methods for determining the architecture, especially early in design, are similar to the use of traditional point solutions.
Currently, aircraft subsystems are rarely examined during the conceptual design phase, despite the fact that this phase has a significant influence on aircraft cost and performance. For this reason, there is a critical need to examine subsystem architecture trades and investigate the design space during the conceptual design of an aircraft. Traditionally, after the aircraft conceptual design phase, subsystems are developed in a process that begins with the point selection of the architecture, then continues with its development and analysis, and concludes in the detailed development of the subsystems. The choice of the point design of the architecture to be developed can be made using simplified models to explore the design space. This method known as conceptual architecting is explored in this dissertation.
This dissertation also focuses on bringing actuation subsystem architecture trades into conceptual design because of the significant cost impact of this design phase and the interdependence of vehicle sizing with the subsystems impact on the aircraft. The extent of these interdependencies is examined and found to be significant. As a result, this coupling must be captured to enable better informed decision making. A methodology to examine the design space of aircraft subsystem architectures during the conceptual design of aircraft, while incorporating this coupling, is presented herein and applied specifically to actuation architectures.
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Wilson, Jamal Omari. "A systematic approach to bio-inspired conceptual design." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26483.
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Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009.Committee Chair: Rosen, David; Committee Member: Allen, Janet; Committee Member: Bras, Bert; Committee Member: Ku, David; Committee Member: Shofner, Meisha; Committee Member: Yen, Jeannette. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Fantini, Paolo. "Effective multiobjective MDO for conceptual design - An aircraft design perspective." Thesis, Cranfield University, 2007. http://hdl.handle.net/1826/2219.
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Once the requirements for a new aircraft have been defined, the Conceptual design phase is launched. During this phase one or more designers have the goal of defining and investigating a number of alternative solutions. Through discussion with industry it has become apparent that optimisation tools are seldom used, even though these could greatly enhance the work of the designers.
The objective of the work carried forward has been of identifying, comparing and where necessary improving the most suitable techniques, as well as schemes for their integration, in order to perform effectively Multidisciplinary Design and Optimisation (MDO) in the Conceptual phase of the aircraft design. The techniques that have been investigated include: multi-objective optimisation algorithms, MDO algorithms for treating non-hierarchically decomposable systems and Automatic Differentiation (AD).
As a result an algorithm for performing multiobjective MDO has been developed. Given a complete model for a complex non-hierarchically decomposable system and given a number of objectives and constraints, the algorithm is capable of determining a set of well distributed solutions, representative of both local and global Pareto frontiers.
A number of test cases have been used for evaluating the alternative methodologies and the proposed algorithm. These include a set of complex algebraic test cases typically used for evaluating global optimisation algorithms and a simplified aircraft conceptual design model, which was provided by industry.
The results demonstrate the unique capability of the algorithm of determining well distributed solutions on the global and local Pareto frontiers for global multiobjective continuous nonlinear constrained optimisation problems. The results also show this capability when the algorithm is applied to non-hierarchically decomposable systems, as typically encountered when performing MDO. Further work could extend the approach in order to handle mixed discrete/continuous variables.
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Padulo, Mattia. "Computational engineering design under uncertainty : an aircraft conceptual design perspective." Thesis, Cranfield University, 2009. http://hdl.handle.net/1826/4462.
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Presented in this thesis is a novel methodology for aircraft design optimization in the presence of uncertainty, with emphasis on the conceptual design stage.
In the initial part of the thesis, the uncertainty typologies of interest for aircraft design are identied within a broader epistemological framework. The main implications for non-deterministic computational design are also outlined.
The focus is then restricted to uncertainties that can be modeled by probability theory. In this context, a methodology is developed to enhance robust design optimization (RDO). Firstly, the problem is formulated in order to relax, when required, the common RDO assumption about the normality of objectives and constraints. Secondly, starting from engineering considerations about the risk related with design unfeasibility, suitable estimates of tail conditional expectation are introduced in the set of robustness metrics.
