@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} } @inproceedings{NeuJanserKhatibietal.2015, author = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.}, title = {Operational modal analysis of a cantilever in a wind tunnel using optical fiber bragg grating sensors}, series = {6th International Operational Modal Analysis Conference. IOMAC´15. 2015 May 12-14 Gijon - Spain}, booktitle = {6th International Operational Modal Analysis Conference. IOMAC´15. 2015 May 12-14 Gijon - Spain}, doi = {10.13140/RG.2.1.3753.0324}, pages = {10 S.}, year = {2015}, language = {en} } @inproceedings{NeuJanserKhatibietal.2016, author = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.}, title = {In-flight vibration-based structural health monitoring of aircraft wings}, series = {30th Congress of the internatonal council of the aeronautical sciences : 25.-30. September 2016, Daejeon, Korea}, booktitle = {30th Congress of the internatonal council of the aeronautical sciences : 25.-30. September 2016, Daejeon, Korea}, pages = {10 Seiten}, year = {2016}, abstract = {This work presents a methodology for automated damage-sensitive feature extraction and anomaly detection under multivariate operational variability for in-flight assessment of wings. The method uses a passive excitation approach, i. e. without the need for artificial actuation. The modal system properties (natural frequencies and damping ratios) are used as damage-sensitive features. Special emphasis is placed on the use of Fiber Bragg Grating (FBG) sensing technology and the consideration of Operational and Environmental Variability (OEV). Measurements from a wind tunnel investigation with a composite cantilever equipped with FBG and piezoelectric sensors are used to successfully detect an impact damage. In addition, the feasibility of damage localisation and severity estimation is evaluated based on the coupling found between damageand OEV-induced feature changes.}, language = {en} } @article{NeuJanserKhatibietal.2017, author = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.}, title = {Fully Automated Operational Modal Analysis using multi-stage clustering}, series = {Mechanical Systems and Signal Processing}, volume = {Vol. 84, Part A}, journal = {Mechanical Systems and Signal Processing}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0888-3270}, doi = {10.1016/j.ymssp.2016.07.031}, pages = {308 -- 323}, year = {2017}, language = {en} } @article{NeuJanserKhatibietal.2016, author = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.}, title = {Automated modal parameter-based anomaly detection under varying wind excitation}, series = {Structural Health Monitoring}, volume = {15}, journal = {Structural Health Monitoring}, number = {6}, publisher = {Sage}, address = {London}, issn = {1475-9217}, doi = {10.1177/1475921716665803}, pages = {1 -- 20}, year = {2016}, abstract = {Wind-induced operational variability is one of the major challenges for structural health monitoring of slender engineering structures like aircraft wings or wind turbine blades. Damage sensitive features often show an even bigger sensitivity to operational variability. In this study a composite cantilever was subjected to multiple mass configurations, velocities and angles of attack in a controlled wind tunnel environment. A small-scale impact damage was introduced to the specimen and the structural response measurements were repeated. The proposed damage detection methodology is based on automated operational modal analysis. A novel baseline preparation procedure is described that reduces the amount of user interaction to the provision of a single consistency threshold. The procedure starts with an indeterminate number of operational modal analysis identifications from a large number of datasets and returns a complete baseline matrix of natural frequencies and damping ratios that is suitable for subsequent anomaly detection. Mahalanobis distance-based anomaly detection is then applied to successfully detect the damage under varying severities of operational variability and with various degrees of knowledge about the present operational conditions. The damage detection capabilities of the proposed methodology were found to be excellent under varying velocities and angles of attack. Damage detection was less successful under joint mass and wind variability but could be significantly improved through the provision of the currently encountered operational conditions.}, language = {en} } @inproceedings{NiedermeierClemensKowalskietal.2014, author = {Niedermeier, H. and Clemens, J. and Kowalski, Julia and Macht, S. and Heinen, D. and Hoffmann, R. and Linder, Peter}, title = {Navigation system for a research ice probe for antarctic glaciers}, series = {IEEE/ION Position, Location and Navigation Symposium (PLANS) ; 5-8 May 2014, Monterey, Calif.}, booktitle = {IEEE/ION Position, Location and Navigation Symposium (PLANS) ; 5-8 May 2014, Monterey, Calif.}, publisher = {IEEE}, address = {Piscataway, NJ}, organization = {Position, Location and Navigation Symposium <2014, Monterey, Calif.