Publications

2017

• Ocean Wave Rectifier water canal
  
  • Carmigniani Rémi
  , 2017. How to generate currents from water waves? Inspired by nature original way of pumping in the embryonic heart, two wave pumps are studied in the present thesis: the resonance wave pump directly inspired by the Liebau's pump and the waves above a submerged plate pump. The origin of the observed circulation is linked to the wave mass transport term: it corresponds to the amount of mass advected by the waves in the surface layer. The latter is the domain between the crest and the trough of the waves and is a part of the flow that is not always submerged. It is possible to amplify this surface term by resonance and by varying the bathymetry. The latter enables to generate local suction toward the surface layer and leads to mean circulation. The problem is described using a simple potential theory and a dissipative model is proposed to take into account wave dissipation due to friction and wave breaking. The simplified model is compared to experiments and simulations in both cases. It provides a simple framework to predict the pumps behavior: the interesting frequency range and the strength of the flow. It is also a tool for the design of real life applications (10.70675/eaa7c315zbd4bz499ezb196zb9e3cecc7af2)
  DOI : 10.70675/eaa7c315zbd4bz499ezb196zb9e3cecc7af2
• Derivation and numerical approximation of hyperbolic viscoelastic flow systems: Saint-Venant 2D equations for Maxwell fluids
  
  • Boyaval Sébastien
  , 2017. We pursue here the development of models for complex (viscoelastic) fluids in shallow free-surface gravity flows which was initiated by [Bouchut-Boyaval, M3AS (23) 2013] for 1D (translation invariant) cases. The models we propose are hyperbolic quasilinear systems that generalize Saint-Venant shallow-water equations to incompressible Maxwell fluids. The models are compatible with a formulation of the thermo-dynamics second principle. In comparison with Saint-Venant standard shallow-water model, the momentum balance includes extra-stresses associated with an elastic potential energy in addition to a hydrostatic pressure. The extra-stresses are determined by an additional tensor variable solution to a differential equation with various possible time rates. For the numerical evaluation of solutions to Cauchy problems, we also propose explicit schemes discretizing our generalized Saint-Venant systems with Finite-Volume approximations that are entropy-consistent (under a CFL constraint) in addition to satisfy exact (discrete) mass and momentum conservation laws. In comparison with most standard viscoelastic numerical models, our discrete models can be used for any retardation-time values (i.e. in the vanishing " solvent-viscosity " limit). We finally illustrate our hyperbolic viscoelastic flow models numerically using computer simulations in benchmark test cases. On extending to Maxwell fluids some free-shear flow testcases that are standard benchmarks for Newtonian fluids, we first show that our (numerical) models reproduce well the viscoelastic physics, phenomenologically at least, with zero retardation-time. Moreover, with a view to quantitative evaluations, numerical results in the lid-driven cavity testcase show that, in fact, our models can be compared with standard viscoelastic flow models in sheared-flow benchmarks on adequately choosing the physical parameters of our models. Analyzing our models asymptotics should therefore shed new light on the famous High-Weissenberg Number Problem (HWNP), which is a limit for all the existing viscoelastic numerical models.
• A coupled wave–current–sediment transport model for an estuarine system: Application to the Río de la Plata and Montevideo Bay
  
  • Tassi Pablo
  • Santoro Pablo
  • Fossati Mónica
  • Huybrechts Nicolas
  • Pham van Bang Damien
  • Piedra-Cueva J.C. Ismael
  Applied Mathematical Modelling, Elsevier, 2017, 52, pp.107 - 130. (10.1016/j.apm.2017.07.004)
  DOI : 10.1016/j.apm.2017.07.004
• Compréhension et maîtrise des risques d'affouillements: développements récents
  