The proposed formulation requires the estimation of mean and variance of objec¬tives and constraints. To calculate such moments, a novel uncertainty propaga¬tion technique is proposed, which achieves a favorable trade-obetween the ac-curacy of the estimates and the required computational cost. Peculiar features of the propagation technique are exploited to couple the propagation and the opti¬mization phases for the classes of gradient-based methods and the derivative-free pattern search methods. Also analyzed are the possible advantages achievable when the two types of algorithms are hybridized.
The usefulness of the proposed methodology for conceptual design optimization is demonstrated with the aid of two engineering design problems, concerning the sizing of passenger aircraft and the design of transonic airfoils.
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Nunez, Marco. "Design exploration for engineering design optimisation : an aircraft conceptual perspective." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6900.
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Most of the efforts in optimisation so far have been focused on the development of novel
or the improvement of existing numerical methods for an effective computation of
optimal solutions. Particular attention has been put on balancing multiple conflicting
objectives, handling the interaction between different disciplines, reducing computational
cost and managing uncertainty. Nonetheless, specific issues of this design methodology
still remain to be properly addressed. In this research, attention is concentrated on
advancing engineering optimisation as a tool for design exploration. The work is put in
the context of conceptual aircraft design.
The overall aim of the present research is to develop a methodology that allows the
designer to effectively conduct an exploration and analysis of alternative design solutions
via a set of methods that can be used separately or conjointly.
The initial part of the thesis introduces two novel methods for assisting the formulation of
an optimisation problem, which generally is assumed to be given a priori. Nonetheless,
the correctness of the optimisation statement, which is not addressed by established
optimisation methods, turns out to be decisive for the feasible design set determination.
The designer is thus provided with an adaptive formulation of functional and designvariable
constraints, which allows the exploration of further promising solutions initially
not contained in the feasible design set. Meaningless results or the loss of important
solutions can therefore be partially avoided.
In a second instance, attention is focused on the visualisation needs for design
exploration. A suitable visualisation methodology has been developed to make the large
multidimensional results of complex design optimisation procedures fully readable and
explanatory. This is achieved by integrating advanced visualisation techniques which provide the designer with diverse perspectives of the data under study and allow him/her
to conduct a number of analysis tasks on it, without the need to be an expert in numerical
optimisation methods.
Last, but not least, a methodology to address conceptual design change problems is
proposed. The decision-maker is enabled to formally state the new design requirements
and priorities introduced by the conceptual change via an adequate problem
reformulation. All the data previously collected can thus be re-used and exploited to drive
an effective exploration of alternative design solutions through design space regions of
interest.
The evaluation of the proposed methodologies has been carried out with a number of test
cases. Analytical examples have been used for the assessment of effectiveness, whereas
codes representative of aircraft sizing procedures have been adopted to evaluate the
methodologies functionality. A visualisation user interface prototype has also been
developed for demonstration and evaluation purposes.
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Valenzuela-Del, Rio Jose Eugenio. "Bayesian adaptive sampling for discrete design alternatives in conceptual design." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50263.
Full textAbstract:
The number of technology alternatives has lately grown to satisfy the increasingly demanding goals in modern engineering. These technology alternatives are handled in the design process as either concepts or categorical design inputs. Additionally, designers desire to bring into early design more and more accurate, but also computationally burdensome, simulation tools to obtain better performing initial designs that are more valuable in subsequent design stages. It constrains the computational budget to optimize the design space. These two factors unveil the need of a conceptual design methodology to use more efficiently sophisticated tools for engineering problems with several concept solutions and categorical design choices. Enhanced initial designs and discrete alternative selection are pursued.
Advances in computational speed and the development of Bayesian adaptive sampling techniques have enabled the industry to move from the use of look-up tables and simplified models to complex physics-based tools in conceptual design. These techniques focus computational resources on promising design areas. Nevertheless, the vast majority of the work has been done on problems with continuous spaces, whereas concepts and categories are treated independently. However, observations show that engineering objectives experience similar topographical trends across many engineering alternatives.
