TY - RPRT A1 - Hebel, Christoph A1 - Merkens, Torsten A1 - Feyerl, Günter A1 - Kemper, Hans A1 - Busse, Daniel T1 - Elektromobilität - Verbundprojekt "COSTARTebus": Comprehensive strategy to accelerate the integration of electric-buses into existing public transport systems - Teilprojekt A : Berichtszeitraum: 01.01.2018-31.10.2020 Y1 - 2021 N1 - Förderkennzeichen BMVI 03EMEN10A Verbundnummer 01182550 PB - Fachhochschule Aachen CY - Aachen ER - TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel Bernhard A1 - Erpicum, Sebastien A1 - Peltier, Yann A1 - Dewals, Benjamin T1 - Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling JF - Journal of Hydro-environment Research N2 - Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models). KW - coherent structures KW - hydraulic modelling KW - model performance KW - Proper Orthogonal Decomposition KW - Q-criterion Y1 - 2022 U6 - https://doi.org/10.1016/j.jher.2022.03.002 SN - 1570-6443 IS - In Press PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hagenkamp, Markus A1 - Blanke, Tobias A1 - Döring, Bernd T1 - Thermoelectric building temperature control: a potential assessment JF - International Journal of Energy and Environmental Engineering N2 - This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 ∘C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand Q˙h=100W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants. Y1 - 2021 U6 - https://doi.org/10.1007/s40095-021-00424-x N1 - Corresponding author: Markus Hagenkamp VL - 13 SP - 241 EP - 254 PB - Springer CY - Berlin ER - TY - JOUR A1 - Blanke, Tobias A1 - Reger, Vitali A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Kuhnhenne, Markus T1 - Koaxiale Stahlenergiepfähle JF - Stahlbau N2 - Ein entscheidender Teil der Energiewende ist die Wärmewende im Gebäudesektor. Ein Schlüsselelement sind hier Wärmepumpen. Diese benötigen eine Wärmequelle, der sie Energie entziehen können, um sie auf ein höheres Temperaturniveau zu transformieren. Diese Wärmequelle kann bspw. das Erdreich sein, dessen Wärme durch Erdsonden erschlossen werden kann. In diesem Beitrag werden in Stahlpfähle integrierte Koaxialsonden mit dem Stand der Technik von Erdsonden gleichen Durchmessers bezüglich ihrer thermischen Leistungsmerkmale verglichen. Die Stahlenergiepfähle bieten neben der Wärmegewinnung weitere Vorteile, da sie auch eine statische Funktion übernehmen und rückstandsfrei zurückgebaut werden können. Es werden analytische und numerische Berechnungen vorgestellt, um die thermischen Potenziale beider Systeme zu vergleichen. Außerdem wird ein Testaufbau gezeigt, bei dem Stahlenergiepfähle in zwei verschiedenen Längen mit vorhandenen gängigen Erdsonden verglichen werden können. Die Berechnungen zeigen einen deutlichen thermischen Mehrertrag zwischen 26 % und 148 % der Stahlenergiepfähle gegenüber dem Stand der Technik abhängig vom Erdreich. Die Messergebnisse zeigen einen thermischen Mehrertrag von über 100 %. Es lässt sich also signifikante Erdsondenlänge einsparen. Dabei ist zu beachten, dass sich damit der thermisch genutzte Bereich des Erdreichs reduziert, wodurch die thermische Regeneration und/oder das Langzeitverhalten des Erdreichs an Bedeutung gewinnt. Y1 - 2021 VL - 90. 2021 IS - 6 SP - 417 EP - 424 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Merkens, Torsten A1 - Hebel, Christoph T1 - Sharing mobility concepts – flexible, sustainable, smart T2 - Proceedings of the 1st UNITED – Southeast Asia Automotive Interest Group (SAIG) International Conference KW - Sharing mobility KW - electro mobility KW - business models KW - mobility behaviour Y1 - 2021 SN - 978-3-902103-94-9 N1 - 1st UNITED-SAIG International Conference, 21-22 APR 2021, Chulalongkorn University, Thailand SP - 43 EP - 44 ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar fow and 60% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the fow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics. Y1 - 2021 U6 - https://doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin ER - TY - JOUR A1 - Valero, Daniel A1 - Schalko, Isabella A1 - Friedrich, Heide A1 - Abad, Jorge D. A1 - Bung, Daniel Bernhard A1 - Donchyts, Gennadii A1 - Felder, Stefan A1 - Ferreira, Rui M. L. A1 - Hohermuth, Benjamin A1 - Kramer, Matthias A1 - Li, Danxun A1 - Mendes, Luis A1 - Moreno-Rodenas, Antonio A1 - Nones, Michael A1 - Paron, Paolo A1 - Ruiz-Villanueva, Virginia A1 - Wang, Ruo-Qian A1 - Franca, Mario J. T1 - Pathways towards democratization of hydro-environment observations and data JF - Iahr White Paper Series Y1 - 2021 IS - 1 SP - 1 EP - 9 PB - International Association for Hydro-Environment Engineering and Research (IAHR) ER - TY - JOUR A1 - Hennes, Philipp A1 - Laumann, Jörg T1 - Ansatz der Drehbehinderung aus Koppelpfetten mit dünnwandigen kaltgeformten Z-Profilen JF - Stahlbau Y1 - 2021 U6 - https://doi.org/10.1002/stab.202000104 SN - 1437-1049 VL - 90 IS - 3 SP - 158 EP - 168 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Erpicum, Sebastien A1 - Crookston, Brian M. A1 - Bombardelli, Fabian A1 - Bung, Daniel Bernhard A1 - Felder, Stefan A1 - Mulligan, Sean A1 - Oertel, Mario A1 - Palermo, Michele T1 - Hydraulic structures engineering: An evolving science in a changing world JF - Wires Water Y1 - 2021 U6 - https://doi.org/10.1002/wat2.1505 SN - 2049-1948 VL - 8 IS - 2 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Bung, Daniel Bernhard A1 - Crookston, Brian M. A1 - Valero, Daniel T1 - Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case JF - Journal of Hydraulic Research Y1 - 2020 U6 - https://doi.org/10.1080/00221686.2020.1844810 SN - 1814-2079 PB - Taylor & Francis CY - London ER - TY - BOOK A1 - Lohse, Wolfram A1 - Laumann, Jörg A1 - Wolf, Christian T1 - Stahlbau 2 Y1 - 2020 SN - 978-3-8348-2116-4 SN - 978-3-8348-1511-8 U6 - https://doi.org/10.1007/978-3-8348-2116-4 PB - Springer Vieweg CY - Wiesbaden ET - 21., vollst. akt. und überarb. Aufl. ER - TY - JOUR A1 - Valero, Daniel A1 - Chanson, Hubert A1 - Bung, Daniel Bernhard T1 - Robust estimators for free surface turbulence characterization: A stepped spillway application JF - Flow Measurement and Instrumentation N2 - Robust estimators are parameters insensitive to the presence of outliers. However, they presume the shape of the variables’ probability density function. This study exemplifies the sensitivity of turbulent quantities to the use of classic and robust estimators and the presence of outliers in turbulent flow depth time series. A wide range of turbulence quantities was analysed based upon a stepped spillway case study, using flow depths sampled with Acoustic Displacement Meters as the flow variable of interest. The studied parameters include: the expected free surface level, the expected fluctuation intensity, the depth skewness, the autocorrelation timescales, the vertical velocity fluctuation intensity, the perturbations celerity and the one-dimensional free surface turbulence spectrum. Three levels of filtering were utilised prior to applying classic and robust estimators, showing that comparable robustness can be obtained either using classic estimators together with an intermediate filtering technique or using robust estimators instead, without any filtering technique. Y1 - 2020 U6 - https://doi.org/10.1016/j.flowmeasinst.2020.101809 SN - 0955-5986 VL - 76 IS - Art. 101809 PB - Elsevier CY - Amsterdam ER - TY - RPRT A1 - Fischedick, Manfred A1 - Schoof, René A1 - Hebel, Christoph A1 - Merkens, Torsten T1 - Sektorenkopplung als Herausforderung und Chance für das Energieland NRW : Handlungsoptionen und Ergebnispapier der Expertengruppe AG 4 „Sektoren- kopplung“ im Netzwerk Netze und Speicher der EnergieAgentur.NRW im Auftrag des Landes Nordrhein-Westfalen / EnergieAgentur.NRW GmbH Y1 - 2018 ER - TY - JOUR A1 - Kuhnhenne, Markus A1 - Reger, Vitali A1 - Pyschny, Dominik A1 - Döring, Bernd T1 - Influence of airtightness of steel sandwich panel joints on heat losses JF - E3S Web of Conferences 12th Nordic Symposium on Building Physics (NSB 2020) N2 - Energy saving ordinances requires that buildings must be designed in such a way that the heat transfer surface including the joints is permanently air impermeable. The prefabricated roof and wall panels in lightweight steel constructions are airtight in the area of the steel covering layers. The sealing of the panel joints contributes to fulfil the comprehensive requirements for an airtight building envelope. To improve the airtightness of steel sandwich panels, additional sealing tapes can be installed in the panel joint. The influence of these sealing tapes was evaluated by measurements carried out by the RWTH Aachen University - Sustainable Metal Building Envelopes. Different installation situations were evaluated by carrying out airtightness tests for different joint distances. In addition, the influence on the heat transfer coefficient was also evaluated using the Finite Element Method (FEM). The combination of obtained air volume flow and transmission losses enables to create an "effective heat transfer coefficient" due to transmission and infiltration. This summarizes both effects in one value and is particularly helpful for approximate calculations on energy efficiency. Y1 - 2020 U6 - https://doi.org/10.1051/e3sconf/202017205008 VL - 172 IS - Art. 05008 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Gronsfeld, Richard A1 - Joachim, Klubert A1 - Malecha, Hartmut T1 - 3-D-Visualisierung von vorhandenen Staubauwerken zur holistischen Planung und Überwachung JF - Wasserwirtschaft Y1 - 2019 U6 - https://doi.org/10.1007/s35147-019-0075-x SN - 2192-8762 N1 - gedruckt in der Bereichsbibliothek Bayernallee unter der Signatur 13 Z 218 vorhanden VL - 109 IS - 5 SP - 82 EP - 85 PB - Springer CY - Berlin ER - TY - CHAP A1 - Bedbur, Christian A1 - Moorkamp, Wilfried A1 - Peterson, Leif Arne A1 - Uibel, Thomas ED - Kuhlmann, Ulrike T1 - Holzbrücken mit Natursteinbelägen - Untersuchungen zur Aktivierung der Verbundwirkung T2 - Doktorandenkolloquium Holzbau Forschung + Praxis 2020 Y1 - 2020 N1 - 8. Doktorandenkolloquium „Holzbau Forschung + Praxis“, 05. und 06. März 2020, Stuttgart SP - 53 EP - 60 PB - Universität Stuttgart, Institut für Konstruktion und Entwurf CY - Stuttgart ER - TY - CHAP A1 - Bedbur, Christian A1 - Thull, J. A1 - Moorkamp, Wilfried A1 - Uibel, Thomas T1 - Standardbrücken für Geh- und Radwege T2 - Tagungsband 4. Aachener Holzbautagung 2019: 12. und 13. September an der FH Aachen Y1 - 2020 SN - 2197-4489 SP - 34 EP - 45 PB - FH Aachen CY - Aachen ER - TY - CHAP A1 - Jockwer, R. A1 - Kleiber, M. A1 - Uibel, Thomas ED - Görlacher, Rainer T1 - Criteria for Evaluating the Simplification of Design Rules for Dowel-type Fasteners T2 - International Network on Timber Engineering Research, INTER : proceedings, meeting 51, 10 - 13 August 2016, Tallinn, Estonia Y1 - 2018 SP - 461 EP - 466 PB - Timber Scientific Publishing, KIT Holzbau und Baukonstruktionen CY - Karlsruhe ER - TY - CHAP A1 - Uibel, Thomas A1 - Moorkamp, Wilfried T1 - Geh- und Radwegbrücken in NRW - Bestandsanalyse und Perspektiven T2 - Holzbrückenbau in der Offensive : Erhaltung, Ertüchtigung, Neubauten : 5. Internationale Holzbrückentage (IHB 2018) FILharmonie Filderstadt, Filderstadt/Stuttgart (DE), 17./18. April 2018 Y1 - 2018 SN - 978-3-906226-19-4 SP - 19 EP - 32 PB - forum-holzbau CY - Biel ER - TY - CHAP A1 - Duffner, Markus A1 - Moorkamp, Wilfried A1 - Peterson, Leif Arne A1 - Uibel, Thomas ED - Kuhlmann, Ulrike T1 - Untersuchungen zur Tragfähigkeit und Steifigkeit eines neuartigen Wandelements in Holzbauweisen T2 - Doktorandenkolloquium Holzbau Forschung + Praxis : Stuttgart, 08./09. März 2018 Y1 - 2018 SP - 131 EP - 139 PB - Universität Stuttgart, Institut für Konstruktion und Entwurf CY - Stuttgart ER -