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Daniel B. Bung
IAHR Member), Professor, Hydraulic Engineering Section, Civil Engineering Department, FH Aachen University of Applied Sciences, Aachen, Germany

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Journal article
Published: 01 January 2021 in Journal of Hydraulic Engineering
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ACS Style

Daniel B. Bung; Sébastien Erpicum; Blake P. Tullis. Advances in Hydraulic Structures Engineering. Journal of Hydraulic Engineering 2021, 147, 02020001 .

AMA Style

Daniel B. Bung, Sébastien Erpicum, Blake P. Tullis. Advances in Hydraulic Structures Engineering. Journal of Hydraulic Engineering. 2021; 147 (1):02020001.

Chicago/Turabian Style

Daniel B. Bung; Sébastien Erpicum; Blake P. Tullis. 2021. "Advances in Hydraulic Structures Engineering." Journal of Hydraulic Engineering 147, no. 1: 02020001.

Research paper
Published: 18 December 2020 in Journal of Hydraulic Research
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Measuring flow depths in free-surface turbulent flows can be challenging due to their fast dynamics and the presence of aeration. This study analyses the suitability of a low-cost sensor, the Intel® RealSense™ D435 RGB-D camera, for characterization of a highly aerated case study: the hydraulic jump. As with all instrumentation, special care must be taken to ensure accurate measurements. In this case, two different methods to calibrate depth estimations (accounting for set-up and any instrument precision) are presented, both leading to similar results. The main advantage of the presented instrumentation is its capability to measure 3D surfaces with high temporal and spatial resolution. Results are presented primarily in 2D in order to evaluate the flow depth estimation quality of this new technique with 2D data available in literature. The employed sensor showed a similar level of uncertainty as previous, well-established instrumentation for the study of free-surface elevations, amplitudes and frequencies of turbulent fluctuations.

ACS Style

Daniel B. Bung; Brian M. Crookston; Daniel Valero. Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case. Journal of Hydraulic Research 2020, 1 -12.

AMA Style

Daniel B. Bung, Brian M. Crookston, Daniel Valero. Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case. Journal of Hydraulic Research. 2020; ():1-12.

Chicago/Turabian Style

Daniel B. Bung; Brian M. Crookston; Daniel Valero. 2020. "Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case." Journal of Hydraulic Research , no. : 1-12.

Journal article
Published: 05 October 2020 in Flow Measurement and Instrumentation
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Robust estimators are parameters insensitive to the presence of outliers. However, they presume the shape of the variables’ probability density function. This study exemplifies the sensitivity of turbulent quantities to the use of classic and robust estimators and the presence of outliers in turbulent flow depth time series. A wide range of turbulence quantities was analysed based upon a stepped spillway case study, using flow depths sampled with Acoustic Displacement Meters as the flow variable of interest. The studied parameters include: the expected free surface level, the expected fluctuation intensity, the depth skewness, the autocorrelation timescales, the vertical velocity fluctuation intensity, the perturbations celerity and the one-dimensional free surface turbulence spectrum. Three levels of filtering were utilised prior to applying classic and robust estimators, showing that comparable robustness can be obtained either using classic estimators together with an intermediate filtering technique or using robust estimators instead, without any filtering technique.

ACS Style

Daniel Valero; Hubert Chanson; Daniel B. Bung. Robust estimators for free surface turbulence characterization: a stepped spillway application. Flow Measurement and Instrumentation 2020, 76, 101809 .

AMA Style

Daniel Valero, Hubert Chanson, Daniel B. Bung. Robust estimators for free surface turbulence characterization: a stepped spillway application. Flow Measurement and Instrumentation. 2020; 76 ():101809.

Chicago/Turabian Style

Daniel Valero; Hubert Chanson; Daniel B. Bung. 2020. "Robust estimators for free surface turbulence characterization: a stepped spillway application." Flow Measurement and Instrumentation 76, no. : 101809.

Preprint
Published: 14 June 2019
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Robust estimators and different filtering techniques are proposed and their impact on the determination of a wide range of turbulence quantities is analysed. High-frequency water level measurements in a stepped spillway are used as a case study. The studied variables contemplated: the expected free surface level, the expected fluctuation intensity, the depth skewness, the autocorrelation timescales, the vertical velocity fluctuation intensity, the perturbations celerity and the one-dimensional free surface turbulence spectrum. When compared to classic techniques, the robust estimators allowed a more accurate prediction of turbulence quantities notwithstanding the filtering technique used.

