TY - JOUR A1 - Blome, Hans-Joachim A1 - Mashhoon, B. T1 - Quasi-normal oscillations of a Schwarzschild black hole JF - Physics Letters A. 100 (1984), H. 5 Y1 - 1984 SN - 0375-9601 SP - 231 EP - 234 ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Kundt, Wolfgang T1 - Leptonic jets from young stellar objects? JF - Astrophysics and Space Science. 148 (1988), H. 2 Y1 - 1988 SN - 0004-640X SP - 343 EP - 361 ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Kundt, W. T1 - Hypersonic Jets from Young Stars in Molecular Clouds JF - Circumstellar matter : proceedings of the 122nd symposium of the Internat. Astronom. Union held in Heidelberg, FRG, June 23 - 27, 1986 / ed. by I. Appenzeller ... Y1 - 1987 SN - 90-277-2511-X SP - 73 EP - 74 PB - Reidel CY - Dordrecht u.a. ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Kosbow, Michael T1 - The Pioneer Anomaly in the context of non-Newtonian Gravity JF - International Astronautical Congress : final papers : October 17-21, 2005, Fukuoka, Japan Y1 - 2005 N1 - Proceedings IAC-2005-C1.P.20 ;International Astronautical Congress ; (56, 2005, Fukuoka, Japan) SP - 20 EP - 20 PB - International Astronautical Federation CY - Paris ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Kosbow, Michael T1 - Perturbation of a satellite orbit by gravitational waves JF - Jahrbuch 2004 der Deutschen Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR) Y1 - 2004 SN - 0070-4083 N1 - DGLR-2004-168 SP - 2083 EP - 2088 PB - DGLR CY - Bonn ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Chu, Y. A1 - Hoell, J A1 - Priester, W. T1 - On the observational discrimination of Friedmann-Lemaître models JF - Large Scale Structures of the Universe: Proceedings of the 130th Symposium of the International Astronomical Union, dedicated to the memory of Marc A. Aaronson (1950-1987) held in Balatonfured, Hungary, June 15-20, 1987. Edited by Jean Audouze, Marie-Christine Pelletan and Sandor Szalay. Y1 - 1988 SN - 90-277-2742-2 N1 - International Astronomical Union. Symposium no. 130 SP - 517 PB - Kluwer Academic Publishers CY - Dordrecht ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Chicone, Carmen A1 - Hehl, Friedrich W. A1 - Mashhoon, Bahram T1 - Nonlocal modification of Newtonian gravity JF - Physical Review D Y1 - 2010 SN - 0556-2821 N1 - 11 pages VL - 81 IS - 6 SP - 065020 ER - TY - JOUR A1 - Blome, Hans-Joachim T1 - The scale of the universe: a unit of length JF - Comments on astrophysics. 17 (1994) Y1 - 1994 SN - 0146-2970 SP - 327 EP - 335 ER - TY - JOUR A1 - Bindal, Gaurav A1 - Sharma, Sparsh A1 - Janser, Frank A1 - Neu, Eugen T1 - Detailed analysis of variables affecting wing kinematics of bat flight JF - SAE International Journal of Aerospace Y1 - 2013 U6 - http://dx.doi.org/10.4271/2013-01-9003 SN - 1946-3901 VL - 6 IS - 2 SP - 811 EP - 818 ER - TY - JOUR A1 - Bergmann, Ole A1 - Möhren, Felix A1 - Braun, Carsten A1 - Janser, Frank T1 - On the influence of elasticity on swept propeller noise JF - AIAA SCITECH 2023 Forum N2 - 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. Y1 - 2023 U6 - http://dx.doi.org/10.2514/6.2023-0210 N1 - Session: Propeller, Open Rotor, and Rotorcraft Noise II AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online PB - AIAA ER - TY - CHAP A1 - Bergmann, Ole A1 - Götten, Falk A1 - Braun, Carsten A1 - Janser, Frank T1 - Comparison and evaluation of blade element methods against RANS simulations and test data T2 - CEAS Aeronautical Journal N2 - This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10% relative error, while appropriate BET tools overpredict the RANS results by 15–20% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results. KW - BET KW - CFD