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Item Open Access Conceptual design synthesis and optimization for new generations of combat aircraft(1996-03) Siegers, F.A numerical design synthesis methodology for new generations of combat aircraft has been developed. It incorporates advanced technology in the form of design for low observables. Aircraft capable of being modelled with this methodology will have internal or external weapons carriage, side mounted intakes, a straight-tapered trapezoidal wing, aft-mounted tail with the option of single or twin fins, and one or two engines with rectangular or axisymmetric nozzles. The design methodology incorporates sufficiently accurate and realistic algorithms for the calculation of the geometry and the estimation of the aerodynamic, mass and the performance properties of the aircraft. The inherent flexibility of the design requirements. A numerical optimization routine was linked to the synthesis, allowing the determination of optimum aircraft design variables for a given set of mission and performance requirements. Results were obtained showing the usefulness of this design tool for setting up parametric trend studies. The numerical accuracy, flexibility of configuration options and high level of advanced aircraft technology of this synthesis make a significant contribution to the continuing development of automated design tools.Item Open Access Design Synthesis for Swept-Wing Combat Aircraft Incorporating Stealth Technology(1994-10) Siegers, F.The College of Aeronautics has been involved in several research contracts funded by the Defence Research Agency of the United Kingdom to investigate the design synthesis and optimization of Military aircraft. This report presents the results of the latest such investigation into the enhancement of a swept-wing combat aircraft design synthesis to incorporate stealth technology. In the light of the current changes in the method of procurement of airborne weapons systems it has become necessary to develop combat aircraft which are effective against a wide range of threats whilst meeting the requirements of both navy and air force. One way of doing this is to incorporate into combat aircraft those features which make it stealthy, in other words reducing their detectability by means of radar, infrared, visual and acoustics identification methods. Although the full benefits of stealthy aircraft may only become apparent when such systems are deployed within appropriate strategic and tactical environment, it is important to define the features inherent to the aircraft at the conceptual design stage. This report briefly describes those features of stealthy aircraft incorporated into the design synthesis, leading to the definition of a baseline aircraft, followed by a full description of the design synthesis methodology. Finally, the development of the design synthesis computer code is outlined, rounded off by plans for future work.Item Open Access Intellectual Property Business Models - A Study of Xaar plc, 2000 to 2009(2010-12-02) Hartwell, Ian P.A 1999 report by investment bank CSFB considered five early-stage companies operating an intellectual property (IP) licensing business model and proposed certain success factors for such companies. The performance of one of the five companies, Xaar plc, has been studied for the ten years since the CSFB report was written, revealing that only some of the factors actually made a positive contribution to Xaar’s success. The role of IP in Xaar’s income has also been considered, together with the various non-IP factors acknowledged by Xaar as contributing to its success. The results are relevant to today’s early-stage engineering companies looking to use IP to best effect.Item Open Access Report of the project design of the Cranfield A-90 short haul 500-seat airliner project(1991-07) Fielding, J. P.This report describes the conceptual and detail design of the A-90 Short-haul 500 seat airliner project. It started with a market investigation which then lead to the specification of the aircraft. The author performed a conceptual design process, to derive the configuration - a twin-engine jet transport with a swept wing, shoulder mounted to a large double-bubble fuselage. Aerodynamic, mass and geometric work was then performed prior to the start of the main design programme in October 1990. The main programme involved 23 MSc students and 5 members of staff and lasted for 8 months. Each student was given responsibility for the detail design of a major component such as outer wing, fuel system, etc. This work is described together with the final design that emerged. This description is aided by the reproduction of numerous engineering drawings. The work was complemented by extra studies, performed by 15 Flight Dynamics students. The report then discusses the final configuration of the A-90. The project showed the potential of meeting mass, cost and airport requirements. It should exceed the range requirements and carry 620 passengers for 1700 n miles, 500 for 2260 n miles or 345 for 3500 n miles. The design showed considerable flexibility and could be relatively easily developed to carry some 1000 passengers. Investigations were performed of several applications of new technology, including variable camber flaps, fibre optic flight controls, "all electric" systems and modern materials. They all looked feasible, and should be investigated further. The main concern was the provision of bleed air and secondary power following the loss of one engine, on such a large aircraft. Careful system design overcame this problem. The A-90 project proved again the validity of Cranfield's group design project as a powerful means of educating design students.