  • Chevalier Christophe
  • Larrarte Frédérique
  • Larrarte Frédérique
  • Schmidt Franziska
  • Pham van Bang Damien
  • Durand Edouard
  • Gondret Philippe
  • de La Roque Sidoine
  • Cheetham Mark
  • Hosseingholian Mohsen
  , 2017, pp.10p. Les processus d'affouillement sont une cause importante d'instabilité et de destruction des ouvrages (ponts, ouvrages en terre et bâtiments) notamment lors des crues majeures. La prise en compte de ces phénomènes d'érosion reste trop empirique, notamment parce qu'ils sont particulièrement complexes et font intervenir de nombreux champs disciplinaires : mécanique des sols, des fluides, des structures... Dans la perspective de dépasser cet empirisme, de développer les connaissances et finalement d'améliorer les méthodes de diagnostic, d'alerte et de gestion, le projet SSHEAR (« Sols, Structures et Hydraulique : Expertise et Recherche Appliquée ») met en synergie les compétences de 6 partenaires avec le soutien de l'ANR (« Agence Nationale de la Recherche »). Dans cette communication, après une présentation du projet, un premier bilan des résultats obtenus depuis le démarrage en 2015 est proposé : développements expérimentaux, modélisation numérique, observations de terrain.
• Extreme meteo-oceanic events
  
  • Mazas Franck
  , 2017. This PhD on published works aims at unifying the works carried out on the topic of extreme metocean events since 2009, while working for SOGREAH then ARTELIA.As these works went along, a leading theme progressively appeared: the notion of event, such as a storm. This concept provides a sound and relevant framework in particular in the case of multivariate extremes (such as joint probabilities of waves and sea levels), as well as a better understanding of the notion of return period, much used for design in the field of engineering.The main results of the works carried out in the last decade are as follows:- updating of the methodology for determining extreme wave heights or wind speeds:- development and justification of a two-step framework for extreme univariate over-threshold modelling introducing the concept of event and the separation of the physical and statistical thresholds,- proposal of practical tools for choosing the statistical threshold,- introduction of the parametric bootstrap approach for computing confidence intervals,- identification of a problematic issue in the behaviour of the Maximum Likelihood Estimator and proposal of a solution: use of 3-parameter distributions along with the L-moments estimator,- application of the POT framework to the Joint Probability Method for determining extreme sea levels:- distinction between sequential values and event peaks through extremal indexes for surge and sea level,- construction of a mixture model for the surge distribution,- refinements for handling tide-surge dependence,- application of the POT-JPM framework for the joint analysis of wave height and sea level:- proposal of an alternative sampling procedure,- separate analysis of tide and surge in order to model the dependence between wave height and surge to be incorporated in the joint distribution of wave height and sea level thanks to a 2D1D convolution operation,- use of extreme-value copulas,- improved presentation of the chi-plot,- introduction of a new classification for multivariate analyses:- Type A: a single phenomenon described by different physical quantities that are not of the same kind,- Type B: a phenomenon made of different components, described by physical quantities of the same kind between one component and another,- Type C: several phenomena described by physical quantities that are not of the same kind,- interpretation of the meaning of multivariate events:- link with the sampling procedure,- link with the different definitions of the return period,- in the bivariate case: transformation of the joint distribution of event-describing variables into the joint distribution of sequential pairs,- generation of alternative output plots such as contours of density for sequential pairs;- a dedicated R package, artextreme, for implementing the methodologies presented above (10.70675/6096dcf9z641az45bcz8087ze021f8c9ab60)
  DOI : 10.70675/6096dcf9z641az45bcz8087ze021f8c9ab60
• Analysis of the linear version of a highly dispersive potential water wave model using a spectral approach in the vertical
  
