References of "Erpicum, Sébastien"
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See detailInfluence of the alveoli slopes on the discharge capacity of Piano Key Weirs
Machiels, Olivier ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Proceedings of the 34th IAHR world congress (2011)

Piano Key Weir is a cost effective solution for rehabilitation as well as for new dam project with a high level of constraints (space, flood discharge, reservoir level).If the efficiency of the Piano Key ... [more ▼]

Piano Key Weir is a cost effective solution for rehabilitation as well as for new dam project with a high level of constraints (space, flood discharge, reservoir level).If the efficiency of the Piano Key Weir has already been well demonstrated, the definition of its optimal geometry has been still poorly approached. In order to improve the design of the complex geometry of this structure, the study of the influence of the mean geometrical parameters on the discharge capacity is an essential stage. Following a former experimental study of the flow over Piano Key Weirs, highlighting the mean influence of three geometrical parameters, this paper presents the results of an experimental parametric study. These results highlight the influence of the alveoli bottom slopes on the Piano Key Weir release capacity. Comparisons with numerical and analytical results, as well as design advices are also provided. [less ▲]

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See detailVarying the alveoli slopes of Piano key Weirs: Interests and limitations
Machiels, Olivier ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Pina, C.; Portela, E.; Gomes, J. (Eds.) Proceedings of the 6th International conference on dam engineering (2011)

Piano Key Weir is a cost effective solution for rehabilitation as well as for new dam project with a high level of constraints (space, flood discharge, reservoir level). Its labyrinth shape permits the ... [more ▼]

Piano Key Weir is a cost effective solution for rehabilitation as well as for new dam project with a high level of constraints (space, flood discharge, reservoir level). Its labyrinth shape permits the evacuation of discharges till four times more important than ogee-crested weirs with the same length at the dam crest, when the use of overhangs permits the building of the auto-equilibrated structure directly on dam crest. If the efficiency of the Piano Key Weir has already been well demonstrated, the definition of its optimal geometry has been still poorly approached. In order to improve the design of the complex geometry of this structure, the study of the influence of the mean geometrical parameters on the discharge capacity is an essential stage. Following a former experimental study of the flow over Piano Key Weirs, highlighting the mean influence of three geometrical parameters, this paper presents the results of an experimental parametric study. These results highlight the influence of the alveoli bottom slopes on the Piano Key Weir release capacity. In this paper, the interests and limitations of the variation of the slopes are explained. Recommendations directly linked to the observation of the experimental models are also provided to improve the design of PKW. [less ▲]

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See detailAn exact Riemann Solver and Godunov Scheme for Simulating Highly Transient Mixed Flows
Kerger, François ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Journal of Computational & Applied Mathematics (2011), 235

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See detailCaractérisation micro-échelle du risque d’inondation : modélisation hydraulique détaillée et quantification des impacts socio-économiques
Dewals, Benjamin ULg; Detrembleur, Sylvain ULg; Archambeau, Pierre ULg et al

in Houille Blanche (2011), (2), 28-34

The paper presents a consistent micro-scale flood risk analysis procedure, relying on detailed 2D inundation modelling as well as on high resolution topographic and land use database. The flow model is ... [more ▼]

The paper presents a consistent micro-scale flood risk analysis procedure, relying on detailed 2D inundation modelling as well as on high resolution topographic and land use database. The flow model is based on the shallow-water equations, solved by means of a finite volume scheme on multiblock structured grids. Using highly accurate laser altimetry, the simulations are performed with a typical grid spacing of 2m, which is fine enough to represent the flow at the scale of individual buildings. The methodology is first described, both in terms of hydraulic modelling and evaluation of people and assets vulnerability. The analysis scale of the procedure enables its development following an object-oriented approach. Finally, the applicability of the procedure is demonstrated through a case study for which three different protection measures are evaluated. Detailed analysis of these measures highlights significantly different influences from those measures on the risk curves. [less ▲]

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See detailResearch axes and conclusions
Erpicum, Sébastien ULg; Boillat, Jean Louis

in Erpicum, Sébastien; Laugier, Frederic; Boillat, Jean Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

The aim of this short paper is to summarize main outcomes of the workshop, in order to guide future developments of research on Piano Key Weirs (PKW) towards most effective and integrated directions. The ... [more ▼]

