@inproceedings{TullisCrookstonBung2019, author = {Tullis, Blake P. and Crookston, Brian M. and Bung, Daniel B.}, title = {Weir head-discharge relationships: A multi-lab exercise}, series = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, pages = {1 -- 15}, year = {2019}, language = {en} } @inproceedings{BungOertel2019, author = {Bung, Daniel B. and Oertel, Mario}, title = {Wave breaking over a submerged horizontal plate: Optical Flow, LES and RANS}, series = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, doi = {10.3850/38WC092019-0509}, pages = {3690 -- 3698}, year = {2019}, language = {en} } @article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel B.}, title = {Vectrino profiler spatial filtering for shear flows based on the mean velocity gradient equation}, series = {Journal of Hydraulic Engineering}, volume = {144}, journal = {Journal of Hydraulic Engineering}, number = {7}, publisher = {ASCE}, address = {Reston, Va.}, issn = {0733-9429}, doi = {10.1061/(ASCE)HY.1943-7900.0001485}, year = {2018}, abstract = {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.}, language = {en} } @inproceedings{BungSunMeirelesetal.2012, author = {Bung, Daniel B. and Sun, Q. and Meireles, I. and Matos, J. and Viseu, T.}, title = {USBR type III stilling basin performance for steep stepped spillways}, series = {Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto}, booktitle = {Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto}, organization = {International Symposium on Hydraulic Structures <4, 2012, Porto>}, isbn = {978-989-8509-01-7}, pages = {Elektronisch publiziert}, year = {2012}, language = {en} } @article{ValeroBungErpicumetal.2022, author = {Valero, Daniel and Bung, Daniel B. and Erpicum, Sebastien and Peltier, Yann and Dewals, Benjamin}, title = {Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling}, series = {Journal of Hydro-environment Research}, journal = {Journal of Hydro-environment Research}, number = {In Press}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1570-6443}, doi = {10.1016/j.jher.2022.03.002}, year = {2022}, abstract = {Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models).}, language = {en} } @article{BungCrookstonValero2020, author = {Bung, Daniel B. and Crookston, Brian M. and Valero, Daniel}, title = {Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case}, series = {Journal of Hydraulic Research}, journal = {Journal of Hydraulic Research}, publisher = {Taylor \& Francis}, address = {London}, issn = {1814-2079}, doi = {10.1080/00221686.2020.1844810}, year = {2020}, language = {en} } @inproceedings{ValeroBungOertel2016, author = {Valero, Daniel and Bung, Daniel B. and Oertel, M.}, title = {Turbulent dispersion in bounded horizontal jets : RANS capabilities and physical modeling comparison}, series = {Sustainable Hydraulics in the Era of Global Change : Proceedings of the 4th IAHR Europe Congress (Liege, Belgium, 27-29 July 2016)}, booktitle = {Sustainable Hydraulics in the Era of Global Change : Proceedings of the 4th IAHR Europe Congress (Liege, Belgium, 27-29 July 2016)}, editor = {Dewals, Benjamin}, publisher = {CRC Press}, isbn = {978-1-138-02977-4}, doi = {10.1201/b21902-13}, pages = {49 -- 55}, year = {2016}, language = {en} } @article{KramerValeroChansonetal.2019, author = {Kramer, Matthias and Valero, Daniel and Chanson, Hubert and Bung, Daniel B.}, title = {Towards reliable turbulence estimations with phase-detection probes: an adaptive window cross-correlation technique}, series = {Experiments in Fluids}, volume = {60}, journal = {Experiments in Fluids}, publisher = {Springer}, address = {Berlin}, issn = {1432-1114}, doi = {10.1007/s00348-018-2650-9}, year = {2019}, language = {en} } @inproceedings{ValeroVogelSchmidtetal.2018, author = {Valero, Daniel and Vogel, Jochen and Schmidt, Daniel and Bung, Daniel B.}, title = {Three-dimensional flow structure inside the cavity of a non-aerated stepped chute}, series = {7th IAHR International Symposium on Hydraulic Structures, Aachen, Germany, 15-18 May}, booktitle = {7th IAHR International Symposium on Hydraulic Structures, Aachen, Germany, 15-18 May}, isbn = {978-0-692-13277-7}, doi = {10.15142/T3GH17}, pages = {12 Seiten}, year = {2018}, language = {en} } @inproceedings{LopesBungLeandroetal.2015, author = {Lopes, Pedro and Bung, Daniel B. and Leandro, Jorge and Carvalho, Rita F.