>}, isbn = {978-1-4799-3319-8}, pages = {959 -- 975}, year = {2014}, language = {en} } @inproceedings{NowackRoethBuehrigPolaczeketal.2008, author = {Nowack, N. and R{\"o}th, Thilo and B{\"u}hrig-Polaczek, Andreas and Klaus, G.}, title = {Advanced Sheet Metal Components Reinforced by Light Metal Cast Structures}, series = {Aluminium alloys : their physical and mechanical properties ; [proceedings of the 11th International Conference on Aluminium Alloys, 22 - 26 Sept. 2008, Aachen, Germany ; ICAA 11]}, booktitle = {Aluminium alloys : their physical and mechanical properties ; [proceedings of the 11th International Conference on Aluminium Alloys, 22 - 26 Sept. 2008, Aachen, Germany ; ICAA 11]}, number = {2}, editor = {Hirsch, J{\"u}rgen}, isbn = {978-3-527-32367-8}, pages = {2374 -- 2381}, year = {2008}, language = {en} } @inproceedings{OhndorfDachwaldSeboldtetal.2011, author = {Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and Schartner, Karl-Heinz}, title = {Flight times to the heliopause using a combination of solar and radioisotope electric propulsion}, series = {32nd International Electric Propulsion Conference}, booktitle = {32nd International Electric Propulsion Conference}, pages = {1 -- 12}, year = {2011}, abstract = {We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks' parameter set. Based on a parameter space study, in which the number of thrust units, the unit's specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere's "nose".}, language = {en} } @article{OlaruKowalskiSethietal.2012, author = {Olaru, Alexandra Maria and Kowalski, Julia and Sethi, Vaishali and Bl{\"u}mich, Bernhard}, title = {Exchange relaxometry of flow at small P{\´e}clet numbers in a glass bead pack}, series = {Journal of Magnetic Resonance (JMR)}, volume = {220}, journal = {Journal of Magnetic Resonance (JMR)}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1096-0856}, doi = {10.1016/j.jmr.2012.04.015}, pages = {32 -- 44}, year = {2012}, abstract = {In this paper we consider low P{\´e}clet number flow in bead packs. A series of relaxation exchange experiments has been conducted and evaluated by ILT analysis. In the resulting correlation maps, we observed a collapse of the signal and a translation towards smaller relaxation times with increasing flow rates, as well as a signal tilt with respect to the diagonal. In the discussion of the phenomena we present a mathematical theory for relaxation exchange experiments that considers both diffusive and advective transport. We perform simulations based on this theory and discuss them with respect to the conducted experiments.}, language = {en} } @inproceedings{OlaruKowalskiSethietal.2011, author = {Olaru, Alexandra Maria and Kowalski, Julia and Sethi, Vaishali and Bl{\"u}mich, Bernhard}, title = {Fluid Transport in Porous Media probed by Relaxation-Exchange NMR}, series = {2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.}, booktitle = {2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.}, year = {2011}, language = {en} } @inproceedings{OttenSchmidWeber2015, author = {Otten, D. and Schmid, M. and Weber, Tobias}, title = {Advances In Sheet Metal-Forming: Reduction Of Tooling Cost By Methodical Optimization}, series = {Proceedings of SAMPE Europe Conference, Amiens , France}, booktitle = {Proceedings of SAMPE Europe Conference, Amiens , France}, year = {2015}, language = {en} } @inproceedings{OttenSchmidtWeber2016, author = {Otten, D. and Schmidt, M. and Weber, Tobias}, title = {Advances in Determination of Material Parameters for Functional Simulations Based on Process Simulations}, series = {SAMPE Europe Conference 16 Liege}, booktitle = {SAMPE Europe Conference 16 Liege}, isbn = {978-1-5108-3800-0}, pages = {570 -- 577}, year = {2016}, language = {en} } @article{OttenWeberArent2018, author = {Otten, Dennis and Weber, Tobias and Arent, Jan-Christoph}, title = {Manufacturing Process Simulation - On Its Way to Industrial Application}, series = {International Journal of Aviation, Aeronautics, and Aerospace}, volume = {5}, journal = {International Journal of Aviation, Aeronautics, and Aerospace}, number = {2}, publisher = {Embry-Riddle Aeronautical University}, address = {Daytona Beach, Fla.}, issn = {2374-6793}, doi = {10.15394/ijaaa.2018.1217}, year = {2018}, abstract = {Manufacturing process simulation (MPS) has become more and more important for aviation and the automobile industry. A highly competitive market requires the use of high performance metals and composite materials in combination with reduced manufacturing cost and time as well as a minimization of the time to market for a new product. However, the use of such materials is expensive and requires sophisticated manufacturing processes. An experience based process and tooling design followed by a lengthy trial-and-error optimization is just not contemporary anymore. Instead, a tooling design process aided by simulation is used more often. This paper provides an overview of the capabilities of MPS in the fields of sheet metal forming and prepreg autoclave manufacturing of composite parts summarizing the resulting benefits for tooling design and manufacturing engineering. The simulation technology is explained briefly in order to show several simplification and optimization techniques for developing industrialized simulation approaches. Small case studies provide examples of an efficient application on an industrial scale.