The aim of this short paper is to summarize main outcomes of the workshop, in order to guide future developments of research on Piano Key Weirs (PKW) towards most effective and integrated directions. The main research topics highlighted in this text came out from the 34 high-quality presentations given during the conference, as well as from the fruitful discussions in which the participants were actively involved. Many more truly innovative and promising ideas can be found throughout the other papers gathered in this proceedings book. [less ▲]

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See detailCreation of a PKW Database - Discussion
Boillat, Jean Louis; Leite Ribeiro, Marcelo; Pralong, Julien et al

in Erpicum, Sébastien; Laugier, Frederic; Boillat, Jean Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

Piano Key Weir description involves a lot of geometrical parameters which designations are now well defined. A naming convention has been developed to enhance exchanges and cooperation between the ... [more ▼]

Piano Key Weir description involves a lot of geometrical parameters which designations are now well defined. A naming convention has been developed to enhance exchanges and cooperation between the numerous developers. This nomenclature was presented and discussed during the workshop and the updated version is included in the present proceedings (Pralong et al., pp. 277-284). In order to make easier the access to experimental or field data from different sources, a Database is required. This document relates the proposal which was presented and discussed during the workshop. The carrying out of this Database is expected in a near future. [less ▲]

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See detailPiano Key Weir design study at Raviege dam
Erpicum, Sébastien ULg; Nagel, Véronique; Laugier, Frederic

in Erpicum, Sébastien; Laugier, Frederic; Boillat, Jean-Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

The 40-m high Raviege dam, built in 1957 and operated by Electricité de France (EDF), is located in South West of France, on the Agout River. The discharge capacity of the two existing gated spillways ... [more ▼]

The 40-m high Raviege dam, built in 1957 and operated by Electricité de France (EDF), is located in South West of France, on the Agout River. The discharge capacity of the two existing gated spillways located in the center of the dam is not sufficient regarding the updated design flood. One of the solutions studied is a project combining the use of the reservoir storage capacity and a new Piano Key Weir spillway on top of the dam, beside the existing gates, aims to increase the dam safety towards floods. Scale model tests have been carried out at the Laboratory of Engineering Hydraulics of the University of Liege to optimize the PKW design and precisely characterize its discharge capacity. The scale model study also focused on the design of energy dissipation structures downstream of the PKW. This rehabilitation project is depicted in the paper, with focus on the PKW design. [less ▲]

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See detailEnergy dissipation on a stepped spillway downstream of a Piano Key Weir - Experimental study
Erpicum, Sébastien ULg; Daux, Christophe; Machiels, Olivier ULg et al

in Erpicum, Sébastien; Laugier, Frederic; Boillat, Jean Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

Piano Key Weir (PKW) is a new type of weir showing appealing hydraulic capacities. Its specific geometric features create different interacting flows and jets downstream of the structure. This suggests ... [more ▼]

Piano Key Weir (PKW) is a new type of weir showing appealing hydraulic capacities. Its specific geometric features create different interacting flows and jets downstream of the structure. This suggests that the use of a PKW to control the flow upstream of a stepped spillway may help in enhancing energy dissipation on the downstream channel. The first results of an experimental study carried out at the Laboratory of Engineering Hydraulics – HACH in the scope of a Coyne & Bellier – Tractebel Engineering project are presented in the paper. The goal of the study was to compare the energy dissipation on a stepped spillway downstream of a PKW with the one which takes place on the same spillway equipped with a standard ogee-crested weir. Despite similar global energy dissipation rates whatever the weir type due to the relative important height of the spillway, significant differences in the aeration of the flow along the spillway have been shown. This paves the way to further investigations. [less ▲]

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See detailPiano Key Weir preliminary design method – Application to a new dam project
Machiels, Olivier ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Erpicum, Sébastien; Laugier, Frederic; Boillat, Jean Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

Within the framework of development of PKW use for rehabilitation as well as for new dam projects, the development of efficient design methods is essential. Currently, the design of PKW projects is done ... [more ▼]

