@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{BungSchlenkhoff2010, author = {Bung, Daniel Bernhard and Schlenkhoff, Andreas}, title = {Selbstbel{\"u}ftete Gerinnestr{\"o}mungen auf Treppenschussrinnen}, series = {Talsperren im Wandel : 15. Deutsches Talsperrensymposium ; Beitr{\"a}ge zur Tagung am 14. bis 16. April 2010 im Eurogress Aachen}, booktitle = {Talsperren im Wandel : 15. Deutsches Talsperrensymposium ; Beitr{\"a}ge zur Tagung am 14. bis 16. April 2010 im Eurogress Aachen}, organization = {Deutsches TalsperrenKomitee}, isbn = {978-3-8322-9043-6}, pages = {39 -- 47}, year = {2010}, language = {de} } @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} } @inproceedings{BungOertelSchlenkhoffetal.2010, author = {Bung, Daniel Bernhard and Oertel, M. and Schlenkhoff, A. and Schlurmann, Torsten}, title = {Flash flood awareness and prevention in Germany}, series = {Early warning for flash floods : international workshop, Praha 2011 : workshop proceedings}, booktitle = {Early warning for flash floods : international workshop, Praha 2011 : workshop proceedings}, editor = {Obrusnik, Ivan}, organization = {Czech Hydrometeorological Institute}, isbn = {978-80-86690-91-9}, pages = {34 -- 40}, year = {2010}, language = {en} } @inproceedings{BungLangohrWaldenberger2023, author = {Bung, Daniel Bernhard and Langohr, Phillip and Waldenberger, Lisa}, title = {Influence of cycle number in CFD studies of labyrinth weirs}, series = {Proceedings of the 40th IAHR World Congress (Vienna, 2023)}, booktitle = {Proceedings of the 40th IAHR World Congress (Vienna, 2023)}, editor = {Habersack, Helmut and Tritthart, Michael}, publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)}, address = {Madrid}, isbn = {978-90-833476-1-5}, issn = {L 2521-7119 (online)}, doi = {10.3850/978-90-833476-1-5_iahr40wc-p0531-cd}, year = {2023}, abstract = {The major advantage of labyrinth weirs over linear weirs is hydraulic efficiency. In hydraulic modeling efforts, this strength contrasts with limited pump capacity as well as limited computational power for CFD simulations. For the latter, reducing the number of investigated cycles can significantly reduce necessary computational time. In this study, a labyrinth weir with different cycle numbers was investigated. The simulations were conducted in FLOW-3D HYDRO as a Large Eddy Simulation. With a mean deviation of 1.75 \% between simulated discharge coefficients and literature design equations, a reasonable agreement was found. For downstream conditions, overall consistent results were observed as well. However, the orientation of labyrinth weirs with a single cycle should be chosen carefully under consideration of the individual research purpose.}, language = {en} } @inproceedings{BungHildebrandtOerteletal.2008, author = {Bung, Daniel Bernhard and Hildebrandt, Arndt and Oertel, Mario and Schlenkhoff, Andreas and Schlurmann, Torsten}, title = {Bore propagation over a submerged horizontal plate by physical and numerical simulation}, series = {Coastal engineering 2008 : proceedings of the 31st international conference; Hamburg, Germany, 31 August - 5 September 2008 ; Vol. 4}, booktitle = {Coastal engineering 2008 : proceedings of the 31st international conference; Hamburg, Germany, 31 August - 5 September 2008 ; Vol. 4}, editor = {McKee Smith, Jane}, isbn = {9814277401 ; 9789814277402}, pages = {3542 -- 3553}, year = {2008}, language = {en} } @article{BungErpicumTullis2020, author = {Bung, Daniel Bernhard and Erpicum, S{\´e}bastien and Tullis, Blanke P.}, title = {Advances in hydraulic structures engineering}, series = {Journal of Hydraulic Engineering}, volume = {147}, journal = {Journal of Hydraulic Engineering}, number = {1}, publisher = {ASCE}, address = {Reston, Va.