TY  - JOUR
A1  - Thoma, Andreas
A1  - Thomessen, Karolin
A1  - Gardi, Alessandro
A1  - Fisher, A.
A1  - Braun, Carsten
T1  - Prioritising paths: An improved cost function for local path planning for UAV in medical applications
JF  - The Aeronautical Journal
N2  - Even the shortest flight through unknown, cluttered environments requires reliable local path planning algorithms to avoid unforeseen obstacles. The algorithm must evaluate alternative flight paths and identify the best path if an obstacle blocks its way. Commonly, weighted sums are used here. This work shows that weighted Chebyshev distances and factorial achievement scalarising functions are suitable alternatives to weighted sums if combined with the 3DVFH* local path planning algorithm. Both methods considerably reduce the failure probability of simulated flights in various environments. The standard 3DVFH* uses a weighted sum and has a failure probability of 50% in the test environments. A factorial achievement scalarising function, which minimises the worst combination of two out of four objective functions, reaches a failure probability of 26%; A weighted Chebyshev distance, which optimises the worst objective, has a failure probability of 30%. These results show promise for further enhancements and to support broader applicability.
KW  - Path planning
KW  - Cost function
KW  - Multi-objective optimization
Y1  - 2023
U6  - https://doi.org/10.1017/aer.2023.68
SN  - 0001-9240 (Print)
SN  - 2059-6464 (Online)
IS  - First View
SP  - 1
EP  - 18
PB  - Cambridge University Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Koch, Christopher
A1  - Böhnisch, Nils
A1  - Verdonck, Hendrik
A1  - Hach, Oliver
A1  - Braun, Carsten
T1  - Comparison of unsteady low- and mid-fidelity propeller aerodynamic methods for whirl flutter applications
JF  - Applied Sciences
N2  - Aircraft configurations with propellers have been drawing more attention in recent times, partly due to new propulsion concepts based on hydrogen fuel cells and electric motors. These configurations are prone to whirl flutter, which is an aeroelastic instability affecting airframes with elastically supported propellers. It commonly needs to be mitigated already during the design phase of such configurations, requiring, among other things, unsteady aerodynamic transfer functions for the propeller. However, no comprehensive assessment of unsteady propeller aerodynamics for aeroelastic analysis is available in the literature. This paper provides a detailed comparison of nine different low- to mid-fidelity aerodynamic methods, demonstrating their impact on linear, unsteady aerodynamics, as well as whirl flutter stability prediction. Quasi-steady and unsteady methods for blade lift with or without coupling to blade element momentum theory are evaluated and compared to mid-fidelity potential flow solvers (UPM and DUST) and classical, derivative-based methods. Time-domain identification of frequency-domain transfer functions for the unsteady propeller hub loads is used to compare the different methods. Predictions of the minimum required pylon stiffness for stability show good agreement among the mid-fidelity methods. The differences in the stability predictions for the low-fidelity methods are higher. Most methods studied yield a more unstable system than classical, derivative-based whirl flutter analysis, indicating that the use of more sophisticated aerodynamic modeling techniques might be required for accurate whirl flutter prediction.
KW  - Aeroelasticity
KW  - Flutter
KW  - Propeller whirl flutter
KW  - Unsteady aerodynamics
KW  - 1P hub loads
Y1  - 2024
U6  - https://doi.org/10.3390/app14020850
SN  - 2076-3417
VL  - 14
IS  - 2
SP  - 1
EP  - 28
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Busse, Daniel
A1  - Esch, Thomas
A1  - Muntaniol, Roman
T1  - Thermal management in E-carsharing vehicles - preconditioning concepts of passenger compartments
T2  - E-Mobility in Europe : trends and good practice
N2  - The issue of thermal management in electric vehicles includes the topics of drivetrain cooling and heating, interior temperature, vehicle body conditioning and safety. In addition to the need to ensure optimal thermal operating conditions of the drivetrain components (drive motor, battery and electrical components), thermal comfort must be provided for the passengers. Thermal comfort is defined as the feeling which expresses the satisfaction of the passengers with the ambient conditions in the compartment. The influencing factors on thermal comfort are the temperature and humidity as well as the speed of the indoor air and the clothing and the activity of the passengers, in addition to the thermal radiation and the temperatures of the interior surfaces. The generation and the maintenance of free visibility (ice- and moisture-free windows) count just as important as on-demand heating and cooling of the entire vehicle. A Carsharing climate concept of the innovative ec2go vehicle stipulates and allows for only seating areas used by passengers to be thermally conditioned in a close-to-body manner. To enable this, a particular feature has been added to the preconditioning of the Carsharing electric vehicle during the electric charging phase at the parking station.
