@inproceedings{DoeringFeldmannKuhnhenne2007, author = {D{\"o}ring, Bernd and Feldmann, Markus and Kuhnhenne, Markus}, title = {An innovative thermally activated light-weight steel deck system - numerical investigations and practical tests}, series = {Clima 2007 WellBeing Indoors: 9th Rehva World Congress, 10-14 June 2007, Helsinki, Finland : proceedings}, booktitle = {Clima 2007 WellBeing Indoors: 9th Rehva World Congress, 10-14 June 2007, Helsinki, Finland : proceedings}, address = {Helsinki}, isbn = {978-952-99898-2-9}, pages = {1 -- 8}, year = {2007}, language = {en} } @inproceedings{DuranParedesMottaghyHerrmannetal.2020, author = {Duran Paredes, Ludwin and Mottaghy, Darius and Herrmann, Ulf and Groß, Rolf Fritz}, title = {Online ground temperature and soil moisture monitoring of a shallow geothermal system with non-conventional components}, series = {EGU General Assembly 2020}, booktitle = {EGU General Assembly 2020}, year = {2020}, abstract = {We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation.}, language = {en} } @inproceedings{CrookstonBung2022, author = {Crookston, Brian M. and Bung, Daniel Bernhard}, title = {Application of RGB-D cameras in hydraulic laboratory studies}, series = {Proceedings of the 39th IAHR World Congress}, booktitle = {Proceedings of the 39th IAHR World Congress}, editor = {Ortega-S{\´a}nchez, Miguel}, publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)}, address = {Madrid}, isbn = {978-90-832612-1-8}, issn = {2521-7119 (print)}, doi = {10.3850/IAHR-39WC252171192022964}, pages = {5127 -- 5133}, year = {2022}, abstract = {Non-intrusive measuring techniques have attained a lot of interest in relation to both hydraulic modeling and prototype applications. Complimenting acoustic techniques, significant progress has been made for the development of new optical methods. Computer vision techniques can help to extract new information, e. g. high-resolution velocity and depth data, from videos captured with relatively inexpensive, consumer-grade cameras. Depth cameras are sensors providing information on the distance between the camera and observed features. Currently, sensors with different working principles are available. Stereoscopic systems reference physical image features (passive system) from two perspectives; in order to enhance the number of features and improve the results, a sensor may also estimate the disparity from a detected light to its original projection (active stereo system). In the current study, the RGB-D camera Intel RealSense D435, working on such stereo vision principle, is used in different, typical hydraulic modeling applications. All tests have been conducted at the Utah Water Research Laboratory. This paper will demonstrate the performance and limitations of the RGB-D sensor, installed as a single camera and as camera arrays, applied to 1) detect the free surface for highly turbulent, aerated hydraulic jumps, for free-falling jets and for an energy dissipation basin downstream of a labyrinth weir and 2) to monitor local scours upstream and downstream of a Piano Key Weir. It is intended to share the authors' experiences with respect to camera settings, calibration, lightning conditions and other requirements in order to promote this useful, easily accessible device. Results will be compared to data from classical instrumentation and the literature. It will be shown that even in difficult application, e. g. the detection of a highly turbulent, fluctuating free-surface, the RGB-D sensor may yield similar accuracy as classical, intrusive probes.}, language = {en} } @techreport{ConanD'HaeyerBeguinetal.2006, author = {Conan, Yulian and D'Haeyer, R. and B{\´e}guin, P. and D{\"o}ring, Bernd and Kuhnhenne, Markus and Bayo, E.}, title = {Steel in low-rise building : a symbiosis of cold formed sections and light rolled profiles : final report. Contract-No. 7215-PP/070. EUR 22080 en}, publisher = {Office for Official Publications of the European Communities}, address = {Luxembourg}, isbn = {92-79-02082-X}, pages = {200 S.}, year = {2006}, language = {en} } @article{CheenakulaGriebelMontagetal.2023, author = {Cheenakula, Dheeraja and Griebel, Kai and Montag, David and Gr{\"o}mping, Markus}, title = {Concept development of a mainstream deammonification and comparison with conventional process in terms of energy, performance and economical construction perspectives}, series = {Frontiers in Microbiology}, volume = {14}, journal = {Frontiers in Microbiology}, number = {11155235}, editor = {Huang, Xiaowu}, publisher = {Frontiers}, issn = {1664-302X}, doi = {10.3389/fmicb.2023.1155235}, pages = {1 -- 15}, year = {2023}, abstract = {Deammonification for nitrogen removal in municipal wastewater in temperate and cold climate zones is currently limited to the side stream of municipal wastewater treatment plants (MWWTP). This study developed a conceptual model of a mainstream deammonification plant, designed for 30,000 P.E., considering possible solutions corresponding to the challenging mainstream conditions in Germany. In addition, the energy-saving potential, nitrogen elimination performance and construction-related