TY - JOUR A1 - Finger, Felix A1 - Braun, Carsten A1 - Bil, Cees T1 - Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft JF - Journal of Aircraft N2 - Until electric energy storage systems are ready to allow fully electric aircraft, the combination of combustion engine and electric motor as a hybrid-electric propulsion system seems to be a promising intermediate solution. Consequently, the design space for future aircraft is expanded considerably, as serial hybrid-electric, parallel hybrid-electric, fully electric, and conventional propulsion systems must all be considered. While the best propulsion system depends on a multitude of requirements and considerations, trends can be observed for certain types of aircraft and certain types of missions. This Paper provides insight into some factors that drive a new design toward either conventional or hybrid propulsion systems. General aviation aircraft, regional transport aircraft vertical takeoff and landing air taxis, and unmanned aerial vehicles are chosen as case studies. Typical missions for each class are considered, and the aircraft are analyzed regarding their takeoff mass and primary energy consumption. For these case studies, a high-level approach is chosen, using an initial sizing methodology. Only parallel-hybrid-electric powertrains are taken into account. Aeropropulsive interaction effects are neglected. Results indicate that hybrid-electric propulsion systems should be considered if the propulsion system is sized by short-duration power constraints. However, if the propulsion system is sized by a continuous power requirement, hybrid-electric systems offer hardly any benefit. Y1 - 2020 U6 - https://doi.org/10.2514/1.C035897 SN - 1533-3868 VL - 57 IS - 5 PB - AIAA CY - Reston, Va. ER - TY - CHAP A1 - Geiben, Benedikt A1 - Götten, Falk A1 - Havermann, Marc T1 - Aerodynamic analysis of a winged sub-orbital spaceplane N2 - This paper primarily presents an aerodynamic CFD analysis of a winged spaceplane geometry based on the Japanese Space Walker proposal. StarCCM was used to calculate aerodynamic coefficients for a typical space flight trajectory including super-, trans- and subsonic Mach numbers and two angles of attack. Since the solution of the RANS equations in such supersonic flight regimes is still computationally expensive, inviscid Euler simulations can principally lead to a significant reduction in computational effort. The impact on accuracy of aerodynamic properties is further analysed by comparing both methods for different flight regimes up to a Mach number of 4. Y1 - 2020 U6 - https://doi.org/10.25967/530170 N1 - 69. Deutscher Luft- und Raumfahrtkongress 2020, 1. September 2020 - 3. September 2020, online PB - DGLR CY - Bonn 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 - TY - CHAP A1 - Götten, Falk A1 - Finger, Felix A1 - Havermann, Marc A1 - Braun, Carsten A1 - Marino, Matthew A1 - Bil, Cees T1 - Full Configuration Drag Estimation of Small-to-Medium Range UAVs and its Impact on Initial Sizing Optimization T2 - CEAS Aeronautical Journal N2 - The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used on surveillance, reconnaissance, and search and rescue missions. The aircraft are simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft. Y1 - 2020 U6 - https://doi.org/10.1007/s13272-021-00522-w SN - 1869-5590 N1 - 69. Deutscher Luft- und Raumfahrtkongress 2020, 1. September 2020 - 3. September 2020, online VL - 12 SP - 589 EP - 603 PB - Springer CY - Wien ER - TY - CHAP A1 - Sildatke, Michael A1 - Karwanni, Hendrik A1 - Kraft, Bodo A1 - Schmidts, Oliver A1 - Zündorf, Albert T1 - Automated Software Quality Monitoring in Research Collaboration Projects T2 - ICSEW'20: Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops N2 - In collaborative research projects, both researchers and practitioners work together solving business-critical challenges. These projects often deal with ETL processes, in which humans extract information from non-machine-readable documents by hand. AI-based machine learning models can help to solve this problem. Since machine learning approaches are not deterministic, their quality of output may decrease over time. This fact leads to an overall quality loss of the application which embeds machine learning models. Hence, the software qualities in development and production may differ. Machine learning models are black boxes. That makes practitioners skeptical and increases the inhibition threshold for early productive use of research prototypes. Continuous monitoring of software quality in production offers an early response capability on quality loss and encourages the use of machine learning approaches. Furthermore, experts have to ensure that they integrate possible new inputs into the model training as quickly as possible. In this paper, we introduce an architecture pattern with a reference implementation that extends the concept of Metrics Driven Research Collaboration with an automated software quality monitoring in productive use and a possibility to auto-generate new test data coming from processed documents in production. Through automated monitoring of the software quality and auto-generated test data, this approach ensures that the software quality meets and keeps requested thresholds in productive use, even during further continuous