propeller simulation KW - Propeller aerodynamics KW - Actuator disk modelling KW - Propeller performance Y1 - 2022 U6 - http://dx.doi.org/10.1007/s13272-022-00579-1 SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Ole Bergmann VL - 13 SP - 535 EP - 557 PB - Springer CY - Wien ER - TY - CHAP A1 - Bergmann, Kevin A1 - Gräbener, Josefine A1 - Wild, Dominik A1 - Ulfers, H. A1 - Czupalla, Markus T1 - Study on thermal stabilization of a GEO-stationary telescope baffling system by integral application of phase change material T2 - International Conference on Environmental Systems N2 - The utilization of phase change material (PCM) for latent heat storage and thermal control of spacecraft has been demonstrated in the past in few missions only. One limiting factor was the fact that all concepts developed so far envisioned the PCM to be applied as an additional capacitor, encapsulated in its own housing, leading to mass, efficiency and accommodation challenges. Recently, the application of PCM within the scan cavity of a GEOS type satellite has been suggested, in order to tackle thermal issues due to direct sun intrusion (Choi, M., 2014). However, the application of PCM in such complex mechanical structures is extremely challenging. A new concept to tackle this issue is currently under development at the FH Aachen University of Applied Sciences. The concept "Infused Thermal Solutions (ITS)" is based on the idea to 3D print metallic structures in their regular functional shape, but double walled with internal lattice support structures, allowing the infusion of a PCM layer directly into the voids and eliminating the need for additional parts and interfaces. Together with OHB System, FH Aachen theoretically studied the application of this technology to the Meteosat Third Generation (MTG) Infra-Red Sounder (IRS) instrument. The study focuses on the scan cavity and entrance baffling assembly (EBA) of the IRS. It consists of thermal analyses, 3D-redesign and bread boarding of a scaled and PCM infused EBA version. In the thermal design of the alternative EBA, PCM was applied directly into the EBA, simulating the worst hot case sun intrusion of the mission. By applying 4kg of PCM (to a 60kg baffle) the EBA temperature excursions during sun intrusion were limited from 140K to 30K, leading to a significant thermo-opto-elastic performance gain. This paper introduces the ITS concept development status. Y1 - 2019 N1 - 49th International Conference on Environmental Systems, 7-11 July 2019, Boston, Massachusetts ; ICES-2019-72 SP - 1 EP - 14 ER - TY - BOOK A1 - Benkö, Marietta A1 - Plescher, Engelbert T1 - Space law: reconsidering the definition/delimitation question and the passage of spacecraft through foreign airspace. (Essential air and space law ; 12) Y1 - 2013 SN - 9789462360761 ; 9462360766 ; 9789460948176 PB - Eleven International Publishing CY - The Hague 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 - GEN A1 - Baumgartner, Thomas A1 - Wunderlich, Florian A1 - Jaunich, Arthur A1 - Sato, Tomoo A1 - Bundy, Georg A1 - Grießmann, Nadine A1 - Kowalski, Julia A1 - Burghardt, Stefan A1 - Hanebrink, Jörg T1 - Lighting the way: Perspectives on the global lighting market Y1 - 2012 CY - McKinsey ET - 2nd ed. ER - TY - CHAP A1 - Barnat, Miriam A1 - Bosse, Elke T1 - The challenge of creating meta-inferences: Combining data representing institutional and individual perspectives on first-year support in higher education T2 - 9th Conference on Social Science Methodology of the International Sociological Association, Leicester, UK Y1 - 2016 N1 - RC33 Conference 2016 SP - 1 EP - 20 ER - TY - CHAP A1 - Ballmann, Josef A1 - Dafnis, Athanasios A1 - Braun, Carsten