References of "Erpicum, Sébastien"
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See detailModélisation hydrodynamique 2D et SIG à haute résolution pour l’évaluation de mesures de protection contre les inondations en milieu urbain
Ernst, Julien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in 3e journées doctorales en hydrologie urbaine (2008, October)

Within the global framework of climate change, the majority of the regional climatic models (RCM - Regional Climatic Model) predict an increase in the frequency and importance of the rainy events ... [more ▼]

Within the global framework of climate change, the majority of the regional climatic models (RCM - Regional Climatic Model) predict an increase in the frequency and importance of the rainy events. Therefore, the populations will have to face an increased risk of flooding. In order to draw up suitable protection strategy in this context, decision-making tool must be developed to select the adequate mitigation measure among the whole of the possible protection measures. This system has to take into account parameters such as hydraulic economic, social or environmental. This paper focuses on the integration between the economic evaluation of the undergone damage and the two-dimensional hydrodynamic modelling implemented using the model WOLF 2D. The integration is ensured by the use of pointed geographical information systems and an automated procedure, based on the methods of geomatic, guaranteeing a perfect applicability of methodology for the analysis of urban areas. The whole of methodology is then applied to the evaluation of a measurement of adaptation to Ourthe (basin of the Meuse), namely the rehabilitation of an old channel formerly used to allow the river transport to the river. [less ▲]

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See detailSimulation numérique des écoulements mixtes hautement transitoires dans les conduits d’évacuation des eaux
Kerger, François ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Proceedings 3ème Journées Doctorales En Hydrologie Urbaine (2008, October)

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See detailImproved one-dimensional numerical simulation of transient mixed flow in water pipes network
Kerger, François ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Proceedings of the 2nd ENVITAM PhD Day (2008, January 29)

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See detailHétérogénéité des échelles spatio-temporelles d'écoulements hydrosédimentaires et modélisation numérique
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Houille Blanche (2008), (5), 109-114

Les modèles numériques hydrosédimentaires doivent être aptes à prendre en compte la très grande hétérogénéité des échelles spatiales et surtout temporelles affectant les divers phénomènes à simuler. Pour ... [more ▼]

Les modèles numériques hydrosédimentaires doivent être aptes à prendre en compte la très grande hétérogénéité des échelles spatiales et surtout temporelles affectant les divers phénomènes à simuler. Pour ce faire, différents niveaux de couplage entre sous-modèles doivent être prévus (calcul hydrodynamique stationnaire, quasi stationnaire ou instationnaire complet). Outre une discussion du formalisme mathématique sous-jacent, la présente communication décrit le système de modélisation WOLF, développé à l’Université de Liège et permettant de couvrir la majorité des échelles de temps pertinentes au moyen d’approches numériques spécifiquement adaptées. L’applicabilité du système de modélisation est illustrée sur base de plusieurs exemples de simulations relatives à la conception et aux modes de gestion d’un grand ouvrage hydroélectrique en Inde. [less ▲]

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See detailAn explicit projection method for solving incompressible Navier-Stokes equations
Detrembleur, Sylvain ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Pagliara, Stefano (Ed.) Hydraulic Structures (2008)

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See detailExperimental and numerical analysis of flow instabilities in rectangular shallow basins
Dewals, Benjamin ULg; Kantoush, Sameh; Erpicum, Sébastien ULg et al

in Environmental Fluid Mechanics (2008), 8(1), 31-54

Free surface flows in several shallow rectangular basins have been analyzed experimentally, numerically and theoretically. Different geometries, characterized by different widths and lengths, are ... [more ▼]

Free surface flows in several shallow rectangular basins have been analyzed experimentally, numerically and theoretically. Different geometries, characterized by different widths and lengths, are considered as well as different hydraulic conditions. First, the results of a series of experimental tests are briefly depicted. They reveal that, under clearly identified hydraulic and geometrical conditions, the flow pattern is found to become nonsymmetric, in spite of the symmetrical inflow conditions, outflow conditions and geometry of the basin. This non-symmetric motion results from the growth of small disturbances actually present in the experimental initial and boundary conditions. Second, numerical simulations are conducted based on a depth-averaged approach and a finite volume scheme. The simulation results reproduce the global pattern of the flow observed experimentally and succeed in predicting the stability or instability of a symmetric flow pattern for all tested configurations. Finally, an analytical study provides mathematical insights into the conditions under which the symmetric flow pattern becomes unstable and clarifies the governing physical processes. [less ▲]

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See detailModélisation hydrologique à grande échelle des zones imperméables égouttées
Khuat Duy, Bruno; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in 3èmes Journées Doctorales en Hydrologie Urbaine (JDHU) (2008)

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See detailAn experimental analysis of effects induced by moving bodies in shallow water
Kerger, François ULg; Detrembleur, Sylvain ULg; Archambeau, Pierre ULg et al

in Proc. 2nd International Junior Researcher and Engineer Workshop on Hydraulic Structures (2008)

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See detailModélisation numérique et gestion du risque inondation en milieu urbain sur base de modèles topographiques à haute résolution
Detrembleur, Sylvain ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in 3e journées doctorales en hydrologie urbaine (2008)