ACS Style

Daniel Valero; Hubert Chanson; Daniel B. Bung. Robust estimators for turbulence properties assessment. 2019, 1 .

AMA Style

Daniel Valero, Hubert Chanson, Daniel B. Bung. Robust estimators for turbulence properties assessment. . 2019; ():1.

Chicago/Turabian Style

Daniel Valero; Hubert Chanson; Daniel B. Bung. 2019. "Robust estimators for turbulence properties assessment." , no. : 1.

Letter
Published: 26 November 2018 in Experiments in Fluids
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Air–water flow turbulence was derived from pseudo-instantaneous velocities measured with a dual-tip phase-detection probe. This new technique is proposed based upon adaptive time windows for cross-correlation analysis combined with robust filtering criteria, allowing computation of velocity time series in highly aerated flows. Each velocity estimation corresponded to a small group of bubbles or droplets. Stochastic synthetic velocity fields were generated to assess the limitations and uncertainties related to the proposed analysis. Subsequently, capabilities of the technique were demonstrated through an application to a real two-phase flow on a large-size stepped spillway.

ACS Style

Matthias Kramer; Daniel Valero; Hubert Chanson; Daniel B. Bung. Towards reliable turbulence estimations with phase-detection probes: an adaptive window cross-correlation technique. Experiments in Fluids 2018, 60, 2 .

AMA Style

Matthias Kramer, Daniel Valero, Hubert Chanson, Daniel B. Bung. Towards reliable turbulence estimations with phase-detection probes: an adaptive window cross-correlation technique. Experiments in Fluids. 2018; 60 (1):2.

Chicago/Turabian Style

Matthias Kramer; Daniel Valero; Hubert Chanson; Daniel B. Bung. 2018. "Towards reliable turbulence estimations with phase-detection probes: an adaptive window cross-correlation technique." Experiments in Fluids 60, no. 1: 2.

Journal article
Published: 05 September 2018 in Geosciences
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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.

ACS Style

Daniel B. Bung; Daniel Valero. Re-Aeration on Stepped Spillways with Special Consideration of Entrained and Entrapped Air. Geosciences 2018, 8, 333 .

AMA Style

Daniel B. Bung, Daniel Valero. Re-Aeration on Stepped Spillways with Special Consideration of Entrained and Entrapped Air. Geosciences. 2018; 8 (9):333.

Chicago/Turabian Style

Daniel B. Bung; Daniel Valero. 2018. "Re-Aeration on Stepped Spillways with Special Consideration of Entrained and Entrapped Air." Geosciences 8, no. 9: 333.

Journal article
Published: 01 July 2018 in Journal of Hydraulic Engineering
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New information regarding the influence of a stepped chute on the hydraulic performance of the United States Bureau of Reclamation (Reclamation) Type III hydraulic jump stilling basin is presented for design (steady) and adverse (decreasing tailwater) conditions. Using published experimental data and computational fluid dynamics (CFD) models, this paper presents a detailed comparison between smooth-chute and stepped-chute configurations for chute slopes of 0.8H:1V and 4H:1V and Froude numbers (F) ranging from 3.1 to 9.5 for a Type III basin designed for F = 8. For both stepped and smooth chutes, the relative role of each basin element was quantified, up to the most hydraulic extreme case of jump sweep-out. It was found that, relative to a smooth chute, the turbulence generated by a stepped chute causes a higher maximum velocity decay within the stilling basin, which represents an enhancement of the Type III basin’s performance but also a change in the relative role of the basin elements. Results provide insight into the ability of the CFD models [unsteady Reynolds-averaged Navier-Stokes (RANS) equations with renormalization group (RNG) k-ϵ turbulence model and volume-of-fluid (VOF) for free surface tracking] to predict the transient basin flow structure and velocity profiles. Type III basins can perform adequately with a stepped chute despite the effects steps have on the relative role of each basin element. It is concluded that the classic Type III basin design, based upon methodology by reclamation specific to smooth chutes, can be hydraulically improved for the case of stepped chutes for design and adverse flow conditions using the information presented herein.

ACS Style

D. Valero; D. B. Bung; B. M. Crookston. Energy Dissipation of a Type III Basin under Design and Adverse Conditions for Stepped and Smooth Spillways. Journal of Hydraulic Engineering 2018, 144, 04018036 .

AMA Style

D. Valero, D. B. Bung, B. M. Crookston. Energy Dissipation of a Type III Basin under Design and Adverse Conditions for Stepped and Smooth Spillways. Journal of Hydraulic Engineering. 2018; 144 (7):04018036.