In order to address these challenges, two meta-models are developed. The first one borrows the Hamming distance and function space norms from machine learning and functional analysis, respectively. These distances allow defining categorical metrics that are used to build an unique probabilistic surrogate whose domain includes, not only continuous and integer variables, but also categorical ones. The second meta-model is based on a multi-fidelity approach that enhances a concept prediction with previous concept observations. These methodologies leverage similar trends seen from observations and make a better use of sample points increasing the quality of the output in the discrete alternative selection and initial designs for a given analysis budget. An extension of stochastic mixed-integer optimization techniques to include the categorical dimension is developed by adding appropriate generation, mutation, and crossover operators. The resulted stochastic algorithm is employed to adaptively sample mixed-integer-categorical design spaces.
The proposed surrogates are compared against traditional independent methods for a set of canonical problems and a physics-based rotor-craft model on a screened design space. Next, adaptive sampling algorithms on the developed surrogates are applied to the same problems. These tests provide evidence of the merit of the proposed methodologies. Finally, a multi-objective rotor-craft design application is performed in a large domain space.
This thesis provides several novel academic contributions. The first contribution is the development of new efficient surrogates for systems with categorical design choices. Secondly, an adaptive sampling algorithm is proposed for systems with mixed-integer-categorical design spaces. Finally, previously sampled concepts can be brought to construct efficient surrogates of novel concepts. With engineering judgment, design community could apply these contributions to discrete alternative selection and initial design assessment when similar topographical trends are observed across different categories and/or concepts. Also, it could be crucial to overcome the current cost of carrying a set of concepts and wider design spaces in the categorical dimension forward into preliminary design.
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Sim, Diana. "Design of an IT solution for distributed conceptual design processes." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40487.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaf 16).
This thesis explores the need for software tools to aid in the conceptual stage of product design processes in a geographically distributed work environment. While the need for such a solution exists, there have been few strides to update the tools engineers currently use. The 2.009 design process is used as a model to better understand the particular needs of conceptual design. The intent of the study is to identify elements of a software solution that can support the design process. The structure of the design is a result of analysis of potential users as well as involvement in the type of design process to which the solution is intended to cater. The solution is motivated by recent advancements in internet and software technology. The final design addresses six important needs: communication of ideas, data and deadlines, general meeting scheduling, task force communication, scheduling, timeline and purpose, remote meeting, data & communication archival, and notification of design & communication changes. This thesis provides the preliminary research necessary to support the an IT design solution.
y Diana Sim.
S.B.
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Safavi, Edris. "Collaborative Multidisciplinary Design Optimization for Conceptual Design of Complex Products." Doctoral thesis, Linköpings universitet, Maskinkonstruktion, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-131792.
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MULTIDESCIPLINARY design optimization (MDO) has developed in theory andpractice during the last three decades with the aim of optimizing complexproducts as well as cutting costs and product development time. Despite thisdevelopment, the implementation of such a method in industry is still a challenge andmany complex products suffer time and cost overruns. Employing higher fidelity models (HFMs) in conceptual design, one of the early and most important phases in the design process, can play an important role in increasing the knowledge base regarding the concept under evaluation. However, design space in the presence of HFMs could significantly be expanded. MDO has proven to be an important tool for searching the design space and finding optimal solutions. This leads to a reduction in the number of design iterations later in the design process, with wiser and more robust decisions made early in the design process to rely on. In complex products, different systems from a multitude of engineering disciplines have to work tightly together. This stresses the importance of evolving various domain experts in the design process to improve the design from diverse engineering perspectives. Involving more engineers in the design process early on raises the challenges of collaboration, known to be an important barrier to MDO implementation in industry. Another barrier is the unavailability and lack of MDO experts in industry; those who understand the MDO process and know the implementation tasks involved. In an endeavor to address the mentioned implementation challenges, a novel collaborative multidisciplinary design optimization (CMDO) framework is defined in order to be applied in the conceptual design phase. CMDO provides a platform where many engineers team up to increase the likelihood of more accurate decisions being taken early on. The structured way to define the engineering responsibilities and tasks involved in MDO helps to facilitate the implementation process. It will be further elaborated that educating active engineers with MDO knowledge is an expensive and time-consuming process for industries. Therefore, a guideline for CMDO implementation in conceptual design is proposed in this thesis that can be easily followed by design engineers with limited prior knowledge in MDO. The performance of the framework is evaluated in a number of case studies, including applications such as aircraft design and the design of a tidal water power plant, and by engineers in industry and student groups in academia.