  • Benoit Michel
  • Raoult Cécile
  • Yates Marissa L.
  Wave Motion, Elsevier, 2017, 74, pp.159 - 181. h i g h l i g h t s • Highly dispersive potential flow model for water wave propagation. • Linear dispersion relation accurate in very deep water conditions (kh up to 100). • Accurate prediction of wave kinematics (orbital velocities) in deep water. • Validation of linear shoaling properties of the model. • Good prediction of reflected and transmitted waves on a Roseau-type bottom profile. a b s t r a c t The properties and accuracy of the linearized version of the fully dispersive and nonlinear wave model developed in Yates and Benoit (2015) and Raoult et al. (2016) are analyzed for both flat and variable bottom bathymetries. This model considers only a single layer of fluid and uses a basis of orthogonal Chebyshev polynomials to project the vertical structure of the potential. This approach results in an exponential convergence rate with the maximum degree of the Chebyshev polynomial, denoted N T , while only first-and second-order derivatives in space need to be evaluated. For the constant water depth case, the linear dispersion relation of the model is derived analytically, and expressions are established for N T ranging from 2 to 15. The analysis shows a rapid increase in accuracy in the deep water range with increasing N T. For instance, the relative error in the calculated wave celerity (in comparison with Stokes' analytical solution) remains smaller than 2.5% for deep water cases with kh up to 100 using N T ≥ 9 (k and h are the representative wavenumber and water depth, respectively). The wave kinematics, vertical profiles of the horizontal and vertical orbital velocities, converge to the Stokes profiles for kh up to 60 when using a sufficiently high value of N T. The vertically-averaged relative errors of the horizontal and vertical velocities remain below 6% and 3%, respectively, for kh up to 60 when using N T ≥ 11. The presented model shows better dispersive properties in deep water than several high-order Boussinesq-type models. For variable bottom bathymetries, the shoaling properties of the model are studied numerically, exhibiting good agreement with results from Stokes linear theory in the case of mild bottom slopes, using a sufficiently high value of N T with respect to the offshore relative water depth. For an offshore water depth of kh = 10 (i.e. more than 3 times the deep water limit), accurate wave heights in shallow water (kh = 0.25) are obtained with N T = 6 (or higher). Finally, the linear version of the model is validated with comparisons to analytical solutions of the reflection and transmission coefficients of regular waves over Roseau-type bathymetric profiles. Two bottom profiles are considered, including one with a steep slope, whose maximum value reaches about 1:0.7 (i.e. an angle of about 54.9 deg.). Using N T = 7, small differences (<0.4%) with the analytical solution are observed for the four considered cases, confirming the ability of the linear model to represent accurately the effects of steep bottom gradients on wave propagation dynamics. (10.1016/j.wavemoti.2017.07.002)
  DOI : 10.1016/j.wavemoti.2017.07.002
• Three-dimensional numerical modeling of the Bulle effect: the nonlinear distribution of near-bed sediment at fluvial diversions
  
  • Tassi Pablo
  • Dutta Som
  • Wang Dongchen
  • Garcia Marcelo
  Earth Surface Processes and Landforms, Wiley, 2017, 42 (14), pp.2322 - 2337. (10.1002/esp.4186)
  DOI : 10.1002/esp.4186
• Modelling bed-load sediment transport through a granular approach in SPH
  
  • Ghaïtanellis Alex
  , 2017. This thesis presents the development and application of a Smoothed Particle Hydrodynamics (SPH) model to bed-load transport. While state of the art simulation methods commonly rely on a fluid dynamics solver coupled to semi-empirical relationships to model the sediment transport, a completely different approach is investigated in this work. The sediment is treated as a continuum whose behaviour law takes account for its granular nature. citepos{ulrich2013smoothed} elastic-viscoplastic model is thus implemented in an in-house code based on the Cuda language, and improved on physical and numerical aspects. The sediment behaviour depends on a yield stress determined according to Drucker-Prager's criterion. In unyielded regions, the shear stresses are calculated in line with the linear elastic theory. In yielded regions, a shear thinning rheological law is used and the transitions between solid and liquid states are ensured by a blending function driven by the strain rate magnitude and sediment granular properties. Water and sediment are modelled as two immiscible phases in the frame of a multi-phase SPH model with semi-analytical wall boundary conditions cite{ferrand2013unified}. An implicit viscous forces integration scheme is also developed to improve the code performance as for low-Reynolds flows.The multi-phase model, as well as the implicit viscous forces integration scheme, were validated on analytical test cases and good agreement was obtained. The multi-phase formulation has also proven its capability to handle flows involving high density ratio, while the implicit viscous forces integration scheme was successfully applied to the simulation of a non-Newtonian flow. The elastic-viscoplastic model was tested on dry and submerged granular flow problems. The model was able to correctly capture the liquid and solid states of the granular material, as well as the failure and the regime transitions. It was also applied to bed-load transport problems for which a good agreement with the experiment was generally found (10.70675/65cc236dz2dc0z43c3za906z5f19b79145d4)
  DOI : 10.70675/65cc236dz2dc0z43c3za906z5f19b79145d4
• Finite element approximation of the FENE-P model
  
