@techreport{HebelMerkensFeyerletal.2021, author = {Hebel, Christoph and Merkens, Torsten and Feyerl, G{\"u}nter and Kemper, Hans and Busse, Daniel}, title = {Elektromobilit{\"a}t - 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}, publisher = {Fachhochschule Aachen}, address = {Aachen}, pages = {219 Seiten}, year = {2021}, language = {de} } @article{ValeroBungErpicumetal.2022, author = {Valero, Daniel and Bung, Daniel Bernhard and Erpicum, Sebastien and Peltier, Yann and Dewals, Benjamin}, title = {Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling}, series = {Journal of Hydro-environment Research}, journal = {Journal of Hydro-environment Research}, number = {In Press}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1570-6443}, doi = {10.1016/j.jher.2022.03.002}, year = {2022}, abstract = {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).}, language = {en} } @article{HagenkampBlankeDoering2021, author = {Hagenkamp, Markus and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Thermoelectric building temperature control: a potential assessment}, series = {International Journal of Energy and Environmental Engineering}, volume = {13}, journal = {International Journal of Energy and Environmental Engineering}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s40095-021-00424-x}, pages = {241 -- 254}, year = {2021}, abstract = {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.}, language = {en} } @article{BlankeRegerDoeringetal.2021, author = {Blanke, Tobias and Reger, Vitali and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Kuhnhenne, Markus}, title = {Koaxiale Stahlenergiepf{\"a}hle}, series = {Stahlbau}, volume = {90. 2021}, journal = {Stahlbau}, number = {6}, publisher = {Wiley}, address = {Weinheim}, pages = {417 -- 424}, year = {2021}, abstract = {Ein entscheidender Teil der Energiewende ist die W{\"a}rmewende im Geb{\"a}udesektor. Ein Schl{\"u}sselelement sind hier W{\"a}rmepumpen. Diese ben{\"o}tigen eine W{\"a}rmequelle, der sie Energie entziehen k{\"o}nnen, um sie auf ein h{\"o}heres Temperaturniveau zu transformieren. Diese W{\"a}rmequelle kann bspw. das Erdreich sein, dessen W{\"a}rme durch Erdsonden erschlossen werden kann. In diesem Beitrag werden in Stahlpf{\"a}hle integrierte Koaxialsonden mit dem Stand der Technik von Erdsonden gleichen Durchmessers bez{\"u}glich ihrer thermischen Leistungsmerkmale verglichen. Die Stahlenergiepf{\"a}hle bieten neben der W{\"a}rmegewinnung weitere Vorteile, da sie auch eine statische Funktion {\"u}bernehmen und r{\"u}ckstandsfrei zur{\"u}ckgebaut werden k{\"o}nnen. Es werden analytische und numerische Berechnungen vorgestellt, um die thermischen Potenziale beider Systeme zu vergleichen. Außerdem wird ein Testaufbau gezeigt, bei dem Stahlenergiepf{\"a}hle in zwei verschiedenen L{\"a}ngen mit vorhandenen g{\"a}ngigen Erdsonden verglichen werden k{\"o}nnen. Die Berechnungen zeigen einen deutlichen thermischen Mehrertrag zwischen 26 \% und 148 \% der Stahlenergiepf{\"a}hle gegen{\"u}ber dem Stand der Technik abh{\"a}ngig vom Erdreich. Die Messergebnisse zeigen einen thermischen Mehrertrag von {\"u}ber 100 \%. Es l{\"a}sst sich also signifikante Erdsondenl{\"a}nge 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.}, language = {de} } @inproceedings{MerkensHebel2021, author = {Merkens, Torsten and Hebel, Christoph}, title = {Sharing mobility concepts - flexible, sustainable, smart}, series = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG) International Conference}, booktitle = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG) International Conference}, isbn = {978-3-902103-94-9}, pages = {43 -- 44}, year = {2021}, language = {en} } @article{BlankeHagenkampDoeringetal.2021, author = {Blanke, Tobias and Hagenkamp, Markus and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Reger, Vitali and Kuhnhenne, Markus}, title = {Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates}, series = {Geothermal Energy}, volume = {9}, journal = {Geothermal Energy}, number = {Article number: 19}, publisher = {Springer}, address = {Berlin}, issn = {2195-9706}, doi = {10.1186/s40517-021-00201-3}, pages = {23 Seiten}, year = {2021}, abstract = {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 Hellstr{\"o}m'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.