Chicago/Turabian Style

D. Valero; D. B. Bung; B. M. Crookston. 2018. "Energy Dissipation of a Type III Basin under Design and Adverse Conditions for Stepped and Smooth Spillways." Journal of Hydraulic Engineering 144, no. 7: 04018036.

Journal article
Published: 01 July 2018 in Journal of Hydraulic Engineering
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A new methodology is proposed to spatially filter acoustic Doppler velocimetry data from a Vectrino profiler based on the differential mean velocity equation. Lower and upper bounds are formulated in terms of physically based flow constraints. Practical implementation is discussed, and its application is tested against data gathered from an open-channel flow over a stepped macroroughness surface. The method has proven to detect outliers occurring all over the distance range sampled by the Vectrino profiler and has shown to remain applicable out of the region of validity of the velocity gradient equation. Finally, a statistical analysis suggests that physically obtained bounds are asymptotically representative.

ACS Style

Daniel Valero; Daniel B. Bung. Vectrino Profiler Spatial Filtering for Shear Flows Based on the Mean Velocity Gradient Equation. Journal of Hydraulic Engineering 2018, 144, 04018037 .

AMA Style

Daniel Valero, Daniel B. Bung. Vectrino Profiler Spatial Filtering for Shear Flows Based on the Mean Velocity Gradient Equation. Journal of Hydraulic Engineering. 2018; 144 (7):04018037.

Chicago/Turabian Style

Daniel Valero; Daniel B. Bung. 2018. "Vectrino Profiler Spatial Filtering for Shear Flows Based on the Mean Velocity Gradient Equation." Journal of Hydraulic Engineering 144, no. 7: 04018037.

Journal article
Published: 01 March 2018 in International Journal of Multiphase Flow
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A new formulation for the prediction of free surface dynamics related to the turbulence occurring nearby is proposed. This formulation, altogether with a breakup criterion, can be used to compute the inception of self-aeration in high velocity flows like those occurring in hydraulic structures. Assuming a simple perturbation geometry, a kinematic and a non-linear momentum-based dynamic equation are formulated and forces acting on a control volume are approximated. Limiting steepness is proposed as an adequate breakup criterion. Role of the velocity fluctuations normal to the free surface is shown to be the main turbulence quantity related to self-aeration and the role of the scales contained in the turbulence spectrum are depicted. Surface tension force is integrated accounting for large displacements by using differential geometry for the curvature estimation. Gravity and pressure effects are also contemplated in the proposed formulation. The obtained equations can be numerically integrated for each wavelength, hence resulting in different growth rates and allowing computation of the free surface roughness wavelength distribution. Application to a prototype scale spillway (at the Aviemore dam) revealed that most unstable wavelength was close to the Taylor lengthscale. Amplitude distributions have been also obtained observing different scaling for perturbations stabilized by gravity or surface tension. The proposed theoretical framework represents a new conceptualization of self-aeration which explains the characteristic rough surface at the non-aerated region as well as other previous experimental observations which remained unresolved for several decades.

ACS Style

Daniel Valero; Daniel B. Bung. Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment. International Journal of Multiphase Flow 2018, 100, 127 -142.

AMA Style

Daniel Valero, Daniel B. Bung. Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment. International Journal of Multiphase Flow. 2018; 100 ():127-142.

Chicago/Turabian Style

Daniel Valero; Daniel B. Bung. 2018. "Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment." International Journal of Multiphase Flow 100, no. : 127-142.

Article
Published: 08 July 2017 in Journal of Ocean University of China
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To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment, hydraulic model tests with steady flow conditions are conducted and correlated with unsteady flow conditions of the wave run-up within a short time frame. Under irregular waves, the run-up reduction over a stepped revetment is dependent on the Iribarren number and decreases for decreasing Iribarren numbers. Velocity gradients are found to be similar in a steady and unsteady flow regime near the pseudo-bottom.

ACS Style

Nils B. Kerpen; Daniel B. Bung; Daniel Valero; Torsten Schlurmann. Energy dissipation within the wave run-up at stepped revetments. Journal of Ocean University of China 2017, 16, 649 -654.

AMA Style

Nils B. Kerpen, Daniel B. Bung, Daniel Valero, Torsten Schlurmann. Energy dissipation within the wave run-up at stepped revetments. Journal of Ocean University of China. 2017; 16 (4):649-654.

