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- Amadori, Kristian, et al.
(author)
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A Framework for Aerodynamic and Structural Optimization in Conceptual Design
- 2007
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In: 25th AIAA Applied Aerodynamics Conference, 25-28 June, Miami, FL, USA. - : AIAA. ; , s. 4061-
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Conference paper (other academic/artistic)abstract
- Aircraft design is an inherently multidisciplinary activity that requires different models and tools for various aspects of the design. At Linköping University a novel design framework is being developed to support the initial conceptual design phase of a new aircraft. In this work main attention has been paid to wing design, with respect to aerodynamic efficiency and loads, and to structural analysis. By linking together various modules via a user-friendly interface based on a spreadsheet, the framework allows multidisciplinary analysis and optimizations to be carried out. This paper will present the framework, give an overview of its development status and give an indication on the future work.
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| 2. |
- Amadori, Kristian, 1976-, et al.
(author)
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Aircraft Conceptual Design Optimization
- 2008
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In: International Congress of the Aeronautical Sciences ICAS,2008. - Stockholm, Sweden : ICAS.
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Conference paper (peer-reviewed)abstract
- Aircraft design is an inherently multidisciplinary activity that requires different models and tools for various aspects of the design. At Linköping University a novel design framework is being developed to support the initial conceptual design phase of new aircraft. By linking together various modules via a userfriendly spreadsheet interface, the framework allows multidisciplinary analysis and optimizations to be carried out. The geometrical model created with a high-end CAD system, contains all the available information on the product and thus it plays a central role in the framework. In this work great attention has been paid to techniques that allow creating robust yet highly flexible CAD models. Two different case studies are presented. The first one is a hypothetic wing-box design that is studied with respect to aerodynamic efficiency and loads, and to structural analysis. In this study two approaches were compared. In one case the wing-box design was optimized with a fixed number of structural elements, where only dimensions and position were allowed to change. Then the same wing-box was analyzed allowing also the number of structural elements to vary. Thus only the parts that are required are left and a more efficient design can be obtained. In the second case study a mission simulation is performed on a UAV-type aircraft. Required data for the simulation are gathered from the CAD model and from aerodynamic analysis carried out with PANAIR, a high order panel code. The obtained data are then used as inputs parameters for flight simulation in order to determined hydraulic systems characteristics.
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| 3. |
- Amadori, Kristian, 1976-
(author)
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On Aircraft Conceptual Design : A Framework for Knowledge Based Engineering and Design Optimization
- 2008
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Licentiate thesis (other academic/artistic)abstract
- This thesis presents a design framework where analytical tools are linked together and operated from an efficient system level interface. The application field is aircraft conceptual design. Particular attention has been paid to CAD system integration and design optimization.Aircraft design is an inherently multidisciplinary process. The goal is to search for the design that, in the best of possible ways, fulfills the requirements. It is therefore desirable to be able to effectively investigate and analyze solutions from a variety of points of view, weighting together the results and gathering a general figure of merit. At the same time, increasing competition on a global market forces to shorten the design process and to reduce costs. Thus a system that allows a tight and efficient integration of different disciplines and improving data flow and storage plays a key role.Integrating a CAD system to the framework is of central relevance. The geometrical model includes most of the information; specific data, required to carry out particular analysis, can be extracted from it. This is possible adopting parametric associative models that are controlled from a spreadsheet user interface. Strategies for building CAD models with a very high degree of flexibility are presented. Not only the external shape can be changed, but also the internal structure can be completely modified. Structural elements can be added or removed, and their position and shaping changed.In this work the design of an Unmanned Aerial Vehicle is used as test case for comparing three different optimization algorithms. The presented framework is also used for automatically design Micro Aerial Vehicles, starting from a short list of requirements and ending with a physical prototype produced by a rapid prototyping machine.
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| 4. |
- Amadori, Kristian, et al.