}, language = {en} } @article{OverduinBlomeHoell2007, author = {Overduin, James and Blome, Hans-Joachim and Hoell, Josef}, title = {Wolfgang Priester: from the big bounce to the Lambda-dominated universe}, series = {Naturwissenschaften}, volume = {94}, journal = {Naturwissenschaften}, number = {6}, isbn = {0028-1042}, pages = {417 -- 429}, year = {2007}, language = {en} } @inproceedings{PeekenTroederSchmidtetal.1985, author = {Peeken, Heinz and Troeder, Christoph and Schmidt, J. and Rosenkranz, Josef}, title = {Principles of machine noise reduction}, series = {Inter-noise 85 : proceedings ; 1985 international conference on noise control engineering ; Munich, Sept. 18 - 20, 1985. - (Schriftenreihe der Bundesanstalt f{\"u}r Arbeitsschutz : Tagungsbericht ; 39)}, booktitle = {Inter-noise 85 : proceedings ; 1985 international conference on noise control engineering ; Munich, Sept. 18 - 20, 1985. - (Schriftenreihe der Bundesanstalt f{\"u}r Arbeitsschutz : Tagungsbericht ; 39)}, publisher = {Bundesanstalt f{\"u}r Arbeitsschutz [u.a.]}, address = {Dortmund [u.a.]}, isbn = {3-88314-417-7}, pages = {23 -- 36}, year = {1985}, language = {en} } @inproceedings{PeloniCeriottiDachwald2015, author = {Peloni, A. and Ceriotti, M. and Dachwald, Bernd}, title = {Preliminary trajectory design of a multiple NEO rendezvous mission through solar sailing}, series = {Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014}, booktitle = {Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-63439-986-9}, pages = {5352 -- 5366}, year = {2015}, language = {en} } @article{PeloniCeriottiDachwald2016, author = {Peloni, Alessandro and Ceriotti, Matteo and Dachwald, Bernd}, title = {Solar-sail trajectory design for a multiple near-earth-asteroid rendezvous mission}, series = {Journal of Guidance, Control, and Dynamics}, volume = {39}, journal = {Journal of Guidance, Control, and Dynamics}, number = {12}, publisher = {AIAA}, address = {Reston, Va.}, issn = {0731-5090}, doi = {10.2514/1.G000470}, pages = {2712 -- 2724}, year = {2016}, abstract = {The scientific interest for near-Earth asteroids as well as the interest in potentially hazardous asteroids from the perspective of planetary defense led the space community to focus on near-Earth asteroid mission studies. A multiple near-Earth asteroid rendezvous mission with close-up observations of several objects can help to improve the characterization of these asteroids. This work explores the design of a solar-sail spacecraft for such a mission, focusing on the search of possible sequences of encounters and the trajectory optimization. This is done in two sequential steps: a sequence search by means of a simplified trajectory model and a set of heuristic rules based on astrodynamics, and a subsequent optimization phase. A shape-based approach for solar sailing has been developed and is used for the first phase. The effectiveness of the proposed approach is demonstrated through a fully optimized multiple near-Earth asteroid rendezvous mission. The results show that it is possible to visit five near-Earth asteroids within 10 years with near-term solar-sail technology.}, language = {en} } @article{PeloniDachwaldCeriotti2017, author = {Peloni, Alessandro and Dachwald, Bernd and Ceriotti, Matteo}, title = {Multiple near-earth asteroid rendezvous mission: Solar-sailing options}, series = {Advances in Space Research}, journal = {Advances in Space Research}, number = {In Press, Corrected Proof}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2017.10.017}, year = {2017}, language = {en} } @inproceedings{PeloniDachwaldCeriotti2017, author = {Peloni, Alessandro and Dachwald, Bernd and Ceriotti, Matteo}, title = {Multiple NEA rendezvous mission: Solar sailing options}, series = {Fourth International Symposium on Solar Sailing}, booktitle = {Fourth International Symposium on Solar Sailing}, pages = {1 -- 11}, year = {2017}, abstract = {The scientific interest in near-Earth asteroids (NEAs) and the classification of some of those as potentially hazardous asteroid for the Earth stipulated the interest in NEA exploration. Close-up observations of these objects will increase drastically our knowledge about the overall NEA population. For this reason, a multiple NEA rendezvous mission through solar sailing is investigated, taking advantage of the propellantless nature of this groundbreaking propulsion technology. Considering a spacecraft based on the DLR/ESA Gossamer technology, this work focuses on the search of possible sequences of NEA encounters. The effectiveness of this approach is demonstrated through a number of fully-optimized trajectories. The results show that it is possible to visit five NEAs within 10 years with near-term solar-sail technology. Moreover, a study on a reduced NEA database demonstrates the reliability of the approach used, showing that 58\% of the sequences found with an approximated trajectory model can be converted into real solar-sail trajectories. Lastly, this second study shows the effectiveness of the proposed automatic optimization algorithm, which is able to find solutions for a large number of mission scenarios without any input required from the user.