@inproceedings{BergmannGoettenBraunetal.2022, author = {Bergmann, Ole and G{\"o}tten, Falk and Braun, Carsten and Janser, Frank}, title = {Comparison and evaluation of blade element methods against RANS simulations and test data}, series = {CEAS Aeronautical Journal}, volume = {13}, booktitle = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-022-00579-1}, pages = {535 -- 557}, year = {2022}, abstract = {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.}, language = {en} } @inproceedings{BaaderReiswichBartschetal.2018, author = {Baader, Fabian and Reiswich, M. and Bartsch, M. and Keller, D. and Tiede, E. and Keck, G. and Demircian, A. and Friedrich, M. and Dachwald, Bernd and Sch{\"u}ller, K. and Lehmann, R. and Chojetzki, R. and Durand, C. and Rapp, L. and Kowalski, Julia and F{\"o}rstner, R.}, title = {VIPER - Student research on extraterrestrical ice penetration technology}, series = {Proceedings of the 2nd Symposium on Space Educational Activities}, booktitle = {Proceedings of the 2nd Symposium on Space Educational Activities}, pages = {1 -- 6}, year = {2018}, abstract = {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.}, language = {en} } @inproceedings{JungFrotscherStaat2018, author = {Jung, Alexander and Frotscher, Ralf and Staat, Manfred}, title = {Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts}, series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, pages = {11 Seiten}, year = {2018}, abstract = {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.}, language = {en} } @inproceedings{HueningHeuermannWache2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef}, title = {Wireless CAN}, series = {Tagungsband AALE 2018 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 15. Fachkonferenz, Regensburg ; [15. Konferenz f{\"u}r Angewandte Automatisierungstechnik in Lehre und Entwicklung / TH K{\"o}ln; VFAALE, Verein der Freunde und F{\"o}rderer der Angewandten Automatisierungstechnik]}, booktitle = {Tagungsband AALE 2018 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 15. Fachkonferenz, Regensburg ; [15. Konferenz f{\"u}r Angewandte Automatisierungstechnik in Lehre und Entwicklung / TH K{\"o}ln; VFAALE, Verein der Freunde und F{\"o}rderer der Angewandten Automatisierungstechnik]}, publisher = {VDE Verlag}, pages = {135 -- 144}, year = {2018}, abstract = {Das vorgestellte System zu Wireless CAN bietet die M{\"o}glichkeit, CAN kabellos zu {\"u}bertragen. Beide vorgestellten und entwickelten Konzepte funktionieren korrekt und erm{\"o}glichen den Auf-bau von kabellosen CAN Schnittstellen. Durch den kleinen Aufbau kann diese Technologie auch f{\"u}r eingebettete Systeme verwendet werden. Zudem bietet dieser Ansatz die M{\"o}glichkeit, durch die Entwicklung von geeigneten ICs die Gr{\"o}ße des Systems bis auf Bauteilgr{\"o}ße zu reduzieren, um eine noch bessere Integration in eingebettete Systeme zu erm{\"o}glichen. Dadurch wird die Technologie attraktiv f{\"u}r Einsatzgebiete, wo die oben aufgelisteten Vorteile zum Tragen kommen k{\"o}nnen. Diese Einsatzgebiete k{\"o}nnen sowohl im Automobil als auch im Industriebereich liegen.}, language = {de} } @inproceedings{SchreiberKraftZuendorf2017, author = {Schreiber, Marc and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {Metrics Driven Research Collaboration: Focusing on Common Project Goals Continuously}, series = {39th International Conference on Software Engineering, May 20-28, 2017 - Buenos Aires, Argentina}, booktitle = {39th International Conference on Software Engineering, May 20-28, 2017 - Buenos Aires, Argentina}, pages = {8 Seiten}, year = {2017}, abstract = {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.}, language = {en} } @inproceedings{GoettscheRoether2014, author = {G{\"o}ttsche, Joachim and R{\"o}ther, Sascha}, title = {Science College Overbach - Innovatives Bildungszentrum in J{\"u}lich-Barmen}, series = {18. Internationale Passivhaustagung, Aachen, April 2014}, booktitle = {18. Internationale Passivhaustagung, Aachen, April 2014}, pages = {6 Seiten}, year = {2014}, abstract = {Preprint der Autoren}, language = {de} } @inproceedings{GoettscheKornAmato2015, author = {G{\"o}ttsche, Joachim and Korn, Michael and Amato, Alexandre}, title = {The Passivhaus concept for the Arabian Peninsula - An energetic-economical evaluation considering the thermal comfort}, series = {QScience Proceedings: Vol 2015}, booktitle = {QScience Proceedings: Vol 2015}, doi = {10.5339/qproc.2015.qgbc.38}, pages = {8 Seiten}, year = {2015}, abstract = {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 J{\"u}lich 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.