References of "Dewals, Benjamin"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailExperimental analysis of the stability of coarse sediments
Duma, Diana-Maria ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Symposium on Two-phase Modelling for Sediment Dynamics in Geophysical Flows (2013, June 12)

To predict the inception of sediment motion, Shields diagram remains the most widely used criterion in engineering practice so far. However, this approach faces several limitations and a number of gaps in ... [more ▼]

To predict the inception of sediment motion, Shields diagram remains the most widely used criterion in engineering practice so far. However, this approach faces several limitations and a number of gaps in knowledge still remain. The present research aims to provide new knowledge about the inception of motion in rivers with coarse sediments. A series of experiments was conducted in a flume horizontal 6 m long and 15 cm wide. The bottom was paved, either entirely or partly, with gravels of approximately 12 mm in diameter. Ultrasonic sensors were used to measure the water depth, a flowmeter for the discharge, an ultrasonic velocity profiler (UVP) transducer for the flow velocity. Three different thresholds were defined to distinguish between the following states: no motion, vibration of stones, local motion, and large scale motion. The overwhelming influence of turbulence was emphasized by the conducted tests. This paper details the results of these experiments and demonstrates the need for further research in order to better quantify these effects. [less ▲]

Detailed reference viewed: 118 (17 ULg)
Full Text
Peer Reviewed
See detailParapet wall effect on Piano Key Weirs efficiency
Machiels, Olivier; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Journal of Irrigation & Drainage Engineering (2013), 139(6), 506-511

Piano Key Weir is a cost effective solution for rehabilitation as well as for new dam projects with a high level of constraints (limited space, high specific flood discharge, small reservoir level ... [more ▼]

Piano Key Weir is a cost effective solution for rehabilitation as well as for new dam projects with a high level of constraints (limited space, high specific flood discharge, small reservoir level variation). While the higher efficiency of the Piano Key Weir compared to standard linear weirs has already been demonstrated, its optimal geometry is still poorly defined. In order to improve the design of the complex geometry of this structure, the use of parapet walls has been tested. They consist of vertical extensions placed over the weir crest. Following a former study of the influence of the weir height on its discharge capacity, this paper presents the results of an experimental campaign dedicated to investigating the effect of parapet walls to increase weir height while reducing bottom slopes and keeping the weir height constant. These results indicate the relative influences of the alveoli bottom slopes and of the weir height on the Piano Key Weir release capacity. Comparisons with former experimental results as well as design guidelines are also provided. [less ▲]

Detailed reference viewed: 93 (10 ULg)
Full Text
See detailHydraulic modelling in civil and environmental engineering
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Scientific conference (2013, May 08)

Detailed reference viewed: 24 (3 ULg)
Full Text
Peer Reviewed
See detailModélisation numérique hydrosédimentaire au service de la gestion durable des sédiments
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Recyclage et Valorisation (2013), 41

La gestion des sédiments revêt une importance croissante pour l’exploitation des voies navigables et nombre de projets de construction de barrages et de complexes hydroélectriques. L’impact des apports en ... [more ▼]

La gestion des sédiments revêt une importance croissante pour l’exploitation des voies navigables et nombre de projets de construction de barrages et de complexes hydroélectriques. L’impact des apports en matériaux solides se manifeste tant par des effets à long terme, telle la réduction de la capacité du réservoir, que par des conséquences à plus court terme, telle l’usure prématurée des turbines. L’étude détaillée des effets sédimentaires s’impose donc de plus en plus tôt dans la conception de nouveaux aménagements. Elle est aussi un objectif tout au long de l’exploitation des ouvrages, dans une perspective de gestion sécuritaire et durable. [less ▲]

Detailed reference viewed: 37 (12 ULg)
Full Text
Peer Reviewed
See detailEffects of climate change on the river Meuse: Hydraulic 2D modeling from Amspin to Maaseik (and beyond)
Huismans, Ymkje; Dewals, Benjamin ULg; van der Mark, Rolien et al

Poster (2013, March 22)

