TY  - JOUR
A1  - Valero, Daniel
A1  - Chanson, Hubert
A1  - Bung, Daniel Bernhard
T1  - Robust estimators for free surface turbulence characterization: A stepped spillway application
JF  - Flow Measurement and Instrumentation
N2  - 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.
Y1  - 2020
U6  - https://doi.org/10.1016/j.flowmeasinst.2020.101809
SN  - 0955-5986
VL  - 76
IS  - Art. 101809
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Valero, D.
A1  - Bung, Daniel Bernhard
A1  - Crookston, B. M.
T1  - Closure to “Energy Dissipation of a Type III Basin under Design and Adverse Conditions for Stepped and Smooth Spillways”
JF  - Journal of Hydraulic Engineering
Y1  - 2019
U6  - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001669
VL  - 146
IS  - 2
PB  - ASCE
CY  - Reston, Va.
ER  - 
TY  - CHAP
A1  - Valero, Daniel
A1  - Bung, Daniel Bernhard
A1  - Oertel, M.
ED  - Dewals, Benjamin
T1  - Turbulent dispersion in bounded horizontal jets : RANS capabilities and physical modeling comparison
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  - https://doi.org/10.1201/b21902-13
SP  - 49
EP  - 55
PB  - CRC Press
ER  - 
TY  - JOUR
A1  - Lopes, Pedro
A1  - Leandro, Jorge
A1  - Carvalho, Rita F.
A1  - Bung, Daniel Bernhard
T1  - Alternating skimming flow over a stepped spillway
JF  - Environmental Fluid Mechanics
Y1  - 2017
U6  - https://doi.org/10.1007/s10652-016-9484-x
SN  - 1573-1510
VL  - 17
IS  - 2
SP  - 303
EP  - 322
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Valero, Daniel
A1  - Bung, Daniel Bernhard
A1  - Crookston, B.M.
T1  - Energy dissipation of a Type III basin under design and adverse conditions for stepped and smooth spillways
JF  - Journal of Hydraulic Engineering
N2  - 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.
Y1  - 2018
U6  - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001482
SN  - 0733-9429
N1  - Article number 04018036
VL  - 144
IS  - 7
PB  - ASCE
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Valero, Daniel
A1  - Bung, Daniel Bernhard
T1  - Vectrino profiler spatial filtering for shear flows based on the mean velocity gradient equation
JF  - Journal of Hydraulic Engineering
N2  - 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.
Y1  - 2018
U6  - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001485
SN  - 0733-9429
N1  - Article number 04018037
VL  - 144
IS  - 7
PB  - ASCE
CY  - Reston, Va.
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  - Valero, Daniel
A1  - Bung, Daniel Bernhard
T1  - Hybrid investigation of air transport processes in moderately sloped stepped spillway flows
T2  - E-proceedings of the 36th IAHR World Congress 28 June – 3 July, 2015, The Hague, the Netherlands
Y1  - 2015
SP  - 1
EP  - 10
ER  - 
TY  - CHAP
A1  - Chanson, Hubert
A1  - Bung, Daniel Bernhard
A1  - Matos, J.
T1  - Stepped spillways and cascades
T2  - Energy dissipation in hydraulic structures / Hubert Chanson (ed.)
Y1  - 2015
SN  - 978-1-138-02755-8 (print) ; 978-1-315-68029-3 (e-Book)
SP  - 45
EP  - 64
PB  - CRC Press
CY  - Boca Raton, Fla. [u.a.]
ER  - 
TY  - CHAP
A1  - Bühler, P.
A1  - Leandro, J.
A1  - Bung, Daniel Bernhard
A1  - Lopes, P.
A1  - Carvalho, R.
T1  - Measuring void fraction of a stepped spillway with non-intrusive methods using different image resolutions
T2  - 2nd International Workshop on Hydraulic Structures : Data Validation : Coimbra, Portugal, 8-9 May 2015
Y1  - 2015
SP  - 1
EP  - 8
ER  - 
TY  - CHAP
A1  - Oertel, Mario
A1  - Balmes, Jan P.
A1  - Bung, Daniel Bernhard
T1  - Numerical simulation of erosion processes on crossbar block ramps
T2  - E-proceedings of the 36th IAHR World Congress 28 June – 3 July, 2015, The Hague, the Netherlands
Y1  - 2015
SP  - 1
EP  - 8
ER  - 
TY  - CHAP
A1  - Bung, Daniel Bernhard
A1  - Valero, Daniel
T1  - Image processing for bubble image velocimetry in self-aerated flows
T2  - E-proceedings of the 36th IAHR World Congress 28 June – 3 July, 2015, The Hague, the Netherlands
Y1  - 2015
SP  - 1
EP  - 8
ER  - 
TY  - CHAP
A1  - Valero, Daniel
A1  - Bung, Daniel Bernhard
T1  - Interfacial velocity estimation in highly aerated stepped spillway flows with a single tip fibre optical probe and Artificial Neural Networks
T2  - 6th IAHR International Junior Researcher and Engineer Workshop on Hydraulic Structures, May 30th to June 1st 2016. Lübeck, Germany
N2  - Air-water flows can be found in different engineering applications: from nuclear engineering to huge hydraulic structures. In this paper, a single tip fibre optical probe has been used to record high frequency (over 1 MHz) phase functions at different locations of a stepped spillway. These phase functions have been related to the interfacial velocities by means of Artificial Neural Networks (ANN) and the measurements of a classical double tip conductivity probe. Special attention has been put to the input selection and the ANN dimensions. Finally, ANN have shown to be able to link the signal rising times and plateau shapes to the air-water interfacial velocity.
Y1  - 2016
U6  - https://doi.org/10.15142/T3Q590
ER  - 
TY  - CHAP
A1  - Valero, Daniel
A1  - Kramer, Matthias
A1  - Bung, Daniel Bernhard
A1  - Chanson, Hubert
T1  - A stochastic bubble generator for air-water flow research
T2  - E-proceedings of the 38th IAHR World Congress, September 1-6, 2019, Panama City, Panama
Y1  - 2019
U6  - https://doi.org/10.3850/38WC092019-0909
SP  - 5714
EP  - 5721
ER  - 
TY  - CHAP
A1  - Kerpen, N. B.
A1  - Bung, Daniel Bernhard
A1  - Schlurmann, Torsten
ED  - Janssen, Robert
T1  - Physical model investigations of ships passing through a lock
T2  - Hydraulic structures: useful water harvesting systems or relics? : Third International Junior Researcher and Engineer Workshop on Hydraulic Structures (IJREWHS'10) : Edinburgh, Scotland, U.K., 2-3 May 2010
Y1  - 2010
SN  - 9781742720159
SP  - 93
EP  - 100
PB  - School of Civil Engineeering, The University of Queensland
CY  - Brisbane
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
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  - Schlenkhoff, Andreas
A1  - Bung, Daniel Bernhard
T1  - Prediction of oxygen transfer in 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 Bernhard
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  - Oertel, M.
A1  - Bung, Daniel Bernhard
A1  - Schlenkhoff, Andreas
T1  - Flash flood awareness and prevention
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  -