costs of mainstream deammonification were compared to a conventional plant model, having a single-stage activated sludge process with upstream denitrification. The results revealed that an additional treatment step by combining chemical precipitation and ultra-fine screening is advantageous prior the mainstream deammonification. Hereby chemical oxygen demand (COD) can be reduced by 80\% so that the COD:N ratio can be reduced from 12 to 2.5. Laboratory experiments testing mainstream conditions of temperature (8-20°C), pH (6-9) and COD:N ratio (1-6) showed an achievable volumetric nitrogen removal rate (VNRR) of at least 50 gN/(m3∙d) for various deammonifying sludges from side stream deammonification systems in the state of North Rhine-Westphalia, Germany, where m3 denotes reactor volume. Assuming a retained Norganic content of 0.0035 kgNorg./(P.E.∙d) from the daily loads of N at carbon removal stage and a VNRR of 50 gN/(m3∙d) under mainstream conditions, a resident-specific reactor volume of 0.115 m3/(P.E.) is required for mainstream deammonification. This is in the same order of magnitude as the conventional activated sludge process, i.e., 0.173 m3/(P.E.) for an MWWTP of size class of 4. The conventional plant model yielded a total specific electricity demand of 35 kWh/(P.E.∙a) for the operation of the whole MWWTP and an energy recovery potential of 15.8 kWh/(P.E.∙a) through anaerobic digestion. In contrast, the developed mainstream deammonification model plant would require only a 21.5 kWh/(P.E.∙a) energy demand and result in 24 kWh/(P.E.∙a) energy recovery potential, enabling the mainstream deammonification model plant to be self-sufficient. The retrofitting costs for the implementation of mainstream deammonification in existing conventional MWWTPs are nearly negligible as the existing units like activated sludge reactors, aerators and monitoring technology are reusable. However, the mainstream deammonification must meet the performance requirement of VNRR of about 50 gN/(m3∙d) in this case.}, language = {en} } @incollection{ChansonBungMatos2015, author = {Chanson, Hubert and Bung, Daniel Bernhard and Matos, J.}, title = {Stepped spillways and cascades}, series = {Energy dissipation in hydraulic structures / Hubert Chanson (ed.)}, booktitle = {Energy dissipation in hydraulic structures / Hubert Chanson (ed.)}, publisher = {CRC Press}, address = {Boca Raton, Fla. [u.a.]}, isbn = {978-1-138-02755-8 (print) ; 978-1-315-68029-3 (e-Book)}, pages = {45 -- 64}, year = {2015}, language = {en} } @inproceedings{BungValero2017, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {FlowCV - An open-source toolbox for computer vision applications in turbulent flows}, series = {Proceedings of the 37th IAHR World Congress August 13 - 18, 2017, Kuala Lumpur, Malaysia}, booktitle = {Proceedings of the 37th IAHR World Congress August 13 - 18, 2017, Kuala Lumpur, Malaysia}, issn = {2521-716X}, pages = {5356 -- 5365}, year = {2017}, language = {en} } @inproceedings{BungValero2016, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {Application of the optical flow method to velocity determination in hydraulic structure models}, series = {Hydraulic Structures and Water System Management. 6th IAHR International Symposium on Hydraulic Structures, Portland, OR, 27-30 June 2016}, booktitle = {Hydraulic Structures and Water System Management. 6th IAHR International Symposium on Hydraulic Structures, Portland, OR, 27-30 June 2016}, editor = {Crookston, B. and Tullis, B.}, isbn = {978-1-884575-75-4}, doi = {10.15142/T3150628160853}, pages = {223 -- 232}, year = {2016}, language = {en} } @article{BungValero2018, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {Re-aeration on stepped spillways with special consideration of entrained and entrapped air}, series = {Geosciences}, volume = {8}, journal = {Geosciences}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2076-3263}, pages = {Article number 333}, year = {2018}, abstract = {As with most high-velocity free-surface flows, stepped spillway flows become self-aerated when the drop height exceeds a critical value. Due to the step-induced macro-roughness, the flow field becomes more turbulent than on a similar smooth-invert chute. For this reason, cascades are oftentimes used as re-aeration structures in wastewater treatment. However, for stepped spillways as flood release structures downstream of deoxygenated reservoirs, gas transfer is also of crucial significance to meet ecological requirements. Prediction of mass transfer velocities becomes challenging, as the flow regime differs from typical previously studied flow conditions. In this paper, detailed air-water flow measurements are conducted on stepped spillway models with different geometry, with the aim to estimate the specific air-water interface. Re-aeration performances are determined by applying the absorption method. In contrast to earlier studies, the aerated water body is considered a continuous mixture up to a level where 75\% air concentration is reached. Above this level, a homogenous surface wave field is considered, which is found to significantly affect the total air-water interface available for mass transfer. Geometrical characteristics of these surface waves are obtained from high-speed camera investigations. The results show that both the mean air concentration and the mean flow velocity have influence on the mass transfer. Finally, an empirical relationship for the mass transfer on stepped spillway models is proposed.