TY - JOUR A1 - Christen, Marc A1 - Bartelt, Perry A1 - Kowalski, Julia T1 - Back calculation of the In den Arelen avalanche with RAMMS: Interpretation of model results JF - Annals of Glaciology N2 - Two- and three-dimensional avalanche dynamics models are being increasingly used in hazard-mitigation studies. These models can provide improved and more accurate results for hazard mapping than the simple one-dimensional models presently used in practice. However, two- and three-dimensional models generate an extensive amount of output data, making the interpretation of simulation results more difficult. To perform a simulation in three-dimensional terrain, numerical models require a digital elevation model, specification of avalanche release areas (spatial extent and volume), selection of solution methods, finding an adequate calculation resolution and, finally, the choice of friction parameters. In this paper, the importance and difficulty of correctly setting up and analysing the results of a numerical avalanche dynamics simulation is discussed. We apply the two-dimensional simulation program RAMMS to the 1968 extreme avalanche event In den Arelen. We show the effect of model input variations on simulation results and the dangers and complexities in their interpretation. KW - avalanche Y1 - 2010 SN - 1727-5644 U6 - https://doi.org/10.3189/172756410791386553 VL - 51 IS - 54 SP - 161 EP - 168 PB - Cambridge University Press CY - Cambridge ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Priester, W. T1 - Big Bounce in the very early Universe JF - Astronomy and Astrophysics. 250 (1991), H. 1 Y1 - 1991 SN - 0004-6361 SP - 43 EP - 49 ER - TY - JOUR A1 - Thomessen, Karolin A1 - Thoma, Andreas A1 - Braun, Carsten T1 - Bio-inspired altitude changing extension to the 3DVFH* local obstacle avoidance algorithm JF - CEAS Aeronautical Journal N2 - Obstacle avoidance is critical for unmanned aerial vehicles (UAVs) operating autonomously. Obstacle avoidance algorithms either rely on global environment data or local sensor data. Local path planners react to unforeseen objects and plan purely on local sensor information. Similarly, animals need to find feasible paths based on local information about their surroundings. Therefore, their behavior is a valuable source of inspiration for path planning. Bumblebees tend to fly vertically over far-away obstacles and horizontally around close ones, implying two zones for different flight strategies depending on the distance to obstacles. This work enhances the local path planner 3DVFH* with this bio-inspired strategy. The algorithm alters the goal-driven function of the 3DVFH* to climb-preferring if obstacles are far away. Prior experiments with bumblebees led to two definitions of flight zone limits depending on the distance to obstacles, leading to two algorithm variants. Both variants reduce the probability of not reaching the goal of a 3DVFH* implementation in Matlab/Simulink. The best variant, 3DVFH*b-b, reduces this probability from 70.7 to 18.6% in city-like worlds using a strong vertical evasion strategy. Energy consumption is higher, and flight paths are longer compared to the algorithm version with pronounced horizontal evasion tendency. A parameter study analyzes the effect of different weighting factors in the cost function. The best parameter combination shows a failure probability of 6.9% in city-like worlds and reduces energy consumption by 28%. Our findings demonstrate the potential of bio-inspired approaches for improving the performance of local path planning algorithms for UAV. KW - UAV KW - Obstacle avoidance KW - Autonomy KW - Local path planning Y1 - 2023 U6 - https://doi.org/10.1007/s13272-023-00691-w SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Karolin Thomessen PB - Springer CY - Wien ER - TY - GEN A1 - Eickmann, Matthias A1 - Esch, Thomas A1 - Funke, Harald A1 - Abanteriba, Sylvester A1 - Roosen, Petra T1 - Biofuels in Aviation – Safety Implications of Bio-Ethanol Usage in General Aviation Aircraft N2 - Up in the clouds and above fuels and construction materials must be very carefully selected to ensure a smooth flight and touchdown. Out of around 38,000 single and dual-engined propeller aeroplanes, roughly a third are affected by a new trend in the fuel sector that may lead to operating troubles or even emergency landings: The admixture of bio-ethanol to conventional gasoline. Experiences with these fuels may be projected to alternative mixtures containing new components. Y1 - 2014 N1 - 2. International Conference of the Cluster of Excellence Tailor-Made Fuels from Biomass, Aachen 2013 ER - TY - JOUR A1 - Esch, Thomas A1 - Funke, Harald A1 - Roosen, Peter A1 - Jarolimek, Ulrich T1 - Biogenic Vehicle Fuels in General Aviation Aircrafts JF - MTZ worldwide. 72 (2011), H. 1 Y1 - 2011 N1 - recherchierbar für Angehörige der FH Aachen SP - 38 EP - 43 PB - Springer Automotive Media CY - Wiesbaden ER - TY - BOOK A1 - Havermann, Marc A1 - Seiler, Friedrich T1 - Boundary layer influence on supersonic jet cross flow interaction in hypersonic flow : DGLR/STAB-Fachsymposium Strömungsmechanik 2004, Bremer Innovations- und Technologiezentrum (BITZ), Bremen, FRG, 16. - 18. November 2004 / Havermann, M.; Seiler, F. Institut Franco-Allemand de Recherches de Saint-Louis Y1 - 2004 N1 - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 658 PB - ISL CY - Saint-Louis ER - TY - JOUR A1 - Havermann, Marc A1 - Seiler, F. T1 - Boundary Layer Influence on Supersonic Jet/Cross-Flow Interaction in Hypersonic Flow / Havermann, M. ; Seiler, F. JF - Notes on Numerical Fluid Mechanics and Multidisciplinary Design. 92 (2006) Y1 - 2006 SN - 1612-2909 N1 - New results in numerical and experimental fluid mechanics ; V ; ISBN 978-3-540-33287-9 SP - 281 EP - 288 PB - - ER - TY - JOUR A1 - Gerhardt, Hans Joachim A1 - Krüger, O. T1 - Building shape influence on local wind loads JF - Proceedings of the 2nd European & African Conference on Wind Engineering : 2 EACWE, Palazzo Ducale, Genova, Italy, June 22-26, 1997 / ed. by Giovanni Solari. - Vol. 2 Y1 - 1997 SN - 88-86281-19-6 N1 - European and African Conference on Wind Engineering <2, 1997, Genova> ; ISBN für beide Bände PB - Servizi Grafici Editoriali CY - Padova ER - TY - CHAP A1 - Christen, Marc A1 - Bartelt, Perry A1 - Kowalski, Julia A1 - Stoffel, Lukus T1 - Calculation of dense snow avalanches in three-dimensional terrain with the numerical simulation programm RAMMS T2 - Proceedings ISSW 2008 ; International Snow Science Workshop. Whistler 2008 N2 - Numerical models have become an essential part of snow avalanche engineering. Recent advances in understanding the rheology of flowing snow and the mechanics of entrainment and deposition have made numerical models more reliable. Coupled with field observations and historical records, they are especially helpful in understanding avalanche flow in complex terrain. However, the application of numerical models poses several new challenges to avalanche engineers. A detailed understanding of the avalanche phenomena is required to specify initial conditions (release zone dimensions and snowcover entrainment rates) as well as the friction parameters, which are no longer based on empirical back-calculations, rather terrain roughness, vegetation and snow properties. In this paper we discuss these problems by presenting the computer model RAMMS, which was specially designed by the SLF as a practical tool for avalanche engineers. RAMMS solves the depth-averaged equations governing avalanche flow with first and second-order numerical solution schemes. A tremendous effort has been invested in the implementation of