  • Barrett John W
  • Boyaval Sébastien
  IMA Journal of Numerical Analysis, Oxford University Press (OUP), 2017. We extend our analysis on the Oldroyd-B model in Barrett and Boyaval [1] to consider the finite element approximation of the FENE-P system of equations, which models a dilute polymeric fluid, in a bounded domain $D ⊂ R d , d = 2 or 3$, subject to no flow boundary conditions. Our schemes are based on approximating the pressure and the symmetric conforma-tion tensor by either (a) piecewise constants or (b) continuous piecewise linears. In case (a) the velocity field is approximated by continuous piecewise quadratics ($d = 2$) or a reduced version, where the tangential component on each simplicial edge ($d = 2$) or face ($d = 3$) is linear. In case (b) the velocity field is approximated by continuous piecewise quadratics or the mini-element. We show that both of these types of schemes, based on the backward Euler type time discretiza-tion, satisfy a free energy bound, which involves the logarithm of both the conformation tensor and a linear function of its trace, without any constraint on the time step. Furthermore, for our approximation (b) in the presence of an additional dissipative term in the stress equation, the so-called FENE-P model with stress diffusion, we show (subsequence) convergence in the case $d = 2$, as the spatial and temporal discretization parameters tend to zero, towards global-in-time weak solutions of this FENE-P system. Hence, we prove existence of global-in-time weak solutions to the FENE-P model with stress diffusion in two spatial dimensions. (10.1093/imanum/drx061)
  DOI : 10.1093/imanum/drx061
• Global Sensitivity Analysis applied to the Telemac2D numerical forecast model of high water levels in the Gironde estuary
  
  • Laborie Vanessya
  • Goutal Nicole
  • Ricci Sophie
  • de Lozzo Matthias
  • Sergent Philippe
  , 2017, 1. In the context of the development and the implementation of data assimilation techniques in Gironde estuary for flood forecasting, a Telemac 2D model is used to calculate water depths and velocity fields at each node of an unstructured mesh. Upstream, the model boundaries are respectively La Réole and Pessac on the Garonne and Dordogne river. The maritime boundary is 32 km off the mouth of Gironde estuary, located in Verdon. This model, which contains 7351 nodes and 12838 finite elements, does not take into account overflows. It has been calibrated on 4 non-overflowing events and then validated on 6 overflowing events. In a first step, a propagation and quantification of uncertainties by an unidirectional analysis method (creation of a set of 2000 members perturbed for each parameter and input forcings and analysis of output water depths) was carried out on the numerical parameters (wind influence coefficient, Strickler friction coefficients for 4 zones) and forcings of the model (rivers discharges and maritime boundary conditions, meteorological forcings). The objective is to determine the variation coefficient of water depths for 13 major events between 1981 and 2016. The exploitation of 1981 event results shows a predominance of the influence of the maritime boundary conditions and the Strickler coefficient for the estuarine part and the confluence, to which must be added the Garonne discharge as a predominant parameter for the latter. Unsurprisingly, river zones are influenced primarily by the coefficient of friction and the respective river flows of Garonne and Dordogne rivers. On the second hand, a Global Sensitivity Analysis (GSA) by variance analysis (ANOVA) was carried out, by calculating the total and partial Sobol’ indices, integrating the time- and/or space dependent forcing variables. It has led to the identification of parameters and forcings to which the model is most sensitive, as well as their inter-dependencies, in order to choose the variables to assimilate. The GSA shows that the tidal signal imposed at the maritime boundary condition and provided by a more extended surge levels model is the key input variable. Moving from the mouth to the upstream part of the Garonne and Dordogne rivers, the influence of the friction coefficient increases and hydrological forcings have a very local influence upstream the rivers.
• Influence of timescales on the generation of seismic tsunamis
  
  • Le Gal Marine
  • Violeau Damien
  • Benoit Michel
  European Journal of Mechanics - B/Fluids, Elsevier, 2017, 65, pp.257 - 273. (10.1016/j.euromechflu.2017.03.008)
  DOI : 10.1016/j.euromechflu.2017.03.008
• A Reduced-Basis Approach to Two-Phase Flow in Porous Media
  