KW  - Carsharing
KW  - Thermal management
KW  - Thermal comfort
KW  - Electrical vehicle
KW  - Passenger compartment
Y1  - 2015
SN  - 978-3-319-13193-1
U6  - https://doi.org/10.1007/978-3-319-13194-8_18
SP  - 327
EP  - 343
PB  - Springer
CY  - Cham [u.a.]
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Chen, B.-H.
A1  - Ballmann, Josef
T1  - Computational aeroelastic analysis and design of the HIRENASD wind tunnel wing model and tests
T2  - Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden
Y1  - 2007
PB  - KTH
CY  - Stockholm
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro A.
A1  - Circi, Christian
T1  - Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ;  Bernd Dachwald
JF  - Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2
Y1  - 2007
SN  - 0162-3192
N1  - 2. ISBN: 0731-5090
SP  - 512
EP  - 520
ER  - 
TY  - CHAP
A1  - Rings, René
A1  - Ludowicy, Jonas
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Sensitivity Analysis of General Aviation Aircraft with Parallel Hybrid-Electric Propulsion Systems
T2  - Asia Pacific International Symposium on Aerospace Technology. APISAT 2019
Y1  - 2019
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
A1  - Wie, Bong
T1  - Solar Sail Trajectory Optimization for the Solar Polar Imager (SPI) Mission
JF  - AIAA Guidance, Navigation, and Control Conference & Exhibit - AIAA Atmospheric Flight Mechanics Conference & Exhibit - AIAA Modeling and Simulation Technologies Conference & Exhibit - AIAA/AAS Astrodynamics Specialist Conference & Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )
Y1  - 2006
SN  - 1-56347-802-1
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; American Astronautical Society ; AIAA/AAS Astrodynamics Specialist Conference & Exhibit <2006,  Keystone, Colo.> ; AIAA paper number: AIAA-2006-6177
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro A
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R
T1  - Optical solar sail degradation modelling
T2  - 1st International Symposium on Solar Sailing
N2  - We propose a simple parametric OSSD model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails.
Y1  - 2007
N1  - 1st International Symposium on Solar Sailing 27–29 June 2007, Herrsching, Germany
SP  - 1
EP  - 27
ER  - 
TY  - CHAP
A1  - Schildt, Philipp
A1  - Marzocca, Pier
A1  - Braun, Carsten
A1  - Dahmann, Peter
A1  - Keimer, Jona
T1  - Effects of atmospheric excitation on vibration based condition monitoring methods for hybrid-electric aircraft propulsion systems
T2  - 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)
Y1  - 2019
SN  - 9781925627213
SP  - 923
EP  - 928
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Schmidt, Tanja D.
A1  - Seboldt, Wolfgang
A1  - Auweter-Kurtz, 
T1  - Flight Opportunities from Mars to Earth for Piloted Missions Using Continuous Thrust Propulsion / Schmidt, Tanja D. ; Dachwald, Bernd ; Seboldt, Wolfgang ; Auweter-Kurtz, Monika
Y1  - 2003
N1  - 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
20-23 July 2003, Huntsville, Alabama ; AIAA 2003-4573
SP  - 1
EP  - 9
PB  - -
ER  - 
TY  - JOUR
A1  - Hein, Andreas M.
A1  - Eubanks, T. Marshall
A1  - Hibberd, Adam
A1  - Fries, Dan
A1  - Schneider, Jean
A1  - Lingam, Manasvi
A1  - Kennedy, Robert
A1  - Perakis, Nikolaos
A1  - Dachwald, Bernd
A1  - Kervella, Pierre
T1  - Interstellar Now! Missions to and sample returns from nearby interstellar objects
N2  - The recently discovered first high velocity hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Interstellar objects likely formed very far from the solar system in both time and space; their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.
Y1  - 2020
SP  - 1
EP  - 8
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Campen, R.
A1  - Kowalski, Julia
A1  - Lyons, W.B.
A1  - Tulaczyk, S.
A1  - Dachwald, Bernd
A1  - Pettit, E.
A1  - Welch, K. A.
A1  - Mikucki, J.A.