advanced input and output features. Simulation results are therefore clearly and easily visualized to simplify their interpretation. More importantly, RAMMS has been applied to a series of well-documented avalanches to gauge model performance. In this paper we present the governing differential equations, highlight some of the input and output features of RAMMS and then discuss the simulation of the Gatschiefer avalanche that occurred in April 2008, near Klosters/Monbiel, Switzerland. KW - snow KW - avalanche Y1 - 2008 SP - 709 EP - 716 ER - TY - CHAP A1 - Wahle, Michael T1 - Calculation of the response of heat exchanger tubes with regard to nonlinear and prestressing effects T2 - Vibration in nuclear plant : proceedings of the 3rd International Conference on Vibration in Nuclear Plant held on 11 - 14 May 1982, Keswick ; vol. 1 Y1 - 1983 SN - 0-7277-0192-4 (Druckausg.) SN - 978-0-7277-5270-3 (E-Book) N1 - International Conference on Vibration in Nuclear Plant <3, 1982, Keswick> N1 - Paper 1.10 (Log No. 71) SP - 162 EP - 183 PB - British Nuclear Energy Society CY - London ER - TY - JOUR A1 - Jan Thimo, Grundmann A1 - Bauer, Waldemar A1 - Biele, Jens A1 - Boden, Ralf A1 - Ceriotti, Matteo A1 - Cordero, Federico A1 - Dachwald, Bernd A1 - Dumont, Etienne A1 - Grimm, Christian D. A1 - Hercik, David T1 - Capabilities of Gossamer-1 derived small spacecraft solar sails carrying Mascot-derived nanolanders for in-situ surveying of NEAs JF - Acta Astronautica Y1 - 2019 U6 - https://doi.org/10.1016/j.actaastro.2018.03.019 SN - 0094-5765 VL - 156 IS - 3 SP - 330 EP - 362 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Finger, Felix A1 - Braun, Carsten A1 - Bil, Cees T1 - Case studies in initial sizing for hybrid-electric general aviation aircraft T2 - 2018 AIAA/IEEE Electric Aircraft Technologies Symposium, Cincinnati, Ohio Y1 - 2018 U6 - https://doi.org/10.2514/6.2018-5005 ER - TY - PAT A1 - Artmann, Gerhard A1 - Linder, Peter A1 - Bayer, Robin A1 - Gossmann, Matthias T1 - Celldrum electrode arrangement for measuring mechanical stress [Patent of invention] N2 - The invention pertains to a CellDrum electrode arrangement for measuring mechanical stress, comprising a mechanical holder (1 ) and a non-conductive membrane (4), whereby the membrane (4) is at least partially fixed at its circumference to the mechanical holder (1), keeping it in place when the membrane (4) may bend due to forces acting on the membrane (4), the mechanical holder (1) and the membrane (4) forming a container, whereby the membrane (1) within the container comprises an cell- membrane compound layer or biological material (3) adhered to the deformable membrane 4 which in response to stimulation by an agent may exert mechanical stress to the membrane (4) such that the membrane bending stage changes whereby the container may be filled with an electrolyte, whereby an electric contact (2) is arranged allowing to contact said electrolyte when filled into to the container, whereby within a predefined geometry to the fixing of the membrane (4) an electrode (7) is arranged, whereby the electrode (7) is electrically insulated with respect to the electric contact (2) as well as said electrolyte, whereby mechanical stress due to an agent may be measured as a change in capacitance. Y1 - 2017 N1 - Patent auch unter EP3403090, CN109477828, US2019033245 und LU92948 veröffentlicht. PB - WIPO CY - Geneva ER - TY - CHAP A1 - Mertens, Josef ED - Sobieczky, H. T1 - Certification of supersonic civil transports T2 - New design concepts for high speed air transport. - (Courses and lectures / International Centre for Mechanical Sciences ; 366) N2 - Since certification of Concorde new certification standards were introduced including many new regulations to improve flight safety. Most of these standards are to prevent severe accidents