Detailed reference viewed: 14 (6 ULg)
Full Text
See detailScientific basis for transnational flood management in the Meuse basin
Dewals, Benjamin ULg; Huismans, Ymkje; Detrembleur, Sylvain et al

Conference (2013, March 22)

Detailed reference viewed: 50 (25 ULg)
Full Text
Peer Reviewed
See detailImpact of climate change on inundation hazard along the river Meuse
Dewals, Benjamin ULg; Drogue, Gilles; Erpicum, Sébastien ULg et al

in Transboundary Water Management in a Changing Climate (2013, March)

As a part of the effort to scientifically inform the development of the adaptation strategy for the Meuse basin, we detail hereafter the generation of integrated climate and hydrological scenarios for the ... [more ▼]

As a part of the effort to scientifically inform the development of the adaptation strategy for the Meuse basin, we detail hereafter the generation of integrated climate and hydrological scenarios for the whole basin. We also present the setup of a first coordinated hydraulic modelling from spring to mouth of the river Meuse. The latter has enabled to compute the range of change in inundation hazard under the “wet” transnational hydrological scenario for the time slices 2021-2050 and 2071-2100. A significantly higher impact of climate change has been found in the middle part of the Meuse basin, compared to the upper and the lower parts. These conclusions have been further confirmed by a refined analysis conducted for a 100 km-long stretch of the river Meuse crossing the Belgian-Dutch border. [less ▲]

Detailed reference viewed: 45 (14 ULg)
See detailEvolution du risque lié aux inondations de la Meuse : Influences relatives du climat et de la croissance des zones résidentielles
Beckers, Arnaud ULg; Detrembleur, Sylvain; Dewals, Benjamin ULg et al

Scientific conference (2013, February 28)

Chaque année, les inondations par débordement des rivières provoquent des dommages significatifs en Wallonie. L’ampleur de ceux-ci est liée à l’importance des crues elles-mêmes, mais aussi à l’occupation ... [more ▼]

Chaque année, les inondations par débordement des rivières provoquent des dommages significatifs en Wallonie. L’ampleur de ceux-ci est liée à l’importance des crues elles-mêmes, mais aussi à l’occupation du sol des terrains inondés. Dans le contexte des changements climatiques, comment évolueront les débits des crues « extrêmes » ? Quelle pourrait être l’influence de l’évolution de l’occupation du sol sur les dommages ? La vallée de la Meuse a été choisie pour investiguer et concrétiser les réponses à ces questions. Les dommages liés à une crue centennale ont été calculés pour la situation actuelle ainsi que pour différentes situations potentielles en 2100, suivant un scénario d’évolution climatique et neuf scénarios d’urbanisation de la Wallonie. L'accent sera mis sur tant sur le développement de ces scénarios que sur les conclusions robustes tirées des résultats obtenus en termes d’influence relative du climat et de l’occupation du sol sur les dommages futurs. [less ▲]

Detailed reference viewed: 85 (22 ULg)
Full Text
Peer Reviewed
See detailPhysical and numerical modelling in low-head structures design
Dewals, Benjamin ULg; Archambeau, Pierre ULg; Rulot, François et al

in Bung, Daniel; Pagliara, Stefano (Eds.) Proceedings of the International Workshop on Hydraulic Design of Low-Head Structures (2013, February)

Physical and numerical modelling may be combined within so-called composite or hybrid modelling. This enables to optimally take benefit of the respective strengths of each modelling approach, while ... [more ▼]

Physical and numerical modelling may be combined within so-called composite or hybrid modelling. This enables to optimally take benefit of the respective strengths of each modelling approach, while compensating for their specific drawbacks. Different types of composite modelling may be identified, such as embedding a detailed physical model within a broader scale numerical model, interconnecting different physical and numerical models focusing each on specific processes, or validating a numerical model from experimental data before exploiting the numerical model to generate more results than availa-ble from the experimental facility. Besides, specifically in more basic research, composite modelling may also be used to improve in-depth understanding of the relative importance of different processes which act simultaneously in the experimental test and may be artificially separated in numerical simulations. [less ▲]