Within the framework of development of PKW use for rehabilitation as well as for new dam projects, the development of efficient design methods is essential. Currently, the design of PKW projects is done by mean of scale modeling, on the basis of a geometry initially designed based on the general knowledge issued from idealized experimental studies and former PKW buildings. This paper presents a systematic method for PKW preliminary design. The method is based on extrapolation of existing experimental results to develop one or several available project designs, regarding the project constraints (discharge, reservoir levels, available space, …). The model permits then the optimization of the design depending on technical and economical interests (increase of the safety, decrease of the maximal head, limiting the weir dimensions, limiting construction costs, …). The application of the method to a new large dam project is presented, highlighting the interest of the method for the optimization of the design depending on technical and economical interests. [less ▲]

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See detailInfluence of the PKW height on its discharge capacity
Machiels, Olivier ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Erpicum, Sébastien; Laugier, Frédéric; Boillat, Jean Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

Within the framework of Piano Key Weir (PKW) development, the hydraulic optimization of its geometry seems essential. First systematic studies of all the geometrical parameters of the PKW highlight a more ... [more ▼]

Within the framework of Piano Key Weir (PKW) development, the hydraulic optimization of its geometry seems essential. First systematic studies of all the geometrical parameters of the PKW highlight a more important influence of some parameters compared to other ones. A former study led, at the University of Liege, on a large scale model of PKW highlights the main influence of the inlet cross section on the global discharge capacity of the weir. Based on this finding, the geometrical parameters influencing the inlet cross section seem to be the most influential parameters of the weir efficiency. This paper presents results of an experimental study using models of PKW with varying height. The mean non-dimensional parameters characterizing the geometry of the models are maintained constant, only varying the slope of the alveoli. The results of the 7 models studied, with a wide range of slopes (height over length) from 0.25 to 1.5, are presented. Based on these results, an analytical formulation of the unit discharge over a PKW as a function of its height is developed. [less ▲]

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See detailEfficient hydraulic numerical modeling with multiblock grids and linked models
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Houille Blanche (2011), 3

In the field of numerical hydraulic engineering, the size of the simulations is one of the current challenges to consider with sufficient precision the large areas involved by practical applications. In ... [more ▼]

In the field of numerical hydraulic engineering, the size of the simulations is one of the current challenges to consider with sufficient precision the large areas involved by practical applications. In this scope, the linking in the same computational domain of different solvers, each one used in the part of the simulation where its characteristics are most suitable, opens the door to huge modeling possibilities. Such optimized hydraulic numerical modeling is presented in this paper with a multiblock multimodel 2D solver and its linking to a 1D model. After a description of the solvers, with emphasis on the linking procedures, theoretical test cases and real applications are presented. [less ▲]

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See detailWOLF 1D PKW - 1D numerical model of the flow over a piano key weir
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

Software (2011)

The Piano Key Weir (PKW) is a new type of free weir, similar to a labyrinth weir, showing appealing performance to release high discharges under limited head levels in the upstream reservoir. Because of ... [more ▼]

The Piano Key Weir (PKW) is a new type of free weir, similar to a labyrinth weir, showing appealing performance to release high discharges under limited head levels in the upstream reservoir. Because of the PKW geometric specificities, its hydraulic capacity remains difficult to predict without using experimental techniques. Wolf1D PKW numerical model has been developed at the Research Unit HACH at the University of Liege to model the flow over a PKW. It is based on a 1D modelling of the PKW main elements separately (the inlet and the outlet), with a single upstream reservoir and interactions between both flows by exchange of mass and momentum along the lateral crest. [less ▲]

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See detailA naming convention for the Piano Key Weirs geometrical parameters
Pralong, Julien; Vermeulen, Julien; Blancher, Benoit et al

in Erpicum, Sébastien; Laugier, Frédérique; Boillat, Jean-Louis (Eds.) et al Labyrinth and Piano Key Weirs - PKW 2011 (2011)

Flood management is more than ever an issue for dam designers and engineering consulting firms in charge of rehabilitation works. Piano Key Weirs are a new cost-effective type of spillway designed to ... [more ▼]