Chicago/Turabian Style

Nils B. Kerpen; Daniel B. Bung; Daniel Valero; Torsten Schlurmann. 2017. "Energy dissipation within the wave run-up at stepped revetments." Journal of Ocean University of China 16, no. 4: 649-654.

Journal article
Published: 01 September 2016 in International Journal of Multiphase Flow
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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.

ACS Style

Daniel Valero; Daniel B. Bung. 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. International Journal of Multiphase Flow 2016, 84, 66 -74.

AMA Style

Daniel Valero, Daniel B. Bung. 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. International Journal of Multiphase Flow. 2016; 84 ():66-74.

Chicago/Turabian Style

Daniel Valero; Daniel B. Bung. 2016. "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." International Journal of Multiphase Flow 84, no. : 66-74.

Journal article
Published: 01 August 2016 in Environmental Modelling & Software
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ACS Style

Daniel Valero; Daniel B. Bung. Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow. Environmental Modelling & Software 2016, 82, 218 -228.

AMA Style

Daniel Valero, Daniel B. Bung. Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow. Environmental Modelling & Software. 2016; 82 ():218-228.

Chicago/Turabian Style

Daniel Valero; Daniel B. Bung. 2016. "Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow." Environmental Modelling & Software 82, no. : 218-228.

Journal article
Published: 29 April 2016 in Journal of Hydraulic Research
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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.Peer reviewe

ACS Style

Daniel B. Bung; Daniel Valero. Optical flow estimation in aerated flows. Journal of Hydraulic Research 2016, 54, 575 -580.

AMA Style

Daniel B. Bung, Daniel Valero. Optical flow estimation in aerated flows. Journal of Hydraulic Research. 2016; 54 (5):575-580.

Chicago/Turabian Style

Daniel B. Bung; Daniel Valero. 2016. "Optical flow estimation in aerated flows." Journal of Hydraulic Research 54, no. 5: 575-580.

Journal article
Published: 01 December 2015 in International Journal of Sediment Research
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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.

ACS Style

Mario Oertel; Daniel B. Bung. Stability and scour development of bed material on crossbar block ramps. International Journal of Sediment Research 2015, 30, 344 -350.

AMA Style

Mario Oertel, Daniel B. Bung. Stability and scour development of bed material on crossbar block ramps. International Journal of Sediment Research. 2015; 30 (4):344-350.

Chicago/Turabian Style

Mario Oertel; Daniel B. Bung. 2015. "Stability and scour development of bed material on crossbar block ramps." International Journal of Sediment Research 30, no. 4: 344-350.

Book chapter
Published: 01 July 2015 in Flood Risk in the Upper Vistula Basin
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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.

ACS Style

Daniel B. Bung. Laboratory Models of Free-Surface Flows. Flood Risk in the Upper Vistula Basin 2015, 213 -227.

AMA Style

Daniel B. Bung. Laboratory Models of Free-Surface Flows. Flood Risk in the Upper Vistula Basin. 2015; ():213-227.

Chicago/Turabian Style

Daniel B. Bung. 2015. "Laboratory Models of Free-Surface Flows." Flood Risk in the Upper Vistula Basin , no. : 213-227.

Journal article
Published: 06 May 2014 in Experiments in Fluids
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Stepped spillways have higher energy dissipation than smoother hydraulic structures used to divert flood discharges. The inception point related to air entrainment is, however, located further upstream causing an undesired bulking of the flow depth. For large discharge rates and for straight stepped spillways, the skimming flow regime may be assumed two dimensional; this is an attractive feature for the application of non-intrusive flow visualization techniques because these methods measure the flow characteristics in the vicinity of the sidewalls which are likely to correlate with the flow at the centre of the flume. This paper tests the hypothesis that such techniques can be used to measure the flow inside the flume. The hypothesis is tested against measurements taken with an intrusive probe. Void fraction contour lines and velocity fields are obtained in 12 different stepped spillway configurations using the image processing procedure and the bubble image velocimetry, respectively. The void fraction and velocity results are overall consistent with the probe measurements. The velocity fields show a persistent underestimation of the probe measurements which can at least be partially explained by sidewall effects and possible probe’s overestimation.

ACS Style

J. Leandro; D. B. Bung; R. Carvalho. Measuring void fraction and velocity fields of a stepped spillway for skimming flow using non-intrusive methods. Experiments in Fluids 2014, 55, 1 -17.

AMA Style

J. Leandro, D. B. Bung, R. Carvalho. Measuring void fraction and velocity fields of a stepped spillway for skimming flow using non-intrusive methods. Experiments in Fluids. 2014; 55 (5):1-17.