deployment and changing input data. Y1 - 2020 U6 - https://doi.org/10.1145/3387940.3391478 N1 - ICSE '20: 42nd International Conference on Software Engineering, Seoul, Republic of Korea, 27 June 2020 - 19 July 2020 SP - 603 EP - 610 PB - IEEE CY - New York, NY ER - TY - BOOK A1 - Yoshinobu, Tatsuo A1 - Schöning, Michael Josef ED - Yoshinobu, Tatsuo ED - Schöning, Michael Josef T1 - Light-addressing and chemical imaging technologies for electrochemical sensing Y1 - 2020 SN - 978-3-03943-029-1 U6 - https://doi.org/10.3390/books978-3-03943-029-1 N1 - This book is a printed edition of the Special Issue Light-Addressing and Chemical Imaging Technologies for Electrochemical Sensing that was published in Sensors PB - MDPI CY - Basel ER - TY - CHAP A1 - Frantz, Cathy A1 - Binder, Matthias A1 - Busch, Konrad A1 - Ebert, Miriam A1 - Heinrich, Andreas A1 - Kaczmarkiewicz, Nadine A1 - Schlögl-Knothe, Bärbel A1 - Kunze, Tobias A1 - Schuhbauer, Christian A1 - Stetka, Markus A1 - Schwager, Christian A1 - Spiegel, Michael A1 - Teixeira Boura, Cristiano José A1 - Bauer, Thomas A1 - Bonk, Alexander A1 - Eisen, Stefan A1 - Funck, Bernhard T1 - Basic Engineering of a High Performance Molten Salt Tower Receiver System T2 - AIP Conference Proceedings N2 - The production of dispatchable renewable energy will be one of the most important key factors of the future energy supply. Concentrated solar power (CSP) plants operated with molten salt as heat transfer and storage media are one opportunity to meet this challenge. Due to the high concentration factor of the solar tower technology the maximum process temperature can be further increased which ultimately decreases the levelized costs of electricity of the technology (LCOE). The development of an improved tubular molten salt receiver for the next generation of molten salt solar tower plants is the aim of this work. The receiver is designed for a receiver outlet temperature up to 600 °C. Together with a complete molten salt system, the receiver will be integrated into the Multi-Focus-Tower (MFT) in Jülich (Germany). The paper describes the basic engineering of the receiver, the molten salt tower system and a laboratory corrosion setup. Y1 - 2020 U6 - https://doi.org/10.1063/5.0085895 N1 - SOLARPACES 2020: 26th International Conference on Concentrating Solar Power and Chemical Energy Systems, 28 September – 2 October 2020, Freiburg, Germany SP - 1 EP - 10 ER - TY - JOUR A1 - Stulpe, Werner T1 - Pairwise coexistence of effects versus coexistence JF - Journal of Physics: Conference Series Y1 - 2020 U6 - https://doi.org/10.1088/1742-6596/1638/1/012004 SN - 1742-6596 VL - 1638 IS - 012004 SP - 1 EP - 21 PB - IOP CY - Bristol ER - TY - CHAP A1 - Marinkovic, Marko A1 - Butenweg, Christoph T1 - Seismic behaviour of RC frames with uncoupled masonry infills having two storeys or two bays T2 - Brick and Block Masonry - From Historical to Sustainable Masonry. Proceedings of the 17th International Brick/Block Masonry Conference N2 - Reinforced concrete (RC) structures with masonry infills are widely used for several types of buildings all over the world. However, it is well known that traditional masonry infills constructed with rigid contact to the surrounding RC frame performed rather poor in past earthquakes. Masonry infills showed severe in-plane damages and failed in many cases under out-of-plane seismic loading. As the undesired interactions between frames and infills changes the load transfer on building level, complete collapses of buildings were observed. A possible solution is uncoupling of masonry infills to the frame to reduce the infill contribution activated by the frame deformation under horizontal loading. The paper presents numerical simulations on RC frames equipped with the innovative decoupling system INODIS. The system was developed within the European project INSYSME and allows an effective uncoupling of frame and infill. The simulations are carried out with a micro-modelling approach, which is able to predict the complex nonlinear behaviour resulting from the different materials and their interaction. Each brick is modelled individually and connected taking into account nonlinearity of a brick mortar interface. The calibration of the model is based on small specimen tests and experimental results for one bay one storey frame are used for the validation. The validated model is further used for parametric studies on two storey and two bay infilled frames. The response and change of the structural stiffness are analysed and compared to the traditionally infilled frame. The results confirm the effectiveness of the INODIS system with less damage and relatively low contribution of the infill at high drift levels. In contrast to the uncoupled system configurations, traditionally infilled frames experienced brittle failure at rather low drift levels. Y1 - 2020 U6 - https://doi.org/10.1201/9781003098508-72 N1 - 17th International Brick/Block Masonry Conference (17thIB2MaC 2020), July 5-8, 2020, Kraków, Poland SP - 1 EP - 7 PB - CRC Press CY - London ER - TY - BOOK A1 - Butenweg, Christoph A1 - Hoffmeister, Benno A1 - Holtschoppen, Britta A1 - Klinkel, Sven A1 - Rosin, Julia A1 - Schmitt, Timo T1 - Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference) Y1 - 2020 SN - 978-3-86359-729-0 PB - Apprimus Verlag CY - Aachen ER -