References of "Dewals, Benjamin"
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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)

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See detailDetailed 2D numerical modeling for flood extension forecasting
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Proceedings of the 4th International Conference on Fluvial Hydraulics: River Flow 2008 (2008)

In the global framework of recurrent large flood events all over the world and in Europein particular, relevant and detailed inundation maps represent a tool of prime interest fordecision makers ... [more ▼]

In the global framework of recurrent large flood events all over the world and in Europein particular, relevant and detailed inundation maps represent a tool of prime interest fordecision makers, emergency services or insurance companies. In 2003 in Belgium, following a Regional Government decision, hydraulic 2D numerical modelling has been chosen to compute inundation maps on 800 km of the main rivers of the Walloon Region, using high resolution Digital Elevation Models. The present paper covers a detailed description of the state-of-the-art 2D finite volume model used to fulfil this task. As a part of this project, the model has been extensively validated by comparisons with observations during recent real flood events. It shows a very good agreement with observations, in particular regarding free surface elevations. Following this first step toward flood management, the Belgian National project “ADAPT” is presented. It aims to develop an efficient decision support tool for the integrated assessment ofadaptation measures against climate change induced flooding. In this scope, the model has been applied to predict inundations induced by floods, taking into account different climate change scenarios. The results of these simulations serve as input for a subsequent economic, social and ecological analysis by other scientific research teams. [less ▲]

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See detailDam-break flow computation using high resolution DEM
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Hogge, Michel; Van Keer, R.; Noels, L. (Eds.) et al Proceedings of the 4th International Conference on Advanced Computational Methods in Engineering (2008)

Dam-break flow computation is a task of prime interest in the scope of risk analysis processes related to dams and reservoirs. High resolution Digital Elevation Models (DEMs) available today provide ... [more ▼]

Dam-break flow computation is a task of prime interest in the scope of risk analysis processes related to dams and reservoirs. High resolution Digital Elevation Models (DEMs) available today provide extremely dense and accurate topography information in the valley downstream of these structures, even in urban area. In this paper, a 2D finite volume flow solver, able to deal with these DEMs, is presented in details. Validation examples are comprehensively described. [less ▲]

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See detailAutomatic shape optimization with GAs and a 2D free surface flow solver
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Pirotton, Michel ULg

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

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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 Proceedings of the 2nd International Junior Researcher and Engineer Workshop on Hydraulic Structures (2008)

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See detailA systematic procedure to predict flows induced by major dysfunctions on complexes or cascades of dams
Dewals, Benjamin ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Proceedings of the 3rd IAHR-International Symposium on Hydraulic Structures (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 modeling of the flows generated by all possible scenarios. Therefore, the present paper describes a rational methodology for analyzing 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 twodimensional flow solver WOLF 2D and a simplified lumped hydrodynamic model, to simulate (i) the flows induced on the dams complex, (ii) the potential breaching in cascade of other dams, as well as (iii) 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 detailA 2D finite volume multiblock flow solver applied to flood extension forecasting
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Detrembleur, Sylvain ULg et al

in García-Navarro, Pilar; Playán, Enrique (Eds.) Numerical modelling of hydrodynamics for water ressources (2008)

ABSTRACT: this paper describes a quasi-3D free surface flow solver,developed for almost ten years at the University of Liege, and its application to flood extension forecasting. Based on the classical SWE ... [more ▼]

ABSTRACT: this paper describes a quasi-3D free surface flow solver,developed for almost ten years at the University of Liege, and its application to flood extension forecasting. Based on the classical SWE, the finite volume numerical model deals with real topography and wetting-drying cells while exactly conserving the water volume. Multiblock options allow local refine-ment of the structured calculation grid and automatic mesh refinement enhances greatly compu-tation time. An additional depth-averaged k-ε type turbulence model increases the potentialities of the solver to represent real complex flows. Following a Regional Government decision, this solver has been officially chosen in 2003 to be used to compute inundation maps on 800 km of the main rivers of the Walloon Region in Belgium with a spatial resolution of 5 x 5 to 2 x 2 me-ters and using high resolution Digital Elevation Models. Results are presented in this paper. [less ▲]

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

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

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See detailHydraulique Urbaine
Pirotton, Michel ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

Learning material (2008)

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See detailModelling of sewer systems as a component of a global hydrological model
Khuat Duy, Bruno ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

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

Hydrology often takes an important place in the domain of hydraulic structures management, and is a key component of many hydraulic studies. Modelling the main hydrological processes requires a particular ... [more ▼]

Hydrology often takes an important place in the domain of hydraulic structures management, and is a key component of many hydraulic studies. Modelling the main hydrological processes requires a particular attention in order to deal with problems in an optimal way. Instrumented basins studies has pointed out the considerable impact of the sewer system on the hydrological outputs dynamics on small basins, even poorly urbanized. The current models often take into account the distributed impervious areas by adapting the corresponding surfaces runoff or infiltration coefficients. This approach, which is suited to produce correct runoff volumes, is however unable to represent the real flow outputs dynamics in which important variations can occur with a hourly time step. Modelling this flow component is essential to catch the rapidly-varying flow inputs generated by the runoff on drained impervious areas. An efficient modelling method has therefore been developed to include the sewer system in a global hydrological model (WOLF), using accurate landuse data in vector format and available data on the sewage system. These developments have been successfully tested on the Berwinne basin, Belgium. [less ▲]

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See detailAutomatic geometrical optimization by way of numerical flow models
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proceedings of the 3rd IAHR-International Symposium on Hydraulic Structures (2008)

The potentialities in numerical flow modeling available today allow performing more and more representative and accurate computations of an increasing part of hydraulic engineering practical problems. In ... [more ▼]

The potentialities in numerical flow modeling available today allow performing more and more representative and accurate computations of an increasing part of hydraulic engineering practical problems. In some cases, numerical simulation can be used as an alternative, or at least an efficient pre-design tool, to more classic physical modeling. In this framework, the paper presents the application of integrated numerical tools to the automatic optimization of the geometry of a guide-wall at the entrance of a channel. The simulations have been performed by using a Genetic Algorithm based optimization tool coupled to a 2D free surface flow model. This finite volume multibock flow solver, WOLF2D, solves the conservative form of the classical shallow water equations together with a depth-integrated k-ε type turbulence model. The calculations have been performed on a cluster of 12 processors to reach a satisfactory solution in less than 2.5 days (96 solutions tested). On the basis of the numerical results and of the value of the suitability indicators, the optimal solution is objectively better than the other tested geometries. This confirms the efficiency of the automatic optimization procedure. [less ▲]

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See detailDetailed flood extension forecasting in the Walloon region with a 2D finite volume multiblock free surface flow solver
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Detrembleur, Sylvain ULg et al

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

Detailed reference viewed: 32 (8 ULg)