}, language = {en} } @article{ValeroSchalkoFriedrichetal.2021, author = {Valero, Daniel and Schalko, Isabella and Friedrich, Heide and Abad, Jorge D. and Bung, Daniel Bernhard and Donchyts, Gennadii and Felder, Stefan and Ferreira, Rui M. L. and Hohermuth, Benjamin and Kramer, Matthias and Li, Danxun and Mendes, Luis and Moreno-Rodenas, Antonio and Nones, Michael and Paron, Paolo and Ruiz-Villanueva, Virginia and Wang, Ruo-Qian and Franca, Mario J.}, title = {Pathways towards democratization of hydro-environment observations and data}, series = {Iahr White Paper Series}, journal = {Iahr White Paper Series}, number = {1}, publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)}, pages = {1 -- 9}, year = {2021}, language = {en} } @article{HennesLaumann2021, author = {Hennes, Philipp and Laumann, J{\"o}rg}, title = {Ansatz der Drehbehinderung aus Koppelpfetten mit d{\"u}nnwandigen kaltgeformten Z-Profilen}, series = {Stahlbau}, volume = {90}, journal = {Stahlbau}, number = {3}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-1049}, doi = {10.1002/stab.202000104}, pages = {158 -- 168}, year = {2021}, language = {de} } @article{ErpicumCrookstonBombardellietal.2021, author = {Erpicum, Sebastien and Crookston, Brian M. and Bombardelli, Fabian and Bung, Daniel Bernhard and Felder, Stefan and Mulligan, Sean and Oertel, Mario and Palermo, Michele}, title = {Hydraulic structures engineering: An evolving science in a changing world}, series = {Wires Water}, volume = {8}, journal = {Wires Water}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {2049-1948}, doi = {10.1002/wat2.1505}, year = {2021}, language = {en} } @article{BungCrookstonValero2020, author = {Bung, Daniel Bernhard and Crookston, Brian M. and Valero, Daniel}, title = {Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case}, series = {Journal of Hydraulic Research}, journal = {Journal of Hydraulic Research}, publisher = {Taylor \& Francis}, address = {London}, issn = {1814-2079}, doi = {10.1080/00221686.2020.1844810}, year = {2020}, language = {en} } @book{LohseLaumannWolf2020, author = {Lohse, Wolfram and Laumann, J{\"o}rg and Wolf, Christian}, title = {Stahlbau 2}, edition = {21., vollst. akt. und {\"u}berarb. Aufl.}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-8348-2116-4}, doi = {10.1007/978-3-8348-2116-4}, year = {2020}, language = {de} } @article{ValeroChansonBung2020, author = {Valero, Daniel and Chanson, Hubert and Bung, Daniel Bernhard}, title = {Robust estimators for free surface turbulence characterization: A stepped spillway application}, series = {Flow Measurement and Instrumentation}, volume = {76}, journal = {Flow Measurement and Instrumentation}, number = {Art. 101809}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-5986}, doi = {10.1016/j.flowmeasinst.2020.101809}, year = {2020}, abstract = {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.}, language = {en} } @techreport{FischedickSchoofHebeletal.2018, type = {Working Paper}, author = {Fischedick, Manfred and Schoof, Ren{\´e} and Hebel, Christoph and Merkens, Torsten}, title = {Sektorenkopplung als Herausforderung und Chance f{\"u}r 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}, pages = {68 Seiten}, year = {2018}, language = {de} } @article{KuhnhenneRegerPyschnyetal.2020, author = {Kuhnhenne, Markus and Reger, Vitali and Pyschny, Dominik and D{\"o}ring, Bernd}, title = {Influence of airtightness of steel sandwich panel joints on heat losses}, series = {E3S Web of Conferences 12th Nordic Symposium on Building Physics (NSB 2020)}, volume = {172}, journal = {E3S Web of Conferences 12th Nordic Symposium on Building Physics (NSB 2020)}, number = {Art. 05008}, publisher = {EDP Sciences}, address = {Les Ulis}, doi = {10.1051/e3sconf/202017205008}, pages = {6}, year = {2020}, abstract = {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.