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 - 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 - 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 - TY - JOUR A1 - Bung, Daniel Bernhard T1 - Developing flow in skimming flow regime on embankment stepped spillways JF - Journal of hydraulic research Y1 - 2011 SN - 1814-2079 (E-Journal); 0022-1686 (Print) VL - Vol. 49 IS - Iss. 5 SP - 639 EP - 648 PB - Taylor & Francis CY - London ER - TY - CHAP A1 - Bung, Daniel Bernhard T1 - A comparative study of self-aerated stepped spillway and smooth invert chute flow: the effect of step-induced macro roughness T2 - 5th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering : CG JOINT 2010 Y1 - 2010 SN - 978-7-5618-3671-2 SP - 451 EP - 456 PB - Univ. Press CY - Tianjin ER - TY - CHAP A1 - Bung, Daniel Bernhard T1 - Non-intrusive measuring of air-water flow properties in self-aerated stepped spillway flow T2 - Balance and uncertainty - water in a changing world : proceedings of the 34th IAHR world congress ; 33rd Hydrology and Water Resources Symposium ; 10th Conference on Hydraulics in Water Engineering ; 26 June - 1 July 2011, Brisbane, Australia Y1 - 2011 SN - 978-0-85825-868-6 SP - 2380 EP - 2387 ER - TY - CHAP A1 - Bung, Daniel Bernhard T1 - Air-water surface roughness in self-aerated stepped spillway flows T2 - 35th IAHR world congress : 8.-13.9.2013, Chengdu, China Y1 - 2013 SP - Artikelkennnummer: A11045 PB - Tsinghua Univ. Press CY - Beijing ER - TY - CHAP A1 - Bung, Daniel Bernhard ED - Rowinski, Pawel T1 - Laboratory models of free-surface flows T2 - Rivers - physical, fluvial and environmental processes N2 - Hydraulic modeling is the classical approach to investigate and describe complex fluid motion. Many empirical formulas in the literature used for the hydraulic design of river training measures and structures have been developed using experimental data from the laboratory. Although computer capacities have increased to a high level which allows to run complex numerical simulations on standard workstation nowadays, non-standard design of structures may still raise the need to perform physical model investigations. These investigations deliver insight into details of flow patterns and the effect of varying boundary conditions. Data from hydraulic model tests may be used for calibration of numerical models as well. As the field of hydraulic modeling is very complex, this chapter intends to give a short overview on capacities and limits of hydraulic modeling in regard to river flows and hydraulic structures only. The reader shall get a first idea of modeling principles and basic considerations. More detailed information can be found in the references. KW - Physical modeling KW - Similitude KW - Open channels KW - Hydraulic structures Y1 - 2015 SN - 978-3-319-17718-2 ; 978-3-319-17719-9 U6 - https://doi.org/10.1007/978-3-319-17719-9_9 SP - 213 EP - 228 PB - Springer CY - Cham ER - TY - CHAP A1 - Blanke, Tobias A1 - Schmidt, Katharina S. A1 - Göttsche, Joachim A1 - Döring, Bernd A1 - Frisch, Jérôme A1 - van Treeck, Christoph ED - Weidlich, Anke ED - Neumann, Dirk ED - Gust, Gunther ED - Staudt, Philipp ED - Schäfer, Mirko T1 - Time series aggregation for energy system design: review and extension of modelling seasonal storages T2 - Energy Informatics N2 - Using optimization to design a renewable energy system has become a computationally demanding task as the high temporal fluctuations of demand and supply arise within the considered time series. The aggregation of typical operation periods has become a popular method to reduce effort. These operation periods are modelled independently and cannot interact in most cases. Consequently, seasonal storage is not reproducible. This inability can lead to a significant error, especially for energy systems with a high share of fluctuating renewable energy. The previous paper, “Time series aggregation for energy system design: Modeling seasonal storage”, has developed a seasonal storage model to address this issue. Simultaneously, the paper “Optimal design of multi-energy