  • Tran Quang Huy
  • Enchéry Guillaume
  • Sanchez Riad
  • Boyaval Sébastien
  , 2017. Reduced-basis methods (RB) have demonstrated their efficiency for a wide variety of problems, most of which are elliptic PDEs solved by finite element methods. In this work, we attempt to apply the RB philosophy to a simple “real-life” model for two-phase flows in porous media, whose reference scheme is a finite volume method. This model is parameterized by the viscosity of water. Because of the mixed parabolic-elliptic nature of the system, we first propose to restrict the RB approach to the pressure subsystem corresponding to the end time. The resulting parametric dependence is, however, much more intricate than in the classical examples. This difficulty will be discussed and illustrated by numerical results. (10.1007/978-3-319-57394-6_50)
  DOI : 10.1007/978-3-319-57394-6_50
• Uncertainty quantification in hydrodynamics bidimensional models : the case of Gironde estuary forecast model
  
  • Laborie Vanessya
  • Goutal Nicole
  • Ricci Sophie
  • Sergent Philippe
  , 2017, 19, pp.2017 - 312. In the context of the development and the implementation of data assimilation techniques in Gironde estuary for flood forecasting, a Telemac 2D model is used to calculate water depths and velocity fields at each node of an unstructured mesh. Upstream, the model boundaries are respectively La Réole and Pessac on the Garonne and Dordogne river. The maritime boundary is 32 km off the mouth of Gironde estuary, located in Verdon. This model, which contains 7351 nodes and 12838 finite elements, does not take into account overflows. It has been calibrated on 4 non-overflowing events and then validated on 6 overflowing events. In a first step, a mesh convergence study was carried out in order to evaluate the error related to the spatial discretization and to determine the mesh allowing to obtain results "independent" of it. Three additional meshes obtained by dividing the number of finite elements at each refinement by 4 were realized and used to simulate the event of 2003. It appears that a mesh of intermediate size (approximately 27000 nodes) seems required. In a second step, propagation and quantification of uncertainties by an unidirectional analysis method (creation of a set of 2000 members perturbed for each parameter and input forcings and analysis of output water depths) was carried out on the numerical parameters (wind influence coefficient, Strickler friction coefficients for 4 zones) and forcings of the model (rivers discharges and maritime boundary conditions, meteorological forcings). The objective is to determine the variation coefficient (if possible standardized by the input variation coefficient) of water depths for 13 major events between 1981 and 2016. The exploitation of 1981 event results shows a predominance of the influence of the maritime boundary conditions and the Strickler coefficient corresponding to the zone studied for the estuarine part and the confluence, to which must be added the Garonne discharge as a predominant parameter for the latter. Unsurprisingly, river zones are influenced primarily by the coefficient of friction and the respective river flows of Garonne and Dordogne rivers. The non-normalized variation coefficients were also calculated by taking into account the time shift of the maritime input signal and, independently, the Arpege Ensemble Predictions provided by METEO-FRANCE. The relative influence of the phase shift and the PEARP has also been determined. On the second hand, a variance sensitivity study (ANOVA) was carried out, by calculating the total and partial Sobol indices, integrating the forcing variables time-and/or space dependent. It has led to the identification of parameters and forcings to which the model is most sensitive, as well as their inter-dependencies, in order to choose the variables to assimilate. Finally, it should be noted that this work has already made it possible to create a database of multi-temporal simulations (over 13 time periods) on Gironde estuary that can, after formatting, feed the SWOT simulator for Gironde Estuary, which is used to prepare the Franco-American mission for the study of ocean and continental water depths .
• Effect of Sediment Transport Boundary Conditions on the Numerical Modeling of Bed Morphodynamics
  
  • Tassi Pablo
  • Mendoza Alejandro
  • Abad Jorge
  • Langendoen Eddy
  • Wang Dongchen
  • Abderrezzak Kamal El Kadi
  Journal of Hydraulic Engineering, American Society of Civil Engineers, 2017, 143 (4). (10.1061/(ASCE)HY.1943-7900.0001208)
  DOI : 10.1061/(ASCE)HY.1943-7900.0001208
• Overtopping induced failure of noncohesive, homogeneous fluvial dikes
  