}, language = {en} } @article{PichlerGeorgeSeileretal.2009, author = {Pichler, A. and George, A. and Seiler, F. and Srulijes, J. and Havermann, Marc}, title = {Doppler Picture Velocimetry (DPV) applied to hypersonics}, series = {Shock Waves [Elektronische Ressource] : 26th International Symposium on Shock Waves, Volume 1 / edited by Klaus Hannemann, Friedrich Seiler}, journal = {Shock Waves [Elektronische Ressource] : 26th International Symposium on Shock Waves, Volume 1 / edited by Klaus Hannemann, Friedrich Seiler}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-85168-4}, pages = {503 -- 508}, year = {2009}, language = {en} } @inproceedings{PirovanoSeefeldtDachwaldetal.2015, author = {Pirovano, Laura and Seefeldt, Patric and Dachwald, Bernd and Noomen, Ron}, title = {Attitude and Orbital Dynamics Modeling for an Uncontrolled Solar-Sail Experiment in Low-Earth Orbit}, series = {25th International Symposium on Spaceflight Dynamics, 2015, Munich, Germany}, booktitle = {25th International Symposium on Spaceflight Dynamics, 2015, Munich, Germany}, pages = {15 S.}, year = {2015}, language = {en} } @inproceedings{PirovanoSeefeldtDachwaldetal.2015, author = {Pirovano, Laura and Seefeldt, Patric and Dachwald, Bernd and Noomen, Ron}, title = {Attitude and orbital modeling of an uncontrolled solar-sail experiment in low-Earth orbit}, series = {25th International Symposium on Space Flight Dynamics ISSFD}, booktitle = {25th International Symposium on Space Flight Dynamics ISSFD}, pages = {1 -- 15}, year = {2015}, abstract = {Gossamer-1 is the first project of the three-step Gossamer roadmap, the purpose of which is to develop, prove and demonstrate that solar-sail technology is a safe and reliable propulsion technique for long-lasting and high-energy missions. This paper firstly presents the structural analysis performed on the sail to understand its elastic behavior. The results are then used in attitude and orbital simulations. The model considers the main forces and torques that a satellite experiences in low-Earth orbit coupled with the sail deformation. Doing the simulations for varying initial conditions in attitude and rotation rate, the results show initial states to avoid and maximum rotation rates reached for correct and faulty deployment of the sail. Lastly comparisons with the classic flat sail model are carried out to test the hypothesis that the elastic behavior does play a role in the attitude and orbital behavior of the sail}, language = {en} } @inproceedings{PlescherMathiakWillnecker2005, author = {Plescher, Engelbert and Mathiak, Gerhard and Willnecker, Rainer}, title = {Technical aspects of liquid diffusion model experiments}, series = {55th International Astronautical Congress : October 4 - 8, 2004, Vancouver, Canada / International Astronautical Federation. Bd. 8. IAC-04-J.5.04}, booktitle = {55th International Astronautical Congress : October 4 - 8, 2004, Vancouver, Canada / International Astronautical Federation. Bd. 8. IAC-04-J.5.04}, publisher = {International Astronautical Federation}, address = {Paris}, organization = {International Astronautical Congress <55, 2004, Vancouver>}, pages = {5019 -- 5025}, year = {2005}, language = {en} } @inproceedings{QuitterMarinoBauschat2019, author = {Quitter, Julius and Marino, Matthew and Bauschat, J.-Michael}, title = {Highly Non-Planar Aircraft Configurations: Estimation of Flight Mechanical Derivatives Using Low-Order Methods}, series = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, pages = {10 Seiten}, year = {2019}, language = {en} } @inproceedings{ReckerBosschaertsWagemakersetal.2010, author = {Recker, Elmar and Bosschaerts, Walter and Wagemakers, Rolf and Hendrick, Patrick and Funke, Harald and B{\"o}rner, Sebastian}, title = {Experimental study of a round jet in cross-flow at low momentum ratio}, pages = {13 Seiten}, year = {2010}, abstract = {With the final objective of optimizing the "Micromix" hydrogen combustion principle, a round jet in a laminar cross-flow prior to its combustion is investigated experimentally using Stereoscopic Particle Image Velocimetry. Measurements are performed at a jet to cross-stream momentum ratio of 1 and a Reynolds number, based on the jet diameter and jet velocity, of 1600. The suitability to combine side, top and end views is analyzed statistically. The statistical theory of testing hypotheses, pertaining to the joint distribution of the averaged velocity along intersecting observation