@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{FunkeKeinzKustereretal.2016,
  author    = {Funke, Harald and Keinz, Jan and Kusterer, Karsten and Ayed, Anis Haj and Kazari, Masahide and Kitajima, Junichi and Horikawa, Atsushi and Okada, Kunio},
  title     = {Experimental and Numerical Study on Optimizing the Dry Low NOₓ Micromix Hydrogen Combustion Principle for Industrial Gas Turbine Applications},
  series = {Journal of Thermal Science and Engineering Applications},
  volume    = {9},
  journal   = {Journal of Thermal Science and Engineering Applications},
  number    = {2},
  publisher = {ASME},
  address   = {New York, NY},
  issn      = {1948-5093},
  doi       = {10.1115/1.4034849},
  pages     = {021001 -- 021001-10},
  year      = {2016},
  abstract  = {Combined with the use of renewable energy sources for its production, hydrogen represents a possible alternative gas turbine fuel for future low-emission power generation. Due to the 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 to dry low NOₓ (DLN) hydrogen combustion. The DLN micromix combustion of hydrogen has been under development for many years, since it has the promise to significantly reduce NOₓ emissions. This combustion principle for air-breathing engines is based on crossflow mixing of air and gaseous hydrogen. Air and hydrogen react in multiple miniaturized diffusion-type flames with an inherent safety against flashback and with low NOₓ emissions due to a very short residence time of the reactants in the flame region. The paper presents an advanced DLN micromix hydrogen application. The experimental and numerical study shows a combustor configuration with a significantly reduced number of enlarged fuel injectors with high-thermal power output at constant energy density. Larger fuel injectors reduce manufacturing costs, are more robust and less sensitive to fuel contamination and blockage in industrial environments. The experimental and numerical results confirm the successful application of high-energy injectors, while the DLN micromix characteristics of the design point, under part-load conditions, and under off-design operation are maintained. Atmospheric test rig data on NOₓ emissions, optical flame-structure, and combustor material temperatures are compared to numerical simulations and show good agreement. The impact of the applied scaling and design laws on the miniaturized micromix flamelets is particularly investigated numerically for the resulting flow field, the flame-structure, and NOₓ formation.},
  language  = {en}
}
@article{NeuJanserKhatibietal.2016,
  author    = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Braun, Carsten and Orifici, Adrian C.},
  title     = {Operational Modal Analysis of a wing excited by transonic flow},
  series = {Aerospace Science and Technology},
  volume    = {49},
  journal   = {Aerospace Science and Technology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1270-9638},
  doi       = {10.1016/j.ast.2015.11.032},
  pages     = {73 -- 79},
  year      = {2016},
  abstract  = {Operational Modal Analysis (OMA) is a promising candidate for flutter testing and Structural Health Monitoring (SHM) of aircraft wings that are passively excited by wind loads. However, no studies have been published where OMA is tested in transonic flows, which is the dominant condition for large civil aircraft and is characterized by complex and unique aerodynamic phenomena. We use data from the HIRENASD large-scale wind tunnel experiment to automatically extract modal parameters from an ambiently excited wing operated in the transonic regime using two OMA methods: Stochastic Subspace Identification (SSI) and Frequency Domain Decomposition (FDD). The system response is evaluated based on accelerometer measurements. The excitation is investigated from surface pressure measurements. The forcing function is shown to be non-white, non-stationary and contaminated by narrow-banded transonic disturbances. All these properties violate fundamental OMA assumptions about the forcing function. Despite this, all physical modes in the investigated frequency range were successfully identified, and in addition transonic pressure waves were identified as physical modes as well. The SSI method showed superior identification capabilities for the investigated case. The investigation shows that complex transonic flows can interfere with OMA. This can make existing approaches for modal tracking unsuitable for their application to aircraft wings operated in the transonic flight regime. Approaches to separate the true physical modes from the transonic disturbances are discussed.},
