Goll, Annalena

Kopmann, Rebekka

Villaret, Catherine

English

Hydraulic Engineering Repository

Conference Poster, Published VersionGoll, Annalena; Kopmann, Rebekka; Villaret, CatherineNumerical modelling of flumes with moving dunesVerfügbar unter/Available at: https://hdl.handle.net/20.500.11970/105991Vorgeschlagene Zitierweise/Suggested citation:Goll, Annalena; Kopmann, Rebekka; Villaret, Catherine (2013): Numerical modelling offlumes with moving dunes. Poster präsentiert bei: MARID 4 - Marine & River DuneDynamics.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.www.baw.de15. - 16. April 2013, MARID IV, Bruges  ·  contact: A. Goll ·  Tel.: +49 (0) 721 9726-3930  ·  annalena.goll@baw.deNumerical modelling of fl umes with moving dunesTELEMAC3D and Sisyphe1 Federal Waterways Engineering and Research Institute (BAW), 76187 Karlsruhe, Germany2 Université Paris-Est, Saint-Venant Laboratory for Hydraulics, ENPC, EDF R&D, CETMEF, 78400 Chatou, France3 EDF R&D Laboratoire National d'Hydraulique et Environnement (LNHE), 78400 Chatou, FranceAnnalena Goll1,2 , Rebekka Kopmann1 and Catherine Villaret3Experimental fl umeExperimental Flume• Length: 30m • Width: 5m (2x2m)• First half moveable, second half fi xed bed• Discharges: 77-240 l/s• Water level: 15-25cm• Slope: leveled to 0.6‰ (1.2‰)• Bed-load: sand (D50≈1mm)• Installations:  none, groynes, fi xed bedThe experimental fl ume is situated at BAW, Karlsruhe, Germany. In its two halves moving and fi xed dunes are studied. Several instal-lations and discharges have been recorded in the fi rst half with moving dunes and can be used to calibrate the numerical model. In the second half naturally formed dunes have been fi xed and al-low to study the fl ow around these three-dimensional dune forms in  detail.The laboratory based three-dimensional photogrammetric meas-urement system (3D-PTV) for monitoring the alluvial bed topo-graphy allows for repeated, instantaneous recording of dune beds during water fl ow. Over the fi xed dunes an Acoustic Doppler Ve-locimetry (Vectrino I+II) records the velocities and their standard deviations for all three spatial directions.Left: groyne installations, initial state; Right: fully developed, fi xed dunesDue to unsatisfying translation of the simulation pa-rameters on other experiments, in a second step the turbulent hydrodynamics of the BAW fl ume are stud-ied in detail.Measurements of the fl ow fi eld around the fi xed dunes are compared to hydrodynamic simulations with Telemac3D.The fl ow fi eld is matched very well. The pattern of the turbulent kinetic energy is good, but the values are not in the same range: the simulated ones are about eight times lower.Longitudinal velocities of the fl ow fi eld around fi xed dunesCircles: measurements with ADV; Contour plot: simulation results length [m]height [m]velocity U [m/s]Validation of hydrodynamicsConclusionsIt was shown that dune modelling is possible with the TELEMAC suite. The correct dune shapes are sub-ject to several infl uencing factors such as bed load transport formula, slope eff ect and deviation  for-mulas, morphodynamic time step as well as hydrody-namic parameters. It seems that the results are not easily reproducible with other boundary conditions or models.Analysis of the highly turbulent fl ow fi eld around the dunes have shown, that the turbulence model might be not suffi  cient. The next step will be further calibra-tion of the turbulence model with the shown meas-urements.Turbulent kinetic energy kTop: simulation k [ 101 * m²/s² ] ; Bottom: measurements k [ m²/s² ]Numerical simulationsWith the open source TELEMAC suite (opentelemac.org)with the modules Telemac3D and Sisyphe it was pos-sible to simulate the emergence, development and movement of three-dimensional dunes.The overall best results compared to the measurements are presented here. They were gained with the bed load formulas of Engelund & Hansen and Yang & Lim. Comparison of the bottom topography af-ter 18h (left) and the corresponding aver-age dune height and length (top right) show that even though the formed features of the bottom match the measurements quite well and the overall performance of the simu-lation was very good, the values of dune height are not in the same range.Due to this, the used parameter settings were tested on an other fl ume based at Hok-kaido University, Japan (Giri and Shimizu, 2006). The fl ume is 10cm wide, 30m long and the bottom sediment is uniform sand (D50≈0.28mm). In the experiment two-di-mensional dunes were produced. Simula-tions of  the fl ume (bottom right) did not yield completely satisfying results. Diff erent parameter sets and mesh confi gurations were tested, but the simulation results did not have the same quality as the ones of the BAW fl ume.Measurements of 3 BAW runs at diff erent times compared to simulations 1) slope eff ect Soulsby and deviation Talmon,2) slope eff ect  Koch&Flokstra and deviation Apsley&StansbyMeasurements of Hokkaido experiment compared to diff erent simulations with mesh and  parameter combinationsMeasurements S10W1T2 compared to simulation (after 18h) Bedload transportformula of Engelund & Hansen and Yang & Lim,1) slope eff ect Soulsby and deviation Talmon,2) slope eff ect  Koch&Flokstra and deviation Apsley&Stansbyheight [m]x [m]y [m]19.5 20.0 20.5 21.0 21.5 22.5 22.5 23.5length [m]0.450.400.350.300.250.200.15 k [ m²/s² ]0.0195  0.02100.0180  0.01950.0165  0.01800.0150  0.01650.0135  0.01500.0120  0.01350.0105  0.01200.0090  0.01050.0075  0.00900.0060  0.00750.0045  0.00600.0030  0.00450.0015  0.00300.0000  0.0015L:H = 1:519.5 20.0 20.5 21.0 21.5 22.5 22.5 23.50.450.400.350.300.250.200.150.0240  0.02550.0225  0.02400.0210  0.02250.0195  0.02100.0180  0.01950.0165  0.01800.0150  0.01650.0135  0.01500.0120  0.01350.0105  0.01200.0090  0.01050.0075  0.00900.0060  0.00750.0045  0.00600.0030  0.00450.0015  0.00300.0000  0.0015 k [ 101 * m²/s² ]L:H = 1:5

Numerical modelling of flumes with moving dunes

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Numerical modelling of flumes with moving dunes

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