One of the most promising powered-lift concepts is Upper Surface Blowing (USB), where the engines are placed above the wing and the engine exhaust jet becomes attached to the upper surface. The jet thrust can then be vectored by use of the trailing edge curvature since the jet flow tends to remain attached by the "Coanda Effect". Wind tunnel and flight-testing have shown USB aircraft to be capable of producing maximum lift coefficients near 10. They have the additional benefit of shielding the engine noise above the wing and away from the ground. Given the potential gains from USB aircraft, one would expect that conceptual design methods exist for their development. This is not the case however. While relatively complex solutions are available, there is currently no adequate low-fidelity methodology for the conceptual and preliminary design of USB or USB/distributed propulsion aircraft. The focus of the current work is to provide such a methodology for conceptual design of USB aircraft. Based on limited experimental data, the new methodology is shown to compare well with wind tunnel data. In this thesis we have described the new approach, correlated it with available 2-D data, and presented comparisons of our predictions with published USB data and an existing non-linear vortex lattice method. The current approach has been shown to produce good results over a broad range of propulsion system parameters, wing geometries, and flap deflections. In addition, the semi-analytical nature of the methodology will lend itself well to aircraft design programs/optimizers such as ACSYNT. These factors make the current method a useful tool for the design of USB and USB/distributed propulsion aircraft. / Master of Science

no / This paper presents an overview of existing function-based conceptual design expert (CDE) systems with a view to identifying their scope in the contexts of functional modeling knowledge representation and conceptual design process. A number of heterogeneous function-based CDE systems are identified and listed. A key comprehensive benchmarking framework is developed in this paper that helps in identifying the trend, gaps and scope of current function-based CDE systems. Accordingly, the gaps in the aforementioned contexts are discussed which are to date have not been summarized and highlighted for a well-balanced system development for a product conceptual design.

The comparison of aerodynamic characteristics for a combat aircraft studywas addressed in this work. The thesis is a feasibility study which reviewsthe workload and output quality efficiency of different numerical and experimentalmethods often used during conceptual aircraft design.For this reason the Vortex Lattice Method (VLM), Euler or Reynolds-Averaged-Navier-Stokes (RANS) simulations were compared to the moreheavier Large Eddy Simulation (LES) which also has the capability to capturealso more complex flow physics, such as those that occur, for example,at high angles of attack. To be able to crosscheck the numerical results,the same static alpha sweep tests were executed in a tunnel. Thereby itwas discovered that it was quite challenging to reach the same values in thewater tunnel as those previously calculated in computational fluid dynamics(CFD) due to different technical issues.However it could be shown that LES simulations can be today a suitabletool for conceptual aircraft design, as they offer much higher levels ofaccuracy and give the designer the possibility to check the new study at anearly stage along the border of the aircraft’s flight envelope.

The mass production of aircrafts has been mainly led by the objective of both maximizing technological performances and minimizing the manufacturing costs. Within also the constraints of safety and security rules defined by certification organisms, the traditional innovation management has consisted above all in implementing a "technology-push" approach. New developed aircrafts have been then mostly driven by Research and Technology projects outputs. Nevertheless, current market competitiveness and complexity lead to change this approach. The needs of aeronautical customers evolve, change and become diversified, which raise multiple specific profiles to be taken into account as early as possible in today's development programs. In order to ensure high value and differentiation perception by all the stakeholders, the innovation policy has to shift from mass production to mass customization, and to integrate both "market-read" and 'technology-push" approaches in the preliminary phase of innovation. The goal of this PhD thesis is to provide the aircraft program managers with a methodological support, named Concept-to-Value, to steer by value the so called Fuzzy Front End of Innovation stage in the literature. At the bridge between the Product Planning and Conceptual Design research works, our contribution improves the existing methodologies on the Business and Engineering domains integration. Concept-to-Value brings a more agile and integrated collaboration of multidisciplinary players: a common language and value model represent their innovation Knowledge, Problems and Solutions. Finally, a convergence process is also defined to conduct the preliminary phase and to deliver high value aircraft concepts.

PhD / In design literature, how designers think and how they design have been identified as a reflection of how they interact with their sketches. Sketching in architectural design is still a central concern which shapes our understanding of the design process and the development of new tools. Sketching not only serves as a visual aid to store and retrieve conceptualisations, but as a medium to facilitate more ideas, and to revise and refine these ideas. This thesis examined how mental imagery and sketching is used in designing by conducting a protocol analysis study with six expert architects. Each architect was required to think aloud and design under two different conditions: one in which s/he had access to sketching and one in which s/he was blindfolded (s/he did not have access to sketching). At the end of the blindfold condition the architects were required to quickly sketch what they held in their minds. The architects were able to come up with satisfying design solutions and some reported that using their imagery could be another way of designing. The resulting sketches were assessed by judges and were found to have no significant differences in overall quality. Expert architects were able to construct and maintain the design of a building without having access to sketching. The analysis of the blindfold and sketching design protocols did not demonstrate any differences in the quantity of cognitive actions in perceptual, conceptual, functional and evaluative categories. Each architect’s cognitive structure and designing behaviour in the blindfold activity mimicked her/his cognitive structure and designing behaviour in the sketching activity. The analysis of links between the design ideas demonstrated that architects’ performance in idea development was higher under the blindfold condition, compared to their sketching condition. It was also found that architects’ blindfold design performance was improved when they were more familiar with the site layout. These results imply that expert designers may not need sketching as a medium for their reflective conversation with the situation. This study indicates that constructing internal representations can be a strong tool for designing. Future studies may show that designers may not need sketching for the generation of certain designs during the early phases of conceptual designing.

