References of "Archambeau, Pierre"
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See detailTheoretical and numerical analysis of the hydrodynamic waves induced by dam breaks and their interaction with structures located downstream
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Proceedings of the 7th National Congress on theoretical and applied Mechanics (2006)

The present paper first describes briefly the hydrodynamic model WOLF 2D, developed at the University of Liege and suitable for conducting dam break risk assessment. Secondly, the simulation of the flood ... [more ▼]

The present paper first describes briefly the hydrodynamic model WOLF 2D, developed at the University of Liege and suitable for conducting dam break risk assessment. Secondly, the simulation of the flood induced by the Malpasset dam break enables to highlight the effectiveness of WOLF 2D. Lastly, the model is applied to demonstrate the key advantages of the most contemporary approach for reproducing the effect of buildings on the flow behaviour. The recommended modelling technique is based on a high resolution Digital Elevation Model, provided by laser measurements. [less ▲]

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See detailInteractions between numerical and physical modelling for the design and optimization of hydraulic structures - Example of a large hydroelectric complex
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of the International Symposium on Hydraulic Structures, XXII Congreso Latinoamericano de Hidráhulica (2006)

This paper describes the successful combination of both physical and numerical modelling techniques applied to the scale model study of a large hydroelectric complex in India. Thanks to accurate numerical ... [more ▼]

This paper describes the successful combination of both physical and numerical modelling techniques applied to the scale model study of a large hydroelectric complex in India. Thanks to accurate numerical simulations, the physical model layout and the time to studies have been drastically reduced. First, prior to the design of the scale model, a global numerical simulation of the dam reservoir has been carried out, on the basis of the entire set of available topographic data. The simulation results supply the flow conditions in the upstream reservoir, particularly in the vicinity of the dam and the spillway crest. Subsequently, a second numerical computation has been performed to simulate the flow in a scale model representing only a small part of the reservoir upstream of the dam. The suitable correspondence between flow conditions in both cases has been demonstrated. This two-steps approach has enabled a significant reduction in the size of the scale model, and hence, a lower cost as well as a shorter delay for building the model. Simultaneously, it has been possible to decrease the scale factor at constant cost. In conclusion, the present paper provides convincing evidence that the increase in computers performance and the efficiency of contemporary free-surface flow solvers lead to useful numerical information for the optimal design and exploitation of scale models. [less ▲]

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See detailDepth-integrated flow modelling taking into account bottom curvature
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Journal of Hydraulic Research (2006), 44(6), 787-795

Successfully modelling flows over a spillway and on strongly vertically curved bottoms is a challenge for any depth-integrated model. This type of computation requires the use of axes properly inclined ... [more ▼]

Successfully modelling flows over a spillway and on strongly vertically curved bottoms is a challenge for any depth-integrated 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 proposed generalized model per-forms such computations by means of suitable curvilinear coordinates in the vertical plane, leading to a fully integrated approach. This means that the flows in the upstream reservoir, on the spillway, in the stilling basin and in the downstream river reach are all handled in a single simulation. The velocity profile is generalized in comparison with the uniform one usually assumed in the classical shallow water equations. The pressure dis-tribution is modified as a function of the bottom curvature and is thus not purely hydrostatic. Representative test cases, as well as the application of the extended model to the design of a large hydraulic structure in Bel-gium, lead to satisfactory validation results. [less ▲]

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See detailModern techniques for flood risk analysis: quasi-3D simulations in a GIS environment
Archambeau, Pierre ULg; Erpicum, Sébastien ULg; Dewals, Benjamin ULg et al

in Geophysical Research Abstracts (2005), 7(09348),

Human beings have continuously attempted to adapt their environment to their needs. However, many natural phenomena still remain challenging to control and the populations must undergo sometimes heavily ... [more ▼]

