@inproceedings{KerpenSchooneesSchlurmannetal.2019, author = {Kerpen, Nils B. and Schoonees, Talia and Schlurmann, Torsten and Valero, Daniel and Bung, Daniel Bernhard}, title = {waveSTEPS - Wellenauf- und Wellen{\"u}berlauf an getreppten Deckwerken}, series = {24. KFKI-Seminar 2019, 21.11.2019}, booktitle = {24. KFKI-Seminar 2019, 21.11.2019}, pages = {2 Seiten}, year = {2019}, language = {de} } @inproceedings{ValeroKramerBungetal.2019, author = {Valero, Daniel and Kramer, Matthias and Bung, Daniel Bernhard and Chanson, Hubert}, title = {A stochastic bubble generator for air-water flow research}, series = {E-proceedings of the 38th IAHR World Congress, September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress, September 1-6, 2019, Panama City, Panama}, doi = {10.3850/38WC092019-0909}, pages = {5714 -- 5721}, year = {2019}, language = {en} } @inproceedings{TullisCrookstonBung2019, author = {Tullis, Blake P. and Crookston, Brian M. and Bung, Daniel Bernhard}, title = {Weir head-discharge relationships: A multi-lab exercise}, series = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, pages = {1 -- 15}, year = {2019}, 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{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} } @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{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{BungValero2016, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {Optical flow estimation in aerated flows}, series = {Journal of Hydraulic Research}, volume = {54}, journal = {Journal of Hydraulic Research}, number = {5}, publisher = {Taylor \& Francis}, address = {London}, doi = {10.1080/00221686.2016.1173600}, pages = {575 -- 580}, year = {2016}, abstract = {Optical flow estimation is known from Computer Vision where it is used to determine obstacle movements through a sequence of images following an assumption of brightness conservation. This paper presents the first study on application of the optical flow method to aerated stepped spillway flows. For this purpose, the flow is captured with a high-speed camera and illuminated with a synchronized LED light source. The flow velocities, obtained using a basic Horn-Schunck method for estimation of the optical flow coupled with an image pyramid multi-resolution approach for image filtering, compare well with data from intrusive conductivity probe measurements. Application of the Horn-Schunck method yields densely populated flow field data sets with velocity information for every pixel. It is found that the image pyramid approach has the most significant effect on the accuracy compared to other image processing techniques. However, the final results show some dependency on the pixel intensity distribution, with better accuracy found for grey values between 100 and 150.}, language = {en} } @inproceedings{KerpenBungValeroetal.2016, author = {Kerpen, Nils B. and Bung, Daniel Bernhard and Valero, Daniel and Schlurmann, Torsten}, title = {Energy dissipation within the wave run-up at stepped revetments}, series = {8th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, Qingdao, China}, booktitle = {8th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, Qingdao, China}, pages = {6 Seiten}, year = {2016}, language = {en} } @inproceedings{BungValero2016, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {Image processing techniques for velocity estimation in highly aerated flows: bubble image velocimetry vs. optical flow}, series = {Sustainable Hydraulics in the Era of Global Change : Proceedings of the 4th IAHR Europe Congress (Liege, Belgium, 27-29 July 2016)}, booktitle = {Sustainable Hydraulics in the Era of Global Change : Proceedings of the 4th IAHR Europe Congress (Liege, Belgium, 27-29 July 2016)}, editor = {Dewals, Benjamin}, publisher = {CRC Press}, isbn = {978-1-138-02977-4}, doi = {10.1201/b21902-31}, pages = {151 -- 157}, year = {2016}, language = {en} } @article{Hebel2017, author = {Hebel, Christoph}, title = {Erfahrungen mit der RIN und aktuelle Weiterentwicklungen}, series = {Straßenverkehrstechnik: Organ der Forschungsgesellschaft f{\"u}r Straßen- und Verkehrswesen, der Bundesvereinigung der Straßenbau- und Verkehrsingenieure und der {\"O}sterreichischen Forschungsgesellschaft Straße und Verkehr; Zeitschrift f{\"u}r Verkehrsplanung, Verkehrsmanagement, Verkehrssicherheit, Verkehrstechnik}, volume = {61}, journal = {Straßenverkehrstechnik: Organ der Forschungsgesellschaft f{\"u}r Straßen- und Verkehrswesen, der Bundesvereinigung der Straßenbau- und Verkehrsingenieure und der {\"O}sterreichischen Forschungsgesellschaft Straße und Verkehr; Zeitschrift f{\"u}r Verkehrsplanung, Verkehrsmanagement, Verkehrssicherheit, Verkehrstechnik}, number = {7}, publisher = {Kirschbaum-Verlag}, address = {Bonn}, issn = {0039-2219}, pages = {443 -- 448}, year = {2017}, language = {de} } @article{PetersonRoethUibel2017, author = {Peterson, Leif Arne and R{\"o}th, Thilo and Uibel, Thomas}, title = {Einsatz von Holzwerkstoffen in Fahrzeugstrukturen}, series = {Bauen mit Holz}, journal = {Bauen mit Holz}, number = {3}, publisher = {Bruderverlag}, address = {K{\"o}ln}, issn = {0005-6545}, pages = {32 -- 38}, year = {2017}, language = {de} } @article{Uibel2016, author = {Uibel, Thomas}, title = {Untersuchungen zum Spaltverhalten von Holzschrauben. Teil 1}, series = {Bauen mit Holz}, journal = {Bauen mit Holz}, number = {10}, publisher = {Rudolf M{\"u}ller}, address = {K{\"o}ln}, issn = {0005-6545}, pages = {40 -- 42}, year = {2016}, language = {de} } @article{MoorkampPetersonUibel2016, author = {Moorkamp, Wilfried and Peterson, Leif Arne and Uibel, Thomas}, title = {Mit guten Aussichten. Bericht {\"u}ber den Studiengang Holzingenieurwesen an der FH Aachen}, series = {Bauen mit Holz}, journal = {Bauen mit Holz}, number = {5}, publisher = {Rudolf M{\"u}ller}, address = {K{\"o}ln}, issn = {0005-6545}, pages = {33 -- 36}, year = {2016}, language = {de} } @inproceedings{PetersonRoethUibel2017, author = {Peterson, Leif Arne and R{\"o}th, Thilo and Uibel, Thomas}, title = {Holzwerkstoffe in Karosseriestrukturen}, series = {Tagungsband Aachener Holzbautagung 2017}, booktitle = {Tagungsband Aachener Holzbautagung 2017}, editor = {Uibel, Thormas and Peterson, Leif Arne and Baumann, Marcus}, issn = {2197-4489}, pages = {34 -- 45}, year = {2017}, language = {de} } @book{UibelPeterson2017, author = {Uibel, Thomas and Peterson, Leif Arne}, title = {Tagungsband Aachener Holzbautagung 2017}, editor = {Uibel, Thomas and Peterson, Leif Arne}, publisher = {FH Aachen}, address = {Aachen}, issn = {2197-4489}, pages = {96 Seiten ; Illustrationen, graph. Darst.}, year = {2017}, language = {de} } @book{UibelPeterson2015, author = {Uibel, Thomas and Peterson, Leif Arne}, title = {Tagungsband Aachener Holzbautagung 2015}, editor = {Uibel, Thomas and Peterson, Leif Arne}, publisher = {FH Aachen}, address = {Aachen}, issn = {2197-4489}, pages = {85 Seiten. , Illustrationen, graph. Darst.}, year = {2015}, language = {de} } @article{LaumannMainzKrahwinkel2017, author = {Laumann, J{\"o}rg and Mainz, Stefan and Krahwinkel, Manuel}, title = {Traglastuntersuchungen an Koppelpfetten bei Biegung um die schwache Achse und Torsion}, series = {Stahlbau}, volume = {86}, journal = {Stahlbau}, number = {11}, publisher = {Wiley}, address = {Weinheim}, issn = {0038-9145}, doi = {10.1002/stab.201710544}, pages = {1005 -- 1016}, year = {2017}, language = {de} } @article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel Bernhard}, title = {Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment}, series = {International Journal of Multiphase Flow}, volume = {100}, journal = {International Journal of Multiphase Flow}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-9322}, doi = {10.1016/j.ijmultiphaseflow.2017.12.011}, pages = {127 -- 142}, year = {2018}, abstract = {A new formulation for the prediction of free surface dynamics related to the turbulence occurring nearby is proposed. This formulation, altogether with a breakup criterion, can be used to compute the inception of self-aeration in high velocity flows like those occurring in hydraulic structures. Assuming a simple perturbation geometry, a kinematic and a non-linear momentum-based dynamic equation are formulated and forces acting on a control volume are approximated. Limiting steepness is proposed as an adequate breakup criterion. Role of the velocity fluctuations normal to the free surface is shown to be the main turbulence quantity related to self-aeration and the role of the scales contained in the turbulence spectrum are depicted. Surface tension force is integrated accounting for large displacements by using differential geometry for the curvature estimation. Gravity and pressure effects are also contemplated in the proposed formulation. The obtained equations can be numerically integrated for each wavelength, hence resulting in different growth rates and allowing computation of the free surface roughness wavelength distribution. Application to a prototype scale spillway (at the Aviemore dam) revealed that most unstable wavelength was close to the Taylor lengthscale. Amplitude distributions have been also obtained observing different scaling for perturbations stabilized by gravity or surface tension. The proposed theoretical framework represents a new conceptualization of self-aeration which explains the characteristic rough surface at the non-aerated region as well as other previous experimental observations which remained unresolved for several decades.}, language = {en} } @article{ValeroBung2017, author = {Valero, Daniel and Bung, Daniel Bernhard}, title = {Artificial Neural Networks and pattern recognition for air-water flow velocity estimation using a single-tip optical fibre probe}, series = {Journal of Hydro-environment Research}, volume = {19}, journal = {Journal of Hydro-environment Research}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1570-6443}, doi = {10.1016/j.jher.2017.08.004}, pages = {150 -- 159}, year = {2017}, language = {en} }