}, language = {en} } @inproceedings{BagheriSchleupenDahmannetal.2016, author = {Bagheri, Mohsen and Schleupen, Josef and Dahmann, Peter and Kallweit, Stephan}, title = {Kletternde Wartungsplattform f{\"u}r die wetterunabh{\"a}ngige Instandhaltung von Rotorbl{\"a}ttern an Windenergieanlagen - SMART}, series = {AKIDA 2016 Aachener Kolloquium f{\"u}r Instandhaltung, Diagnose und Anlagen{\"u}berwachung (AKIDA) am 15. und 16.11.2016, Technologiezentrum Aachen}, booktitle = {AKIDA 2016 Aachener Kolloquium f{\"u}r Instandhaltung, Diagnose und Anlagen{\"u}berwachung (AKIDA) am 15. und 16.11.2016, Technologiezentrum Aachen}, pages = {21 Folien}, year = {2016}, abstract = {In Deutschland liegt der Anteil der Windkraft an der Gesamtstromerzeugung bei 13,3\% mit mehr als 25.000 installierten Windenergieanlagen (WEA). Weltweit erf{\"a}hrt die Windbranche ein rasantes Wachstum. Indien und China berichten eine j{\"a}hrliche Wachstumsrate an Neuinstallationen von 45\%. Die Technologie zur Erzeugung elektrischer Energie aus Windkraft ist noch vergleichsweise jung. Durch die weltweit steigende Anzahl an Windenergieanlagen w{\"a}chst zunehmend der Bedarf an innovativen Wartungsl{\"o}sungen. Komponenten wie Generator oder Getriebe sind inzwischen weitestgehend ausgereift. Der Fokus richtet sich zunehmend auf die wesentliche Kernkomponente - die Rotorbl{\"a}tter. Industriekletterer inspizieren die Rotorbl{\"a}tter oder T{\"u}rme i.d.R. in einem zwei Jahres Rhythmus. Sie werden zunehmend durch Seilarbeitsb{\"u}hnen unterst{\"u}tzt. F{\"u}r gr{\"o}ßere Reparaturen kommen Kr{\"a}ne zum Einsatz, mit denen das Rotorblatt f{\"u}r die Instandhaltung demontiert wird. Die Standardinspektion besteht aus Sicht- und Klopfpr{\"u}fung der Rotorblattoberfl{\"a}che und ist nur bei sehr ruhiger Wetterlage durchf{\"u}hrbar. Seit September 2014 wird das Forschungsprojekt SMART (Scanning, Monitoring, Analysis, Repair and Transportation), Entwicklung einer Wartungsplattform f{\"u}r WEA, vom BMWi gef{\"o}rdert. Das Konsortium besteht aus zwei Firmen und der Fachhochschule Aachen. Die SMART-Anlage klettert reibschl{\"u}ssig am Turm der WEA mittels speziellen Kettenfahrwerken (Abbildung) auf- und abw{\"a}rts. Ein ringf{\"o}rmiges Spannsystems, basierend auf dem Konzept der „N{\"u}rnberger"-Schere, erzeugt die erforderliche Anpresskraft f{\"u}r den Kletterprozess. Wettergesch{\"u}tzte Arbeitskabinen erm{\"o}glichen die ganzj{\"a}hrige Instandhaltung von Rotorbl{\"a}ttern und ebenso T{\"u}rmen. Dadurch k{\"o}nnen 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 Qualit{\"a}t der Instandhaltungsarbeiten erheblich verbessern. Langfristiges Ziel von SMART ist ein Condition Monitoring f{\"u}r Rotorbl{\"a}tter und T{\"u}rme auf Basis digitalisierter dreidimensionaler Volumenscans. Der kooperative Einsatz mit UAVs erweitert die Instandhaltungsstrategie. UAVs erm{\"o}glichen die schnelle, kosteng{\"u}nstige globale optische Inspektion von Rotorblattoberfl{\"a}chen zur Detektion potentieller Fehlstellen. Der „Proof-of-Concept" Meilenstein wurde mit der Demonstration eines funktionsf{\"a}higen Modells im Dezember 2015 erfolgreich abgeschlossen.}, language = {de} } @inproceedings{FredebeulKrein2016, author = {Fredebeul-Krein, Markus}, title = {Towards trade facilitation via regulatory convergence: An analysis of the TTIP chapter on Electronic Communications}, series = {Regional ITS Conference of the International Telecommunications Society. Cambridge, United Kingdom, 7-9 September 2016}, booktitle = {Regional ITS Conference of the International Telecommunications Society. Cambridge, United Kingdom, 7-9 September 2016}, pages = {29 Seiten}, year = {2016}, abstract = {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.}, language = {en} } @inproceedings{StaatDuong2016, author = {Staat, Manfred and Duong, Minh Tuan}, title = {Smoothed Finite Element Methods for Nonlinear Solid Mechanics Problems: 2D and 3D Case Studies}, series = {Proceedings of the National Science and Technology Conference on Mechanical - Transportation Engineering (NSCMET 2016), 13th October 2016, Hanoi, Vietnam, Vol.2}, booktitle = {Proceedings of the National Science and Technology Conference on Mechanical - Transportation Engineering (NSCMET 2016), 13th October 2016, Hanoi, Vietnam, Vol.2}, pages = {440 -- 445}, year = {2016}, abstract = {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.}, language = {en} }