}, language = {en} } @article{GronsfeldJoachimMalecha2019, author = {Gronsfeld, Richard and Joachim, Klubert and Malecha, Hartmut}, title = {3-D-Visualisierung von vorhandenen Staubauwerken zur holistischen Planung und {\"U}berwachung}, series = {Wasserwirtschaft}, volume = {109}, journal = {Wasserwirtschaft}, number = {5}, publisher = {Springer}, address = {Berlin}, issn = {2192-8762}, doi = {10.1007/s35147-019-0075-x}, pages = {82 -- 85}, year = {2019}, language = {de} } @inproceedings{BedburMoorkampPetersonetal.2020, author = {Bedbur, Christian and Moorkamp, Wilfried and Peterson, Leif Arne and Uibel, Thomas}, title = {Holzbr{\"u}cken mit Natursteinbel{\"a}gen - Untersuchungen zur Aktivierung der Verbundwirkung}, series = {Doktorandenkolloquium Holzbau Forschung + Praxis 2020}, booktitle = {Doktorandenkolloquium Holzbau Forschung + Praxis 2020}, editor = {Kuhlmann, Ulrike}, publisher = {Universit{\"a}t Stuttgart, Institut f{\"u}r Konstruktion und Entwurf}, address = {Stuttgart}, pages = {53 -- 60}, year = {2020}, language = {de} } @inproceedings{BedburThullMoorkampetal.2019, author = {Bedbur, Christian and Thull, J. and Moorkamp, Wilfried and Uibel, Thomas}, title = {Standardbr{\"u}cken f{\"u}r Geh- und Radwege}, series = {Tagungsband 4. Aachener Holzbautagung 2019: 12. und 13. September an der FH Aachen}, booktitle = {Tagungsband 4. Aachener Holzbautagung 2019: 12. und 13. September an der FH Aachen}, publisher = {FH Aachen}, address = {Aachen}, issn = {2197-4489}, pages = {34 -- 45}, year = {2019}, language = {de} } @inproceedings{JockwerKleiberUibel2018, author = {Jockwer, R. and Kleiber, M. and Uibel, Thomas}, title = {Criteria for Evaluating the Simplification of Design Rules for Dowel-type Fasteners}, series = {International Network on Timber Engineering Research, INTER : proceedings, meeting 51, 10 - 13 August 2016, Tallinn, Estonia}, booktitle = {International Network on Timber Engineering Research, INTER : proceedings, meeting 51, 10 - 13 August 2016, Tallinn, Estonia}, editor = {G{\"o}rlacher, Rainer}, publisher = {Timber Scientific Publishing, KIT Holzbau und Baukonstruktionen}, address = {Karlsruhe}, pages = {461 -- 466}, year = {2018}, language = {en} } @inproceedings{UibelMoorkamp2018, author = {Uibel, Thomas and Moorkamp, Wilfried}, title = {Geh- und Radwegbr{\"u}cken in NRW - Bestandsanalyse und Perspektiven}, series = {Holzbr{\"u}ckenbau in der Offensive : Erhaltung, Ert{\"u}chtigung, Neubauten : 5. Internationale Holzbr{\"u}ckentage (IHB 2018) FILharmonie Filderstadt, Filderstadt/Stuttgart (DE), 17./18. April 2018}, booktitle = {Holzbr{\"u}ckenbau in der Offensive : Erhaltung, Ert{\"u}chtigung, Neubauten : 5. Internationale Holzbr{\"u}ckentage (IHB 2018) FILharmonie Filderstadt, Filderstadt/Stuttgart (DE), 17./18. April 2018}, publisher = {forum-holzbau}, address = {Biel}, isbn = {978-3-906226-19-4}, pages = {19 -- 32}, year = {2018}, language = {de} } @inproceedings{DuffnerMoorkampPetersonetal.2018, author = {Duffner, Markus and Moorkamp, Wilfried and Peterson, Leif Arne and Uibel, Thomas}, title = {Untersuchungen zur Tragf{\"a}higkeit und Steifigkeit eines neuartigen Wandelements in Holzbauweisen}, series = {Doktorandenkolloquium Holzbau Forschung + Praxis : Stuttgart, 08./09. M{\"a}rz 2018}, booktitle = {Doktorandenkolloquium Holzbau Forschung + Praxis : Stuttgart, 08./09. M{\"a}rz 2018}, editor = {Kuhlmann, Ulrike}, publisher = {Universit{\"a}t Stuttgart, Institut f{\"u}r Konstruktion und Entwurf}, address = {Stuttgart}, pages = {131 -- 139}, year = {2018}, language = {de} }