A1 - Korsch, Helge A1 - Reimerdes, Hans-Günther A1 - Braun, Carsten A1 - Ballmann, Josef T1 - The HIRENASD project: High Reynolds number aerostructural dynamics experiments in the European Transonic Wind Tunnel (ETW) T2 - ICAS 2006 proceedings : 25th Congress of the International Council of the Aeronautical Sciences ; Hamburg, Germany, 3 - 8 September, 2006 : 25th International Congress of Aeronautical Sciences Y1 - 2006 SN - 0-9533991-7-6 SP - Paper No. 2006-5.11.2 PB - Optimage CY - Edinburgh ER - TY - CHAP A1 - Ballmann, Josef A1 - Boucke, Alexander A1 - Braun, Carsten T1 - Aeroelastic sensitivity in the transonic regime T2 - Symposium Transsonicum IV : proceedings of the IUTAM symposium held in Göttingen, Germany, 2 - 6 September 2002 / ed. by Helmut Sobieczky. Fluid mechanics and its applications. Vol. 73 Y1 - 2003 SN - 978-94-010-3998-7 SP - 225 EP - 236 PB - Kluwer Academic CY - Dordrecht ER - TY - CHAP A1 - Bagheri, Mohsen A1 - Schleupen, Josef A1 - Dahmann, Peter A1 - Kallweit, Stephan T1 - A multi-functional device applying for the safe maintenance at high-altitude on wind turbines T2 - 20th International Conference on Composite Materials : Copenhagen, 19 - 24th July 2015 Y1 - 2015 SP - 1 EP - 6 ER - TY - CHAP A1 - Baader, Fabian A1 - Reiswich, M. A1 - Bartsch, M. A1 - Keller, D. A1 - Tiede, E. A1 - Keck, G. A1 - Demircian, A. A1 - Friedrich, M. A1 - Dachwald, Bernd A1 - Schüller, K. A1 - Lehmann, R. A1 - Chojetzki, R. A1 - Durand, C. A1 - Rapp, L. A1 - Kowalski, Julia A1 - Förstner, R. T1 - VIPER - Student research on extraterrestrical ice penetration technology T2 - Proceedings of the 2nd Symposium on Space Educational Activities N2 - Recent analysis of scientific data from Cassini and earth-based observations gave evidence for a global ocean under a surrounding solid ice shell on Saturn's moon Enceladus. Images of Enceladus' South Pole showed several fissures in the ice shell with plumes constantly exhausting frozen water particles, building up the E-Ring, one of the outer rings of Saturn. In this southern region of Enceladus, the ice shell is considered to be as thin as 2 km, about an order of magnitude thinner than on the rest of the moon. Under the ice shell, there is a global ocean consisting of liquid water. Scientists are discussing different approaches the possibilities of taking samples of water, i.e. by melting through the ice using a melting probe. FH Aachen UAS developed a prototype of maneuverable melting probe which can navigate through the ice that has already been tested successfully in a terrestrial environment. This means no atmosphere and or ambient pressure, low ice temperatures of around 100 to 150K (near the South Pole) and a very low gravity of 0,114 m/s^2 or 1100 μg. Two of these influencing measures are about to be investigated at FH Aachen UAS in 2017, low ice temperature and low ambient pressure below the triple point of water. Low gravity cannot be easily simulated inside a large experiment chamber, though. Numerical simulations of the melting process at RWTH Aachen however are showing a gravity dependence of melting behavior. Considering this aspect, VIPER provides a link between large-scale experimental simulations at FH Aachen UAS and numerical simulations at RWTH Aachen. To analyze the melting process, about 90 seconds of experiment time in reduced gravity and low ambient pressure is provided by the REXUS rocket. In this time frame, the melting speed and contact force between ice and probes are measured, as well as heating power and a two-dimensional array of ice temperatures. Additionally, visual and infrared cameras are used to observe the melting process. Y1 - 2018 SP - 1 EP - 6 ER -