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The purpose of this paper is to find optimal reef parameters to minimize the maximum instantaneous opening load for a reefed parachute with geometry and environmental…
The purpose of this paper is to find optimal reef parameters to minimize the maximum instantaneous opening load for a reefed parachute with geometry and environmental parameters given in the model.
The dynamic model Drop Test Vehicle Simulation (DTVSim) is used to model the inflation and descent of the reefed parachute system. It is solved by the fourth-order Runge–Kutta method, and the opening load values are thereby obtained. A parallel genetic algorithm (GA) code is developed to optimize the reefed parachute. A penalty scheme is used to have the maximum dynamic pressure restricted within a certain range.
The simulation results from DTVSim fit well with experimental data from drop tests, showing that the simulator has high accuracy. The one-stage and two-stage reefed parachute systems are optimized by GA and their maximum opening loads are decreased by 43 and 25 per cent, respectively. With the optimal reef parameters, two of the peaks in the opening load curve are almost equal. The velocity, loiter time and flight path angle of the parachute system all change, but these changes have no negative effect on the parachute’s operational performance.
An optimization method for reefed parachute design is proposed for the first time. This methodology can be used in the preliminary design phase for a reefed parachute system and significantly improve design efficiency.
This aircraft, or more exactly this integrated weapons system, is undoubtedly of major importance to both the British aircraft industry and the Royal Air Force. It is beyond question the most exacting project which the British industry has undertaken and as such has demanded adoption of the latest techniques, materials, equipment and management procedures as well as pursuit of research and development programmes on an unprecedented scale. In terms of air power, this system represents a substantial advance on any comparable aircraft or system currently in service and will give the Royal Air Force a strike and reconnaissance capability at high and low level which is possibly unmatched by any other air force in the world. The design philosophy of the TSR‐2 as it applies to an aircraft designed primarily for the high‐speed, low‐level strike/reconnaissance role was described in detail in the December 1963 issue of Aircraft Engineering (Ref. 1) but since that initial appraisal of the TSR‐2 was written some eleven months ago, there has been a gradual release of further information concerning the aircraft, its systems, power plant and equipment. It is the purpose of this article to bring the story up to date in that particular context, although it should be emphasized that the TSR‐2 is still subject to the strictest security embargo and it will be many years before a detailed study of the complete weapons system can be published. It is not intended to cover the same ground as the earlier article (Ref. 1) attempted but, before proceeding to detailed consideration of the systems, a brief overall description of the aircraft is given for the sake of completeness.
OF the various countries involved in the development of guided missiles, the United Kingdom has a unique problem. It is that, apart from the preliminary use of the small…
OF the various countries involved in the development of guided missiles, the United Kingdom has a unique problem. It is that, apart from the preliminary use of the small artillery range at Lark Hill for scaled down missile trials, the major development has taken place over a sea range, at Aberporth. The test vehicles are almost invariably lost and much use has to be made of information transmitted in flight to ground equipment. A huge amount of technical effort has been expended to develop telemetery systems with great success. Even the ability to recover the test vehicle in one piece, a facility which can be readily obtained on a land range, is not a substitute for the collection of information in flight, for the operation of vital equipment has to be checked in actual working conditions and subsequent ground examination does not, necessarily, show if and why a failure has occurred.
Parachute recovery systems are described from a systems perspective. Parachute recovery is particularly suited to tactical fixed wing UAV systems that require a high degree of mobility by allowing air vehicle recovery onto unprepared terrain. The descent environment is described, and the impact of wind on recovery is considered. The relative merits of cruciform, round and parafoil canopies are assessed, taking three real‐world systems as design examples. Throughout, design considerations are approached from a systems perspective, with a view to producing safe, autonomous and accurate recovery systems.
To delay the full opening of a parachute after initial deployment, the skirt is provided with one or more reefing lines 20 formed with looped ends 22 which engage over a rod 16 forming part of a spring loaded time delay mechanism 13 carried on the parachute canopy 10 by a mounting plate 14. The outer end of the rod is guided by a plate 17, spaced from the mechanism 13 to accommodate the loops 13 and the rod is drilled at 18 for a locking pin 19 secured by a lan‐yard 23 to one of the rigging lines 11. When the parachute is launched tensioning by the load of the rigging lines withdraws pin 19, permitting mechanism 13 to retract rod 16 and free lines 20, thus permitting full deployment of the parachute. Two mechanisms 13 may be arranged diametrically opposite on the skirt.
Details of Some Components Used for Subsidiary Services in Aircraft, Missiles and Space Vehicles. The Aircraft Division of Martin Thomas Ltd., Hayes Road, Southall, Middlesex, has introduced an addition to its ‘Hi‐Way’ range of aluminium staging. The unit is the airportable maintenance tower.
Attempts to discover an internal logic in the high‐speed events taking place in the former Soviet Union. In addressing the problems of the country′s disintegration, examines the issue in its socioeconomic, political and territorial‐administrative aspects. Analyses, for this purpose, the nature of Soviet society prior to Gorbachev′s reforms, its present transitional stage and its probable direction in the near future.
Introduces MTV Networks Europe, where the author is Senior Vice‐President of Research and Planning, as Europe’s largest 24‐hour television network and an organisation which is constantly in touch with its vast Europe‐wide audience, including the youth market. Discusses youth culture and the youth market’s characteristics in an age of media explosion and disappearing national frontiers, where everything seems to comment on itself, context is everything, and individuality and authenticity are prized yet true originality is rare. Identifies the freedom that is on offer as essentially materialistic rather than political. Outlines the key influences on young people: the celebrity culture, music and fashion, technology and innovation, and family and friends. Points out that brand loyalty is weaker than in the past, and that branding tends to hide sameness rather than indicate difference. Describes the Collections of Cool research project at MTV, which analyses the youth market, and MTV’s “Switched On” publication covering microtrends in youth culture: this has identified likely hot artists and styles before they actually became successful. Lists some typical youth style trends: trucker caps, parachute pants, velour tracksuits, bling, school ties. Concludes with a look at the importance of music in youth culture and its links with fashion.
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the U.S. National Advisory Committee for Aeronautics, and publications of other similar research bodies as issued