  language  = {en}
}
@article{GrundmannDachwaldGrimmetal.2015,
  author    = {Grundmann, Jan Thimo and Dachwald, Bernd and Grimm, Christian D. and Kahle, Ralph and Koch, Aaron Dexter and Krause, Christian and Lange, Caroline and Quantius, Dominik and Ulamec, Stephan},
  title     = {Spacecraft for Hypervelocity Impact Research - An Overview of Capabilities, Constraints and the Challenges of Getting There},
  series = {Procedia Engineering},
  volume    = {Vol. 103},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2015.04.021},
  pages     = {151 -- 158},
  year      = {2015},
  language  = {en}
}
@article{KowalskiLinderZierkeetal.2016,
  author    = {Kowalski, Julia and Linder, Peter and Zierke, S. and Wulfen, B. van and Clemens, J. and Konstantinidis, K. and Ameres, G. and Hoffmann, R. and Mikucki, J. and Tulaczyk, S. and Funke, O. and Blandfort, D. and Espe, Clemens and Feldmann, Marco and Francke, Gero and Hiecker, S. and Plescher, Engelbert and Sch{\"o}ngarth, Sarah and Dachwald, Bernd and Digel, Ilya and Artmann, Gerhard and Eliseev, D. and Heinen, D. and Scholz, F. and Wiebusch, C. and Macht, S. and Bestmann, U. and Reineking, T. and Zetzsche, C. and Schill, K. and F{\"o}rstner, R. and Niedermeier, H. and Szumski, A. and Eissfeller, B. and Naumann, U. and Helbing, K.},
  title     = {Navigation technology for exploration of glacier ice with maneuverable melting probes},
  series = {Cold Regions Science and Technology},
  journal   = {Cold Regions Science and Technology},
  number    = {123},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0165-232X},
  doi       = {10.1016/j.coldregions.2015.11.006},
  pages     = {53 -- 70},
  year      = {2016},
  abstract  = {The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.},
  language  = {en}
}
@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{HajAyedKustererFunkeetal.2015,
  author    = {Haj Ayed, A. and Kusterer, K. and Funke, Harald and Keinz, Jan and Striegan, Constantin and Bohn, D.},
  title     = {Improvement study for the dry-low-NOx hydrogen micromix combustion technology},
  series = {Propulsion and power research},
  volume    = {Vol. 4},
  journal   = {Propulsion and power research},
  number    = {Iss. 3},
  issn      = {2212-540X},
  doi       = {10.1016/j.jppr.2015.07.003},
  pages     = {132 -- 140},
  year      = {2015},
  language  = {en}
}
@article{HajAyedKustererFunkeetal.2015,
  author    = {Haj Ayed, A. and Kusterer, K. and Funke, Harald and Keinz, Jan and Striegan, Constantin and Bohn, D.},
  title     = {Experimental and numerical investigations of the dry-low-NOx hydrogen micromix combustion chamber of an industrial gas turbine},
  series = {Propulsion and power research},
  volume    = {Vol. 4},
  journal   = {Propulsion and power research},
  number    = {Iss. 3},
  issn      = {2212-540X},
  doi       = {10.1016/j.jppr.2015.07.005},
  pages     = {123 -- 131},
  year      = {2015},
  language  = {en}
}
@article{SeifarthGossmannGrosseetal.2015,
  author    = {Seifarth, Volker and Goßmann, Matthias and Grosse, J. O. and Becker, C. and Heschel, I. and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l},
  title     = {Development of a Bioreactor to Culture Tissue Engineered Ureters Based on the Application of Tubular OPTIMAIX 3D Scaffolds},
  series = {Urologia Internationalis},
  volume    = {2015},
  journal   = {Urologia Internationalis},
  number    = {95},
  publisher = {Karger},
  address   = {Basel},
  issn      = {0042-1138},
  doi       = {10.1159/000368419},
  pages     = {106 -- 113},
  year      = {2015},
  language  = {en}
}
@article{MathiakWillneckerPlescher2005,
  author    = {Mathiak, Gerhard and Willnecker, Rainer and Plescher, Engelbert},
  title     = {Vibrational effects on diffusion experiments},
  series = {Microgravity science and technology : international journal for microgravity research and applications},
  volume    = {Vol. 15},
  journal   = {Microgravity science and technology : international journal for microgravity research and applications},
  number    = {No. 1},
  issn      = {0938-0108},
  pages     = {295 -- 300},
  year      = {2005},
  language  = {en}
}
@article{MathiakPlescherWillnecker2005,
  author    = {Mathiak, Gerhard and Plescher, Engelbert and Willnecker, Rainer},
  title     = {Liquid metal diffusion experiments in microgravity - Vibrational effects},
  series = {Measurement science and technology},
  volume    = {Vol. 16},
  journal   = {Measurement science and technology},
  number    = {No. 2},
  issn      = {0957-0233},