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailAn analytical approach for Piano Key weir hydraulic design
Machiels, Olivier; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Erpicum, Sébastien; Laugier, Frédéric; Pfister, Michael (Eds.) et al Labyrinth and Piano Key weirs II - PKW 2013 (2013)

A hydraulic design equation for Piano Key Weirs is set up using the results of a large experimental parametric study. Comparison of the analytical formulation with experi-mental data from various physical ... [more ▼]

A hydraulic design equation for Piano Key Weirs is set up using the results of a large experimental parametric study. Comparison of the analytical formulation with experi-mental data from various physical modeling studies, considering idealized as well as real projects Piano Key Weirs configurations, shows a 15% accuracy in unit discharge prediction on a large range of geometric parameters values. Comparison of the proposed formulation to two other recently proposed equations highlights the importance to consider such analytical approaches inside the range of parameter values for which they have been validated. [less ▲]

Detailed reference viewed: 12 (1 ULg)
Full Text
Peer Reviewed
See detailComparative analysis of the energy dissipation on a stepped spillway downstream of a Piano Key Weir
Silvestri, Aurélien ULg; Archambeau, Pierre ULg; Pirotton, Michel ULg et al

in Erpicum, Sébastien; Laugier, Frédéric; Pfister, Michael (Eds.) et al Labyrinth and Piano Key Weirs II - PKW 2013 (2013)

A systematic experimental study has been carried out to compare the residual energy at the toe of a stepped spillway of varied length considering a classical ogee-crested weir (OCW) or two different piano ... [more ▼]

A systematic experimental study has been carried out to compare the residual energy at the toe of a stepped spillway of varied length considering a classical ogee-crested weir (OCW) or two different piano key weirs (PKW) at the top of the structure. Four spillway lengths have been considered on a wide range of discharge. An indirect method has been used to compute the residual flow energy at the spillway toe from water depth measurements in a horizontal channel downstream. The results indicate that uniform flow conditions, i.e. flow energy at the spillway toe independent of the spillway length, are reached on significantly shorter spillways downstream of a PKW than downstream of an OCW. However, the uniform flow energy at constant discharge on the spillway is found to vary depending on the weir type. In particular, it is smaller downstream of the OCW than downstream of the PKWs. [less ▲]

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailEscouloubre Piano Key weir: prototype versus scale models
Erpicum, Sébastien ULg; Silvestri, Aurélien ULg; Dewals, Benjamin ULg et al

in Erpicum, Sébastien; Laugier, Frédéric; Pfister, Michael (Eds.) et al Labyrinth and Piano Key Weirs II - PKW 2013 (2013)

A 1.77 m high piano key weir in operation on the Escouloubre balance basin enabled the observation of real size flows for discharges ranging from 1.2 to 10 m³/s, corresponding to upstream heads ranging ... [more ▼]

A 1.77 m high piano key weir in operation on the Escouloubre balance basin enabled the observation of real size flows for discharges ranging from 1.2 to 10 m³/s, corresponding to upstream heads ranging from 11 to 48 cm. These observations are depicted and compared to the results gained on three physical models of the weir, built and operated considering a Froude similitude and geometric scale factors of, respectively, 1:7, 1:15 and 1:25. The study highlights the scale effects which may affect piano key weirs scale model studies and provides criteria to limit them. In particular, the results analysis shows that the scale models succeed in representing the flow conditions on the weir when the model upstream head is higher than 60 mm, and succeed in predicting the weir discharge capacity when the model upstream head is higher than 30 mm. [less ▲]

Detailed reference viewed: 18 (1 ULg)
Full Text
Peer Reviewed
See detailCoupling between flow and sediment deposition in rectangular shallow reservoirs
Camnasio, Erica; Erpicum, Sébastien ULg; Orsi, Enrico et al

in Journal of Hydraulic Research (2013), 51(5), 535-547

Flow velocity and sedimentation patterns were investigated experimentally and numerically in shallow rectangular reservoirs with different asymmetric locations of the inlet and outlet channels. Velocity ... [more ▼]