systems with seasonal storage” has developed a different approach. This paper aims to review these models and extend the first model. The extension is a mathematical reformulation to decrease the number of variables and constraints. Furthermore, it aims to reduce the calculation time while achieving the same results. KW - Energy system KW - Renewable energy KW - Mixed integer linear programming (MILP) KW - Typical periods KW - Time-series aggregation Y1 - 2022 U6 - https://doi.org/10.1186/s42162-022-00208-5 SN - 2520-8942 N1 - 11th DACH+ Conference on Energy Informatics, 15-16 September 2022, Freiburg, Germany VL - 5 IS - 1, Article number: 17 PB - Springer Nature ER - TY - JOUR A1 - Biener, Ernst A1 - Wemhoff, T. A1 - Bethke, H. T1 - Stability and settlement problems based on the example of the Blockland landfill in Bremen JF - Sardinia 95 : Fifth International Landfill Symposium ; (2 - 6 October 1995, S. Margheritadi Pula - Cagliari, Sardinia, Italy) ; proceedings / coord.: Thomas H. Christensen ... - Bd. 2 : Siting, lining, drainage & landfill mechanics Y1 - 1995 N1 - International Landfill Symposium <5, 1995, Santa Margherita, Pula> SP - 843 EP - 853 PB - CISA, Environmental Sanitary Engineering Centre CY - Cagliari ER - TY - JOUR A1 - Biener, Ernst A1 - Sasse, T. A1 - Wernhoff, T. T1 - Using harbour dredged material for combination sealing of the former Bockhorner Weg disposal site in Bremen, Germany JF - Proceedings of the International Harbour Congress. 13 (2003) Y1 - 2003 N1 - International Harbour Congress <13, 2003, Antwerpen> SP - 101 EP - 109 ER - TY - JOUR A1 - Biener, Ernst A1 - Sasse, T. A1 - Konertz, K. T1 - Preparation of mineral sealing materials for landfills by different processing technologies / Sasse, T. ; Biener, E. ; Konertz, K. JF - Sardinia 93 : Fourth International Landfill Symposium "Barrier systems, environmental aspects, upgrading and remediation, siting, monofills, effects of waste pretreatment, landfilling in developing countries" ; 11 - 15 October 1993, S. Margherita di Pula (Cagliari), Sardinia, Italy ; proceedings / coord. by Thomas H. Christensen ... - Bd. 1 Y1 - 1993 N1 - International Landfill Symposium <4, 1993, Santa Margherita, Pula> SP - 275 EP - 283 PB - CISA, Environmental Sanitary Engineering Centre CY - Cagliari ER - TY - JOUR A1 - Biener, Ernst A1 - Sasse, T. A1 - Bökers, H. T1 - Preliminary or final capping of sanitary landfills? : Technical and economical aspects JF - Sardinia 99 : proceedings / Seventh International Waste Management and Landfill Symposium, [4 - 8 October 1999, S. Margherita di Pula, Cagliari, Sardinia, Italy]. Ed.: Thomas H. Christensen. - Bd. 3 : Barriers, waste mechanics and landfill design Y1 - 1999 N1 - International Waste Management and Landfill Symposium <7, 1999, Cagliari> SP - 287 EP - 294 PB - CISA, Environmental Sanitary Engineering Centre CY - Cagliari ER - TY - JOUR A1 - Biener, Ernst A1 - Sasse, T. A1 - Arnold, J. A1 - Woltering, S. T1 - New treatment of harbour sludge in Bremen and Bremerhaven / E. Biener ; T. Sasse ; J. Arnold ; S. Woltering ; N. Binder JF - Characterisation and treatment of sediments : Antwerpen, Belgium, September 15 - 17, 1999 ; [preceded by 12th International Harbour Congress] ; proceedings / CATS 4. Ed.: G. De Schutter. Organized by: Technologisch Instituut, Koninklijke Vlaamse Ingenieursvereniging Y1 - 1999 SN - 9076019118 N1 - CATS <4, 1999, Anvers> SP - 115 EP - 122 PB - Technolog. Inst. CY - Anvers ER - TY - JOUR A1 - Biener, Ernst A1 - Sasse, T. T1 - Construction and rehabilitation of landfill shafts JF - Sardinia 93 : Fourth International Landfill Symposium "Barrier systems, environmental aspects, upgrading and remediation, siting, monofills, effects of waste pretreatment, landfilling in developing countries" ; 11 - 15 October 1993, S. Margherita di Pula (Cagliari), Sardinia, Italy ; proceedings / coord. by Thomas H. Christensen ... - Bd. 1 Y1 - 1993 N1 - International Landfill Symposium <4, 1993, Santa Margherita, Pula> SP - 451 EP - 460 PB - CISA, Environmental Sanitary Engineering Centre CY - Cagliari ER -