TY - CHAP A1 - Bung, Daniel B. A1 - Valero, Daniel ED - Crookston, B. ED - Tullis, B. T1 - Application of the optical flow method to velocity determination in hydraulic structure models BT - Session 11: Fish passage and shiplocks T2 - Hydraulic Structures and Water System Management. 6th IAHR International Symposium on Hydraulic Structures, Portland, OR, 27-30 June 2016 Y1 - 2016 SN - 978-1-884575-75-4 U6 - http://dx.doi.org/10.15142/T3150628160853 SP - 223 EP - 232 ER - TY - CHAP A1 - Bung, Daniel B. A1 - Valero, Daniel ED - Dewals, Benjamin T1 - Image processing techniques for velocity estimation in highly aerated flows: bubble image velocimetry vs. optical flow T2 - Sustainable Hydraulics in the Era of Global Change : Proceedings of the 4th IAHR Europe Congress (Liege, Belgium, 27-29 July 2016) Y1 - 2016 SN - 978-1-138-02977-4 SN - 978-1-4987-8149-7 (eBook) U6 - http://dx.doi.org/10.1201/b21902-31 SP - 151 EP - 157 PB - CRC Press ER - TY - CHAP A1 - Bung, Daniel B. A1 - Valero, Daniel T1 - FlowCV - An open-source toolbox for computer vision applications in turbulent flows T2 - Proceedings of the 37th IAHR World Congress August 13 – 18, 2017, Kuala Lumpur, Malaysia Y1 - 2017 SN - 2521-716X SP - 5356 EP - 5365 ER - TY - JOUR A1 - Bung, Daniel B. A1 - Valero, Daniel T1 - Re-aeration on stepped spillways with special consideration of entrained and entrapped air JF - Geosciences N2 - 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. Y1 - 2018 SN - 2076-3263 VL - 8 IS - 9 SP - Article number 333 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bung, Daniel B. A1 - Valero, Daniel T1 - Optical flow estimation in aerated flows JF - Journal of Hydraulic Research N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1080/00221686.2016.1173600 VL - 54 IS - 5 SP - 575 EP - 580 PB - Taylor & Francis CY - London ER - TY - CHAP A1 - Bung, Daniel B. A1 - Tullis, Blake T1 - Hydraulic Structures - ISHS2018 in Perspective T2 - 7th IAHR International Symposium on Hydraulic Structures, Aachen, Germany, 15-18 May Y1 - 2018 SN - 978-0-692-13277-7 U6 - http://dx.doi.org/10.15142/T3WH2B ER - TY - CHAP A1 - Bung, Daniel B. 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 B. 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 B. 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 B. 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 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 - JOUR A1 - Bung, Daniel B. 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 B. 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 - 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 - THES A1 - Bung, Daniel B. T1 - Zur selbstbelüfteten Gerinneströmung auf Kaskaden mit gemäßigter Neigung. (Bericht / Fachbereich Bautechnik, Lehr- und Forschungsgebiet Wasserbau und Wasserwirtschaft, Bergische Universität Gesamthochschule Wuppertal ; Bd. 16) Y1 - 2009 SN - 978-3-8322-8382-7 N1 - Zugl.: Wuppertal, Univ., Diss., 2009 PB - Shaker CY - Aachen 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 - BOOK A1 - Bleninger, T. A1 - Brenda, M. A1 - Bung, Daniel B. A1 - Hengl, M. A1 - Schmid, B.H. A1 - Schneider, E. A1 - Sonnenburg, A. A1 - Stoschek, O. T1 - DWA-Regelwerk M 544-1 : Merkblatt: Ausbreitungsprobleme von Einleitungen - Prozesse, Methoden und Modelle - Teil 1: Anwendungsgrundlagen, Schätzformeln und eindimensionale Modelle Y1 - 2016 SN - 978-3-88721-280-3 CY - Hennef ER - TY - BOOK A1 - Bleninger, T. A1 - Brenda, M. A1 - Bung, Daniel B. A1 - Hengl, M. A1 - Schmid, B.H. A1 - Schneider, E. A1 - Sonnenburg, A. A1 - Stoschek, O. T1 - DWA-Regelwerk M 544-2 : Merkblatt: Ausbreitungsprobleme von Einleitungen - Prozesse, Methoden und Modelle - Teil 2: Mehrdimensionale Modelle Y1 - 2016 SN - 978-3-88721-281-0 CY - Hennef ER - TY - CHAP A1 - Ahmed, H. A1 - Schlenkhoff, A. A1 - Bung, Daniel B. T1 - Hydrodynamic characteristics of vertical slotted wall breakwaters 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 - 1179 EP - 1186 ER -