(author)
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Use of Panel Code Modeling in a Framework for Aircraft Concept Optimization
- 2006
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In: 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, 6-8 September, Portsmouth, Virginia, USA. ; , s. 7084-
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Conference paper (other academic/artistic)abstract
- In this study the use of a high-order panel code within a framework for aircraft concept design is discussed. The framework is intended to be a multidisciplinary optimization tool to be adopted from the very beginning of the conceptual design phase in order to define and refine the aircraft design, with respect to its aerodynamic, stability and control, structure and basic aircraft systems. The presented work is aimed at developing a module for aerodynamic analysis of concepts as a basis for a direct search optimization of the concept layout. The design criterion, used in the example presented here, is to minimize the maximum take-off weight required to fulfil the mission. Classic and simple equations are used together with the data generated by the panel code solver to calculate the aircraft’s performances. Weights are calculated by means of statistical group weight equations, but the weight could also be calculated from a CAD-model. The design of an Unmanned Combat Air Vehicle is used as test case for three different optimization algorithms: one gradient method based (Fmincon), one non-gradient based (Complex) and one Genetic Algorithm (GA). Comparison of results and performances shows that the Genetic Algorithm is best fitted for the specific problem, having the by far best hit rate, even if it is at a cost of longer computing time. The Complex algorithm requires less iterations and is also able to find the optimum solution, but with a worse hit rate, while Fmincon can not reach to a global optimum. The suggested optimized configuration for the aircraft is very similar to the Boeing X-45C and Northrop Grumman X-47B.
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| 5. |
- Amadori, Kristian, 1976-, et al.
(author)
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Using CAD-Tools and Aerodynamic Codes in a Distributed Conceptual Design Framework
- 2007
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In: Aerospace Sciences Meeting and Exhibit,2007. - USA : AIAA.
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Conference paper (peer-reviewed)abstract
- Aircraft design is an inherently multi-disciplinary activity that requires different models and tools for various aspects of the design. At Linköping University a novel design framework is being developed to support the initial conceptual design phase of a new aircraft. Different modules are included, each one addressed to analyze and evaluate different aspects of the airplane, such as its aerodynamics, its weight and structure, its sub systems and its performances. All modules are easily accessible from a user-friendly interface based on an Excel spreadsheet. The link between all modules is based on Service Oriented Architecture (SOA) and allows both distribution and integration of all functions. This paper will present the framework, give an overview of its development status and give an indication on the future work.
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| 6. |
- Andersson, Henric, 1963-
(author)
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Aircraft Systems Modeling : Model Based Systems Engineering in Avionics Design and Aircraft Simulation
- 2009
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Licentiate thesis (other academic/artistic)abstract
- Aircraft developers like other development and manufacturing companies, are experiencing increasing complexity in their products and growing competition in the global market. One way to confront the challenges is to make the development process more efficient and to shorten time to market for new products/variants by using design and development methods based on models. Model Based Systems Engineering (MBSE) is introduced to, in a structured way, support engineers with aids and rules in order to engineer systems in a new way.In this thesis, model based strategies for aircraft and avionics development are studied. A background to avionics architectures and in particular Integrated Modular Avionics is described. The integrating discipline Systems Engineering, MBSE and applicable standards are also described. A survey on available and emerging modeling techniques and tools, such as Hosted Simulation, is presented and Modeling Domains are defined in order to analyze the engineering environment with all its vital parts to support an MBSE approach.Time and money may be saved by using modeling techniques that enable understanding of the engineering problem, state-of-the-art analysis and team communication, with preserved or increased quality and sense of control. Dynamic simulation is an activity increasingly used in aerospace, for several reasons; to prove the product concept, to validate stated requirements, and to verify the final implementation. Simulation is also used for end-user training, with specialized training simulators, but with the same underlying models. As models grow in complexity, and the set of simulation platforms is expanded, new needs for specification, model building and configuration support arise, which requires a modeling framework to be efficient.
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| 10. |
- Gavel, Hampus, 1964-
(author)
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On aircraft fuel systems : conceptual design and modeling
- 2007
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Doctoral thesis (other academic/artistic)abstract
- The largest and most important fluid system in an aircraft is the fuel system. Obviously, future aircraft projects involve the design of fuel system to some degree. In this project design methodologies for aircraft fuel systems are studied, with the aim to shortening the system development time.This is done by means of illustrative examples of how optimization and the use of matrix methods, such as the morphological matrix, house of quality and the design structure matrix, have been developed and implemented at Saab Aerospace in the conceptual design of aircraft fuel systems. The methods introduce automation early in the development process and increase understanding of how top requirements regarding the aircraft level impact low-level engineering parameters such as pipe diameter, pump size, etc. The morphological matrix and the house of quality matrix are quantified, which opens up for use of design optimization and probabilistic design.The thesis also discusses a systematic approach when building a large simulation model of a fluid system where the objective is to minimize the development time by applying a strategy that enables parallel development and collaborative engineering, and also by building the model to the correct level of detail. By correct level of detail is meant the level that yields a simulation outcome that meets the stakeholders’ expectations. The experienced gained at Saab in building a simulation model, mainly from the Gripen fuel system, but also the accumulated experience from other system models, is condensed and fitted into an overall process.
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