@article{AyedKustererFunkeetal.2016, author = {Ayed, Anis Haj and Kusterer, Karsten and Funke, Harald and Keinz, Jan}, title = {CFD Based Improvement of the DLN Hydrogen Micromix Combustion Technology at Increased Energy Densities}, series = {American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)}, volume = {26}, journal = {American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)}, number = {3}, publisher = {GSSRR}, issn = {2313-4402}, pages = {290 -- 303}, year = {2016}, abstract = {Combined with the use of renewable energy sources for its production, Hydrogen represents a possible alternative gas turbine fuel within future low emission power generation. Due to the large difference in the physical properties of Hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for Dry Low NOx (DLN) Hydrogen combustion. Thus, the development of DLN combustion technologies is an essential and challenging task for the future of Hydrogen fuelled gas turbines. The DLN Micromix combustion principle for hydrogen fuel has been developed to significantly reduce NOx-emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized diffusion-type flames. The major advantages of this combustion principle are the inherent safety against flash-back and the low NOx-emissions due to a very short residence time of reactants in the flame region of the micro-flames. The Micromix Combustion technology has been already proven experimentally and numerically for pure Hydrogen fuel operation at different energy density levels. The aim of the present study is to analyze the influence of different geometry parameter variations on the flame structure and the NOx emission and to identify the most relevant design parameters, aiming to provide a physical understanding of the Micromix flame sensitivity to the burner design and identify further optimization potential of this innovative combustion technology while increasing its energy density and making it mature enough for real gas turbine application. The study reveals great optimization potential of the Micromix Combustion technology with respect to the DLN characteristics and gives insight into the impact of geometry modifications on flame structure and NOx emission. This allows to further increase the energy density of the Micromix burners and to integrate this technology in industrial gas turbines.}, language = {en} } @article{AyedKustererFunkeetal.2017, author = {Ayed, Anis Haj and Kusterer, Karsten and Funke, Harald and Keinz, Jan and Bohn, D.}, title = {CFD based exploration of the dry-low-NOx hydrogen micromix combustion technology at increased energy densities}, series = {Propulsion and Power Research}, volume = {6}, journal = {Propulsion and Power Research}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {2212-540X}, doi = {10.1016/j.jppr.2017.01.005}, pages = {15 -- 24}, year = {2017}, language = {en} } @article{BaaderBoxbergChenetal.2023, author = {Baader, Fabian and Boxberg, Marc S. and Chen, Qian and F{\"o}rstner, Roger and Kowalski, Julia and Dachwald, Bernd}, title = {Field-test performance of an ice-melting probe in a terrestrial analogue environment}, series = {Icarus}, journal = {Icarus}, number = {409}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.icarus.2023.115852}, pages = {Artikel 115852}, year = {2023}, abstract = {Melting probes are a proven tool for the exploration of thick ice layers and clean sampling of subglacial water on Earth. Their compact size and ease of operation also make them a key technology for the future exploration of icy moons in our Solar System, most prominently Europa and Enceladus. For both mission planning and hardware engineering, metrics such as efficiency and expected performance in terms of achievable speed, power requirements, and necessary heating power have to be known. Theoretical studies aim at describing thermal losses on the one hand, while laboratory experiments and field tests allow an empirical investigation of the true performance on the other hand. To investigate the practical value of a performance model for the operational performance in extraterrestrial environments, we first contrast measured data from terrestrial field tests on temperate and