}, issn = {0733-9429 (Druckausgabe)}, doi = {10.1061/(ASCE)HY.1943-7900.0001851}, pages = {1 Seite}, year = {2020}, 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} } @phdthesis{Bung2023, author = {Bung, Daniel Bernhard}, title = {Imaging techniques for investigation of free-surface flows in hydraulic laboratories}, doi = {10.25926/BUW/0-172}, pages = {XXIII, 218 Seiten}, year = {2023}, abstract = {This thesis aims at the presentation and discussion of well-accepted and new imaging techniques applied to different types of flow in common hydraulic engineering environments. All studies are conducted in laboratory conditions and focus on flow depth and velocity measurements. Investigated flows cover a wide range of complexity, e.g. propagation of waves, dam-break flows, slightly and fully aerated spillway flows as well as highly turbulent hydraulic jumps. Newimagingmethods are compared to different types of sensorswhich are frequently employed in contemporary laboratory studies. This classical instrumentation as well as the general concept of hydraulic modeling is introduced to give an overview on experimental methods. Flow depths are commonly measured by means of ultrasonic sensors, also known as acoustic displacement sensors. These sensors may provide accurate data with high sample rates in case of simple flow conditions, e.g. low-turbulent clear water flows. However, with increasing turbulence, higher uncertainty must be considered. Moreover, ultrasonic sensors can provide point data only, while the relatively large acoustic beam footprint may lead to another source of uncertainty in case of relatively short, highly turbulent surface fluctuations (ripples) or free-surface air-water flows. Analysis of turbulent length and time scales of surface fluctuations from point measurements is also difficult. Imaging techniques with different dimensionality, however, may close this gap. It is shown in this thesis that edge detection methods (known from computer vision) may be used for two-dimensional free-surface extraction (i.e. from images taken through transparant sidewalls in laboratory flumes). Another opportunity in hydraulic laboratory studies comes with the application of stereo vision. Low-cost RGB-D sensors can be used to gather instantaneous, three-dimensional free-surface elevations, even in flows with very high complexity (e.g. aerated hydraulic jumps). It will be shown that the uncertainty of these methods is of similar order as for classical instruments. Particle Image Velocimetry (PIV) is a well-accepted and widespread imaging technique for velocity determination in laboratory conditions. In combination with high-speed cameras, PIV can give time-resolved velocity fields in 2D/3D or even as volumetric flow fields. PIV is based on a cross-correlation technique applied to small subimages of seeded flows. The minimum size of these subimages defines the maximum spatial resolution of resulting velocity fields. A derivative of PIV for aerated flows is also available, i.e. the so-called Bubble Image Velocimetry (BIV). This thesis emphasizes the capacities and limitations of both methods, using relatively simple setups with halogen and LED illuminations. It will be demonstrated that PIV/BIV images may also be processed by means of Optical Flow (OF) techniques. OF is another method originating from the computer vision discipline, based on the assumption of image brightness conservation within a sequence of images. The Horn-Schunck approach, which has been first employed to hydraulic engineering problems in the studies presented herein, yields dense velocity fields, i.e. pixelwise velocity data. As discussed hereinafter, the accuracy of OF competes well with PIV for clear-water flows and even improves results (compared to BIV) for aerated flow conditions. In order to independently benchmark the OF approach, synthetic images with defined turbulence intensitiy are used. Computer vision offers new opportunities that may help to improve the understanding of fluid mechanics and fluid-structure interactions in laboratory investigations. In prototype environments, it can be employed for obstacle detection (e.g. identification of potential fish migration corridors) and recognition (e.g. fish species for monitoring in a fishway) or surface reconstruction (e.g. inspection of hydraulic structures). It can thus be expected that applications to hydraulic engineering problems will develop rapidly in near future. Current methods have not been developed for fluids in motion. Systematic future developments are needed to improve the results in such difficult conditions.