  • Rifai Ismail
  • Erpicum Sébastien
  • Archambeau Pierre
  • Violeau Damien
  • Pirotton Michel
  • El Kadi Abderrezzak Kamal
  • Dewals Benjamin J.
  Water Resources Research, American Geophysical Union, 2017, 53 (4), pp.3373 - 3386. (10.1002/2016WR020053)
  DOI : 10.1002/2016WR020053
• Theoretical and numerical study of seismic tsunami dynamics
  
  • Le Gal Marine
  , 2017. The impact of tsunamis on mankind is well known. During recent years, several events showed us the disasters they can trigger which reiterate the importance of understanding their dynamics. Due to the lack of in-situ data, the generation is the least known aspect of tsunamis. As a result, simplified models of the source are used for numerical tsunami modeling, as for seismic generation for which the traditional approach neglects several phenomena, among which is the kinematic deformation of the sea floor. This motion canbe characterized by two temporal parameters: the rupture velocity vp and a hydraulic rise time tr. The novelty here, is to investigate both parameters simultaneously and to extend the linear theoretical development to a non-linear numerical study. From these works, a resonance zone is identified for small tr and vp close to the long wave celerity. For these particular values, the waves are amplified beside the sea floor deformation and dispersive effects develop. To illustrate this theory, the 1947 New Zealand tsunami is simulatedwith the Non-Linear Shallow Water and Boussinesq models of Telemac2D. This seismic event corresponds to a tsunami earthquake with slow kinematics of deformation. Four generation models, with different values of vp and tr are compared. The impact of vp on the generated wave amplitudes is strong whereas the influence due to tr is significantly smaller. Additionally, it was found that the expected dispersive effects did not develop during the numerical modeling. Meanwhile, in the scope of the TANDEM project, the validation of the Telemac system is performed through test cases, covering: generation, propagation and run-up of tsunamis. Globally, the models from the Telemac system match the validation data, however we note a reliance on numerical parameters for sensitive cases as the propagation of a solitary wave. Finally, the Non-Linear Shallow Water model of Telemac2D is used to simulate the Tohoku-Oki tsunami that hit Japan in 2011. Thenumerical model succeeds in representing this real event incorporating all the stages of tsunami life, from generation to flooded areas. Some limitations in using the method were found, which one discussed in detail within the present manuscript (10.70675/0d5ad289zcd01z41b8za512z92e959d68345)
  DOI : 10.70675/0d5ad289zcd01z41b8za512z92e959d68345
• Resonance wave pumping with surface waves
  
  • Carmigniani Rémi Arthur
  • Benoit Michel
  • Violeau Damien
  • Gharib Morteza
  Journal of Fluid Mechanics, Cambridge University Press (CUP), 2017, 811, pp.1 - 36. (10.1017/jfm.2016.720)
  DOI : 10.1017/jfm.2016.720
• Pressure and velocity on an ogee spillway crest operating at high head ratio: Experimental measurements and validation
  
  • Peltier Yann
  • Dewals Benjamin
  • Archambeau Pierre
  • Pirotton Michel
  • Erpicum Sebastien
  Journal of Hydro-environment Research, Elsevier, 2017. (10.1016/j.jher.2017.03.002)
  DOI : 10.1016/j.jher.2017.03.002
• Intermittent large amplitude internal waves observed in Port Susan, Puget Sound
  
  • Harris J. C.
  • Decker L.
  Estuarine, Coastal and Shelf Science, Elsevier, 2017, 194, pp.143-149. (10.1016/j.ecss.2017.04.022)
  DOI : 10.1016/j.ecss.2017.04.022
• Mixing layer and coherent structures in compound channel flows: Effects of transverse flow, velocity ratio, and vertical confinement
  
  • Proust Sébastien
  • Fernandes Joao N.
  • Leal Joao B.
  • Rivière Nicolas
  • Peltier Yann
  Water Resources Research, American Geophysical Union, 2017, 53 (4), pp.3387-3406. no abstract (10.1002/2016WR019873)
  DOI : 10.1002/2016WR019873
• Residual distribution advection schemes in Telemac
  