}, title = {The effect of cross-waves in physical stepped spillway models}, series = {E-proceedings of the 36th IAHR World Congress ; 28 June - 3 July, 2015, The Hague, the Netherlands}, booktitle = {E-proceedings of the 36th IAHR World Congress ; 28 June - 3 July, 2015, The Hague, the Netherlands}, organization = {International Association for Hydro-Environment Engineering and Research}, pages = {1 -- 9}, year = {2015}, language = {en} } @incollection{ChansonBungMatos2015, author = {Chanson, Hubert and Bung, Daniel B. and Matos, J.}, title = {Stepped spillways and cascades}, series = {Energy dissipation in hydraulic structures / Hubert Chanson (ed.)}, booktitle = {Energy dissipation in hydraulic structures / Hubert Chanson (ed.)}, publisher = {CRC Press}, address = {Boca Raton, Fla. [u.a.]}, isbn = {978-1-138-02755-8 (print) ; 978-1-315-68029-3 (e-Book)}, pages = {45 -- 64}, year = {2015}, language = {en} } @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} } @inproceedings{Bung2012, author = {Bung, Daniel B.}, title = {Sensitivity of phase detection techniques in aerated chute flows to hydraulic design parameters}, series = {2nd European IAHR congress : 27. - 29. June 2012, M{\"u}nchen}, booktitle = {2nd European IAHR congress : 27. - 29. June 2012, M{\"u}nchen}, publisher = {Lehrstuhl u. Versuchsanst. f{\"u}r Wasserbau u. Wasserwirtschaft d. TU M{\"u}nchen}, address = {M{\"u}nchen}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {978-3-943683-03-5}, pages = {Artikelkennnummer: B15}, year = {2012}, language = {en} } @inproceedings{BungSchlenkhoff2010, author = {Bung, Daniel B. and Schlenkhoff, Andreas}, title = {Self-aerated skimming flow on embankment stepped spillways : the effect of additional micro-roughness on energy dissipation and oxygen transfer}, series = {Proceedings from first IAHR European congress : May 2010, Edinburgh}, booktitle = {Proceedings from first IAHR European congress : May 2010, Edinburgh}, publisher = {Heriot-Watt University, School of the Built Environment}, address = {Edinburgh}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {9780956595102}, pages = {Artikelkennnummer HSIIId}, year = {2010}, language = {en} } @inproceedings{BungSchlenkhoffOertel2009, author = {Bung, Daniel B. and Schlenkhoff, Andreas and Oertel, M.}, title = {Self-aerated skimming flow on embankment stepped spillways}, series = {Water engineering for sustainable environment : 33rd IAHR congress ; 9 - 14 August 2009, Vancouver, British Columbia, Canada}, booktitle = {Water engineering for sustainable environment : 33rd IAHR congress ; 9 - 14 August 2009, Vancouver, British Columbia, Canada}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {9789078046080}, pages = {1 CD-ROM}, year = {2009}, language = {en} } @inproceedings{OertelBung2016, author = {Oertel, M. and Bung, Daniel B.}, title = {Scouring processes downstream a crossbar block ramp}, series = {Hydraulic Structures and Water System Management. 6th IAHR International Symposium on Hydraulic Structures, Portland, OR, 27-30 June 2016}, booktitle = {Hydraulic Structures and Water System Management. 6th IAHR International Symposium on Hydraulic Structures, Portland, OR, 27-30 June 2016}, editor = {Crookston, B. and Tullis, B.}, isbn = {978-1-884575-75-4}, doi = {10.15142/T3340628160853}, pages = {549 -- 559}, year = {2016}, language = {en} } @article{ValeroChansonBung2019, author = {Valero, Daniel and Chanson, Hubert and Bung, Daniel B.}, title = {Robust estimators for turbulence properties assessment}, pages = {1 -- 24}, year = {2019}, language = {en} } @article{ValeroChansonBung2020, author = {Valero, Daniel and Chanson, Hubert and Bung, Daniel B.}, title = {Robust estimators for free surface turbulence characterization: A stepped spillway application}, series = {Flow Measurement and Instrumentation}, volume = {76}, journal = {Flow Measurement and Instrumentation}, number = {Art. 101809}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-5986}, doi = {10.1016/j.flowmeasinst.2020.101809}, year = {2020}, abstract = {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.}, language = {en} } @article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel B.}, title = {Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment}, series = {International Journal of Multiphase Flow}, volume = {100}, journal = {International Journal of Multiphase Flow}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-9322}, doi = {10.1016/j.ijmultiphaseflow.2017.12.011}, pages = {127 -- 142}, year = {2018}, abstract = {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.}, language = {en} }