Flood management is more than ever an issue for dam designers and engineering consulting firms in charge of rehabilitation works. Piano Key Weirs are a new cost-effective type of spillway designed to improve dams discharge capacity. These structures are particularly attractive: they can easily be built on existing structures and enable very high discharge capacities. Therefore, Piano Key Weirs are nowadays studied worldwide. Piano Key Weir description involves a lot of geometrical parameters (more than 30), which designations are not already universally defined. A naming convention is required to enhance exchanges and cooperation between the numerous developers. A naming convention has been developed at EDF – Hydro Engineering Center in cooperation with the Laboratory of Hydraulic Constructions (LCH), Ecole Polytechnique Fédérale de Lausanne and the Laboratory of Hydrology, Applied Hydrodynamics and Hydraulic Constructions (HACH), University of Liege. This paper describes the proposed naming convention and gives definitions and notations of the various geometrical parameters. This work represents a first attempt which should be updated with the contribution of stakeholders involved in this topic. [less ▲]

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See detailLabyrinth and Piano Key Weirs - PKW 2011
Erpicum, Sébastien ULg; Laugier, Frédéric; Boillat, Jean Louis et al

Book published by CRC Press/Balkema (2011)

The Piano Key Weir (PKW) is a weir of particular geometry, associating to a labyrinth shape the use of overhangs to reduce the basis length. The PKW can thus be directly placed on a dam crest. Together ... [more ▼]

The Piano Key Weir (PKW) is a weir of particular geometry, associating to a labyrinth shape the use of overhangs to reduce the basis length. The PKW can thus be directly placed on a dam crest. Together with its important discharge capacity for low heads (several times the one of a linear Creager weir), this geometric feature makes the PKW an interesting solution for dams rehabilitation as well as new constructions. However, PKW constitutes a new type of weir, firstly designed in 2001 and built for the first time in 2006 by EDF. With several researches and projects on PKW all over the world, the workshop about Labyrinth and Piano Key Weirs aimed at bringing together all the people (engineers, researchers,...) interested to state and summarize the current knowledge on this still non conventional hydraulic structure. The main themes tackled during the conference concern followings: • Physical Modeling. Hydraulic capacity • Physical Modeling. Downstream fittings • Numerical Modeling • Hydraulic Design • Planned and achieved projects • Nomenclature, Database, Future developments The papers reviewed and accepted by an International Scientific Committee and presented during the workshop sessions are published in the present book which constitutes a reference on the subject. [less ▲]

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See detailOn the Assessment of a Modified Diffusion-Wave Approximation Model in the Framework of Overland Flow
Paulus, Raphaël ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Chanson, Hubert (Ed.) Balance and Uncertainty: Water in a Changing World (2011)

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See detailHandling of the 3D Behaviour of the Unsaturated Layer using a Vertical 1D Model for the Richards Equation along with Diffusive Horizontal Fluxes
Paulus, Raphaël ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Chanson, Hubert (Ed.) Balance and Uncertainty: Water in a Changing World (2011)

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See detailFailure of dams arranged in series or in complex
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Detrembleur, Sylvain ULg et al

in Natural Hazards (2011), 56(3), 917-939

A practical methodology has been developed for predicting flows generated by dam failures or malfunctions in a complex or a series of dams. A twofold approach is followed. First, the waves induced in the ... [more ▼]

A practical methodology has been developed for predicting flows generated by dam failures or malfunctions in a complex or a series of dams. A twofold approach is followed. First, the waves induced in the downstream reservoirs are computed, as well as hydrodynamic impacts induced on downstream dams and dikes are estimated. Second, the flood wave propagation and the inundation process are simulated in the downstream valley, accounting for possible dam collapse or breaching in cascade. Two complementary flow models are combined: a two-dimensional fully dynamic model and a simplified lumped model. At each stage, the methodology provides guidelines to select the most appropriate model for efficiently computing the induced flows. Both models handle parametric modeling of gradual dam breaching. The procedure also incorporates prediction of breach formation time and final width, as well as sensitivity analysis to compensate for the high uncertainties remaining in the estimation of breach parameters. The applicability of the modeling procedure is demonstrated for a case study involving a 70m-high gravity concrete dam located upstream of four other dams. [less ▲]

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See detailIncorporating climate change scenarios into new operating rules for large reservoirs: a transnational assessment in the Meuse basin
Dewals, Benjamin ULg; Detrembleur, Sylvain ULg; Archambeau, Pierre ULg et al

in Schleiss, Anton (Ed.) Dams and Reservoirs under changing Challenges (2011)

