@inproceedings{MoehrenBergmannJanseretal.2023, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {On the determination of harmonic propeller loads}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, doi = {10.2514/6.2023-2404}, pages = {12 Seiten}, year = {2023}, abstract = {Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures.}, language = {en} } @inproceedings{Dachwald2005, author = {Dachwald, Bernd}, title = {Global optimization of low-thrust space missions using evolutionary neurocontrol}, series = {Proceedings of the international workshop on global optimization}, booktitle = {Proceedings of the international workshop on global optimization}, pages = {85 -- 90}, year = {2005}, abstract = {Low-thrust space propulsion systems enable flexible high-energy deep space missions, but the design and optimization of the interplanetary transfer trajectory is usually difficult. It involves much experience and expert knowledge because the convergence behavior of traditional local trajectory optimization methods depends strongly on an adequate initial guess. Within this extended abstract, evolutionary neurocontrol, a method that fuses artificial neural networks and evolutionary algorithms, is proposed as a smart global method for low-thrust trajectory optimization. It does not require an initial guess. The implementation of evolutionary neurocontrol is detailed and its performance is shown for an exemplary mission.}, language = {en} } @inproceedings{SchartnerLoebDachwaldetal.2009, author = {Schartner, Karl-Heinz and Loeb, H. W. and Dachwald, Bernd and Ohndorf, Andreas}, title = {Perspectives of electric propulsion for outer planetary and deep space missions}, series = {European Planetary Science Congress 2009}, booktitle = {European Planetary Science Congress 2009}, pages = {416 -- 416}, year = {2009}, abstract = {Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low-thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3].}, language = {en} } @inproceedings{GrundmannBodenCeriottietal.2017, author = {Grundmann, Jan Thimo and Boden, Ralf and Ceriotti, Matteo and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Lange, Caroline and Lichtenheldt, Roy and Pelivan, Ivanka and Peloni, Alessandro and Riemann, Johannes and Spr{\"o}witz, Tom and Tardivel, Simon}, title = {Soil to sail-asteroid landers on near-term sailcraft as an evolution of the GOSSAMER small spacecraft solar sail concept for in-situ characterization}, series = {5th IAA Planetary Defense Conference}, booktitle = {5th IAA Planetary Defense Conference}, pages = {30 Seiten}, year = {2017}, language = {en} } @inproceedings{WolfSchlickHerbstetal.1996, author = {Wolf, Martin R. and Schlick, Christopher and Herbst, D. and Springer, J.}, title = {Einflussfaktoren auf den Erfolg von Telekooperation in großen Unternehmen}, series = {Computer Supported Cooperative Work (CSCW) in großen Unternehmungen : Tagungsband zum Workshop der GI-Fachgruppe 5.5.1 "CSCW in Organisationen" und dem Technologiezentrum Darmstadt der Deutschen Telekom AG vom 09. - 10. Mai 1996}, booktitle = {Computer Supported Cooperative Work (CSCW) in großen Unternehmungen : Tagungsband zum Workshop der GI-Fachgruppe 5.5.1 "CSCW in Organisationen" und dem Technologiezentrum Darmstadt der Deutschen Telekom AG vom 09. - 10. Mai 1996}, editor = {Uellner, Stefan}, publisher = {Dt. Telekom}, address = {Darmstadt}, pages = {1 -- 12}, year = {1996}, language = {de} } @inproceedings{BertschMeineckeWolfetal.2019, author = {Bertsch, Timo and Meinecke, Matthias and Wolf, Martin R. and Schmunk, Karina}, title = {Smart-Living-Services nur gegen Daten? Process-Mining als M{\"o}glichkeit zur Steigerung der Akzeptanz!}, series = {Angewandte Forschung in der Wirtschaftsinformatik 2019 : Tagungsband zur 32. AKWI-Jahrestagung / hrsg. von Martin R. Wolf, Thomas Barton, Frank Herrmann, Vera G. Meister, Christian M{\"u}ller, Christian Seel}, booktitle = {Angewandte Forschung in der Wirtschaftsinformatik 2019 : Tagungsband zur 32. AKWI-Jahrestagung / hrsg. von Martin R. Wolf, Thomas Barton, Frank Herrmann, Vera G. Meister, Christian M{\"u}ller, Christian Seel}, publisher = {mana-Buch}, address = {Heide}, isbn = {978-3-944330-62-4}, pages = {216 -- 226}, year = {2019}, abstract = {Seit Jahren etablieren sich Technologien in unserem Alltag, die mit Hilfe von smarten Komponenten neue Services und Vernetzungsm{\"o}glichkeiten schaffen. Dieses Paper beschreibt die Ergebnisse einer Studie, die die Akzeptanz von IoT-gest{\"u}tzten, smarten Services im privaten Umfeld untersucht. Dabei wird eine zentrale Datenverarbeitung mit automatisierter Erstellung smarter Services der dezentralen Datenverarbeitung mit manueller Serviceerstellung in sieben Kategorien gegen{\"u}bergestellt. Die Auswertung der Studie legt die Forschungsfrage nahe, ob das Nutzerverhalten im Kontext Smart Living nicht auch mit einem dezentralen L{\"o}sungsansatz, und somit unabh{\"a}ngig von großen Unternehmen, analysiert werden kann. Hierf{\"u}r wird im zweiten Teil des Papers die Anwendbarkeit von Process-Mining im Bereich Smart Living untersucht und prototypisch getestet.