in the future which happened in the past (here: after Concorde’s certification). A new SCT has to fulfill these standards, although Concorde had none of these accidents. But accidents - although they sometimes occurred only for a specific aircraft type - have to be avoided for any (new) aircraft. Because of existing aircraft without typical accident types having demonstrated their reliability, they are allowed to go on based on their old certification; although sometimes new rules prevent accident types which are not connected to specific aircraft types - like e.g. evacuation rules. Anyway, Concorde is allowed to fly based on its old certification, and hopefully in the future will fly as safely as in the past. But a new SCT has to fulfill updated rules like any other aircraft, and it has to be “just another aircraft” [75]. KW - Noise Exposure KW - Evacuation Rule KW - Severe Accident KW - Certification Rule KW - Thermal Fatigue Testing Y1 - 1997 SN - 3-2118-2815-X U6 - https://doi.org/10.1007/978-3-7091-2658-5_6 SP - 97 EP - 103 PB - Springer CY - Wien [u.a.] ER - TY - JOUR A1 - Ayed, Anis Haj A1 - Kusterer, Karsten A1 - Funke, Harald A1 - Keinz, Jan A1 - Bohn, D. T1 - CFD based exploration of the dry-low-NOx hydrogen micromix combustion technology at increased energy densities JF - Propulsion and Power Research KW - Micromix combustion KW - Hydrogen gas turbine KW - Hydrogen combustion KW - High hydrogen combustion KW - Dry-low-NOx (DLN) combustion Y1 - 2017 SN - 2212-540X U6 - https://doi.org/10.1016/j.jppr.2017.01.005 VL - 6 IS - 1 SP - 15 EP - 24 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ayed, Anis Haj A1 - Kusterer, Karsten A1 - Funke, Harald A1 - Keinz, Jan T1 - CFD Based Improvement of the DLN Hydrogen Micromix Combustion Technology at Increased Energy Densities JF - American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) N2 - 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. Y1 - 2016 SN - 2313-4402 VL - 26 IS - 3 SP - 290 EP - 303 PB - GSSRR ER - TY - CHAP A1 - Digel, Ilya A1 - Sadykov, R. A1 - Temiz Artmann, Aysegül A1 - Artmann, Gerhard T1 - Changes in intestinal microflora in rats induced by oral exposure to low lead (II) concentrations T2 - Lead Exposure and Poisoning: Clinical Symptoms, Medical Management and Preventive Strategies Y1 - 2015 SN - 9781634826990 SP - 75 EP - 99 PB - Nova Science Publ. ER - TY - THES A1 - Beckmann, Nils T1 - Characterization of the hydrogen-dry-low-Nox-micromix-combustion-principle for hydrogen-methane fuel mixtures KW - Low NOx KW - Hydrogen KW - Combustion KW - Low emission Y1 - 2019 N1 - Dissertation, RMIT University, August 2019 PB - RMIT University CY - Melbourne ER - TY - CHAP A1 - Weber, Tobias A1 - Tellis, Jane J. A1 - Duhovic, Miro T1 - Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation T2 - ECCM 17, 17th European Conference on Composite Materials, München, DE, Jun 26-30, 2016 Y1 - 2016 SN - 978-3-00-053387-7 SP - 1 EP - 7 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Ulamec, Stephan A1 - Biele, Jens T1 - Clean in situ subsurface exploration of icy environments in the solar system T2 - Habitability of other planets and satellites. - (Cellular origin, life in extreme habitats and astrobiology ; 28) N2 - "To assess the habitability of the icy environments in the solar system, for example, on Mars, Europa, and Enceladus, the scientific analysis of material embedded in or underneath their ice layers is very important. We consider self-steering robotic ice melting probes to be the best method to cleanly access these environments, that is, in compliance with planetary protection standards. The required technologies are currently developed and tested." Y1 - 2013 SN - 978-94-007-6545-0 (Druckausgabe) SN - 978-94-007-6546-7 (E-Book) SP - 367 EP - 397 PB - Springer CY - Dordrecht ER -