polythermal glaciers with results from basic heat loss models and a melt trajectory model. For this purpose, we propose conventions for the determination of two different efficiencies that can be applied to both measured data and models. One definition of efficiency is related to the melting head only, while the other definition considers the melting probe as a whole. We also present methods to combine several sources of heat loss for probes with a circular cross-section, and to translate the geometry of probes with a non-circular cross-section to analyse them in the same way. The models were selected in a way that minimizes the need to make assumptions about unknown parameters of the probe or the ice environment. The results indicate that currently used models do not yet reliably reproduce the performance of a probe under realistic conditions. Melting velocities and efficiencies are constantly overestimated by 15 to 50 \% in the models, but qualitatively agree with the field test data. Hence, losses are observed, that are not yet covered and quantified by the available loss models. We find that the deviation increases with decreasing ice temperature. We suspect that this mismatch is mainly due to the too restrictive idealization of the probe model and the fact that the probe was not operated in an efficiency-optimized manner during the field tests. With respect to space mission engineering, we find that performance and efficiency models must be used with caution in unknown ice environments, as various ice parameters have a significant effect on the melting process. Some of these are difficult to estimate from afar.}, language = {en} } @article{BarnatFariaBosse2017, author = {Barnat, Miriam and Faria, Joana Abelha and Bosse, Elke}, title = {Heterogenit{\"a}t und Studierf{\"a}higkeit: Erste Ergebnisse einer L{\"a}ngsschnittbefragung}, series = {Qualit{\"a}t in der Wissenschaft: QiW ; Zeitschrift f{\"u}r Qualit{\"a}tsentwicklung in Forschung, Studium und Administration}, volume = {11}, journal = {Qualit{\"a}t in der Wissenschaft: QiW ; Zeitschrift f{\"u}r Qualit{\"a}tsentwicklung in Forschung, Studium und Administration}, number = {1}, publisher = {UVW Universit{\"a}ts-Verlag Webler}, address = {Bielefeld}, issn = {1860-3041}, pages = {17 -- 24}, year = {2017}, language = {de} } @article{Baums1992, author = {Baums, Bodo}, title = {Hubschrauberzellen aus Faserverbund-Werkstoffen}, series = {Kunststoffe. 82 (1992), H. 11}, journal = {Kunststoffe. 82 (1992), H. 11}, isbn = {0023-5563}, pages = {1114 -- 1118}, year = {1992}, language = {de} } @article{BergmannMoehrenBraunetal.2023, author = {Bergmann, Ole and M{\"o}hren, Felix and Braun, Carsten and Janser, Frank}, title = {On the influence of elasticity on swept propeller noise}, series = {AIAA SCITECH 2023 Forum}, journal = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, doi = {10.2514/6.2023-0210}, year = {2023}, abstract = {High aerodynamic efficiency requires propellers with high aspect ratios, while propeller sweep potentially reduces noise. Propeller sweep and high aspect ratios increase elasticity and coupling of structural mechanics and aerodynamics, affecting the propeller performance and noise. Therefore, this paper analyzes the influence of elasticity on forward-swept, backward-swept, and unswept propellers in hover conditions. A reduced-order blade element momentum approach is coupled with a one-dimensional Timoshenko beam theory and Farassat's formulation 1A. The results of the aeroelastic simulation are used as input for the aeroacoustic calculation. The analysis shows that elasticity influences noise radiation because thickness and loading noise respond differently to deformations. In the case of the backward-swept propeller, the location of the maximum sound pressure level shifts forward by 0.5 °, while in the case of the forward-swept propeller, it shifts backward by 0.5 °. Therefore, aeroacoustic optimization requires the consideration of propeller deformation.