Human beings have continuously attempted to adapt their environment to their needs. However, many natural phenomena still remain challenging to control and the populations must undergo sometimes heavily damaging consequences. It is consequently essential to study these phenomena in order to assess their potential hazards. In particular, the scope of the present paper focus on floods. The intense floods met these last years showed the importance of this phenomenon as well as its many devastating effects. Thanks to recent important breakthroughs, both in the field of conceptual and numerical modelling of complex flows and in the calculation power of computers, it is henceforth possible to study the effects of potential floods on the basis of numerical simulations, with an accuracy never reached beforehand. The Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) of the University of Liege has always made this kind of study one of its core competencies, thanks to • the development of modern and powerful modelling tools (quasi-three dimensional software for flow simulation by finite volume), • the use of a broad range of data enabling a proper representation of the studied fields (topography, occupation of the ground...) • the systematic validation of simulation results. These tools are currently intensively used within the framework of a general study of the flood-prone zones of the Walloon area of Belgium, which corresponds to more than 800 km of rivers. [less ▲]

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See detailNumerical tools for the optimization of hydroelectric power stations in cascade
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Dick, Erik; Hogge, Michel; Van Keer, Roger (Eds.) Proceedings of the 3rd Internationale Conference on Advanced Computational Methods in Engineering (2005)

The numerical optimization process of the system of hydroelectric power stations installed on a 60 km long section of the rivers Amblève and Warche in Belgium is presented in detail. The river network is ... [more ▼]

The numerical optimization process of the system of hydroelectric power stations installed on a 60 km long section of the rivers Amblève and Warche in Belgium is presented in detail. The river network is modelled in quasi-2D using real natural topographic data on almost 1,100 finite volumes. In a first step, the hydrological balance is closed using a numerical solver and roughness coefficients are calibrated from water level and discharge field measurements. Secondly, the hydroelectric production is maximised by an automatic calibration of the parameters of the hydrograph released in the network at the upstream dam. This approach leads to a substantial gain in hydroelectric production, brings significant financial benefits and deals with all management and security criteria of the river network. [less ▲]

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See detailOptimisation of hydroelectric power stations operations with WOLF package
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Repp, K.; Westeren, T.; Sandlund, O. T. (Eds.) et al Proceedings of the 5th International Conference on Hydropower - The backbone of sustainable energy supply (2005)

For years, original free-surface flow solvers have been developed and continuously improved by the Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) at the University of Liège. The ... [more ▼]

For years, original free-surface flow solvers have been developed and continuously improved by the Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) at the University of Liège. The resulting fully integrated WOLF computation package allows engineers to accurately study a very wide range of various free surface flows, from hydrological runoff (WOLF HYDRO) and river propagation (WOLF 1D) to extreme erosive flows on realistic mobile topography (WOLF 2D), such as gradual dam breaching processes. All the finite volume models, process oriented, use efficient and original numerical methods to solve free surface flows equations. Each code handles general multiblock meshes, dealing with natural topography, dry and wet cells and mobile bed simultaneously, for any unsteady situation with mixed regimes and moving hydraulic jumps. The interactive and unique user-interface, with high performance pre- and post-processing, allows monitoring 3-D large-scale runs graphically while they proceed, as well as generating 3D videos. In addition, powerful optimisation capabilities based on the Genetic Algorithms technique (WOLF AG) are implemented within WOLF, interconnecting all the package components. An efficient tool is thus available to calibrate physical parameters in any of the models and to manage any problem of optimisation with the different solvers. In this paper, the numerical optimisation process of the system of hydroelectric power stations installed on a 60 km long section of the rivers Amblève and Warche in Belgium is presented in detail. The river network is modelled in quasi-2D using real natural topographic data on almost 1,100 finite volumes. In a first step, the hydrological balance is closed using the solver WOLF HYDRO. Roughness coefficients are calibrated from water level and discharge field measurements. Secondly, the hydroelectric production is maximised by an automatic calibration of the parameters of the hydrograph released in the network at the upstream dam. This approach leads to a substantial gain in hydroelectric production, brings significant financial benefits and deals with all management and security criteria of the river network. [less ▲]

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See detailModelling suspended load with moment equations and linear concentration profiles
Khuat Duy, Bruno ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Raghay, S.; Ouazar, D.; Benkhaldoun, F. (Eds.) Finite volumes for complex applications (2005)

In numerical simulations, it is always necessary to find an optimum between the simplicity of the model and a good representation of real phenomena. In the field of hydraulic flows simulations, the models ... [more ▼]