Dans le cadre général des grands événements récurrents d'inondation enregistrés à travers le monde et en Europe en particulier, des cartes d'inondation représenteraient un outil de grand intérêt pour les ... [more ▼]

Dans le cadre général des grands événements récurrents d'inondation enregistrés à travers le monde et en Europe en particulier, des cartes d'inondation représenteraient un outil de grand intérêt pour les décideurs en matière d’aménagement du territoire mais aussi pour les compagnies d'assurance afin d’évaluer les risques liés à l'inondation ou encore pour permettre une gestion de crise efficace sur le terrain. Dans ce but, des cartes complètes et précises sont nécessaires pour différents événements de probabilités données. En Belgique, début 2003, suivant une décision du gouvernement wallon, le modèle d’écoulements à surface libre WOLF2D a été officiellement choisi pour calculer des cartes d'inondation sur 800 kilomètres de cours d’eau en région wallonne en utilisant un modèle numérique de terrain à très haute résolution. Les résultats de ces calculs ont, par la suite, été utilisés par l'administration wallonne afin de concevoir la carte d’aléa inondation sur l’ensemble du territoire. Le modèle hydraulique employé est intégré dans la suite logicielle WOLF, qui est développée depuis plus de dix ans à l'Université de Liège. Basée sur la formulation classique des équations en eaux peu profondes, sa discrétisation en volumes finis permet de traiter tout écoulement composé de mailles sèches et mouillées tout en assurant exactement la conservation du volume. Le caractère multiblocs du logiciel permet de modéliser des raffinements locaux du maillage au niveau des centres urbains tout en conservant, si nécessaire, des maillages plus lâches dans les grandes plaines inondables. Par ailleurs, des procédés de raffinement automatique du maillage permettent d’accélérer fortement les temps de calcul. Un modèle moyenné de turbulence type k-ε peut également être employé et renforce ainsi les potentialités du modèle face aux écoulements complexes. Une interface permet en outre de gérer l’ensemble des procédures de pré et post processing nécessaires à la conception des modélisations et à l’interprétation des résultats. Les opérations d'importation et d'exportation sont facilement réalisables vers la plupart des outils SIG classiques. Différentes couches de cartes peuvent être manipulées pour analyser les informations relatives à la topographie, à l’occupation du sol, à la densité de la végétation ou encore aux champs hydrodynamiques. Grâce à l'utilisation de modèles topographiques de haute résolution (1 point par mètre carré) disponible sur le lit principal comme sur les plaines d'inondation des cours d’eau étudiés, des modélisations basées sur des maillages composés de cellules carrées de 2m x 2m ont été réalisées notamment au droit des centres urbains traversés par les rivières. Le modèle hydraulique a été intensivement validé par des comparaisons avec des observations lors d’événements récents. L'incertitude globale du modèle s'est avérée inférieure à 10 centimètres en termes de surface libre et permet de décrire l’inondation rue par rue et maison par maison. [less ▲]

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See detailIntegration of accurate 2D inundation modelling, vector land use database and economic damage evaluation
Ernst, Julien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Proceedings of the European Conference on Flood Risk Management - FloodRisk 2008 (2008)

Within the global framework of the climate change, according to most Regional Climate Mod-els the maximum peak discharges in river will increase in importance and frequency. Therefore the people will have ... [more ▼]

Within the global framework of the climate change, according to most Regional Climate Mod-els the maximum peak discharges in river will increase in importance and frequency. Therefore the people will have to face worst inundation conditions. In order to protect themselves from the increasing flood risk, the communities have to draw up suitable flood protection measures. The selection and the evaluation among the different possible flood mitigation measures requires developing decision-support system (DSS). This sys-tem has to take into consideration parameters such as hydraulic, economic, social or environmental. This pa-per focuses on the integration between two components of the DSS, namely the evaluation of the economic impacts of floods and the hydrodynamic modelling. The hydraulic simulations are conducted by means of WOLF 2D flow modelling system and provide as an output high resolution flood maps detailing the distribu-tion of water depth and flow velocity in the floodplains. The integration is ensured by the use of very accurate geographic databases and an automated procedure which makes the most of geomatic methods. The paper de-tails the application of the integrated assessment procedure for a case study along the river Ourthe located in the Meuse basin (Belgium). Moreover, possibilities of validation of the economic damage evaluation proce-dure are investigated by comparing computation results with real damage data recorded by the Belgian Disas-ter Fund after several major flood events (2003, 2002, 1995, and 1993). [less ▲]

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See detailDetailed 2D flow simulations as an onset for evaluating socio-economic impacts of floods
Dewals, Benjamin ULg; Detrembleur, Sylvain ULg; Archambeau, Pierre ULg et al

in Proceedings of the European Conference on Flood Risk Management - FloodRisk 2008 (2008)

A 2D hydraulic numerical model is presented. It is based on the fully dynamic shallow-water equations, solved by means of a finite volume scheme on multiblock structured grids. The model handles highly ... [more ▼]