planes, is employed. Overall, the averaged velocity fields of the varying observation planes feature homogeneity at a 0.05 significance level. Minor discrepancies are related to the given experimental conditions. By use of image maps, averaged and instantaneous velocity fields, an attempt is made to elucidate the flow physics and a kinematically consistent vortex model is proposed. In the time-averaged flow field, the principal vortical systems were identified and the associated mixing visualized. The jet trajectory and physical dimensions scale with the momentum ratio times the jet diameter. The jet/cross-flow mixture converging upon the span-wise centre-line, the lifting action of the Counter Rotating Vortex Pair and the reversed flow region contribute to the high entrainment and mixedness. It is shown that the jet width is larger on the downstream side as compared to the upstream side of the centre-streamline. The deepest penetration of the particles on the outer boundary occurs in the centre-plane. Meanwhile, with increasing off-centre position, the boundaries all lay further from the centre-line position than does the boundary in the centre-plane, corresponding to a kidney-like shape of the flow cross-section. The generation of the Counter Rotating Vortex Pair and the instability mechanism is documented by instantaneous image maps and vector fields. The necessary circulation for the Counter Rotating Vortex Pair originates from a combined effect of steady in-hole, hanging and wake vortices. The strong cross-flow and jet interaction induces a three-dimensional waving, the stream-wise Counter Rotating Vortex Pair pair, leading to the formation of Ring Like Vortices. A secondary Counter Rotating Vortex Pair forms on top of the primary Counter Rotating Vortex Pair, resulting in mixing by "puffs". Overall, Stereoscopic Particle Image Velocimetry proofed capable of elucidating the Jet in Cross-Flow complex flow field. The gained insight in the mixing process will definitely contribute to the "Micromix" hydrogen combustion optimization.}, language = {en} } @inproceedings{ReimerBraunBallmann2006, author = {Reimer, Lars and Braun, Carsten and Ballmann, Josef}, title = {Analysis of the static and dynamic aero-structural response of an elastic swept wing model by direct aeroelastic simulation}, series = {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}, booktitle = {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}, publisher = {Optimage}, address = {Edinburgh}, organization = {International Council of the Aeronautical Sciences (ICAS)}, isbn = {0-9533991-7-6}, pages = {Paper No. 2006-10.3.3}, year = {2006}, language = {en} } @incollection{ReimerBraunBallmann2007, author = {Reimer, Lars and Braun, Carsten and Ballmann, Josef}, title = {Computational study of the aeroelastic equilibrium configuration of a swept wind tunnel wing model in subsonic flow}, series = {High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 / Wolfgang E. Nagel ... Eds.}, booktitle = {High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 / Wolfgang E. Nagel ... Eds.}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-540-36165-7}, pages = {421 -- 434}, year = {2007}, abstract = {In the Collaborative Research Center SFB 401 at RWTH Aachen University, the numerical aeroelastic method SOFIA for direct numerical aeroelastic simulation is being progressively developed. Numerical results obtained by applying SOFIA were compared with measured data of static and dynamic aeroelastic wind tunnel tests for an elastic swept wing in subsonic flow.}, language = {en} } @inproceedings{ReimerBraunChenetal.2007, author = {Reimer, Lars and Braun, Carsten and Chen, B.-H. and Ballmann, Josef}, title = {Computational aeroelastic analysis and design of the HIRENASD wind tunnel wing model and tests}, series = {Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden}, booktitle = {Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden}, publisher = {KTH}, address = {Stockholm}, pages = {1 CD-ROM}, year = {2007}, language = {en} } @incollection{ReimerBraunWellmeretal.2010, author = {Reimer, Lars and Braun, Carsten and Wellmer, Georg and Behr, Marek and Ballmann, Josef}, title = {Development of a modular method for computational aero-structural analysis of aircraft}, series = {Summary of flow modulation and fluid-structure interaction findings. Results of the Collaborative Research Center SFB 401 at the RWTH Aachen University, Aachen, Germany, 1997-2008 / ed.: Wolfgang Schr{\"o}der. Notes on numerical fluid mechanics and multidisciplinary design. Vol. 109}, booktitle = {Summary of flow modulation and fluid-structure interaction findings. Results of the Collaborative Research Center SFB 401 at the RWTH Aachen University, Aachen, Germany, 1997-2008 / ed.: Wolfgang Schr{\"o}der. Notes on numerical fluid mechanics and multidisciplinary design. Vol. 109}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-04087-0}, pages = {205 -- 238}, year = {2010}, language = {en} } @incollection{ReimerWellmerBraunetal.2009, author = {Reimer, Lars and Wellmer, Georg and Braun, Carsten and Ballmann, Josef}, title = {Computational methods for aero-structural analysis and optimisation of aircrafts based on reduced-order structural models}, series = {MEGADESIGN and MegaOpt - German initiatives for aerodynamic simulation and optimization in aircraft design. Results of the closing symposium of the MEGADESIGN and MegaOpt projects, Braunschweig, Germany, 23 - 24 May, 2007 / Norbert Kroll ... (Eds.