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Jonson, Ben. "Design ideation : the conceptual sketch in a digital design culture." Thesis, Goldsmiths College (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415011.
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Raymer, Daniel. "Enhancing Aircraft Conceptual Design using Multidisciplinary Optimization." Doctoral thesis, KTH, Aeronautical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3331.
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Research into the improvement of the Aircraft ConceptualDesign process by the application of MultidisciplinaryOptimization (MDO) is presented. Aircraft conceptual designanalysis codes were incorporated into a variety of optimizationmethods including Orthogonal Steepest Descent (full-factorialstepping search), Monte Carlo, a mutation-based EvolutionaryAlgorithm, and three variants of the Genetic Algorithm withnumerous options. These were compared in the optimization offour notional aircraft concepts, namely an advanced multiroleexport fighter, a commercial airliner, a flying-wing UAV, and ageneral aviation twin of novel asymmetric configuration. Tobetter stress the methods, the commercial airliner design wasdeliberately modified for certain case runs to reflect a verypoor initial choice of design parameters including wingloading, sweep, and aspect ratio.
MDO methods were evaluated in terms of their ability to findthe optimal aircraft, as well as total execution time,convergence history, tendencies to get caught in a localoptimum, sensitivity to the actual problem posed, and overallease of programming and operation. In all, more than a millionparametric variations of these aircraft designs were definedand analyzed in the course of this research.
Following this assessment of the optimization methods, theywere used to study the issue of how the computer optimizationroutine modifies the aircraft geometric inputs to the analysismodules as the design is parametrically changed. Since thiswill ultimately drive the final result obtained, this subjectdeserves serious attention. To investigate this subject,procedures for automated redesign which are suitable foraircraft conceptual design MDO were postulated, programmed, andevaluated as to their impact on optimization results for thesample aircraft and on the realism of the computer-defined"optimum" aircraft. (These are sometimes called vehicle scalinglaws, but should not be confused with aircraft sizing, alsocalled scaling in some circles.)
This study produced several key results with application toboth Aircraft Conceptual Design and MultidisciplinaryOptimization, namely:
MDO techniques truly can improve the weight and cost ofan aircraft design concept in the conceptual design phase.This is accomplished by a relatively small "tweaking" of thekey design variables, and with no additional downstreamcosts.In effect, we get a better airplane for free.
For a smaller number of variables (<6-8), adeterministic searching method (here represented by thefull-factorial Orthogonal Steepest Descent) provides aslightly better final result with about the same number ofcase evaluations
For more variables, evolutionary/genetic methods getclose to the best final result with far-fewer caseevaluations. The eight variables studied herein probablyrepresent the practical upper limit on deterministicsearching methods with todays computer speeds.
Of the evolutionary methods studied herein, the BreederPool approach (which was devised during this research andappears to be new) seems to provide convergence in the fewestnumber ofcase evaluations, and yields results very close tothe deterministic best result. However, all of the methodsstudied produced similar results and any of them is asuitable candidate for use.
Hybrid methods, with a stochastic initial optimizationfollowed by a deterministic final "fine tuning", proved lessdesirable than anticipated.
Not a single case was observed, in over a hundred caseruns totaling over a million parametric design evaluations,of a method returning a local rather than global optimum.Even the modified commercial airliner, with poorly selectedinitial design variables far away from the global solution,was easily "fixed" by all the MDO methods studied.
The postulated set of automated redesign procedures andgeometric constraints provide a more-realistic final result,preventing attainment of an unrealistic "better" finalresult. Especially useful is a new approach defined herein,Net Design Volume, which can prevent unrealisticallyhigh design densities with relatively little setup andcomputational overhead. Further work in this area issuggested, especially in the unexplored area of automatedredesign procedures for discrete variables.
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Krishnakumar, Karthikeyan. "Material and processes selection in conceptual design." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1337.