}, language = {en} } @article{BillerbeckBarnatKnutzen2016, author = {Billerbeck, Katrin and Barnat, Miriam and Knutzen, S{\"o}nke}, title = {Kompetenzorientierung auf dem Pr{\"u}fstand. Erprobung von Indikatoren f{\"u}r den Kulturwandel}, series = {Die Hochschullehre}, volume = {2016}, journal = {Die Hochschullehre}, number = {16}, publisher = {WBV Media}, address = {Bielefeld}, issn = {2199-8825}, doi = {10.3278/HSL1616W}, pages = {16}, year = {2016}, abstract = {Der Beitrag fokussiert die Frage nach dem Stand des durch die Bologna-Reform angestoßenen Kulturwandels im Hinblick auf Kompetenzorientierung am Beispiel der Technischen Universit{\"a}t Hamburg (TUHH). An der TUHH wird bereits seit einigen Jahren daran gearbeitet, die Lehre grundlegend neu auszurichten. Hierf{\"u}r setzt das hochschuldidaktische "Zentrum f{\"u}r Lehre und Lernen" (ZLL) verschiedene Maßnahmen ein, wie z.B. eine finanzielle und didaktische Unterst{\"u}tzung von Lehrenden bei der Umstellung ihrer Veranstaltungen, Weiterqualifizierungsangebote und Informationsmaterial. Die Maßnahmen ebenso wie die innovierten Veranstaltungen werden von Lehrenden und Studierenden gut evaluiert. Nach dem Ansatz des Constructive Alignments l{\"a}sst sich jedoch davon ausgehen, dass der Bereich der Pr{\"u}fungen f{\"u}r eine Einsch{\"a}tzung des Status Quo der Kompetenzorientierung besonders relevant ist. Dieser wird deshalb anhand der beiden Kriterien Pr{\"u}fungsformate und Schwierigkeitsstufen von Pr{\"u}fungsaufgaben n{\"a}her beleuchtet, die eng mit der Kompetenzorientierung zusammen h{\"a}ngen. Ergebnisse hierzu aus einer universit{\"a}tsweiten Datenbank zur Studienorganisation sowie aus einer Online-Umfrage unter Studierenden weisen darauf hin, dass das Pr{\"u}fungsformat "Klausur" nach wie vor am st{\"a}rksten verbreitet ist; zugleich sind die Studierenden nach einer Selbsteinsch{\"a}tzung in Pr{\"u}fungen vorrangig mit Aufgaben auf den Taxonomieniveaus "Wiedergeben" und "Anwenden" konfrontiert. Dies l{\"a}sst sich als Hinweis darauf interpretieren, dass es im Hinblick auf eine Kompetenzorientierung in den Pr{\"u}fungen noch weiteren Ver{\"a}nderungsbedarf gibt.}, language = {de} } @article{BindalSharmaJanseretal.2013, author = {Bindal, Gaurav and Sharma, Sparsh and Janser, Frank and Neu, Eugen}, title = {Detailed analysis of variables affecting wing kinematics of bat flight}, series = {SAE International Journal of Aerospace}, volume = {6}, journal = {SAE International Journal of Aerospace}, number = {2}, issn = {1946-3901}, doi = {10.4271/2013-01-9003}, pages = {811 -- 818}, year = {2013}, language = {en} } @article{Blome1989, author = {Blome, Hans-Joachim}, title = {Das Quantenvakuum und die kosmologische Konstante}, series = {Physikalische Bl{\"a}tter. 45 (1989)}, journal = {Physikalische Bl{\"a}tter. 45 (1989)}, isbn = {0342-4472}, pages = {51 -- 56}, year = {1989}, language = {de} } @article{Blome2004, author = {Blome, Hans-Joachim}, title = {Exploration des Weltalls. Raumfahrt und der Weg des Menschen in den Kosmos}, series = {Telepolis special. Wie Forscher und Raumfahrer Aliens aufsp{\"u}ren wollen}, journal = {Telepolis special. Wie Forscher und Raumfahrer Aliens aufsp{\"u}ren wollen}, publisher = {Heise Zeitschriften Verlag}, address = {Hannover}, year = {2004}, language = {de} } @article{Blome1998, author = {Blome, Hans-Joachim}, title = {Eine Reise an die Grenzen von Raum und Zeit. Wie die Raumfahrt unser Bild vom Kosmos erweitert.}, series = {DLR- Nachrichten. Mitteilungen des Deutschen Zentrums f{\"u}r Luft- und Raumfahrt. 90 (1998)}, journal = {DLR- Nachrichten. Mitteilungen des Deutschen Zentrums f{\"u}r Luft- und Raumfahrt. 90 (1998)}, isbn = {0937-0420}, pages = {20 -- 29}, year = {1998}, language = {de} } @article{Blome1989, author = {Blome, Hans-Joachim}, title = {Wie funktionieren die aktiven Kerne der Galaxien?}, series = {Naturwissenschaften. 76 (1989), H. 7}, journal = {Naturwissenschaften. 76 (1989), H. 7}, isbn = {0028-1042}, pages = {310 -- 317}, year = {1989}, language = {de} } @article{Blome1999, author = {Blome, Hans-Joachim}, title = {Sternstunden der Astronomie Extraterrestrische Grundlagenforschung}, series = {Kultur und Technik. 23 (1999), H. 1}, journal = {Kultur und Technik. 23 (1999), H. 1}, isbn = {0344-5690}, pages = {18 -- 27}, year = {1999}, language = {de} } @article{Blome1994, author = {Blome, Hans-Joachim}, title = {The scale of the universe: a unit of length}, series = {Comments on astrophysics. 