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 - 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 - TY - CHAP A1 - Jung, Alexander A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts T2 - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK N2 - The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample. Y1 - 2018 ER - TY - CHAP A1 - Hüning, Felix A1 - Heuermann, Holger A1 - Wache, Franz-Josef T1 - Wireless CAN T2 - Tagungsband AALE 2018 : das Forum für Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 15. Fachkonferenz, Regensburg ; [15. Konferenz für Angewandte Automatisierungstechnik in Lehre und Entwicklung / TH Köln; VFAALE, Verein der Freunde und Förderer der Angewandten Automatisierungstechnik] N2 - Das vorgestellte System zu Wireless CAN bietet die Möglichkeit, CAN kabellos zu übertragen. Beide vorgestellten und entwickelten Konzepte funktionieren korrekt und ermöglichen den Auf-bau von kabellosen CAN Schnittstellen. Durch den kleinen Aufbau kann diese Technologie auch für eingebettete Systeme verwendet werden. Zudem bietet dieser Ansatz die Möglichkeit, durch die Entwicklung von geeigneten ICs die Größe des Systems bis auf Bauteilgröße zu reduzieren, um eine noch bessere Integration in eingebettete Systeme zu ermöglichen. Dadurch wird die Technologie attraktiv für Einsatzgebiete, wo die oben aufgelisteten Vorteile zum Tragen kommen können. Diese Einsatzgebiete können sowohl im Automobil als auch im Industriebereich liegen. Y1 - 2018 SP - 135 EP - 144 PB - VDE Verlag ER - TY - CHAP A1 - Schreiber, Marc A1 - Kraft, Bodo A1 - Zündorf, Albert T1 - Metrics Driven Research Collaboration: Focusing on Common Project Goals Continuously T2 - 39th International Conference on Software Engineering, May 20-28, 2017 - Buenos Aires, Argentina N2 - Research collaborations provide opportunities for both practitioners and researchers: practitioners need solutions for difficult business challenges and researchers are looking for hard problems to solve and publish. Nevertheless, research collaborations carry the risk that practitioners focus on quick solutions too much and that researchers tackle theoretical problems, resulting in products which do not fulfill the project requirements. In this paper we introduce an approach extending the ideas of agile and lean software development. It helps practitioners and researchers keep track of their common research collaboration goal: a scientifically enriched software product which fulfills the needs of the practitioner’s business model. This approach gives first-class status to application-oriented metrics that measure progress and success of a research collaboration continuously. Those metrics are derived from the collaboration requirements and help to focus on a commonly defined goal. An appropriate tool set evaluates and visualizes those metrics with minimal effort, and all participants will be pushed to focus on their tasks with appropriate effort. Thus project status, challenges and progress are transparent to all research collaboration members at any time. Y1 - 2017 N1 - Software Engineering in Practice (SEIP). ICSE2017 Vorabversion der Autoren ER - TY - CHAP A1 - Göttsche, Joachim A1 - Röther, Sascha T1 - Science College Overbach - Innovatives Bildungszentrum in Jülich-Barmen T2 - 18. Internationale Passivhaustagung, Aachen, April 2014 N2 - Preprint der Autoren Y1 - 2014 ER - TY - CHAP A1 - Göttsche, Joachim A1 - Korn, Michael A1 - Amato, Alexandre T1 - The Passivhaus concept for the Arabian Peninsula – An energetic-economical evaluation considering the thermal comfort T2 - QScience Proceedings: Vol 2015 N2 - The Passivhaus building standard is a concept developed for the realization of energy-efficient and economical buildings with a simultaneous high utilization comfort under European climate conditions. Major elements of the Passivhaus concept are a high thermal insulation of the external walls, the use of heat and/or solar shading glazing as well as an airtight building envelope in combination with energy-efficient technical building installations and heating or cooling generators, such as an efficient