Full textAbstract:
Materials and manufacturing processes are an integral part of the design of a product. The need to combine materials and manufacturing processes selection during the early stages of the design has previously been realized. The work that generally attracts the most attention is by M.F. Ashby. This methodology, like others, concentrates on materials and manufacturing processes selection after the conceptual design is completed and before moving into embodiment design.
The disadvantage of waiting until the conceptual design is completed to address materials and manufacturing processes is that the designer cannot search for conceptual solutions when dealing with issues relating to the materials and manufacturing processes domains. By not considering these issues early on in the design process, the scope for innovation is reduced and this results in the designer being fixated on the configuration at hand. It is well recognized that this is not the best way to address a design challenge and an even worse approach to innovation.
The basic framework for which enhancements and improvements are suggested is the design methodology practiced and taught by the members of the Institute for Innovation and Design in Engineering (IIDE) at Texas A&M University. Conceptual design is very much a part of the IIDE design process; but the current format concentrates on functional parameters and how to search for conceptual solutions for these, and does not highlight materials and manufacturing issues in the preliminary design stages where it could be most helpful.
The work documented in this thesis is an attempt to ensure that there is no disconnect between function oriented design and the materials and manufacturing processes that are applicable to that design. The core of the thesis is to incorporate a thought process which will help the designer during conceptual design phase to:
1. Consciously question if there materials and manufacturing issues; 2. Identify critical parameters in both of these domains; and 3. Search for conceptual solutions to these identified critical parameters.
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Shooter, Steven B. "Conceptual manipulator design for limited access workspaces." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-05092009-040612/.
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Loewen, Nathan. "Conceptual design using probabilistic interval constraint satisfaction." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/14853.
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Dealing with uncertainty is one of the primary challenges engineers face in the conceptual design phase of a project. Engineers must make decisions with regards to uncertain design parameters that influence performance and cost. It is well recognized that decisions made in the concept phase of a project have far greater performance and economic impacts than decisions made during the detailed phase, yet most engineering analysis tools have limited capabilities to carry out risk analysis, sensitivity analysis, optimization, and design space mapping.
This thesis proposes a methodology for coupling probabilistic techniques with recent advances in semi-quantitative analysis, specifically the application of interval analysis to numerical constraint satisfaction problems. The result is a method of analysis referred to as Probabilistic Constraint Satisfaction that can be used to analyze problems with probabilistic input and generate a probabilistic design space as an output. The methodology involves subdivision of the design space to a requested resolution and then testing the consistency of the constraint satisfaction problem at each subdivided location. This approach is very robust and is capable of solving a wide range of problems regardless of linearity or the availability of an explicit solution. Probabilistic data is integrated through the use of a solver which determines the valid interval for each of the probabilistic variables at a given point in the design space. The valid intervals are subsequently used to determine the probability of a feasible solution occurring at that point in the design space.
The characteristics and capabilities of this methodology are illustrated through several engineering examples and a case study that involves the conceptual design of a novel radio antenna concept. The selected case study has several features that are common to conceptual design problems for novel and complex projects including design parameters with continuous domains, trade-offs between performance targets and cost, uncertain costing data, and limited existing experience to base the design on.
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Gangadharan, Venkata Krishnan. "Conceptual Design Tool for Aircraft Electrical System." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-96162.
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The conceptual design stage of an aircraft involves many uncertainties with regard to prediction of weight of systems. The current trend is that electrical systems increasingly replace hydraulic and pneumatic systems in an aircraft. This leads to greater uncertainty in weight, size and power requirement prediction. This work is an attempt at developing a sizing tool that will allow users to estimate the power requirements and weight of electrical systems for a given size of an aircraft specified either by passenger capacity or by aircraft operating empty weight or by maximum take-off weight. As with all predictive tools, the results of this work are based on currently available data, i.e., the specification of existing aircraft. This collection of specification of existing aircrafts would constitute the data library. The accuracy of the result of this work depends greatly on the variety of aircrafts and the level of detail for which the data is available. The tool is made in Microsoft Excel with some codes made in VBA to perform Excel calculations.
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Pun, Raymond Chee Wing. "A decision framework for conceptual engineering design." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/18848.
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