T1  - Microbial diversity of an Antarctic subglacial community and high‐resolution replicate sampling inform hydrological connectivity in a polar desert
JF  - Environmental Microbiology
Y1  - 2019
U6  - https://doi.org/10.1111/1462-2920.14607
SN  - 1462-2920
IS  - accepted article
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Finger, Felix
A1  - Götten, Falk
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Mass, Primary Energy, and Cost - The Impact of Optimization Objectives on the Initial Sizing of Hybrid-Electric General Aviation Aircraft
T2  - Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany
Y1  - 2019
U6  - https://doi.org/10.25967/490012
SP  - 1
EP  - 17
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
T1  - Multiple Near-Earth Asteroid Rendezvous and Sample Return Using First Generation Solar Sailcraft
JF  - Acta Astronautica. 57 (2005), H. 11
Y1  - 2005
SN  - 0094-5765
SP  - 864
EP  - 875
ER  - 
TY  - CHAP
A1  - Peloni, Alessandro
A1  - Dachwald, Bernd
A1  - Ceriotti, Matteo
T1  - Multiple NEA rendezvous mission: Solar sailing options
T2  - Fourth International Symposium on Solar Sailing
N2  - 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.
KW  - Multiphase
KW  - Trajectory Optimization
KW  - Automated Optimization
KW  - Gossamer
KW  - Sequence-Search
Y1  - 2017
N1  - Fourth International Symposium on Solar Sailing (ISSS 2017), Kyoto, Japan, 17-20 Jan 2017.
http://www.jsforum.or.jp/ISSS2017/
SP  - 1
EP  - 11
ER  - 
TY  - CHAP
A1  - Braun, Carsten
A1  - Boucke, Alexander
A1  - Ballmann, Josef
T1  - Numerical study of the influence of dynamic pressure and deflected ailerons on the deformation of a high speed wing model
T2  - High performance computing in science and engineering '04. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2004 /  Eds.: Egon Krause ...
Y1  - 2005
SN  - 3-540-22943-4
SP  - 225
EP  - 236
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Schael, S.
A1  - Atanasyan, A.
A1  - Berdugo, J.
A1  - Bretz, T.
A1  - Czupalla, Markus
A1  - Dachwald, Bernd
A1  - Doetinchem, P. von
A1  - Duranti, M.
A1  - Gast, H.
A1  - Karpinski, W.
A1  - Kirn, T.
A1  - Lübelsmeyer, K.
A1  - Maña, C.
A1  - Marrocchesi, P.S.
A1  - Mertsch, P.
A1  - Moskalenko, I.V.
A1  - Schervan, T.
A1  - Schluse, M.
A1  - Schröder, K.-U.
A1  - Schultz von Dratzig, A.
A1  - Senatore, C.
A1  - Spies, L.
A1  - Wakely, S.P.
A1  - Wlochal, M.
A1  - Uglietti, D.
A1  - Zimmermann, J.
T1  - AMS-100: The next generation magnetic spectrometer in space – An international science platform for physics and astrophysics at Lagrange point 2
JF  - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Y1  - 2019
U6  - https://doi.org/10.1016/j.nima.2019.162561
SN  - 0168-9002
VL  - 944
IS  - 162561
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
T1  - Solar sailcraft of the first generation mission applications to near-earth asteroids
Y1  - 2003
N1  - 54th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law 29 September - 3 October 2003, Bremen, Germany IAC-03-Q.5.06
ER  - 
TY  - JOUR
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Marino, Matthew
A1  - Bil, Cees
T1  - Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach
JF  - SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021
Y1  - 2021
U6  - https://doi.org/10.2514/6.2021-1535
SP  - 1
EP  - 12
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - CHAP
A1  - Hippe, Jonas
A1  - Finger, Felix
A1  - Götten, Falk
A1  - Braun, Carsten
T1  - Propulsion System Qualification of a 25 kg VTOL-UAV: Hover Performance of Single and Coaxial Rotors and Wind-Tunnel Experiments on Cruise Propellers
T2  - Deutscher Luft- und Raumfahrtkongress - DLRK 2020
N2  - This paper presents an approach for UAV propulsion system qualification and validation on the example of FH Aachen's 25 kg cargo UAV "PhoenAIX". Thrust and power consumption are the most important aspects of a propulsion system's layout. In the initial design phase, manufacturers' data has to be trusted, but the validation of components is an essential step in the design process. This process is presented in this paper. The vertical takeoff system is designed for efficient hover; therefore, performance under static conditions is paramount. Because an octo-copter layout with coaxial rotors is considered, the impact of this design choice is analyzed. Data on thrust, voltage stability, power consumption, rotational speed, and temperature development of motors and controllers are presented for different rotors. The fixed-wing propulsion system is designed for efficient cruise flight. At the same time, a certain static thrust has to be provided, as the aircraft needs to accelerate to cruise speed. As for the hover-system, data on different propellers is compared. The measurements were taken for static conditions, as well as for different inflow velocities, using the FH-Aachen's wind-tunnel.
Y1  - 2020
N1  - 69. Deutscher Luft- und Raumfahrtkongress 2020, 1. September 2020 - 3. September 2020, online
ER  -