In numerical simulations, it is always necessary to find an optimum between the simplicity of the model and a good representation of real phenomena. In the field of hydraulic flows simulations, the models using depth-averaged and moment equations are an interesting compromise between full 3D and simple depth-averaged models. This paper presents the use of a moment equation for suspended load transport. A simple but representative model for the sediment concentration profiles is developed. This original bi-linear concentration profile is compared to the traditional Rouse-profiles and shows a good correspondence despite its great simplicity. Advective and diffusive sediment fluxes are developed analytically and lead to a concise formulation, which is an asset for practical use. A differential equation for the sediment concentration moment is also fully developed, and a special attention is cast to the source term. The finite volume scheme has been chosen to implement the model, because it is particularly well suited for highly advective transport equations, it is conservative and it makes the choice of the upwinding easier. 1D simulations show the capacity of the model to reproduce laboratory experiments described in the literature. [less ▲]

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See detailModelling suspended load transport with linear concentration profiles
Khuat Duy, Bruno ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Proceedings of the 8th International Conference on Fluvial Sedimentology (2005)

In numerical simulations, it is always necessary to find an optimum between the simplicity of the model and a good representation of real phenomena. In the field of hydraulic flows simulations, the models ... [more ▼]

In numerical simulations, it is always necessary to find an optimum between the simplicity of the model and a good representation of real phenomena. In the field of hydraulic flows simulations, the models using depth-averaged and moment equations are an interesting compromise between full 3D and simple depth-averaged models. This paper presents the use of a moment equation for suspended load transport. A simple but representative model for the sediment concentration profiles is developed. This original bi-linear concentration profile is compared to the traditional Rouse-profiles and shows a good correspondence despite its great simplicity. Advective and diffusive sediment fluxes are developed analytically and lead to a concise formulation, which is an asset for practical use. A differential equation for the sediment concentration moment is also fully developed, and a special attention is cast to the source term. The finite volume scheme has been chosen to implement the model, because it is particularly well suited for highly advective transport equations, it is conservative and it makes the choice of the upwinding easier. 1D simulations show the capacity of the model to reproduce laboratory experiments described in the literature. [less ▲]

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See detailNumerical modelling with Wolf2D of the sedimentation problem at the entrance of a lock on the river Meuse
Khuat Duy, Bruno ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Dick, Erik; Hogge, Michel; Van Keer, Roger (Eds.) Proceedings of the 3rd International Conference on Advanced Computational Methods in Engineering (2005)

This paper presents the resolution of a practical hydraulic engineering problem thanks to effective numerical tools. A sedimentation study of the lock of Hun (river Meuse, Belgium) is completed using ... [more ▼]

This paper presents the resolution of a practical hydraulic engineering problem thanks to effective numerical tools. A sedimentation study of the lock of Hun (river Meuse, Belgium) is completed using solid transport models integrated in a finite volume free surface flows solver. The silting of the lock entrance is successfully modelled and various layout modifications of the site are tested to predict their effects and to see to what extent they could improve the actual situation. The analysis of the results shows that a regular dredging of the lock entrance is ineluctable. [less ▲]

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See detailMarché de services en vue de simuler l’impact, sur le régime hydrologique de l’Ourthe, de l’implantation de bassins écrêteurs dans les vallées de l’Ourthe et de l’Amblève (MOHICAN)
Deliège, Jean-François ULg; Bourouag, Mohamed ULg; Dautrebande, Sylvia et al

Report (2004)

Le modèle MOHICAN (« Modèle hydrologique intégré pour le calcul des crues et l’amplitude des niveaux d’eau ») a été développé conjointement par l’Université de Liège (Laboratoire d’hydrodynamique ... [more ▼]

Le modèle MOHICAN (« Modèle hydrologique intégré pour le calcul des crues et l’amplitude des niveaux d’eau ») a été développé conjointement par l’Université de Liège (Laboratoire d’hydrodynamique appliquée, Laboratoire de Géologie de l’Ingénieur et d’Hydrogéologie, Centre d’Etude et de Modélisation de l’environnement) et la Faculté Universitaire des Sciences Agronomiques de Gembloux (Unité d’Hydraulique agricole) pour le compte et avec le support du Ministère de l’Equipement et des Transports, Service d’Etudes Hydrologiques (MET/SETHY) de la Région wallonne. En 2004, le SETHY a demandé aux développeurs du projet de simuler l’impact sur le régime hydrologique de l’Ourthe, de bassins écrêteurs dans les vallées de l’Ourthe et de l’Amblève. Plus spécifiquement, les objectifs de l’étude étaient d’estimer l’efficacité réelle de ces bassins écrêteurs (Les Combes, 16.3 Mm³, Ourthe ; Gran Han, 15.0 Mm³, Ourthe ; Stoumont, 5.7 Mm³, Amblève) pour la diminution des débits de pointe et des hauteurs d’eau, en particulier lors de très grandes crues. Dans le cas des grandes crues testée, les simulations montrent clairement la grande sensibilité des résultats aux différentes combinaisons possibles des bassins écrêteurs et surtout aux lois de gestion à utiliser pour ces bassins : il n’existe pas une loi générale qui donne un résultat maximal pour tous les types de grandes crues, et la gestion combinée des bassins est délicate. [less ▲]