}, language = {de} } @inproceedings{Dachwald2004, author = {Dachwald, Bernd}, title = {Solar sail performance requirements for missions to the outer solar system and beyond}, series = {55th International Astronautical Congress 2004}, booktitle = {55th International Astronautical Congress 2004}, doi = {10.2514/6.IAC-04-S.P.11}, pages = {1 -- 9}, year = {2004}, abstract = {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.}, language = {en} } @inproceedings{DigelTemizArtmannArtmannetal.2003, author = {Digel, Ilya and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard and Nojima, H.}, title = {Plasma cluster ions (PCI) influence on microbial cells viability : [abstract]}, year = {2003}, abstract = {Recently, SHARP corporation has developed the world's first "Plasma Cluster Ions (PCI)" air purification technology, which uses plasma discharge to generate cluster ions. The new plasma cluster device releases into the air positive and negative ions, which are harmless to humans and are able to decompose and deactivate airborne substances by chemical reactions. A lot of phenomenological tests of the PCI air purification technology on microbial cells have been conducted. And, in most cases, it has been shown that PCI demonstrate strongly pronounced killing effect. Although, the particular mechanisms of PCI action are still not evident. We studied variations in resistance to PCI among gram-positive airborne microorganisms, as well as some dose-dependent, spatial, cultural and biochemical properties of PCI action in respect of Staphylococcus spp, Enterococcus spp, Micrococcus spp.}, subject = {Clusterion}, language = {en} } @inproceedings{Bung2010, author = {Bung, Daniel Bernhard}, title = {A comparative study of self-aerated stepped spillway and smooth invert chute flow: the effect of step-induced macro roughness}, series = {5th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering : CG JOINT 2010}, booktitle = {5th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering : CG JOINT 2010}, publisher = {Univ. Press}, address = {Tianjin}, organization = {Chinese-German Joint Symposium on Hydraulic and Ocean Engineering <5, 2010, Tianjin>}, isbn = {978-7-5618-3671-2}, pages = {451 -- 456}, year = {2010}, language = {en} } @inproceedings{TomićPennaDeJongetal.2020, author = {Tomić, Igor and Penna, Andrea and DeJong, Matthew and Butenweg, Christoph and Correia, Ant{\´o}nio A. and Candeias, Paulo X. and Senaldi, Ilaria and Guerrini, Gabriele and Malomo, Daniele and Beyer, Katrin}, title = {Seismic testing of adjacent interacting masonry structures}, series = {12th International Conference on Structural Analysis of Historical Constructions (SAHC 2020)}, booktitle = {12th International Conference on Structural Analysis of Historical Constructions (SAHC 2020)}, doi = {10.23967/sahc.2021.234}, pages = {1 -- 12}, year = {2020}, abstract = {In many historical centres in Europe, stone masonry buildings are part of building aggregates, which developed when the layout of the city or village was densified. In these aggregates, adjacent buildings share structural walls to support floors and roofs. Meanwhile, the masonry walls of the fa{\c{c}}ades of adjacent buildings are often connected by dry joints since adjacent buildings were constructed at different times. Observations after for example the recent Central Italy earthquakes showed that the dry joints between the building units were often the first elements to be damaged. As a result, the joints opened up leading to pounding between the building units and a complicated interaction at floor and roof beam supports. The analysis of such building aggregates is very challenging and modelling guidelines do not exist. Advances in the development of analysis methods have been impeded by the lack of experimental data on the seismic response of such aggregates. The objective of the project AIMS (Seismic Testing of Adjacent Interacting Masonry Structures), included in the H2020 project SERA, is to provide such experimental data by testing an aggregate of two buildings under two horizontal components of dynamic excitation. The test unit is built at half-scale, with a two-storey building and a one-storey building. The buildings share one common wall while the fa{\c{c}}ade walls are connected by dry joints. The floors are at different heights leading to a complex dynamic response of this smallest possible building aggregate. The shake table test is conducted at the LNEC seismic testing facility. The testing sequence comprises four levels of shaking: 25\%, 50\%, 75\% and 100\% of nominal shaking table capacity. Extensive instrumentation, including accelerometers, displacement transducers and optical measurement systems, provides detailed information on the building aggregate response. Special attention is paid to the interface opening, the globa}, language = {en} }