"The conceptual design is the early stage of aircraft design process where results are needed fast, both analytically and visually so that the design can be analyzed and eventually improved in the initial phases. Although there is no necessity for a CAD model from the very beginning of the design process, it can be an added advantage to have the model to get the impression and appearance. Furthermore, this means that a seamless transition into preliminary design is achieved since the CAD model can guardedly be made more detailed. For this purpose, knowledge-based aircraft conceptual design applications Tango (Matlab) and RAPID (CATIA) are being developed at Linköping University. Based on a parametric data definition in XML, this approach allows for a full 3D CAD integration. The one-database approach, also explored by many research organizations, enables the flexible and efficient integration of the different multidisciplinary processes during the whole conceptual design phase. This paper describes the knowledge-based design automated methodology of RAPID, data processing between RAPID and Tango and its application in the courses ‘‘Aircraft conceptual design’’ and ‘‘Aircraft project course’’ at Linköping University. A multifaceted user interface is developed to assist the whole design process."

Landing gear weight calculations can be carried out using statistical or analytical methods. Statistical methods were used in the past and offered quick group weights, however, they are not capable of computing with accuracy the weight of unconventional landing gears which have special geometries and performances. In this work, landing gear weight is computed using analytical methods. The procedure established by Kraus and Wille is acquired as a baseline so as to create a program able to deal with landing gear weight calculations. This software has been designed to be as much flexible as possible, giving the user the freedom to modify many options and parameters.

Contemporary aircraft design and development incurs high costs and consumes a lot of time for research and implementation. To minimize the development cost, an improvement of the conceptual design phase is desirable. A framework to support the initial design space exploration and conceptual design phase is presently being developed at Linköping University. In the aircraft design, the geometry carries a critical, discriminating role since it stores a significant part of the information and the data needed for most investigations. Methodology for design automation of a wing with a detailed description such that the geometry is effectively propagated for further analysis is presented in this paper. Initial weight estimation of the wing is performed by combining the weight penalty method with a sophisticated CAD model. This wing model is used for airfoil shape optimization and later for structural optimization. A methodology for automatic meshing of the geometry for CFD and FEM when the surfaces increase or decrease during the design automation is proposed. The framework combining automation capability with shape and structural optimization will enhance the early design phases of aircraft conceptual design.

The presented work considers designing, building and flight testing a solar poweraircraft as a student project. The goal is to allow student to participate in an aircraft projectfrom design to flight test in order to acquire aircraft design knowledge from theoretical andpractical means. A first theoretical part consists of creating a sizing program for studyingdifferent concepts. Then the gathered knowledge will result in the realization of a flyingdemonstrator. This was realized during a student project over a 5 month period

Conceptual design is the early stage of theaircraft design process where results areneeded faster both analytically and visually sothat the design can be modified or changed atthe earliest stages. Although there is nonecessity for a CAD model from the verybeginning of the design process it can be anadded advantage to have the model, to get theimpression and appearance.Tango and RAPID are knowledge basedaircraft conceptual design applications beingdeveloped in Matlab and CATIA respectively.The user can work in parallel with bothprograms and exchange the data between themvia XML. This paper describes the knowledgebased design automated methodology of RAPIDand its application in the courses “Aircraftconceptual design” and “Aircraft projectcourse” at Linköping University. A multifaceteduser interface is developed to assist in the wholedesign processes.

This paper presents the development of a design framework for the initial conceptual design phase. The focus in this project is on a flexible database in XML format, together with close integration of automated CAD, and other tools, which allows the developed geometry to be used directly in the subsequent preliminary design phase. The database and the geometry are also described and an overview is given of included tools like aerodynamic analysis and weight estimation.

Purpose - The purpose of this paper is to present the latest subscale demonstrator aircraft developed at Linkoping University. It has been built as part of a study initiated by the Swedish Material Board (FMV) on a Generic Future Fighter aircraft. The paper will cover different aspects of the performed work: from paper study realised by SAAB to the first flight of the scaled demonstrator. The intention of the paper is to describe what has been realised and explain how the work is may be used to fit within aircraft conceptual design. Design/methodology/approach - The approach has been to address the challenges proposed by the customer of the demonstrator, how to design, manufacture and operate a scaled demonstrator of an aircraft study in conceptual design within five months. Similar research projects have been reviewed in order to perform the current work. Findings - The results obtained so far have led to new questions. In particular, the project indicated that more research is needed within the area of subscale flight testing for usage in aircraft conceptual design, since a scaled demonstrator is likely to answer some questions but will probably open up new ones. Research limitations/implications - The current research is just in its infancy and does not bring any final conclusion but does, however, offer several guidelines for future works. Since the aircraft study was an early phase concept study, not much data are available for validation or comparison. Therefore, the paper is not presenting new methods or general conclusions. Practical implications - Results from a conceptual aircraft study and a realisation of a scaled prototype are presented, which show that scaled flight testing may be used with some restriction in conceptual design. Originality/value - The value of this paper is to show that universities can be involved in prototype development and can work in close collaboration with industries to address issues and solutions within aircraft conceptual design.

Aircraft Conceptual Design Synthesis means design by fitness-for-purpose. Design engineers can jump off from the point of given parameters and requirements - required performance, payloads and other factors. This is the first book for the aeronautical designer devoted to guiding the reader through this highly effective conceptual design synthesis process. This forms the procedure for the initial stage of the aircraft design process - the interpretation of a requirement into the preliminary layout. A logical design sequence is developed utilizing original modules to represent propulsion, lift, drag, mass, and performance. Aircraft Conceptual Design Synthesis includes a disk of spreadsheets that provides core data. Unlike existing approaches, the design synthesis method can be applied to novel aircraft concepts.CONTENTS INCLUDE* The design process* Aircraft configuration* Flight regime and powerplant considerations* Fuselage layout* Configuration of the wing* Basic lift, drag and mass representations* Performance estimation* Parametric analysis and optimisation* Analysis of concept design  "This is an important landmark book and in my view will become a standard by which others will be compared" - Dr E C P Ransom, Kingston University, UK

The presented work is centered on different concept studies for “greener” sport aircraft. The goal is to show the possibility to manufacture a sport aircraft based on different environmental friendly propulsion systems. A first theoretical part consists of creating a sizing program for studying different concepts. Then the gathered knowledge will result in the realization of two flying down-scaled demonstrators. This study was realized during a student project over a 5 month period.

One branch of the current research in aircraft design at Linköping University is focused on fast concept evaluation in early design stages. This covers multidisciplinary optimization using tools of different level of complexity and low-cost subscale flight testing. In some cases a flight test will provide more answers than several computations ever could. In order to achieve this goal a methodology is required to allow fast creation of subscale flying concepts and to obtain as much reliable information as possible from the tests. The methodology is currently being developed. One important part of it is the scaling methodology and the imposed requirements on manufacturing. The present paper presents the latest subscale demonstrator from Linköping University that has been built as part of the study initiated by the Swedish Material Board on a Generic Future Fighter aircraft.