energy-recovery in the building air-conditioning. The objective of this research project is the inquiry to determine the parameters or constraints under which the Passivhaus concept can be implemented under the arid climate conditions in the Arabian Peninsula to achieve an energy-efficient and economical building with high utilization comfort. In cooperation between the Qatar Green Building Council (QGBC), Barwa Real Estate (BRE) and Kahramaa the first Passivhaus was constructed in Qatar and on the Arabian Peninsula in 2013. The Solar-Institut Jülich of Aachen University of Applied Science supports the Qatar Green Building Council with a dynamic building and equipment simulation of the Passivhaus and the neighbouring reference building. This includes simulation studies with different component configurations for the building envelope and different control strategies for heating or cooling systems as well as the air conditioning of buildings to find an energetic-economical optimum. Part of these analyses is the evaluation of the energy efficiency of the used energy recovery system in the Passivhaus air-conditioning and identification of possible energy-saving effects by the use of a bypass function integrated in the heat exchanger. In this way it is expected that on an annual basis the complete electricity demand of the building can be covered by the roof-integrated PV generator. Y1 - 2015 U6 - http://dx.doi.org/10.5339/qproc.2015.qgbc.38 N1 - 10.5339/qproc.2015.qgbc.38 = abstract - Qatar Green Building Conference 2015 - The Vision, 38. ER - TY - CHAP A1 - Bagheri, Mohsen A1 - Schleupen, Josef A1 - Dahmann, Peter A1 - Kallweit, Stephan T1 - Kletternde Wartungsplattform für die wetterunabhängige Instandhaltung von Rotorblättern an Windenergieanlagen - SMART T2 - AKIDA 2016 Aachener Kolloquium für Instandhaltung, Diagnose und Anlagenüberwachung (AKIDA) am 15. und 16.11.2016, Technologiezentrum Aachen N2 - In Deutschland liegt der Anteil der Windkraft an der Gesamtstromerzeugung bei 13,3% mit mehr als 25.000 installierten Windenergieanlagen (WEA). Weltweit erfährt die Windbranche ein rasantes Wachstum. Indien und China berichten eine jährliche Wachstumsrate an Neuinstallationen von 45%. Die Technologie zur Erzeugung elektrischer Energie aus Windkraft ist noch vergleichsweise jung. Durch die weltweit steigende Anzahl an Windenergieanlagen wächst zunehmend der Bedarf an innovativen Wartungslösungen. Komponenten wie Generator oder Getriebe sind inzwischen weitestgehend ausgereift. Der Fokus richtet sich zunehmend auf die wesentliche Kernkomponente - die Rotorblätter. Industriekletterer inspizieren die Rotorblätter oder Türme i.d.R. in einem zwei Jahres Rhythmus. Sie werden zunehmend durch Seilarbeitsbühnen unterstützt. Für größere Reparaturen kommen Kräne zum Einsatz, mit denen das Rotorblatt für die Instandhaltung demontiert wird. Die Standardinspektion besteht aus Sicht- und Klopfprüfung der Rotorblattoberfläche und ist nur bei sehr ruhiger Wetterlage durchführbar. Seit September 2014 wird das Forschungsprojekt SMART (Scanning, Monitoring, Analysis, Repair and Transportation), Entwicklung einer Wartungsplattform für WEA, vom BMWi gefördert. Das Konsortium besteht aus zwei Firmen und der Fachhochschule Aachen. Die SMART-Anlage klettert reibschlüssig am Turm der WEA mittels speziellen Kettenfahrwerken (Abbildung) auf- und abwärts. Ein ringförmiges Spannsystems, basierend auf dem Konzept der „Nürnberger“-Schere, erzeugt die erforderliche Anpresskraft für den Kletterprozess. Wettergeschützte Arbeitskabinen ermöglichen die ganzjährige Instandhaltung von Rotorblättern und ebenso Türmen. Dadurch können Wartungsarbeiten auf 24 Stunden am Tag ausgeweitet werden. Der kombinierte Einsatz (Sensorfusion) bildgebender Messtechnik wie Thermografie, Ultraschall, und Terahertz in der Arbeitskabine kann die Dokumentation, Effizienz und Qualität der Instandhaltungsarbeiten erheblich verbessern. Langfristiges Ziel von SMART ist ein Condition Monitoring für Rotorblätter und Türme auf Basis digitalisierter dreidimensionaler Volumenscans. Der kooperative Einsatz mit UAVs erweitert die Instandhaltungsstrategie. UAVs