A 2D hydraulic numerical model is presented. It is based on the fully dynamic shallow-water equations, solved by means of a finite volume scheme on multiblock structured grids. The model handles highly accurate DSM derived from airborne laser altimetry for the floodplains and sonar detection for the bathymetry of the main channel. The flow simulations are performed with a typical grid spacing of 2m, comparable to the resolution of the DSM and fine enough to represent reliably the flows at the scale of each building. Consequently, the model succeeds in predicting accurately the pattern of flood depth even in densely urbanized floodplains, as confirmed by several validation examples, which also demonstrate the ability of the model to reproduce depth measurements for a wide range of flood discharges without the need for recalibration of the roughness coefficient. Finally, the hydraulic model is exploited as a component of a complete flood risk modelling chain, accounting for socio-economic and ecological impacts of floods and dedicated to the assessment of flood protection measures in the context of climate change. [less ▲]

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See detailConsidering bottom curvature in depth-averaged open-channel flow modelling, based on curvilinear coordinates
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Pirotton, Michel ULg

in Advances in Fluid Mechanics VII (2008)

Accurately modelling open-channel flows on strongly vertically curved bottoms, such as for instance over a spillway, is a challenge for any depth-averaged flow model. This type of computation requires the ... [more ▼]

Accurately modelling open-channel flows on strongly vertically curved bottoms, such as for instance over a spillway, is a challenge for any depth-averaged flow model. This type of computation requires the use of axes properly inclined along the mean flow direction in the vertical plane and a modelling of curvature effects. The present generalized model performs such computations by means of curvilinear coordinates in the vertical plane, enabling for instance to simulate within one single computation domain the flows in the upstream reservoir, over the spillway, in the stilling basin and in the river reach downstream of a dam. The frame of reference is chosen in such a way that one of the two curvilinear axes follows the local bottom curvature. Hence the set of generalized shallow water equations involves explicitly not only the channel bottom slope, but also the channel vertical curvature and its derivative. The velocity profile is generalized in comparison with the uniform one usually assumed in the conventional shallow-water equations. The pressure distribution is also modified as a function of the bottom curvature and is thus not purely hydrostatic but accounts for effects of centrifugal forces. This enhanced mathematical modelling framework has been implemented in a 2D finite volume model. A specific flux vector splitting technique has been developed and demonstrated to be stable for any flow regime and any bottom curvature. The scheme offers the advantage of being dependent only on the sign of the bottom curvature. For a vanishing bottom curvature, the new model converges smoothly towards the conventional shallow-water equations. Finally, two test cases are detailed and lead to satisfactory validation results for the new model. [less ▲]

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See detailNumerical modelling of transient flows with high sediment concentrations
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Pirotton, Michel ULg

in DE WRACHIEN, D. (Ed.) Monitoring, Simulation, Prevention and Remediation of Dense Debris Flows II (2008)

The main purpose of the present paper is to describe and discuss the development, validation and application of a numerical model designed to handle transient flows with high sediment transport rates. The ... [more ▼]

The main purpose of the present paper is to describe and discuss the development, validation and application of a numerical model designed to handle transient flows with high sediment transport rates. The model considers non-equilibrium transport (i.e. accounting for loading / unloading delay) and is numerically as well as physically totally coupled. The closure relations needed to evaluate the exchange fluxes between the fixed bottom and the flowing mixture (erosion and deposition rates) are also detailed in the paper. Finally, the model is validated against experimental data collected in the framework of the European project IMPACT. [less ▲]

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See detailAn efficient global methodology for hazard analysis of dams complexes and cascades
Dewals, Benjamin ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Brebbia, C. A.; Popov, V.; Beriatos, E. (Eds.) Risk analysis Vol. 6 (2008)

Hazard analysis of dams arranged in complex or in cascade may involve the assessment of a large number of different scenarios of combined failures. However, a tremendous computation time would be needed ... [more ▼]

Hazard analysis of dams arranged in complex or in cascade may involve the assessment of a large number of different scenarios of combined failures. However, a tremendous computation time would be needed to perform a detailed modelling of the flows generated by all possible scenarios. Therefore, the present paper describes a methodology for analysing the flows induced by the most relevant incidents occurring on a complex or in a cascade of dams and reservoirs. The methodology combines several hydrodynamic models, including the two-dimensional flow solver WOLF 2D and a simplified lumped hydrodynamic model, to simulate the flows induced on the dams complex, the potential breaching in cascade of other dams, as well as the propagation of the flood wave in the whole downstream valley. The application of the methodology to a practical case study involving a complex of five dams is also described. [less ▲]

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See detailNumerical modelling and theoretical analysis of geometrically-controlled flow instabilities in rectangular basins
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Pirotton, Michel ULg

in Proceedings of the 4th International Conference on Advanced Computational Methods in Engineering (2008)

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See detailNumerical analysis of coupled mechanical and hydraulic effects induced by a blood pressure meter
Paulus, Raphaël ULg; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in Proceedings of the 4th International Conference on Advanced Computational Methods in Engineering (2008)

Detailed reference viewed: 70 (19 ULg)