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- Karosseriebau (6)
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Analyse der Temperatur- und Strömungsungleichförmigkeiten in mehrstufigen Turbinen / Harald Funke
(2001)
1) Module werden die Fahrzeugplattform und den –aufbau in Zukunft weiterhin und in zunehmendem Maße bestimmen. 2) Neue Module und Modulschnittstellen am Fahrzeug werden überdacht und können in der Zukunft erwartet werden. 3) Die Wertschöpfung und der Entwicklungsumfang wird sich vom OEM zum Modullieferanten verlagern. 4) Modulvergaben werden in der Zukunft noch stärker auf Innovation und Kostenreduktion beruhen. 5) Modularisierung des Fahrzeuges heißt ein Aufbrechen der Fahrzeugkarosserie und wird daher von der Beherrschung struktureller Aufgaben sowie der Lösung der (sichtbaren) Modulübergänge bestimmt sein. 6) Neben den Systemintegratoren und den Komponentenspezialisten besetzen die Modullieferanten die erste Lieferantenriege. 7) Der Modullieferant wird neben höchster Fertigungsexpertise ein hohes Maß an (Teil-)fahrzeug-Know-How und Produktentwickler-mentalität bereitstellen.
Sterne und Weltraum
(2002)
Kosmologie
(2002)
Optimization of Interplanetary Rendezvous Trajectories for Solar Sailcraft Using a Neurocontroller
(2002)
Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation.
However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions.
Entrauchung über Seitenwände
(2003)
Solar sails are propelled in space by reflecting solar photons off large mirroring surfaces, thereby transforming the momentum of the photons into a propulsive force. This innovative concept for low-thrust space propulsion works without any propellant and thus provides a wide range of opportunities for highenergy low-cost missions. Offering an efficient way of propulsion, solar sailcraft could close a gap in transportation options for highly demanding exploration missions within our solar system and even beyond. On December 17th, 1999, a significant step was made towards the realization of this technology: a lightweight solar sail structure with an area of 20 m × 20 m was successfully deployed on ground in a large facility at the German Aerospace Center (DLR) at Cologne. The deployment from a package of 60 cm × 60 cm × 65 cm with a total mass of less than 35 kg was achieved using four extremely light-weight carbon fiber reinforced plastics (CFRP) booms with a specific mass of 100 g/m. The paper briefly reviews the basic principles of solar sails as well as the technical concept and its realization in the ground demonstration experiment, performed in close cooperation between DLR and ESA. Next possible steps are outlined. They could comprise the in-orbit demonstration of the sail deployment on the upper stage of a low-cost rocket and the verification of the propulsion concept by an autonomous and free flying solar sail in the frame of a scientific mission. It is expected that the present design could be extended to sail sizes of about (40 m)2 up to even (70 m)2 without significant mass penalty. With these areas, the maximum achievable thrust at 1 AU would range between 10 and 40 mN – comparable to some electric thrusters. Such prototype sails with a mass between 50 and 150 kg plus a micro-spacecraft of 50 to 250 kg would have a maximum acceleration in the order of 0.1 mm/s2 at 1 AU, corresponding to a maximum ∆V-capability of about 3 km/s per year. Two near/medium-term mission examples to a near-Earth asteroid (NEA) will be discussed: a rendezvous mission
and a sample return mission.
Solar sailcraft of the first generation technology development / Seboldt, Wolfgang ; Dachwald, Bernd
(2003)
1) In Karosseriestrukturen steht der richtige Werkstoffeinsatz stärker den je im Spannungsfeld von Leichtbau, Kosten (Stückzahlen) und Leistungsanforderung 2) In „klassischen“ Strukturen von Modulträgern und Klappen hat sich die Materialmischbauweise verstärkt in den letzten Jahren durchgesetzt 3) Unter Aspekten des konzeptionellen Leichtbaus erscheint der verstärkte Einsatz von Leichtbauwerkstoffen im Vorderwagen sowie in der Dachstruktur zielführend 4) Offene Strukturprofile in Materialmischbauweise liefern für eine Vielzahl von Anwendungen ein interessantes und bis dato kaum genutztes Potential 5) Neue Entwicklungen bei den Fügetechnologien (i.b. kontinuierliche Fügeverbindungen und kombinierte Verfahren) unterstützen den wirtschaftlichen Karosserieleichtbau 6) Werkstoffinnovationen sowie neuartige Fertigungsverfahren machen den Konstruktionswerkstoff „Stahl“ auch in der Zukunft im Karosseriebau weiterhin sehr attraktiv
The entangled Universe
(2004)
This paper examines the positive and negative aspects of a range of interpretations of nearest-neighbours models. Measures-oriented and distributionoriented verification methods are applied to categorial, probabilistic and descriptive interpretations of nearest neighbours used operationally in avalanche forecasting in Scotland and Switzerland. The dependence of skill and accuracy measures on base rate is illustrated. The purpose of the forecast and the definition of events are important variables in determining the quality of the forecast. A discussion of the application of different interpretations in operational avalanche forecasting is presented.
Dynamics of Granular Material Avalanches and Numerical Approximations of Savage-Hutter Models
(2004)
Solar sails enable missions to the outer solar system and beyond, although the solar
radiation pressure decreases with the square of solar distance. For such missions, the solar sail may gain a large amount of energy by first making one or more close approaches to the sun. Within this paper, optimal trajectories for solar sail missions to the outer planets and into near interstellar space (200 AU) are presented. Thereby, it is shown that even near/medium-term solar sails with relatively moderate performance allow reasonable transfer times to the boundaries of the solar system.
Recently, in his vision for space exploration, US president Bush announced to extend human presence across the solar system, starting with a human return to the Moon as early as 2015 in preparation for human exploration of Mars and other destinations. In Europe, an exploration program, termed AURORA, was established by ESA in 2001 – funded on a voluntary basis by ESA member states – with a clear focus on Mars and the ultimate goal of landing humans on Mars around 2030 in international cooperation. In 2003, a Human Spaceflight Vision Group was appointed by ESA with the task to develop a vision for the role of human spaceflight during the next quarter of the century. The resulting vision focused on a European-led lunar exploration initiative as part of a multi-decade, international effort to strengthen European identity and economy. After a review of the situation in Europe concerning space exploration, the paper outlines an approach for a consistent positioning of exploration within the existing European space programs, identifies destinations, and develops corresponding scenarios for an integrated strategy, starting with robotic missions to the Moon, Mars, and near-Earth asteroids. The interests of the European planetary in-situ science community, which recently met at DLR Cologne, are considered. Potential robotic lunar missions comprise polar landings to search for frozen volatiles and a sample return. For Mars, the implementation of a modest robotic landing mission in 2009 to demonstrate the capability for landing and prepare more ambitious and complex missions is discussed. For near-Earth asteroid exploration, a low-cost in-situ technology demonstration mission could yield important results. All proposed scenarios offer excellent science and could therefore create synergies between ESA’s mandatory and optional programs in the area of planetary science and exploration. The paper intents to stimulate the European discussion on space exploration and reflects the personal view of the authors.
Technische Thermodynamik
(2005)
Das Drallrohr
(2005)