@article{Bung2011,
  author    = {Bung, Daniel B.},
  title     = {Developing flow in skimming flow regime on embankment stepped spillways},
  series = {Journal of hydraulic research},
  volume    = {Vol. 49},
  journal   = {Journal of hydraulic research},
  number    = {Iss. 5},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1814-2079 (E-Journal); 0022-1686 (Print)},
  pages     = {639 -- 648},
  year      = {2011},
  language  = {en}
}
@article{Bung2011,
  author    = {Bung, Daniel B.},
  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}
}
@article{OertelBung2012,
  author    = {Oertel, Mario and Bung, Daniel B.},
  title     = {Initial stage of two-dimensional dam-break waves: laboratory versus VOF},
  series = {Journal of hydraulic research},
  volume    = {50},
  journal   = {Journal of hydraulic research},
  number    = {1},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1814-2079 (E-Journal); 0022-1686 (Print)},
  doi       = {10.1080/00221686.2011.639981},
  pages     = {89 -- 97},
  year      = {2012},
  abstract  = {Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found.},
  language  = {en}
}
@article{Bung2013,
  author    = {Bung, Daniel B.},
  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{LeandroBungCarvalho2014,
  author    = {Leandro, J. and Bung, Daniel B. and Carvalho, R.},
  title     = {Measuring void fraction and velocity fields of a stepped spillway for skimming flow using non-intrusive methods},
  series = {Experiments in fluids},
  journal   = {Experiments in fluids},
  number    = {55},
  publisher = {Springer Nature},
  address   = {Heidelberg},
  issn      = {0723-4864 (Print) ; 1432-1114 (Online)},
  doi       = {10.1007/s00348-014-1732-6},
  pages     = {Art. 1732},
  year      = {2014},
  language  = {en}
}
@article{OertelBung2015,
  author    = {Oertel, Mario and Bung, Daniel B.},
  title     = {Numerische Str{\"o}mungssimulationen von Fließgew{\"a}ssern : Praxisanwendungen und zuk{\"u}nftige Entwicklungen},
  series = {Korrespondenz Wasserwirtschaft : KW},
  volume    = {8},
  journal   = {Korrespondenz Wasserwirtschaft : KW},
  number    = {H. 3},
  publisher = {Gesellschaft zur F{\"o}rderung der Abwassertechnik},
  address   = {Hennef},
  issn      = {1616-430X},
  pages     = {177 -- 182},
  year      = {2015},
  language  = {de}
}
@article{OertelBung2015,
  author    = {Oertel, Mario and Bung, Daniel B.},
  title     = {Stability and scour development of bed material on crossbar block ramps},
  series = {International journal of sediment research},
  volume    = {30},
  journal   = {International journal of sediment research},
  number    = {4},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1001-6279},
  doi       = {10.1016/j.ijsrc.2014.12.003},
  pages     = {344 -- 350},
  year      = {2015},
  abstract  = {Block ramps are ecologically oriented drop structures with adequate energy dissipation and partially moderate flow velocities. A special case is given with crossbar block ramps, where the upstream and downstream level difference is reduced by a series of basins. To prevent the total structure from failing, the stability of single boulders within the crossbars and the bed material in between must be guaranteed. The present paper addresses the stability of bed material and scour development for various flow regimes. Any bed material erosion may affect the stability of the crossbar boulders, which in turn can result in major damages of the ramp. Therefore new design approaches are developed to choose an appropriate bed material size and to avoid failures of crossbar block ramp structures.},
  language  = {en}
}
@article{ValeroBung2016,
  author    = {Valero, Daniel and Bung, Daniel B.},
  title     = {Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow},
  series = {Environmental Modelling and Software},
  volume    = {82},
  journal   = {Environmental Modelling and Software},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1364-8152 (electronic)},
  doi       = {10.1016/j.envsoft.2016.04.030},
  pages     = {218 -- 228},
  year      = {2016},
  abstract  = {Environmental discharges have been traditionally designed by means of cost-intensive and time-consuming experimental studies. Some extensively validated models based on an integral approach have been often employed for water quality problems, as recommended by USEPA (i.e.: CORMIX). In this study, FLOW-3D is employed for a full 3D RANS modelling of two turbulent jet-to-crossflow cases, including free surface jet impingement. Results are compared to both physical modelling and CORMIX to better assess model performance. Turbulence measurements have been collected for a better understanding of turbulent diffusion's parameter sensitivity. Although both studied models are generally able to reproduce jet trajectory, jet separation downstream of the impingement has been reproduced only by RANS modelling. Additionally, concentrations are better reproduced by FLOW-3D when the proper turbulent Schmidt number is used. This study provides a recommendation on the selection of the turbulence model and the turbulent Schmidt number for future outfall structures design studies.},
  language  = {en}
}
@article{ValeroBung2016,
  author    = {Valero, Daniel and Bung, Daniel B.},
  title     = {Development of the interfacial air layer in the non-aerated region of high-velocity spillway flows: Instabilities growth, entrapped air and influence on the self-aeration onset},
  series = {International Journal of Multiphase Flow},
  volume    = {84},
  journal   = {International Journal of Multiphase Flow},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0301-9322},
  doi       = {10.1016/j.ijmultiphaseflow.2016.04.012},
  pages     = {66 -- 74},
  year      = {2016},
  abstract  = {Self-aeration is traditionally explained by the water turbulent boundary layer outer edge intersection with the free surface. This paper presents a discussion on the commonly accepted hypothesis behind the computation of the critical point of self-aeration in spillway flows and a new formulation is proposed based on the existence of a developing air flow over the free surface. Upstream of the inception point of self-aeration, some surface roughening has been often reported in previous studies which consequently implies some entrapped air transport and air-water flows coupling. Such air flow is proven in this study by presenting measured air velocities and computing the air boundary layer thickness for a 1V:2H smooth chute flow. Additionally, the growth rate of free surface waves has been analysed by means of Ultrasonic Sensors measurements, obtaining also the entrapped air concentration. High-speed camera imaging has been used for qualitative study of the flow perturbations.},
  language  = {en}
}
@article{BungValero2016,
  author    = {Bung, Daniel B. and Valero, Daniel},
  title     = {Optical flow estimation in aerated flows},
  series = {Journal of Hydraulic Research},
  volume    = {54},
  journal   = {Journal of Hydraulic Research},
  number    = {5},
  publisher = {Taylor \& Francis},
  address   = {London},
  doi       = {10.1080/00221686.2016.1173600},
  pages     = {575 -- 580},
  year      = {2016},
  abstract  = {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.},
  language  = {en}
}