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 107}, booktitle = {MEGADESIGN and MegaOpt - German initiatives for aerodynamic simulation and optimization in aircraft design. Results of the closing symposium of the MEGADESIGN and MegaOpt projects, Braunschweig, Germany, 23 - 24 May, 2007 / Norbert Kroll ... (Eds.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 107}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-04092-4}, pages = {135 -- 150}, year = {2009}, abstract = {In this part of the MEGADESIGN project, aeroelastic effects are introduced into the aerodynamic analysis of aircrafts by coupling DLR's flow solvers TAU and FLOWer to a Timoshenko-beam solver. The emerging aeroelastic solvers and a method for the automatic identification of Timoshenko-beam models for wing-box structures were integrated into a simulation environment enabling the combined optimisation of aerodynamic wing shape and structure.}, language = {en} } @misc{ReiswichBrandtCzupalla2019, author = {Reiswich, Martin and Brandt, Hannes and Czupalla, Markus}, title = {Passive thermal control by integration of phase change material into additively manufactured structures}, series = {E2. 47th Student conference}, journal = {E2. 47th Student conference}, year = {2019}, abstract = {Optical Instruments require an extremely stable thermal surrounding to prevent loss of data quality by misalignments of the instrument components resulting from material deformation due to temperature f luctuations (e.g. from solar intrusion). Phase Change Material (PCM) can be applied as a thermal damper to achieve a more uniform temperature distribution. The challenge of this method is, among others, the integration of PCM into affected areas. If correctly designed, incoming heat is latently absorbed during phase change of the PCM, i.e. the temperature of a structure remains almost constant. In a cold phase, the heat during phase change is released again latently until the PCM returns to its original state of aggregation. Thus, the structure is thermally stabilized. At FH Aachen- University of Applied Sciences research is conducted to apply PCM directly into the structures of affected components (baffles, optical benches, electronic boxes, etc.). Through the application of Additive Manufacturing, the necessary voids are directly printed into these structures and filled later with PCM. Additive Manufacturing enables complex structures that would not have been possible with conservative manufacturing methods. A corresponding Breadboard was developed and manufactured by Selective Laser Melting (SLM). The current state of research includes the handling and analysis of the Breadboard, tests and a correlation of the thermal model. The results have shown analytically and practically that it is possible to use PCM as an integral part of the structure as a thermal damper. The results serve as a basis for the further development of the technology, which should maximize performance and enable the integration of PCM into much more complex structures.}, language = {en} } @inproceedings{RingsLudowicyFingeretal.2019, author = {Rings, Ren{\´e} and Ludowicy, Jonas and Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Sensitivity Analysis of General Aviation Aircraft with Parallel Hybrid-Electric Propulsion Systems}, series = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, booktitle = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, pages = {14 Seiten}, year = {2019}, language = {en} } @article{RobinsonFunkeHendrick2011, author = {Robinson, A. E. and Funke, Harald and Hendrick, P.}, title = {Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fueled µ-Scale Gas Turbine}, series = {Journal of engineering for gas turbines and power}, volume = {133}, journal = {Journal of engineering for gas turbines and power}, number = {8}, publisher = {ASME}, address = {New York}, isbn = {1528-8919}, pages = {Art. Nr. 082301 , 8 Seiten}, year = {2011}, language = {en} } @article{RobinsonFunkeHendricketal.2008, author = {Robinson, A. E. and Funke, Harald and Hendrick, P. and Recker, E. and Peirs, J.}, title = {Development of a hydrogen fuelled 1 kW ultra micro gas turbine with special respect to designing, testing and mapping of the µ-scale combustor}, series = {IEEE International Conference on Sustainable Energy Technologies, 2008 : ICSET 2008 ; Singapore, 24 - 27 Nov. 2008.}, journal = {IEEE International Conference on Sustainable Energy Technologies, 2008 : ICSET 2008 ; Singapore, 24 - 27 Nov. 2008.