TY  - JOUR
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Impact of electric propulsion technology and mission requirements on the performance of VTOL UAVs
JF  - CEAS Aeronautical Journal
N2  - One of the engineering challenges in aviation is the design of transitioning vertical take-off and landing (VTOL) aircraft. Thrust-borne flight implies a higher mass fraction of the propulsion system, as well as much increased energy consumption in the take-off and landing phases. This mass increase is typically higher for aircraft with a separate lift propulsion system than for aircraft that use the cruise propulsion system to support a dedicated lift system. However, for a cost–benefit trade study, it is necessary to quantify the impact the VTOL requirement and propulsion configuration has on aircraft mass and size. For this reason, sizing studies are conducted. This paper explores the impact of considering a supplemental electric propulsion system for achieving hovering flight. Key variables in this study, apart from the lift system configuration, are the rotor disk loading and hover flight time, as well as the electrical systems technology level for both batteries and motors. Payload and endurance are typically used as the measures of merit for unmanned aircraft that carry electro-optical sensors, and therefore the analysis focuses on these particular parameters.
Y1  - 2018
U6  - http://dx.doi.org/10.1007/s13272-018-0352-x
SN  - 1869-5582 print
SN  - 1869-5590 online
VL  - 10
IS  - 3
SP  - 843
PB  - Springer
ER  - 
TY  - JOUR
A1  - Otten, Dennis
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
T1  - Manufacturing Process Simulation – On Its Way to Industrial Application
JF  - International Journal of Aviation, Aeronautics, and Aerospace
N2  - 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.
Y1  - 2018
U6  - http://dx.doi.org/10.15394/ijaaa.2018.1217
SN  - 2374-6793
VL  - 5
IS  - 2
PB  - Embry-Riddle Aeronautical University
CY  - Daytona Beach, Fla.
ER  - 
TY  - JOUR
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Orifici, Adrian C.
T1  - Fully Automated Operational Modal Analysis using multi-stage clustering
JF  - Mechanical Systems and Signal Processing
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.ymssp.2016.07.031
SN  - 0888-3270
VL  - Vol. 84, Part A
SP  - 308
EP  - 323
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Peloni, Alessandro
A1  - Dachwald, Bernd
A1  - Ceriotti, Matteo
T1  - Multiple near-earth asteroid rendezvous mission: Solar-sailing options
JF  - Advances in Space Research
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.asr.2017.10.017
SN  - 0273-1177
IS  - In Press, Corrected Proof
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Ruff-Stahl, Hans-Joachim K.
T1  - Advances in Composite Manufacturing of Helicopter Parts
JF  - International Journal of Aviation, Aeronautics, and Aerospace
Y1  - 2017
U6  - http://dx.doi.org/10.15394/ijaaa.2017.1153
SN  - 2374-6793
VL  - 4
IS  - 1
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
A1  - Steffen, Lucas
A1  - Balvers, Johannes M.
A1  - Duhovic, Miro
T1  - Thermal optimization of composite autoclave molds using the shift factor approach for boundary condition estimation
JF  - Journal of Composite Materials
Y1  - 2017
U6  - http://dx.doi.org/10.1177/0021998317699868
SN  - 1530-793X
VL  - 51
IS  - 12
SP  - 1753
EP  - 1767
PB  - Sage
CY  - London
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  - http://dx.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  - Kowalski, Julia
A1  - Linder, Peter
A1  - Zierke, S.
A1  - Wulfen, B. van
A1  - Clemens, J.
A1  - Konstantinidis, K.
A1  - Ameres, G.
A1  - Hoffmann, R.
A1  - Mikucki, J.
A1  - Tulaczyk, S.
A1  - Funke, O.
A1  - Blandfort, D.
A1  - Espe, Clemens
A1  - Feldmann, Marco
A1  - Francke, Gero
A1  - Hiecker, S.
A1  - Plescher, Engelbert
A1  - Schöngarth, Sarah
A1  - Dachwald, Bernd
A1  - Digel, Ilya
A1  - Artmann, Gerhard
A1  - Eliseev, D.
A1  - Heinen, D.
A1  - Scholz, F.
A1  - Wiebusch, C.
A1  - Macht, S.
A1  - Bestmann, U.
A1  - Reineking, T.
A1  - Zetzsche, C.
A1  - Schill, K.
A1  - Förstner, R.
A1  - Niedermeier, H.
A1  - Szumski, A.
A1  - Eissfeller, B.
A1  - Naumann, U.
A1  - Helbing, K.
T1  - Navigation technology for exploration of glacier ice with maneuverable melting probes
JF  - Cold Regions Science and Technology
N2  - The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.coldregions.2015.11.006
SN  - 0165-232X
IS  - 123
SP  - 53
EP  - 70
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Braun, Carsten
A1  - Orifici, Adrian C.
T1  - Operational Modal Analysis of a wing excited by transonic flow
JF  - Aerospace Science and Technology
N2  - 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.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.ast.2015.11.032
SN  - 1270-9638
VL  - 49
SP  - 73
EP  - 79
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Funke, Harald
A1  - Keinz, Jan
A1  - Kusterer, Karsten
A1  - Ayed, Anis Haj
A1  - Kazari, Masahide
A1  - Kitajima, Junichi
A1  - Horikawa, Atsushi
A1  - Okada, Kunio
T1  - Experimental and Numerical Study on Optimizing the Dry Low NOₓ Micromix Hydrogen Combustion Principle for Industrial Gas Turbine Applications
JF  - Journal of Thermal Science and Engineering Applications
N2  - Combined with the use of renewable energy sources for its production, hydrogen represents a possible alternative gas turbine fuel for future low-emission power generation. Due to the difference in the physical properties of hydrogen compared to other fuels such as natural gas, well-established gas turbine combustion systems cannot be directly applied to dry low NOₓ (DLN) hydrogen combustion. The DLN micromix combustion of hydrogen has been under development for many years, since it has the promise to significantly reduce NOₓ emissions. This combustion principle for air-breathing engines is based on crossflow mixing of air and gaseous hydrogen. Air and hydrogen react in multiple miniaturized diffusion-type flames with an inherent safety against flashback and with low NOₓ emissions due to a very short residence time of the reactants in the flame region. The paper presents an advanced DLN micromix hydrogen application. The experimental and numerical study shows a combustor configuration with a significantly reduced number of enlarged fuel injectors with high-thermal power output at constant energy density. Larger fuel injectors reduce manufacturing costs, are more robust and less sensitive to fuel contamination and blockage in industrial environments. The experimental and numerical results confirm the successful application of high-energy injectors, while the DLN micromix characteristics of the design point, under part-load conditions, and under off-design operation are maintained. Atmospheric test rig data on NOₓ emissions, optical flame-structure, and combustor material temperatures are compared to numerical simulations and show good agreement. The impact of the applied scaling and design laws on the miniaturized micromix flamelets is particularly investigated numerically for the resulting flow field, the flame-structure, and NOₓ formation.
Y1  - 2016
U6  - http://dx.doi.org/10.1115/1.4034849
SN  - 1948-5093
N1  - TSEA-15-1227
VL  - 9
IS  - 2
SP  - 021001
EP  - 021001-10
PB  - ASME
CY  - New York, NY
ER  -