This thesis covers some aspects of current aircraft design, and presents how experiment and simulation are used as tools. Together they give enhanced effects over employing either one separately. The work presented has been produced using both simulations and experiments. An overview of aircraft design tools is presented, together with a description of their application in research. Participation in two major design projects, HELIX and the Rescue wing, gave an opportunity to combine traditional experimental and computational tools. They also serve as a platform for developing two new tools, the vortex lattice program Tornado and the DoTrack camera based wind tunnel measurement system. The HELIX project aimed at exploring new, unconventional high-lift systems, such as blown flaps, flaperons and active vortex generators. The concepts were investigated with an array of conceptual design tools, ranging from handbook methods to high Reynold’s number wind tunnels. The research was done in several stages. After each stage the concepts failing to reach specifications were discontinued. The active vortex generator concept is followed in detail from the first phase in the HELIX project, and was finally evaluated by full computational fluid dynamics (CFD) and wind tunnel testing. The lessons learned in HELIX were applied to the Rescue wing project, where a kite balloon system for emergency localization was developed. The project is truly multidisciplinary, and both experiment and simulation had to be used in close conjunction. Lack of appropriate methods for measurement and analysis of this kind of device meant that new methods had to be developed. Recent experience of academia working closely together with industry has shown substantial benefits to all parties involved. The synergy of computer modeling and simulation with experiment plays an important role in the common collaborative modus operandi of academia and industry. In particular, the later stages of aeronautic educational programmes should actively pursue such collaboration. / QC 20100910

The design of manufacturing systems in hazardous environments is complex, requiring interdisciplinary knowledge to determine which components and operators (human or robotic) are feasible. When conceptualizing designs, some options may be overlooked or unknowingly infeasible due to the design engineers' lack of knowledge in a particular field or ineffective communication of requirements between disciplines. To alleviate many of these design issues, we develop a computational design tool to automate the synthesis of conceptual manufacturing system designs and optimization of preliminary layouts. To generate workcell concepts for manufacturing processes, we create a knowledge-based system (KBS) that performs functional modeling using a common language, a generic component database, and a rule set. The KBS produces high-level task plans for specific manufacturing processes and allocates needed material handling tasks between compatible human and/or robotic labor. We develop an extended pattern search (EPS) algorithm to optimize system layouts based on worker dose and cycle time minimization using the functions and sequencing of generated task plans. The KBS and EPS algorithm were applied to the design of glovebox processing systems at Los Alamos National Laboratory (LANL). Our computational design tool successfully generates design concepts with varied task allocation and processing sub-tasks and layouts with favorable manipulation workspaces. This work establishes a framework for automated conceptual design while providing designers with a beneficial tool for designing manufacturing systems in an interdisciplinary and highly constrained domain. / text

The research was conducted in the light of a training programme which will train a total of 150 engineers of AVIC I in Cranfield University during a period of 3 years. Cost has become an essential driver to aircraft design, as well as performances due to either the limited defence budget or competitive airline market. Consequently, knowing the possible cost prior to making actual expenditure will help managers to make proper decisions and allocate resources efficiently, and designers to optimize their work. Existing aircraft cost estimating models are outdated and mainly based on a database including both military and civil aircraft with various missions. This research concentrated on commercial jet aircraft and was to develop a suitable acquisition cost estimating methodology for conceptual design from a commercial aircraft manufacturer’s perspective. The literature reviewing took a comprehensive overview of some widely-applied cost estimating methods: Analogy, Parametric, Bottom-up, Feature-based costing, Activitybased costing (ABC), Expert judgement, and etc. Some practical cost models were also reviewed to learn the application of cost estimating in the aerospace industry. Then, analogy and parametric approaches were selected to perform the methodology development considering the limited data available at the conceptual design phase. An investigation was deployed to identify the actual problems in practice. The results helped to recognize the needs of industry. Also, the preparation works for development are presented to understand the environment. With subjective judgement and statistical techniques, a series of cost estimating relationships (CERs) were achieved, in which some historic explanatory parameters remained or were eliminated, and some new ones introduced. Size of aircraft became another variable besides weight. As to engines, all developed explanatory variables have been revealed in prior researches. The validation of CERs proves that they can provide reliable cost estimates with high accuracy and can be applied to conceptual design. In addition, a case study was conducted using a baseline aircraft defined in the group design project (GDP) and presents cost forecasting for the proposed aircraft. At last, discussion and conclusion presents an overview of the research. A framework for cost estimating system can be educed. Also, the future work is proposed for in-depth research.

Industries want to add value to their offerings but to do this, rather than just accepting customer requirements, they now need to know how their products and/or services have been embedded within their customer’s process to achieve a goal that the customer has; any gaps within the process then present an opportunity for the provider to fill these gaps. The System-In-Use (SIU) Methodology presented in this thesis facilitates customer issues in “pulling” the supply chain into creating new solutions as well as the supply chain “pushing” new value propositions into improving customer processes. It does this by drawing on a detailed theory of value and capability which was developed as part of this research. The method has been applied in five industries in processes encompassing high value-assets with very positive outcomes for each of the stakeholders involved: notably, three solutions have been adopted in industry for which a KT-Box award was granted by Cambridge University. Cont/d.

Industries want to add value to their offerings but to do this, rather than just accepting customer requirements, they now need to know how their products and/or services have been embedded within their customer’s process to achieve a goal that the customer has; any gaps within the process then present an opportunity for the provider to fill these gaps. The System-In-Use (SIU) Methodology presented in this thesis facilitates customer issues in “pulling” the supply chain into creating new solutions as well as the supply chain “pushing” new value propositions into improving customer processes. It does this by drawing on a detailed theory of value and capability which was developed as part of this research. The method has been applied in five industries in processes encompassing high value-assets with very positive outcomes for each of the stakeholders involved: notably, three solutions have been adopted in industry for which a KT-Box award was granted by Cambridge University. Cont/d.