}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-1887-9}, pages = {656 -- 660}, year = {2008}, language = {en} } @article{RobinsonFunkeWagemakersetal.2009, author = {Robinson, A. E. and Funke, Harald and Wagemakers, R. and Grossen, J. and Bosschaerts, W. and Hendrick, P.}, title = {Numerical and Experimental Investigation of a Micromix Combustor for a Hydrogen Fuelled μ-Scale Gas Turbine}, series = {Proceedings of the ASME Turbo Expo 2009 : : presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA / sponsored by the International Gas Turbine Institute}, journal = {Proceedings of the ASME Turbo Expo 2009 : : presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA / sponsored by the International Gas Turbine Institute}, publisher = {ASME}, address = {New York, NY}, isbn = {9780791848869}, pages = {253 -- 262}, year = {2009}, language = {en} } @article{RobinsonRoennaFunke2007, author = {Robinson, A. E. and R{\"o}nna, Uwe and Funke, Harald}, title = {Testing of a 10 kW diffusive micro-mix combustor for hydrogen-fuelled micro-scale gas turbines}, series = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, journal = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, pages = {225 -- 228}, year = {2007}, language = {en} } @inproceedings{RoosenFeyerl2015, author = {Roosen, Petra and Feyerl, G{\"u}nter}, title = {Gender-specific perception and utilization of personal use vehicles}, series = {FISITA World Automotive Congress 2014 : Maastricht, The Netherlands, 2 - 6 June / [organised by the International Federation of Automotive Engineering Societies (FISITA) ...]. Bd. 1}, booktitle = {FISITA World Automotive Congress 2014 : Maastricht, The Netherlands, 2 - 6 June / [organised by the International Federation of Automotive Engineering Societies (FISITA) ...]. Bd. 1}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-5108-0209-4}, pages = {418 -- 425}, year = {2015}, language = {en} } @article{SanchezCespedesLeasureTejedorGaravitoetal.2023, author = {Sanchez-Cespedes, Lina Maria and Leasure, Douglas Ryan and Tejedor-Garavito, Natalia and Amaya Cruz, Glenn Harry and Garcia Velez, Gustavo Adolfo and Mendoza Beltr{\´a}n, Andryu Enrique and Mar{\´i}n-Salazar, Yenny Andrea and Esch, Thomas and Tatem, Andrew J. and Ospina Boh{\´o}rquez, Mariana Francisca}, title = {Social cartography and satellite-derived building coverage for post-census population estimates in difficult-to-access regions of Colombia}, series = {Population studies : a Journal of Demography}, volume = {78}, journal = {Population studies : a Journal of Demography}, number = {1}, publisher = {Taylor \& Francis}, address = {London}, issn = {1477-4747}, doi = {10.1080/00324728.2023.2190151}, pages = {3 -- 20}, year = {2023}, abstract = {Effective government services rely on accurate population numbers to allocate resources. In Colombia and globally, census enumeration is challenging in remote regions and where armed conflict is occurring. During census preparations, the Colombian National Administrative Department of Statistics conducted social cartography workshops, where community representatives estimated numbers of dwellings and people throughout their regions. We repurposed this information, combining it with remotely sensed buildings data and other geospatial data. To estimate building counts and population sizes, we developed hierarchical Bayesian models, trained using nearby full-coverage census enumerations and assessed using 10-fold cross-validation. We compared models to assess the relative contributions of community knowledge, remotely sensed buildings, and their combination to model fit. The Community model was unbiased but imprecise; the Satellite model was more precise but biased; and the Combination model was best for overall accuracy. Results reaffirmed the power of remotely sensed buildings data for population estimation and highlighted the value of incorporating local knowledge.}, language = {en} } @article{SaretzkiBergmannDahmannetal.2021, author = {Saretzki, Charlotte and Bergmann, Ole and Dahmann, Peter and Janser, Frank and Keimer, Jona and Machado, Patricia and Morrison, Audry and Page, Henry and Pluta, Emil and St{\"u}bing, Felix and K{\"u}pper, Thomas}, title = {Are small airplanes safe with regards to COVID-19 transmission?}, series = {Journal of Travel Medicine}, volume = {28}, journal = {Journal of Travel Medicine}, number = {7}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1708-8305}, doi = {10.1093/jtm/taab105}, year = {2021}, language = {en} } @article{SchaelAtanasyanBerdugoetal.2019, author = {Schael, S. and Atanasyan, A. and Berdugo, J. and Bretz, T. and Czupalla, Markus and Dachwald, Bernd and Doetinchem, P. von and Duranti, M. and Gast, H. and Karpinski, W. and Kirn, T. and L{\"u}belsmeyer, K. and Ma{\~n}a, C. and Marrocchesi, P.S. and Mertsch, P. and Moskalenko, I.V. and Schervan, T. and Schluse, M. and Schr{\"o}der, K.-U. and Schultz von Dratzig, A. and Senatore, C. and Spies, L. and Wakely, S.P. and Wlochal, M. and Uglietti, D. and Zimmermann, J.