ermöglichen die schnelle, kostengünstige globale optische Inspektion von Rotorblattoberflächen zur Detektion potentieller Fehlstellen. Der „Proof-of-Concept“ Meilenstein wurde mit der Demonstration eines funktionsfähigen Modells im Dezember 2015 erfolgreich abgeschlossen. Y1 - 2016 ER - TY - CHAP A1 - Fredebeul-Krein, Markus T1 - Towards trade facilitation via regulatory convergence: An analysis of the TTIP chapter on Electronic Communications T2 - Regional ITS Conference of the International Telecommunications Society. Cambridge, United Kingdom, 7-9 September 2016 N2 - To give the exchange of goods and services between the European Union (EU) and the United States (U.S.) new momentum the two parties are currently negotiating the transatlantic free trade agreement Transatlantic Trade and Investment Partnership (TTIP). The aim is to create the largest free trade area in the world. The agreement, once entered into force, will oblige EU countries and the U.S. to further liberalize their markets. The negotiations on TTIP include a chapter on Electronic Communications/ Telecommunications. The challenge therein will be securing commitments for market access to Electronic Communications services. At the same time, these commitments must reflect the legitimate need for consumer protection issues. The need to reduce Electronic Communications-related non-tariff barriers to trade between the Parties is due to the fact that these markets are heavily regulated. Without transnational rules as to regulations national governments can abuse these regulations to deter the market entry by new (foreign) suppliers. Thus the free trade agreement TTIP affects in many respects regulatory provisions on and access to Electronic Communications markets. The objective of this paper is therefore to examine to what extend the regulatory principles for Electronic Communications markets envisaged under TTIP will result in trade facilitation and regulatory convergence between the EU and the U.S. As to this question the result of the analysis is that the chapter on Electronic Communications will be an important step towards facilitating trade in Electronic Communications services. At the same time some regulatory convergence will take place, but this convergence will not lead to a (full) harmonization of regulations. Rather the norm, also after TTIP negotiations will have been concluded successfully, will be mutual recognition of different regulatory regimes. Different regulations being the optimal policy response in different market settings will continue to exist. Moreover, it is very unlikely that such regulatory principles for the Electronic Communications sector are a vehicle for a race to the bottom in levels of consumer protection. KW - regulation KW - liberalisation KW - electronic communications markets KW - TTIP Y1 - 2016 ER - TY - CHAP A1 - Staat, Manfred A1 - Duong, Minh Tuan T1 - Smoothed Finite Element Methods for Nonlinear Solid Mechanics Problems: 2D and 3D Case Studies T2 - Proceedings of the National Science and Technology Conference on Mechanical - Transportation Engineering (NSCMET 2016), 13th October 2016, Hanoi, Vietnam, Vol.2 N2 - The Smoothed Finite Element Method (SFEM) is presented as an edge-based and a facebased techniques for 2D and 3D boundary value problems, respectively. SFEMs avoid shortcomings of the standard Finite Element Method (FEM) with lower order elements such as overly stiff behavior, poor stress solution, and locking effects. Based on the idea of averaging spatially the standard strain field of the FEM over so-called smoothing domains SFEM calculates the stiffness matrix for the same number of degrees of freedom (DOFs) as those of the FEM. However, the SFEMs significantly improve accuracy and convergence even for distorted meshes and/or nearly incompressible materials. Numerical results of the SFEMs for a cardiac tissue membrane (thin plate inflation) and an artery (tension of 3D tube) show clearly their advantageous properties in improving accuracy particularly for the distorted meshes and avoiding shear locking effects. Y1 - 2016 SP - 440 EP - 445 ER -