TY - CHAP A1 - Lopes, Pedro A1 - Bung, Daniel Bernhard A1 - Leandro, Jorge A1 - Carvalho, Rita F. T1 - The effect of cross-waves in physical stepped spillway models T2 - E-proceedings of the 36th IAHR World Congress ; 28 June - 3 July, 2015, The Hague, the Netherlands Y1 - 2015 SP - 1 EP - 9 ER - TY - JOUR A1 - Krause, Thomas T1 - Schalung und Gerüste JF - Beispiele für die Baubetriebspraxis / Hoffmann, Manfred ; Kuhlmann, Willy [Hrsg.]. Y1 - 2006 SN - 978-3-8351-0002-2 N1 - Kapitel 7 SP - 122 EP - 131 PB - Teubner CY - Wiesbaden ER - TY - JOUR A1 - Oertel, Mario A1 - Bung, Daniel Bernhard T1 - Stability and scour development of bed material on crossbar block ramps JF - International journal of sediment research N2 - 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. Y1 - 2015 U6 - https://doi.org/10.1016/j.ijsrc.2014.12.003 SN - 1001-6279 VL - 30 IS - 4 SP - 344 EP - 350 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Krause, Thomas A1 - Ulke, Bernd A1 - Ferger, Martin ED - Krause, Thomas ED - Ulke, Bernd ED - Ferger, Martin T1 - Zahlentafeln für den Baubetrieb Y1 - 2024 SN - 978-3-658-41329-3 (Print) SN - 978-3-658-41330-9 (eBook) U6 - https://doi.org/10.1007/978-3-658-41330-9 PB - Springer Vieweg CY - Wiesbaden ET - 10. Auflage ER - TY - CHAP A1 - Bung, Daniel Bernhard 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 - https://doi.org/10.15142/T3150628160853 SP - 223 EP - 232 ER - TY - CHAP A1 - Krause, Thomas A1 - Kremer, Norbert T1 - Schalung und Gerüste T2 - Zahlentafeln für den Baubetrieb N2 - Systemschalungen und Systemgerüste haben den Baustellenbetrieb in vielen Bereichen sehr vereinfacht. Dennoch sind Kenntnisse in diesen Feldern für eine erfolgreiche und effektive Bauleitung unverzichtbar. In diesem Kapitel werden Hinweise und Empfehlungen für die Bemessung und Einsatz von Schalungen, Trag- und Arbeitsgerüsten für den Baustellenbetrieb gegeben. Y1 - 2016 SN - 978-3-658-02838-1 (Online) SN - 978-3-658-02837-4 (Print) U6 - https://doi.org/10.1007/978-3-658-02838-1_11 SP - 1247 EP - 1296 PB - Springer Vieweg CY - Wiesbaden ET - 9., überarb. und aktual. Aufl. ER - TY - CHAP A1 - Ulke, Bernd ED - Krause, Thomas ED - Ulke, Bernd ED - Ferger, Martin T1 - Bauwirtschaft T2 - Zahlentafeln für den Baubetrieb N2 - Die Leistungen der Bauwirtschaft und deren wirtschaftliche Bedeutung in Deutschland werden anhand einer Vielzahl statistischer Daten verdeutlicht. Die im Vergleich zu anderen Wirtschaftsbereichen auftretenden branchenspezifischen Besonderheiten der Bauwirtschaft werden anhand von verschiedenen Kriterien herausgearbeitet. Das Zusammenspiel der einzelnen Akteure des Sektors und die dabei sich ergebenden bzw. zu beachtenden Rechts- und Vertragsgrundlagen werden dargestellt. Aufgrund der meist erheblichen Höhe des eingesetzten Kapitals werden auch notwendige Formen der Risikoabsicherungen und der in der Branche üblichen und teilweise vorgeschriebenen Versicherungsmöglichkeiten angesprochen. Y1 - 2024 SN - 978-3-658-41329-3 (Print) SN - 978-3-658-41330-9 (eBook) U6 - https://doi.org/10.1007/978-3-658-41330-9_4 SP - 17 EP - 261 PB - Springer Vieweg CY - Wiesbaden ER - TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel Bernhard T1 - Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment JF - International Journal of Multiphase Flow N2 - 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. Y1 - 2018 U6 - https://doi.org/10.1016/j.ijmultiphaseflow.2017.12.011 SN - 0301-9322 VL - 100 SP - 127 EP - 142 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel Bernhard A1 - Erpicum, Sebastien A1 - Peltier, Yann A1 - Dewals, Benjamin T1 - Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling JF - Journal of Hydro-environment Research N2 - 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). KW - coherent structures KW - hydraulic modelling KW - model performance KW - Proper Orthogonal Decomposition KW - Q-criterion Y1 - 2022 U6 - https://doi.org/10.1016/j.jher.2022.03.002 SN - 1570-6443 IS - In Press PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Kerpen, Nils B. A1 - Bung, Daniel Bernhard A1 - Valero, Daniel A1 - Schlurmann, Torsten T1 - Energy dissipation within the wave run-up at stepped revetments T2 - 8th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, Qingdao, China KW - energy disspation KW - wave run-up KW - friction Y1 - 2016 ER -