17 (1994)}, journal = {Comments on astrophysics. 17 (1994)}, isbn = {0146-2970}, pages = {327 -- 335}, year = {1994}, language = {en} } @article{Blome2000, author = {Blome, Hans-Joachim}, title = {Raumfahrt - zwischen Himmel und Erde}, series = {Technologien f{\"u}r das 21. Jahrhundert / [red. Leitung: Birgit Strackenbrock ...]}, journal = {Technologien f{\"u}r das 21. Jahrhundert / [red. Leitung: Birgit Strackenbrock ...]}, publisher = {Brockhaus}, address = {Leipzig [u.a.]}, isbn = {376537945X}, pages = {572 -- 679}, year = {2000}, language = {de} } @article{Blome2001, author = {Blome, Hans-Joachim}, title = {Aspekte der modernen Kosmologie}, series = {Mensch, Leben, Schwerkraft, Kosmos : Perspektiven biowissenschaftlicher Weltraumforschung in Deutschland ; Berichtsband einer Klausurtagung vom 20. - 22.10.2000 in Stuttgart-Hohenheim/Birkach / Hinrich Rahmann ... (Hrsg.). [Ausgerichtet von der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt medizin]}, journal = {Mensch, Leben, Schwerkraft, Kosmos : Perspektiven biowissenschaftlicher Weltraumforschung in Deutschland ; Berichtsband einer Klausurtagung vom 20. - 22.10.2000 in Stuttgart-Hohenheim/Birkach / Hinrich Rahmann ... (Hrsg.). [Ausgerichtet von der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt medizin]}, publisher = {Heimbach}, address = {Stuttgart}, isbn = {3-935380-03-8}, pages = {50 -- 79}, year = {2001}, language = {de} } @article{Blome2002, author = {Blome, Hans-Joachim}, title = {Kosmologie: Geschichte des Kosmos und Extrapolationen in die Zukunft}, series = {Der Mensch im Kosmos. 3. ; Berichtsband eines Workshops vom 19. bis 21. April 2001, Kurverwaltung, Medienzentrum Bad Oeynhausen : Der Mensch im Kosmos / Peter R. Sahm ; Gerhard P. J. Thiele (Hrsg.)}, journal = {Der Mensch im Kosmos. 3. ; Berichtsband eines Workshops vom 19. bis 21. April 2001, Kurverwaltung, Medienzentrum Bad Oeynhausen : Der Mensch im Kosmos / Peter R. Sahm ; Gerhard P. J. Thiele (Hrsg.)}, publisher = {Shaker}, address = {Aachen}, isbn = {3-8265-9737-0}, pages = {319 S. : Ill., graph. Darst.}, year = {2002}, language = {de} } @article{Blome2005, author = {Blome, Hans-Joachim}, title = {Die Entstehung des Kosmos - Vom Anfang der Welt bis zum komplexen Universum}, series = {Homo spaciens - der Mensch im Kosmos : ein interdisziplin{\"a}rer Ausblick auf Ursprung und Zukunft des Menschen im All ; Berichtsband der Tagung "Mensch im Kosmos IV" vom 14. - 16.10.2004 auf Schloß Theuern/Oberpfalz / P. R. Sahm, ... Hans-Joachim Blome(Hrsg.)}, journal = {Homo spaciens - der Mensch im Kosmos : ein interdisziplin{\"a}rer Ausblick auf Ursprung und Zukunft des Menschen im All ; Berichtsband der Tagung "Mensch im Kosmos IV" vom 14. - 16.10.2004 auf Schloß Theuern/Oberpfalz / P. R. Sahm, ... Hans-Joachim Blome(Hrsg.)}, publisher = {Discorsi}, address = {Hamburg}, isbn = {3-9807330-8-4}, pages = {XVIII, 331 S. : Ill., graph. Darst., Kt.}, year = {2005}, language = {de} } @article{Blome2001, author = {Blome, Hans-Joachim}, title = {Raumfahrt und Exploration des Kosmos}, series = {Mensch, Leben, Schwerkraft, Kosmos : Perspektiven biowissenschaftlicher Weltraumforschung in Deutschland ; Berichtsband einer Klausurtagung vom 20. - 22.10.2000 in Stuttgart-Hohenheim/Birkach / Hinrich Rahmann ... (Hrsg.). [Ausgerichtet von der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt medizin]}, journal = {Mensch, Leben, Schwerkraft, Kosmos : Perspektiven biowissenschaftlicher Weltraumforschung in Deutschland ; Berichtsband einer Klausurtagung vom 20. - 22.10.2000 in Stuttgart-Hohenheim/Birkach / Hinrich Rahmann ... (Hrsg.). [Ausgerichtet von der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt medizin]}, publisher = {Heimbach}, address = {Stuttgart}, isbn = {3-935380-03-8}, pages = {80 -- 105}, year = {2001}, language = {de} } @article{BlomeChiconeHehletal.2010, author = {Blome, Hans-Joachim and Chicone, Carmen and Hehl, Friedrich W. and Mashhoon, Bahram}, title = {Nonlocal modification of Newtonian gravity}, series = {Physical Review D}, volume = {81}, journal = {Physical Review D}, number = {6}, isbn = {0556-2821}, pages = {065020}, year = {2010}, language = {en} }