Chicago/Turabian Style

J. Leandro; D. B. Bung; R. Carvalho. 2014. "Measuring void fraction and velocity fields of a stepped spillway for skimming flow using non-intrusive methods." Experiments in Fluids 55, no. 5: 1-17.

Technical notes
Published: 05 March 2013 in Journal of Hydraulic Research
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Stepped spillways are known to enhance the energy dissipation potential when compared with common smooth invert chutes. In the skimming flow regime, the self-aerated flow becomes more chaotic and surface waves (referred to as air–water surface roughness) are enhanced when the discharge decreases. In this study, experiments on smooth invert and stepped chutes models with a slope of 1: 2 were conducted to characterize this surface roughness by the use of a high-speed camera and ultrasonic sensor. It was found that the amount of entrapped air – at the water level where the air concentration is 90% – is reduced when a stepped spillway is considered. With decrease in step height (and on smooth invert chutes), entrapped air became more relevant. Wave heights increased with increase in step height and exceeded significantly the characteristic water level with 90% air concentration which was detected by a conductivity probe. A wide range of wave frequencies indicated the turbulent structure of stepped spillway flows.

ACS Style

Daniel B. Bung. Non-intrusive detection of air–water surface roughness in self-aerated chute flows. Journal of Hydraulic Research 2013, 51, 322 -329.

AMA Style

Daniel B. Bung. Non-intrusive detection of air–water surface roughness in self-aerated chute flows. Journal of Hydraulic Research. 2013; 51 (3):322-329.

Chicago/Turabian Style

Daniel B. Bung. 2013. "Non-intrusive detection of air–water surface roughness in self-aerated chute flows." Journal of Hydraulic Research 51, no. 3: 322-329.

Research papers
Published: 17 November 2011 in Journal of Hydraulic Research
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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.

ACS Style

Mario Oertel; Daniel B. Bung. Initial stage of two-dimensional dam-break waves: laboratory versus VOF. Journal of Hydraulic Research 2011, 50, 89 -97.

AMA Style

Mario Oertel, Daniel B. Bung. Initial stage of two-dimensional dam-break waves: laboratory versus VOF. Journal of Hydraulic Research. 2011; 50 (1):89-97.

Chicago/Turabian Style

Mario Oertel; Daniel B. Bung. 2011. "Initial stage of two-dimensional dam-break waves: laboratory versus VOF." Journal of Hydraulic Research 50, no. 1: 89-97.

Journal article
Published: 26 September 2011 in Journal of Hydraulic Research
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ACS Style

Daniel B. Bung. Developing flow in skimming flow regime on embankment stepped spillways. Journal of Hydraulic Research 2011, 49, 639 -648.

AMA Style

Daniel B. Bung. Developing flow in skimming flow regime on embankment stepped spillways. Journal of Hydraulic Research. 2011; 49 (5):639-648.

Chicago/Turabian Style

Daniel B. Bung. 2011. "Developing flow in skimming flow regime on embankment stepped spillways." Journal of Hydraulic Research 49, no. 5: 639-648.

Journal article
Published: 01 April 2011 in Österreichische Wasser- und Abfallwirtschaft
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Stepped chutes are characterised by increased turbulence and therefore earlier self-aeration, than traditional smooth chutes. This is due to the macroroughness produced by the steps, which in addition reduces the flow velocities. The resulting increased energy dissipation and the greater air-bubble residence time on the structure as well as the greater aerated flow length help to improve gas exchange. The effects of hydraulic and geometrical boundary conditions on the hydromechanical and hydrochemical processes are studied using physical model tests and are expressed in dimensionless design formulae.

ACS Style

Daniel B. Bung. Fließcharakteristik und Sauerstoffeintrag bei selbstbelüfteten Gerinneströmungen auf Kaskaden mit gemäßigter Neigung. Österreichische Wasser- und Abfallwirtschaft 2011, 63, 76 -81.

AMA Style

Daniel B. Bung. Fließcharakteristik und Sauerstoffeintrag bei selbstbelüfteten Gerinneströmungen auf Kaskaden mit gemäßigter Neigung. Österreichische Wasser- und Abfallwirtschaft. 2011; 63 (3):76-81.

Chicago/Turabian Style

Daniel B. Bung. 2011. "Fließcharakteristik und Sauerstoffeintrag bei selbstbelüfteten Gerinneströmungen auf Kaskaden mit gemäßigter Neigung." Österreichische Wasser- und Abfallwirtschaft 63, no. 3: 76-81.