}, 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{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} } @inproceedings{BungValero2015, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {Image processing for bubble image velocimetry in self-aerated flows}, series = {E-proceedings of the 36th IAHR World Congress 28 June - 3 July, 2015, The Hague, the Netherlands}, booktitle = {E-proceedings of the 36th IAHR World Congress 28 June - 3 July, 2015, The Hague, the Netherlands}, organization = {IAHR World Congress <36, 2015, Den Haag>}, pages = {1 -- 8}, year = {2015}, language = {en} } @inproceedings{BungTullis2018, author = {Bung, Daniel Bernhard and Tullis, Blake}, title = {Hydraulic Structures - ISHS2018 in Perspective}, series = {7th IAHR International Symposium on Hydraulic Structures, Aachen, Germany, 15-18 May}, booktitle = {7th IAHR International Symposium on Hydraulic Structures, Aachen, Germany, 15-18 May}, isbn = {978-0-692-13277-7}, doi = {10.15142/T3WH2B}, pages = {9 seiten}, year = {2018}, language = {en} } @inproceedings{BungSunMeirelesetal.2012, author = {Bung, Daniel Bernhard and Sun, Q. and Meireles, I. and Matos, J. and Viseu, T.}, title = {USBR type III stilling basin performance for steep stepped spillways}, series = {Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto}, booktitle = {Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto}, organization = {International Symposium on Hydraulic Structures <4, 2012, Porto>}, isbn = {978-989-8509-01-7}, pages = {Elektronisch publiziert}, year = {2012}, language = {en} } @inproceedings{BungSchlenkhoffOertel2009, author = {Bung, Daniel Bernhard and Schlenkhoff, Andreas and Oertel, M.}, title = {Self-aerated skimming flow on embankment stepped spillways}, series = {Water engineering for sustainable environment : 33rd IAHR congress ; 9 - 14 August 2009, Vancouver, British Columbia, Canada}, booktitle = {Water engineering for sustainable environment : 33rd IAHR congress ; 9 - 14 August 2009, Vancouver, British Columbia, Canada}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {9789078046080}, pages = {1 CD-ROM}, year = {2009}, language = {en} } @inproceedings{BungSchlenkhoff2010, author = {Bung, Daniel Bernhard and Schlenkhoff, Andreas}, title = {Self-aerated skimming flow on embankment stepped spillways : the effect of additional micro-roughness on energy dissipation and oxygen transfer}, series = {Proceedings from first IAHR European congress : May 2010, Edinburgh}, booktitle = {Proceedings from first IAHR European congress : May 2010, Edinburgh}, publisher = {Heriot-Watt University, School of the Built Environment}, address = {Edinburgh}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {9780956595102}, pages = {Artikelkennnummer HSIIId}, year = {2010}, language = {en} } @inproceedings{BungSchlenkhoff2008, author = {Bung, Daniel Bernhard and Schlenkhoff, Andreas}, title = {Optimization of the reaeration potential on embankment stepped spillways in skimming flow regime}, series = {Hydraulic structures : proceedings of the second International Junior Researcher and Engineer Workshop on Hydraulic Structures, Pisa, Italy, 30 July-1 August 2008}, booktitle = {Hydraulic structures : proceedings of the second International Junior Researcher and Engineer Workshop on Hydraulic Structures, Pisa, Italy, 30 July-1 August 2008}, editor = {Pagliara, Stefano}, organization = {International Junior Researcher and Engineer Workshop on Hydraulic Structures <2, 2008, Pisa>}, isbn = {978-88-8492-568-8}, pages = {97 -- 106}, year = {2008}, language = {en} } @inproceedings{BungPagliara2013, author = {Bung, Daniel Bernhard and Pagliara, S.}, title = {Proceedings of the International Workshop on Hydraulic Design of Low-Head Structures : Aachen, Germany, February, 20-22, 2013 / D. Bung ; S. Pagliara (eds.)}, publisher = {Bundesanst. f{\"u}r Wasserbau}, address = {Karlsruhe}, isbn = {978-3-939230-04-5}, pages = {X, 230 S. + 1 CD-ROM}, year = {2013}, language = {en} } @inproceedings{BungOertel2019, author = {Bung, Daniel Bernhard and Oertel, Mario}, title = {Wave breaking over a submerged horizontal plate: Optical Flow, LES and RANS}, 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 = {10.3850/38WC092019-0509}, pages = {3690 -- 3698}, year = {2019}, language = {en} } @inproceedings{BungOertel2014, author = {Bung, Daniel Bernhard and Oertel, Mario}, title = {Manipulation of non-aerated cavity flow on a stepped spillway model}, series = {3rd European IAHR Congress : April 14 - 16, 2014, Porto}, booktitle = {3rd European IAHR Congress : April 14 - 16, 2014, Porto}, publisher = {Univ. of Porto}, address = {Porto}, organization = {International Association of Hydro-Environment Engineering and Research}, year = {2014}, language = {en} }