Antoine, Germain

Claude, Nicolas

Jourdain, Camille

Schwarz, Christian

Temmerman, Stijn

Verschoren, Veerle

Yassine, Rabab

English

Hydraulic Engineering Repository

Conference Paper, Published VersionClaude, Nicolas; Antoine, Germain; Yassine, Rabab; Verschoren, Veerle;Schwarz, Christian; Temmerman, Stijn; Jourdain, CamilleNumerical simulations of flow around vegetation withTelemac2D: application on laboratory experiments and onthe Isère river (France)Zur Verfügung gestellt in Kooperation mit/Provided in Cooperation with:TELEMAC-MASCARET Core GroupVerfügbar unter/Available at: https://hdl.handle.net/20.500.11970/104335Vorgeschlagene Zitierweise/Suggested citation:Claude, Nicolas; Antoine, Germain; Yassine, Rabab; Verschoren, Veerle; Schwarz,Christian; Temmerman, Stijn; Jourdain, Camille (2015): Numerical simulations of flow aroundvegetation with Telemac2D: application on laboratory experiments and on the Isère river(France). In: Moulinec, Charles; Emerson, David (Hg.): Proceedings of the XXII TELEMAC-MASCARET Technical User Conference October 15-16, 2034. Warrington: STFC DaresburyLaboratory. S. 206-207.Standardnutzungsbedingungen/Terms of Use:Die Dokumente in HENRY stehen unter der Creative Commons Lizenz CC BY 4.0, sofern keine abweichendenNutzungsbedingungen getroffen wurden. Damit ist sowohl die kommerzielle Nutzung als auch das Teilen, dieWeiterbearbeitung und Speicherung erlaubt. Das Verwenden und das Bearbeiten stehen unter der Bedingung derNamensnennung. Im Einzelfall kann eine restriktivere Lizenz gelten; dann gelten abweichend von den obigenNutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte.Documents in HENRY are made available under the Creative Commons License CC BY 4.0, if no other license isapplicable. Under CC BY 4.0 commercial use and sharing, remixing, transforming, and building upon the materialof the work is permitted. In some cases a different, more restrictive license may apply; if applicable the terms ofthe restrictive license will be binding.Numerical simulations of flow around vegetation with Telemac2D: application on laboratory experiments and on the Isère river (France)  Nicolas Claude1,2, Germain Antoine1,2, Rabab Yassine1, Veerle Verschoren3,Christian Schwarz3, Stijn Temmerman3, Camille Jourdain4 1 EDF R&D Laboratoire National d'Hydraulique et Environnement (LNHE), 78400 Chatou, France. 2 Université Paris-Est, Laboratoire d’hydraulique Saint Venant, ENPC, EDF R&D, CEREMA, 78400 Chatou, France. 3 University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium 4 Laboratoire d’étude des Transferts en Hydrologie et Environnement (LTHE), Université de Grenoble, France Corresponding author: nicolas-n.claude@edf.fr   Proposed session: Water quality, ecology and environmental impact Keywords: Telemac2D, hydrodynamic, vegetation Speaker: Nicolas Claude  Abstract: Vegetation is a common feature of rivers. In these systems, the plants can significantly affect hydrodynamics and sediment transport. Indeed, vegetation deflects (blocking effect) and reduces (roughness effect) the flows, decreases the sediment transport capacity, and causes the deposition of particles within the plants. Vegetation also influences the morphological evolution of streams by controlling bank erosion, encouraging aggradation of alluvial bars and secondary channels, and by contributing to floodplain development. Thus, it is necessary to take into account the processes associated with vegetation in the numerical codes for fluvial environments.  In hydrodynamic numerical models, the effect of the vegetation is represented either by increasing the bed roughness or by adding a drag force. In this study, we propose to compare these two approaches with Telemac2D. More specifically, the ability of the friction laws of Baptist et al. (2007), and the drag force method to reproduce the flow velocities around vegetation patches was explored for emergent and submerged conditions, and for rigid and flexible plants. The friction law of Lindner (1982) was also evaluated for rigid emergent vegetation. For this purpose, the laboratory experiments of Pasche and Rouve (1985), Zong and Nepf (2012) and Bouma et al. (2013) were numerically simulated. A vegetated bar of the Isère river (France) was also modelled.  Preliminary results show that the friction law of Baptist and the drag force method give very similar results on the selected test cases. These methods enable to estimate correctly the flow velocities for emergent and submerged rigid plants (Figure 1). The results obtained with the friction law of Lindner (only dedicated to emergent rigid plants) are less satisfying. The vortices associated to the presence of vegetation are reproduced by the three tested methods. The flow velocity field around a flexible vegetation is estimated with a lower accuracy. This result indicates that further developments are required to incorporate the effects of the reconfiguration of flexible vegetation in the models.   Figure 1: Longitudinal evolution of flow velocity around a circular patch of rigid emergent cylinders. The patch is located between the abscissas 0 and 0.2. The circular dots correspond to the measurements. The blue line corresponds to flow velocities estimated with the drag force method. The green line corresponds to flow velocities estimated with the friction law of Lindner.  References: Baptist, M., V. Babovic, J. Rodríguez Uthurburu, M. Keijzer, R. Uittenbogaard, A. Mynett, and A. Verwey (2007), On inducing equations for vegetation resistance, Journal of Hydraulic Research, 45(4), 435-450. Bouma, T.J., S. Temmerman, L.A. van Duren, E. Martini, W. Vandenbruwaene, D.P. Callaghan, T. Balke, G. Biermans, P.C. Klaassen, P. van Steeg, F. Dekker, J. van de Koppel, M.B. de Vries, P.M.J. Herman (2013), Organism traits determine the strength of scale-dependent bio-geomorphic feedbacks: A flume study on three intertidal plant species, Geomorphology, 180-181, 57-65. Lindner,K. (1982) Der Strömungswiderstand von Pflanzenbeständen. Mitteilungen 75. Leichtweiss-Institut fürWasserbau, Technische Universität Braunschweig. Pasche, E., and G. Rouve (1985), Overbank flow with vegetatively roughened flood plains, Journal of Hydraulic Engineering, 111(9), 1262-1278. Zong, L., and H. Nepf (2012), Vortex development behind a finite porous obstruction in a channel, Journal of Fluid Mechanics, 691, 368-391. 

Numerical simulations of flow around vegetation with Telemac2D: application on laboratory experiments and on the Isère river (France)

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Numerical simulations of flow around vegetation with Telemac2D: application on laboratory experiments and on the Isère river (France)

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