}, title = {AMS-100: The next generation magnetic spectrometer in space - An international science platform for physics and astrophysics at Lagrange point 2}, series = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {944}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, number = {162561}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-9002}, doi = {10.1016/j.nima.2019.162561}, year = {2019}, 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{SchildtBraunMarcocca2017, author = {Schildt, P. and Braun, Carsten and Marcocca, P.}, title = {Flight testing the extra 330LE flying testbed}, series = {48th Annual International Symposium of the Society of Flight Test Engineers 2017}, booktitle = {48th Annual International Symposium of the Society of Flight Test Engineers 2017}, isbn = {978-151085387-4}, pages = {349 -- 362}, year = {2017}, language = {en} } @article{SchildtBraunMarzocca2019, author = {Schildt, Ph. and Braun, Carsten and Marzocca, P.}, title = {Metric evaluating potentials of condition-monitoring approaches for hybrid electric aircraft propulsion systems}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Berlin}, issn = {1869-5590}, doi = {10.1007/s13272-019-00411-3}, pages = {1 -- 14}, year = {2019}, language = {en} } @inproceedings{SchildtMarzoccaBraunetal.2019, author = {Schildt, Philipp and Marzocca, Pier and Braun, Carsten and Dahmann, Peter and Keimer, Jona}, title = {Effects of atmospheric excitation on vibration based condition monitoring methods for hybrid-electric aircraft propulsion systems}, series = {AIAC 2018: 18th Australian International Aerospace Congress: HUMS - 11th Defence Science and Technology (DST) International Conference on Health and Usage Monitoring (HUMS 2019): ISSFD - 27th International Symposium on Space Flight Dynamics (ISSFD)}, booktitle = {AIAC 2018: 18th Australian International Aerospace Congress: HUMS - 11th Defence Science and Technology (DST) International Conference on Health and Usage Monitoring (HUMS 2019): ISSFD - 27th International Symposium on Space Flight Dynamics (ISSFD)}, isbn = {9781925627213}, pages = {923 -- 928}, year = {2019}, language = {en} } @inproceedings{SchirraBauschatWatmuff2014, author = {Schirra, Julian and Bauschat, J.-Michael and Watmuff, J.H.}, title = {Accurate induced drag prediction for highly non-planar lifting systems}, series = {19th Australasian Fluid Mechanics Conference : 8.-11. Dezember 2014, Melbourne, Australia}, booktitle = {19th Australasian Fluid Mechanics Conference : 8.-11. Dezember 2014, Melbourne, Australia}, pages = {4 Seiten}, year = {2014}, abstract = {The impact of wake model effects is investigated for two highly non-planar lifting systems. Dependent on the geometrical arrangement of the configuration, the wake model shape is found to considerably affect the estimation. Particularly at higher angles of attack, an accurate estimation based on the common linear wake model approaches is involved.}, language = {en} } @article{SchirraBissonnetteBramesfeld2018, author = {Schirra, Julian and Bissonnette, William and Bramesfeld, G{\"o}tz}, title = {Wake-model effects on induced drag prediction of staggered boxwings}, series = {Aerospace}, volume = {5}, journal = {Aerospace}, number = {1}, issn = {2226-4310}, doi = {10.3390/aerospace5010014}, year = {2018}, language = {en} } @inproceedings{SchirraJ2013, author = {Schirra, Julian and J., Watmuff}, title = {Euler-based induced drag estimation for highly non-planar lifting systems during conceptional design}, series = {62. Deutscher Luft- und Raumfahrtkongress 2013 : 10. - 12. September 2032, Stuttgart, Haus der Wirtschaft}, booktitle = {62. Deutscher Luft- und Raumfahrtkongress 2013 : 10. - 12. September 2032, Stuttgart, Haus der Wirtschaft}, publisher = {Dt. Gesellschaft f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, organization = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth}, pages = {1 -- 8}, year = {2013}, language = {en} } @inproceedings{SchirraWatmuffBauschat2014, author = {Schirra, Julian and Watmuff, Jon and Bauschat, J.-Michael}, title = {A relative assessment of existing potential-methodologies to accurately estimate the induced drag of highly non-planar lifting systems}, series = {Advanced aero concepts, design and operations : Applied Aerodynamics Conference : July 22 -24, 2014, Bristol, UK}, booktitle = {Advanced aero concepts, design and operations : Applied Aerodynamics Conference : July 22 -24, 2014, Bristol, UK}, organization = {Applied Aerodynamics Conference <2014, Bristol>}, pages = {1 -- 13}, 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} } @inproceedings{SchleupenEngemannBagherietal.2016, author = {Schleupen, Josef and Engemann, Heiko and Bagheri, Mohsen and Kallweit, Stephan}, title = {The potential of SMART climbing robot combined with a weatherproof cabin for rotor blade maintenance}, series = {17th European Conference on Composite Materials - ECCM, Munich, Germany}, booktitle = {17th European Conference on Composite Materials - ECCM, Munich, Germany}, pages = {1 -- 8}, year = {2016}, language = {en} }