TY - CHAP A1 - Bung, Daniel B. 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 B. 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 B. 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 B. 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 - http://dx.doi.org/10.3850/38WC092019-0509 SP - 3690 EP - 3698 ER - TY - CHAP A1 - Bung, Daniel B. 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 B. 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 B. 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 - http://dx.doi.org/10.1080/00221686.2020.1844810 SN - 1814-2079 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Bung, Daniel B. 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 B. 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 B. 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 B. 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 B. 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 - CHAP A1 - Bung, Daniel B. 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 B. T1 - Observations on non-aerated flow and air entrainment on moderately sloped stepped spillways T2 - 7th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering : 8. - 12. Sept. 2014, Hannover Y1 - 2014 N1 - Kennwortgeschützter Zugang. Passwort bei Prof. Bung, Fachbereich Bauingenieurwesen SP - 1 EP - 8 ER - TY - CHAP A1 - Bung, Daniel B. 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 - http://dx.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 - http://dx.doi.org/10.1186/s42162-022-00208-5 SN - 2520-8942 N1 - Proceedings of the 11th DACH+ Conference on Energy Informatics, 15-16 September 2022, Freiburg, Germany. VL - 5 IS - 1, Article number: 17 SP - 1 EP - 14 PB - Springer Nature ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - 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 Hellström’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. Y1 - 2021 U6 - http://dx.doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin 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 -