  doi       = {10.1088/0957-0233/16/2/003},
  pages     = {336},
  year      = {2005},
  language  = {en}
}
@article{DachwaldMikuckiTulaczyketal.2014,
  author    = {Dachwald, Bernd and Mikucki, Jill and Tulaczyk, Slawek and Digel, Ilya and Espe, Clemens and Feldmann, Marco and Francke, Gero and Kowalski, Julia and Xu, Changsheng},
  title     = {IceMole : A maneuverable probe for clean in situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems},
  series = {Annals of Glaciology},
  volume    = {55},
  journal   = {Annals of Glaciology},
  number    = {65},
  publisher = {Cambridge University Press},
  address   = {Cambridge},
  issn      = {1727-5644},
  doi       = {10.3189/2014AoG65A004},
  pages     = {14 -- 22},
  year      = {2014},
  abstract  = {There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample.},
  language  = {en}
}
@article{KonstantinidisFloresMartinezDachwaldetal.2015,
  author    = {Konstantinidis, Konstantinos and Flores Martinez, Claudio and Dachwald, Bernd and Ohndorf, Andreas and Dykta, Paul and Bowitz, Pascal and Rudolph, Martin and Digel, Ilya and Kowalski, Julia and Voigt, Konstantin and F{\"o}rstner, Roger},
  title     = {A lander mission to probe subglacial water on Saturn's moon enceladus for life},
  series = {Acta astronautica},
  volume    = {Vol. 106},
  journal   = {Acta astronautica},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1879-2030 (E-Journal); 0094-5765 (Print)},
  pages     = {63 -- 89},
  year      = {2015},
  language  = {en}
}
@article{StadlerGarveyEmbsetal.2014,
  author    = {Stadler, Alexander Maximilian and Garvey, Christopher J. and Embs, Jan Peter and Koza, Michael Marek and Unruh, Tobias and Artmann, Gerhard and Zaccai, Guiseppe},
  title     = {Picosecond dynamics in haemoglobin from different species: A quasielastic neutron scattering study},
  series = {Biochimica et biophysica acta (BBA): General Subjects},
  volume    = {1840},
  journal   = {Biochimica et biophysica acta (BBA): General Subjects},
  number    = {10},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1872-8006 (E-Journal); 0304-4165 (Print)},
  doi       = {10.1016/j.bbagen.2014.06.007},
  pages     = {2989 -- 2999},
  year      = {2014},
  language  = {en}
}
@article{SchirraWatmuffBauschat2014,
  author    = {Schirra, Julian and Watmuff, Jonathan and Bauschat, J.-Michael},
  title     = {Highly non-planar lifting systems: a relative assessment of existing potential-methodologies to accurately estimate the induced drag},
  series = {32nd AIAA Applied Aerodynamics Conference 2014 : June, 16-20 2014, Atlanta, Ga.},
  journal   = {32nd AIAA Applied Aerodynamics Conference 2014 : June, 16-20 2014, Atlanta, Ga.},
  organization    = {American Institute of Aeronautics and Astronautics},
  isbn      = {978-1-62410-288-2},
  doi       = {10.2514/6.2014-2988},
  pages     = {Publ. online},
  year      = {2014},
  language  = {en}
}
@article{FunkeDickhoffKeinzetal.2014,
  author    = {Funke, Harald and Dickhoff, J. and Keinz, Jan and Anis, H. A. and Parente, A. and Hendrick, P.},
  title     = {Experimental and numerical study of the micromix combustion principle applied for hydrogen and hydrogen-rich syngas as fuel with increased energy density for industrial gas turbine applications},
  series = {Energy procedia},
  journal   = {Energy procedia},
  number    = {61},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1876-6102 (E-Journal)},
  doi       = {10.1016/j.egypro.2014.12.201},
  pages     = {1736 -- 1739},
  year      = {2014},
  abstract  = {The Dry Low NOx (DLN) Micromix combustion principle with increased energy density is adapted for the industrial gas turbine APU GTCP 36-300 using hydrogen and hydrogen-rich syngas with a composition of 90\%-Vol. hydrogen (H₂) and 10\%-Vol. carbon-monoxide (CO). Experimental and numerical studies of several combustor geometries for hydrogen and syngas show the successful advance of the DLN Micromix combustion from pure hydrogen to hydrogen-rich syngas. The impact of the different fuel properties on the combustion principle and aerodynamic flame stabilization design laws, flow field, flame structure and emission characteristics is investigated by numerical analysis using a hybrid Eddy Break Up combustion model and validated against experimental results.},
  language  = {en}
}
@article{KraemerDaabMuelleretal.2013,
  author    = {Kr{\"a}mer, Stefan and Daab, Dominique Jonas and M{\"u}ller, Brigitte and Wagner, Tobias and Baader, Fabian and Hessel, Joana and Gdalewitsch, Georg and Plescher, Engelbert and Dachwald, Bernd and Wahle, Michael and Gierse, Andreas and Vetter, Rudolf and Pf{\"u}tzenreuter, Lysan},