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See detailModelling of the wave propagation, the coastal currents and the induced topographic changes
Fraikin, Catherine; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Proceedings of the 9th International Symposium on River Sedimentation (2004)

This paper models the sea bottom evolution. This model is built up on three main parts. The first one describes the wave propagation, taking simultaneously into account the refraction, the diffraction and ... [more ▼]

This paper models the sea bottom evolution. This model is built up on three main parts. The first one describes the wave propagation, taking simultaneously into account the refraction, the diffraction and the reflection but also the energy dissipation caused by wave breaking. This model is solved by the numerical method of the finite volumes, using an iterative resolution (the GMRES method). Several validations of this model have been carried out on many examples such as harbors of various geometries and depths, beaches,… The wave induced currents are computed in the second part based on the concept of the radiation stresses describing the excess of the flux momentum caused by the waves. A model based on the complete Navier-Stokes equations integrated on the depth and associated with appropriated forcing and friction terms is used. This model is computed as an update of WOLF software (HACH, ULg) and is applied to some examples such as beaches with or without coastal structures. Finally, the third part is about the sediment transport. It exhibits the topographic modifications of the coastal sea bottom caused by the waves and their currents. A loop execution of these three models ends this work. It gives us an operational tool to describe the topographic evolution of the coastal areas caused by the incident waves, the induced currents and then the resulting sediment transport, fulfilling the objectives of this paper. [less ▲]

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See detailComputation of the Malpasset dam break with a 2D conservative flow solver on a multiblock structured grid
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of the 6th International Conference of Hydroinformatics (2004)

In the global framework of safety, the study of the hydraulic consequences of a dam breaking, sudden and instantaneous for concrete structures, gradual for earth ones, is of major interest in the scope of ... [more ▼]

In the global framework of safety, the study of the hydraulic consequences of a dam breaking, sudden and instantaneous for concrete structures, gradual for earth ones, is of major interest in the scope of prevention policies or protection plans for populations and goods. Suitable numerical models, coupled with contemporary computational possibilities, allow engineers to forecast these complex situations with a great reliability. In this field, WOLF 2D is an efficient analysis and optimisation tool, which has been completely developed by the Applied Hydrodynamics and Hydraulic Constructions team (HACH – http://www.ulg.ac.be/hach) of the University of Liege. It is part of WOLF free surface flows computation package, which includes in the same development environment the resolutions of the 1D Saint-Venant equations, the 2D shallow-water equations as well as a physically based hydrological model and powerful optimisation capabilities based on Genetic Algorithms. The interactive and unique user-interface, with high performance pre- and post-processing, allows monitoring 3-D large-scale runs graphically while they proceed, as well as generation of 3D videos. Each code handles general multiblock meshes, dealing with natural topography and mobile bed simultaneously, for any unsteady situation with mixed regimes and moving hydraulic jumps. By this way, WOLF deals with all free surface hydraulic phenomena, from hydrological runoff and river propagation to extreme erosive flows on realistic mobile topography, such as gradual dam breaching processes. It has moreover proved its efficiency and reliability for years by numerous real applications. The first part of this paper covers a brief description of the 2D multiblock flow solver WOLF 2D and the underlying mathematical model. The second part depicts the application of WOLF computation capabilities to the well-known Malpasset dam break (France, 1959), which induced a catastrophic almost instantaneous release of 48 millions m³ of water in the Reyran river valley down to the town of Frejus and the Mediterranean sea. Data available thanks to the CADAM EU-project are used to assess the results. [less ▲]

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