Opportunities for updating and optimizing current operating rules are being evaluated for the Vesdre reservoirs in Belgium (50 M m³) and the Rur complex in Germany (300 M m³). This assessment is conducted ... [more ▼]

Opportunities for updating and optimizing current operating rules are being evaluated for the Vesdre reservoirs in Belgium (50 M m³) and the Rur complex in Germany (300 M m³). This assessment is conducted transnationally at the scale of the Meuse river basin. Common methodological approaches are followed in both countries and operating rules are analyzed in light of common climate change scenarios, recently defined for the whole Meuse basin. Similar risk-based approaches are used consistently in both countries to evaluate the performance of new operating rules in terms of risk reduction for floods and low flows. [less ▲]

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See detailBlood Flow under External Strains; Phenomenological Approach, Theoretical Developments & Numerical Analysis
Paulus, Raphaël ULg; Erpicum, Sébastien ULg; Dewals, Benjamin ULg et al

in International Journal of Design & Nature and Ecodynamics (2010), 78

In the medical field, the measurement of blood flow characteristics is often necessary. More specifically, blood pressure is an essential measure when it comes to assessing health. All over the world ... [more ▼]

In the medical field, the measurement of blood flow characteristics is often necessary. More specifically, blood pressure is an essential measure when it comes to assessing health. All over the world, many people suffer from hyper- or hypotension, and as it is known that these diseases can lead to serious complications, it is of great interest to determine the blood pressure with high accuracy. Nowadays, such information requires the use of specifi c materials; the present method for the measurement of the arterial pressure, by applying pressure using an armband (with a control device called sphygmomanometer), is known to introduce significant errors due to the inadequacy of the band dimensions (both the length and the circumference). The objective of the present research is to study and simulate the discharge of the blood in an artery subjected to external strains using theoretical developments and a numerical approach. Based on these modelling results, the response of the fluid to the external pressure of the band can be studied, and fi nally appropriate corrective factors for the true pressure and the measured pressure could be assessed. This research has been carried out with the aim of sharing medical and engineering views on the subject. The artery can be modelled as a deformable pipe, where the blood fl owing in it is a fl uid with specifi c properties. Thus, two complementary and interconnected domains are covered, solid mechanics (to obtain analytic relations between the strains and the deformations, using either linear or non-linear theories) and fluid mechanics (to study the discharge of blood in a deformable pipe, using finite volume methods), therefore considering the problem as a loose fl uid–structure interaction (FSI). These two domains, which are well studied for common materials in civil engineering applications, are applied here not only to specifi c materials but especially to uncommon structures that, besides the somehow common FSI developments, lead to the investigation and research of very specifi c boundary conditions, giving them a physically based behaviour. At present, the research has reached the penultimate step, with the two main mentioned axes being fully developed and tested on their own. In particular, the boundary conditions developed for the models have been investigated and modelled in depth. [less ▲]

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See detailModélisation numérique 2D unifiée des écoulements sur des évacuateurs de crue avec déversoir
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Houille Blanche (2010), (6), 102-108

The hydrodynamic modelling system WOLF 2D enables to combine different hydrodynamic sub-models within one single computation domain. For instance, for the purpose of simulating flows in the vicinity of ... [more ▼]

The hydrodynamic modelling system WOLF 2D enables to combine different hydrodynamic sub-models within one single computation domain. For instance, for the purpose of simulating flows in the vicinity of spillways, the following three hydrodynamic sub-models are interconnected: (i) a conventional “shallow-water” model, (ii) a suitable model for the simulation of the flow on the topographic step directly upstream of the spillway and (iii) a model able to accurately account for the bottom curvature near the spillway crest, along the spillway and at its bottom. In the latter model, based on curvilinear coordinates in the vertical plane, takes into consideration not only the bottom slope but also the bottom curvature in the vertical plane. As a result, the velocity profile along the water depth is generalized compared to the uniform profile usually assumed in the standard shallow-water equations and the pressure distribution is also modified as a function of the bottom curvature and is thus not purely hydrostatic but accounts for the effect of centrifugal forces. This extended mathematical model has been implemented within the modelling system WOLF 2D, based on a new finite volume scheme. Several validation examples and a real application demonstrate the accuracy and the practical applicability of the new model. [less ▲]

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