  title     = {Development and flight-testing of a system to isolate vibrations for microgravity experiments on sounding rockets},
  series = {21st ESA Symposium on Rocket and Balloon Research},
  journal   = {21st ESA Symposium on Rocket and Balloon Research},
  pages     = {1 -- 8},
  year      = {2013},
  language  = {en}
}
@article{HeierliPurvesFelberetal.2004,
  author    = {Heierli, Joachim and Purves, Ross S. and Felber, Andreas and Kowalski, Julia},
  title     = {Verification of nearest-neighbours interpretations in avalanche forecasting},
  series = {Annals of Glaciology},
  volume    = {38},
  journal   = {Annals of Glaciology},
  number    = {1},
  isbn      = {1727-5644},
  pages     = {84 -- 88},
  year      = {2004},
  abstract  = {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.},
  language  = {en}
}
@article{McArdellBarteltKowalski2007,
  author    = {McArdell, Brian W. and Bartelt, Perry and Kowalski, Julia},
  title     = {Field observations of basal forces and fluid pore pressure in a debris flow},
  series = {Geophysical Research Letters (GRL)},
  volume    = {34},
  journal   = {Geophysical Research Letters (GRL)},
  number    = {7},
  isbn      = {0094-8276},
  year      = {2007},
  abstract  = {Using results from an 8 m2 instrumented force plate we describe field measurements of normal and shear stresses, and fluid pore pressure for a debris flow. The flow depth increased from 0.1 to 1 m within the first 12 s of flow front arrival, remained relatively constant until 100 s, and then gradually decreased to 0.5 m by 600 s. Normal and shear stresses and pore fluid pressure varied in-phase with the flow depth. Calculated bulk densities are ρb = 2000-2250 kg m-3 for the bulk flow and ρf = 1600-1750 kg m-3 for the fluid phase. The ratio of effective normal stress to shear stress yields a Coulomb basal friction angle of ϕ = 26° at the flow front. We did not find a strong correlation between the degree of agitation in the flow, estimated using the signal from a geophone on the force plate, and an assumed dynamic pore fluid pressure. Our data support the idea that excess pore-fluid pressures are long lived in debris flows and therefore contribute to their unusual mobility.},
  language  = {en}
}
@article{FischerKowalskiPudasainietal.2009,
  author    = {Fischer, Jan-Thomas and Kowalski, Julia and Pudasaini, Shiva P. and Miller, S. A.},
  title     = {Dynamic Avalanche Modeling in Natural Terrain},
  series = {International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009},
  journal   = {International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009},
  pages     = {448 -- 452},
  year      = {2009},
  abstract  = {The powerful avalanche simulation toolbox RAMMS (Rapid Mass Movements) is based on a depth-averaged hydrodynamic system of equations with a Voellmy-Salm friction relation. The two empirical friction parameters μ and � correspond to a dry Coulomb friction and a viscous resistance, respectively. Although μ and � lack a proper physical explanation, 60 years of acquired avalanche data in the Swiss Alps made a systematic calibration possible. RAMMS can therefore successfully model avalanche flow depth, velocities, impact pressure and run out distances. Pudasaini and Hutter (2003) have proposed extended, rigorously derived model equations that account for local curvature and twist. A coordinate transformation into a reference system, applied to the actual mountain topography of the natural avalanche path, is performed. The local curvature and the twist of the avalanche path induce an additional term in the overburden pressure. This leads to a modification of the Coulomb friction, the free-surface pressure gradient, the pressure induced by the channel, and the gravity components along and normal to the curved and twisted reference surface. This eventually guides the flow dynamics and deposits of avalanches. In the present study, we investigate the influence of curvature on avalanche flow in real mountain terrain. Simulations of real avalanche paths are performed and compared for the different models approaches. An algorithm to calculate curvature in real terrain is introduced in RAMMS. This leads to a curvature dependent friction relation in an extended version of the Voellmy-Salm model equations. Our analysis provides yet another step in interpreting the physical meaning and significance of the friction parameters used in the RAMMS computational environment.},
  language  = {en}
}