  • Hervouet Jean-Michel
  • Pavan Sara
  • Ricchiuto Mario
  , 2017, pp.70. This report gives an overview of the different implementations of residual distribution schemes for the advection equation in Telemac (www.opentelemac.org). The formulations considered are obtained starting from the predictor-corrector method initially proposed in (Ricchiuto et Abgrall, JCP 2010). Several iteration techniques (NERD, LIPS and ERIA) are proposed and tested in terms of accuracy and efficiency. The basic idea of NERD is a transfer of fluxes done segment by segment, surprisingly this results in an unconditional stability. LIPS is based upon a local implicitation coefficient, ERIA inspires from NERD and treats the fluxes triangle by triangle. The main advances are the low numerical diffusion coupled with an unconditional stability that allows to deal with shallow or even dry zones in a computational domain.
• Discussion of “Laboratory Study on 3D Flow Structures Induced by Zero-Height Side Weir and Implications for 1D Modeling” by Giovanni Michelazzo, Hocine Oumeraci, and Enio Paris
  
  • Rifai I.
  • Erpicum S.
  • Archambeau P.
  • Violeau D.
  • Pirotton M.
  • Abderrezzak K. El Kadi
  • Dewals B.
  Journal of Hydraulic Engineering, American Society of Civil Engineers, 2017, 143 (3), pp.07016010. (10.1061/(asce)hy.1943-7900.0001256)
  DOI : 10.1061/(asce)hy.1943-7900.0001256
• Equilibrium modeling of the Beach Profile on a Macrotidal Embayed Beach
  
  • Lemos Clara
  • Floc'H France
  • Yates Marissa L.
  • Le Dantec Nicolas
  • Marieu Vincent
  • Hamon Klervi
  • Cuq Véronique
  • Suanez Serge S.
  • Delacourt Christophe
  , 2017 (No. 057), pp.pp. 760-771. Predicting the pluriannual variability of shoreline position in response to hydrodynamic forcing (waves and tides) is of primordial interest scientists, engineers, and beach managers. 11-year time series of monthly profile beach survey and hourly incident wave conditions are analyzed on a macrotidal sandy embayed beach in Brittany (France). An equilibrium model is applied to study the variation of the beach profile position over the whole intertidal zone as a function of the energy wave, wave power and water level. The predictive ability of the equilibrium model is around 60% in the upper intertidal zone but decreases with decreasing elevation in the lower intertidal zone. The predicted result on the lower part taking into account of the still water level is not improved, but the erosion and accretion parameters are more reliable, according to the physical processes and could be compared to other study sites.
• 2D Versus 1D Models for Shallow Water Equations
  
  • Vila Jean-Paul
  • Chazel Florent
  • Noble Pascal
  Procedia IUTAM, Elsevier, 2017, 20, pp.167 - 174. In this paper we present a general framework to construct 1D width averaged models when the flow is constrained-e.g. by topography-to be almost 1D. We start from two dimensional shallow water equations, perform an asymptotic expansion of the fluid elevation and velocity field in the spirit of wave diffusive equations and establish a set of 1D equations made of a mass, momentum and energy equations which are close to the one usually used in hydraulic engineering. We show that in some special cases, like the U-shaped river bed, that our set of equations reduces to the classical 1d shallow water equations. Out of these configurations, there is an O (1) deviation of our model from the classical one. (10.1016/j.piutam.2017.03.023)
  DOI : 10.1016/j.piutam.2017.03.023
• Le rôle de l’hydrologie sur la destruction de la végétation dans le lit d’une rivière à galets aménagée : l’Isère en Combe de Savoie
  
  • Jourdain Camille
  • Belleudy Philippe
  • Tal Michal
  • Malavoi Jean-René
  Géomorphologie : relief, processus, environnement, Groupe français de géomorphologie (GFG) / Société d'Études pour le Développement Économique et Social (Sedes), 2017, 23 (3), pp.203-217. (10.4000/geomorphologie.11761)
  DOI : 10.4000/geomorphologie.11761