Flow velocity and sedimentation patterns were investigated experimentally and numerically in shallow rectangular reservoirs with different asymmetric locations of the inlet and outlet channels. Velocity fields were measured in the entire reservoir, both for clear water flow and with suspended sediments. Thickness of sediment deposits were mapped in the whole reservoir by means of a laser light method. In one of the studied geometric configurations, injection of suspended sediments led to a complete change in the observed flow field. Experimental results were compared with numerical simulations performed with the depth-averaged flow model WOLF 2D, using a depth-averaged k-e turbulence model. The simulations lead to accurate predictions of the velocity profiles and the change in flow pattern as a result of sediment deposits was successfully reproduced. [less ▲]

Detailed reference viewed: 107 (43 ULg)
Full Text
Peer Reviewed
See detailModélisation hydraulique detaillée d’inondations extrêmes sur un tronçon transnational de la Meuse
Dewals, Benjamin ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Evènements extrêmes d’inondation : de l’étude de l’aléa à la gestion du risque pour les ouvrages hydrauliques (2013)

Extreme floods of the river Meuse were simulated based on a detailed 2D unsteady hydraulic model. As part of a coordinated transnational modeling program, the study area considered here extends from ... [more ▼]

Extreme floods of the river Meuse were simulated based on a detailed 2D unsteady hydraulic model. As part of a coordinated transnational modeling program, the study area considered here extends from Ampsin (Belgium) to the Belgian-Dutch border. The results of the present simulations are passed as upstream boundary condition to a second hydraulic model simulating the same flood scenarios in the Meuse in the Netherlands. In the simulations discussed here for the Belgian part of the Meuse, high accuracy and high resolution data were used to represent the main riverbed and the urbanized floodplains. The operation of all influencing mobile dams was represented in the model. The considered flood scenarios include the 100-year flood in the present situation (Q100), as well as two more extreme floods: Q100 + 15 % and Q100 + 30 %. These values correspond to return periods of the order of, respectively 300 and 1000 years in the present climate; but, according to a transnational climate change scenario in the Meuse basin, they may also be considered as estimates of the 100-year flood in 2050 and 2100. The computations have shown a very limited damping of the flood wave in the study area, not exceeding approximately 1 % of the peak discharge for Q100 and Q100 + 15 %, and reaching about 3 % for Q100 + 30 %. Compared to Q100, increases in the flood levels for Q100 + 15 % and Q100 + 30 % are, respectively, in the ranges 0.5-0.9 m and 1.0-1.8 m. Comparisons with the results from previous steady simulations revealed discrepancies not exceeding 5 cm for Q100 and Q100 + 15 %, and reaching a maximum of approximately 30 cm for Q100 + 30 %. Hence, from the perspective of the variation in peak discharge and flood levels, the study concludes that running the hydraulic model in steady mode is reasonable; although some differences occur in terms of inundation extents. The 2D unsteady model constitutes also a tool of primary interest, which is readily available to design and evaluate protection measures for flood-prone areas such as in the city of Liege. [less ▲]

Detailed reference viewed: 58 (3 ULg)
Full Text
Peer Reviewed
See detailDepth-averaged flow modeling in curvilinear coordinates
Stilmant, Frédéric ULg; Egan, Raphael ULg; Archambeau, Pierre ULg et al

Conference (2013)

A set of depth-averaged equations in curvilinear coordinates is presented. This extension of the standard shallow water equations to curved flows and to jet flows leads to a model which is very versatile ... [more ▼]

A set of depth-averaged equations in curvilinear coordinates is presented. This extension of the standard shallow water equations to curved flows and to jet flows leads to a model which is very versatile. Its applicability and precision is assessed by the computation of a discharge coefficient and the nappe profiles for a sharp crested weir. Results confirm the relevance of the approach. Even if not taken into consideration in the set of equations presented here, a discussion shows that head losses could be included in the model so as to extend its application field to many civil and environmental engineering applications. [less ▲]

Detailed reference viewed: 29 (10 ULg)