TY - CHAP A1 - Bung, Daniel Bernhard A1 - Sun, Q. A1 - Meireles, I. A1 - Matos, J. A1 - Viseu, T. T1 - USBR type III stilling basin performance for steep stepped spillways T2 - Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto Y1 - 2012 SN - 978-989-8509-01-7 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Schlenkhoff, Andreas A1 - Oertel, M. T1 - Self-aerated skimming flow on embankment stepped spillways T2 - Water engineering for sustainable environment : 33rd IAHR congress ; 9 - 14 August 2009, Vancouver, British Columbia, Canada Y1 - 2009 SN - 9789078046080 SP - 1 CD-ROM ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Schlenkhoff, Andreas T1 - Self-aerated skimming flow on embankment stepped spillways : the effect of additional micro-roughness on energy dissipation and oxygen transfer T2 - Proceedings from first IAHR European congress : May 2010, Edinburgh Y1 - 2010 SN - 9780956595102 SP - Artikelkennnummer HSIIId PB - Heriot-Watt University, School of the Built Environment CY - Edinburgh ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Schlenkhoff, Andreas ED - Pagliara, Stefano T1 - Optimization of the reaeration potential on embankment stepped spillways in skimming flow regime T2 - Hydraulic structures : proceedings of the second International Junior Researcher and Engineer Workshop on Hydraulic Structures, Pisa, Italy, 30 July-1 August 2008 Y1 - 2008 SN - 978-88-8492-568-8 SP - 97 EP - 106 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Schlenkhoff, Andreas T1 - Selbstbelüftete Gerinneströmungen auf Treppenschussrinnen T2 - Talsperren im Wandel : 15. Deutsches Talsperrensymposium ; Beiträge zur Tagung am 14. bis 16. April 2010 im Eurogress Aachen Y1 - 2010 SN - 978-3-8322-9043-6 SP - 39 EP - 47 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Pagliara, S. T1 - Proceedings of the International Workshop on Hydraulic Design of Low-Head Structures : Aachen, Germany, February, 20-22, 2013 / D. Bung ; S. Pagliara (eds.) Y1 - 2013 SN - 978-3-939230-04-5 PB - Bundesanst. für Wasserbau CY - Karlsruhe ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Oertel, Mario T1 - Wave breaking over a submerged horizontal plate: Optical Flow, LES and RANS T2 - E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama Y1 - 2019 U6 - https://doi.org/10.3850/38WC092019-0509 SP - 3690 EP - 3698 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Oertel, Mario T1 - Manipulation of non-aerated cavity flow on a stepped spillway model T2 - 3rd European IAHR Congress : April 14 – 16, 2014, Porto Y1 - 2014 PB - Univ. of Porto CY - Porto ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Oertel, M. A1 - Schlenkhoff, A. A1 - Schlurmann, Torsten ED - Obrusnik, Ivan T1 - Flash flood awareness and prevention in Germany T2 - Early warning for flash floods : international workshop, Praha 2011 : workshop proceedings Y1 - 2010 SN - 978-80-86690-91-9 SP - 34 EP - 40 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Langohr, Phillip A1 - Waldenberger, Lisa ED - Habersack, Helmut ED - Tritthart, Michael T1 - Influence of cycle number in CFD studies of labyrinth weirs T2 - Proceedings of the 40th IAHR World Congress (Vienna, 2023) N2 - 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. KW - CFD KW - Large Eddy Simulation KW - Labyfrinth weirs Y1 - 2023 SN - 978-90-833476-1-5 U6 - https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0531-cd SN - L 2521-7119 (online) N1 - Vienna, Austria, from August 21 to 25, 2023 PB - International Association for Hydro-Environment Engineering and Research (IAHR) CY - Madrid ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Hildebrandt, Arndt A1 - Oertel, Mario A1 - Schlenkhoff, Andreas A1 - Schlurmann, Torsten ED - McKee Smith, Jane T1 - Bore propagation over a submerged horizontal plate by physical and numerical simulation T2 - Coastal engineering 2008 : proceedings of the 31st international conference; Hamburg, Germany, 31 August - 5 September 2008 ; Vol. 4 Y1 - 2008 SN - 9814277401 ; 9789814277402 SP - 3542 EP - 3553 ER - TY - JOUR A1 - Bung, Daniel Bernhard A1 - Erpicum, Sébastien A1 - Tullis, Blanke P. T1 - Advances in hydraulic structures engineering JF - Journal of Hydraulic Engineering Y1 - 2020 U6 - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001851 SN - 0733-9429 (Druckausgabe) SN - 1943-7900 (Online-Ausgabe) VL - 147 IS - 1 PB - ASCE CY - Reston, Va. 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 - THES A1 - Bung, Daniel Bernhard T1 - Imaging techniques for investigation of free-surface flows in hydraulic laboratories N2 - 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. Y1 - 2023 U6 - https://doi.org/10.25926/BUW/0-172 ER - TY - JOUR A1 - Bung, Daniel Bernhard T1 - Kamerabasierte Fließtiefen- und Geschwindigkeitsmessungen JF - Wasserwirtschaft N2 - In der wasserbaulichen Forschung werden neben klassischen Messinstrumenten zunehmend kamerabasierte Verfahren genutzt. Diese erlauben neben der Bestimmung von Fließgeschwindigkeiten auch die Detektion der freien Wasseroberfläche oder zeitliche Vermessung von Kolken. Durch die hohen räumlichen und zeitlichen Auflösungen, welche neueste Kamerasensoren liefern, können neue Erkenntnisse in turbulenten, komplexen Strömungen gewonnen werden. Auch in der Praxis können diese Verfahren mit geringem Aufwand wichtige Daten liefern. KW - Wasserbau KW - Architektur KW - Wasserwirtschaft KW - Deutschland Y1 - 2024 SN - 0043-0978 VL - 114 IS - 4 SP - 47 EP - 53 PB - Springer Vieweg CY - Wiesbaden ER - TY - CHAP A1 - Bung, Daniel Bernhard ED - Theobald, S. T1 - Optimierung des potentiellen Sauerstoffeintrags auf Treppenschussrinnen mit gemäßigter Neigung T2 - 9. JuWi-Treffen : Beiträge zum Treffen junger Wissenschaftlerinnen und junger Wissenschaftler deutschsprachiger Wasserbauinstitute Y1 - 2009 SP - 73 EP - 78 PB - Universität Kassel CY - Kassel ER - TY - JOUR A1 - Bung, Daniel Bernhard T1 - Fließcharakteristik und Sauerstoffeintrag bei selbstbelüfteten Gerinneströmungen auf Kaskaden mit gemäßigter Neigung JF - Österreichische Wasser- und Abfallwirtschaft Y1 - 2011 SN - 1613-7566 (E-Journal); 0945-358X (Print) VL - Vol. 63 IS - Iss. 3-4 SP - 76 EP - 81 PB - Springer CY - Berlin ER - TY - CHAP A1 - Bung, Daniel Bernhard T1 - Sensitivity of phase detection techniques in aerated chute flows to hydraulic design parameters T2 - 2nd European IAHR congress : 27. - 29. June 2012, München Y1 - 2012 SN - 978-3-943683-03-5 SP - Artikelkennnummer: B15 PB - Lehrstuhl u. Versuchsanst. für Wasserbau u. Wasserwirtschaft d. TU München CY - München ER - TY - JOUR A1 - Bung, Daniel Bernhard T1 - Non-intrusive detection of air–water surface roughness in self-aerated chute flows JF - Journal of hydraulic research Y1 - 2013 SN - 1814-2079 (E-Journal); 0022-1686 (Print) VL - Vol. 51 IS - Iss. 3 SP - 322 EP - 329 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Bung, Daniel Bernhard T1 - Extreme flooding in Western Germany: some thoughts on hazards, return periods and risk JF - Hydrolink N2 - 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. Y1 - 2021 IS - 4 SP - 108 EP - 113 PB - International Association for Hydro-Environment Engineering and Research (IAHR) CY - Madrid ER -