}, language = {en} } @article{Bung2024, author = {Bung, Daniel Bernhard}, title = {Kamerabasierte Fließtiefen- und Geschwindigkeitsmessungen}, series = {Wasserwirtschaft}, volume = {114}, journal = {Wasserwirtschaft}, number = {4}, publisher = {Springer Vieweg}, address = {Wiesbaden}, issn = {0043-0978}, pages = {47 -- 53}, year = {2024}, abstract = {In der wasserbaulichen Forschung werden neben klassischen Messinstrumenten zunehmend kamerabasierte Verfahren genutzt. Diese erlauben neben der Bestimmung von Fließgeschwindigkeiten auch die Detektion der freien Wasseroberfl{\"a}che oder zeitliche Vermessung von Kolken. Durch die hohen r{\"a}umlichen und zeitlichen Aufl{\"o}sungen, welche neueste Kamerasensoren liefern, k{\"o}nnen neue Erkenntnisse in turbulenten, komplexen Str{\"o}mungen gewonnen werden. Auch in der Praxis k{\"o}nnen diese Verfahren mit geringem Aufwand wichtige Daten liefern.}, language = {de} } @inproceedings{Bung2009, author = {Bung, Daniel Bernhard}, title = {Optimierung des potentiellen Sauerstoffeintrags auf Treppenschussrinnen mit gem{\"a}ßigter Neigung}, series = {9. JuWi-Treffen : Beitr{\"a}ge zum Treffen junger Wissenschaftlerinnen und junger Wissenschaftler deutschsprachiger Wasserbauinstitute}, booktitle = {9. JuWi-Treffen : Beitr{\"a}ge zum Treffen junger Wissenschaftlerinnen und junger Wissenschaftler deutschsprachiger Wasserbauinstitute}, editor = {Theobald, S.}, publisher = {Universit{\"a}t Kassel}, address = {Kassel}, pages = {73 -- 78}, year = {2009}, language = {de} } @article{Bung2011, author = {Bung, Daniel Bernhard}, title = {Fließcharakteristik und Sauerstoffeintrag bei selbstbel{\"u}fteten Gerinnestr{\"o}mungen auf Kaskaden mit gem{\"a}ßigter Neigung}, series = {{\"O}sterreichische Wasser- und Abfallwirtschaft}, volume = {Vol. 63}, journal = {{\"O}sterreichische Wasser- und Abfallwirtschaft}, number = {Iss. 3-4}, publisher = {Springer}, address = {Berlin}, issn = {1613-7566 (E-Journal); 0945-358X (Print)}, pages = {76 -- 81}, year = {2011}, language = {de} } @inproceedings{Bung2012, author = {Bung, Daniel Bernhard}, title = {Sensitivity of phase detection techniques in aerated chute flows to hydraulic design parameters}, series = {2nd European IAHR congress : 27. - 29. June 2012, M{\"u}nchen}, booktitle = {2nd European IAHR congress : 27. - 29. June 2012, M{\"u}nchen}, publisher = {Lehrstuhl u. Versuchsanst. f{\"u}r Wasserbau u. Wasserwirtschaft d. TU M{\"u}nchen}, address = {M{\"u}nchen}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {978-3-943683-03-5}, pages = {Artikelkennnummer: B15}, year = {2012}, language = {en} } @article{Bung2013, author = {Bung, Daniel Bernhard}, title = {Non-intrusive detection of air-water surface roughness in self-aerated chute flows}, series = {Journal of hydraulic research}, volume = {Vol. 51}, journal = {Journal of hydraulic research}, number = {Iss. 3}, publisher = {Taylor \& Francis}, address = {London}, issn = {1814-2079 (E-Journal); 0022-1686 (Print)}, pages = {322 -- 329}, year = {2013}, language = {en} } @article{Bung2021, author = {Bung, Daniel Bernhard}, title = {Extreme flooding in Western Germany: some thoughts on hazards, return periods and risk}, series = {Hydrolink}, journal = {Hydrolink}, number = {4}, publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)}, address = {Madrid}, pages = {108 -- 113}, year = {2021}, abstract = {The low-pressure system Bernd involved extreme rainfalls in the Western part of Germany in July 2021, resulting in major floods, severe damages and a tremendous number of casualties. Such extreme events are rare and full flood protection can never be ensured with reasonable financial means. But still, this event must be starting point to reconsider current design concepts. This article aims at sharing some thoughts on potential hazards, the selection of return periods and remaining risk with the focus on Germany.}, language = {en} }