Publications

2022

• Étude physique des courses de natation
  
  • Prétot Charlie
  , 2022. L’objectif est de mieux comprendre la physique des différentes phases d’une course de natation. Nous séparons le bassin en deux zones : les zones proches du bord, où il est toléré d’être complètement immergé, et les zones au centre du bassin où le nageur doit se situer à l’interface. La première partie porte sur les phases nagées. Après une étude des résistances et de la force de propulsion, nous donnons un modèle pour la relation fréquence-vitesse pour les nages avec retour aérien, extensible aux sports à rame comme le kayak. La seconde partie porte sur les phases non nagées : le départ et les virages. Nous analysons les différentes phases du départ : poussée sur le plot, vol, phase aquatique passive, ondulations et nage à la surface. A la suite à cette analyse distincte, nous cherchons à optimiser la trajectoire de départ complète en fonction des paramètres individuels de chaque athlète. Le même travail est conduit pour les virages.
• About the structural stability of Maxwell fluids: convergence toward elastodynamics
  
  • Boyaval Sébastien
  , 2022. Maxwell's models for viscoelastic flows are famous for their potential to unify elastic motions of solids with viscous motions of liquids in the continuum mechanics perspective. But rigorous proofs are lacking. The present note is a contribution toward well-defined viscoelastic flows proved to encompass both solid and (liquid) fluid regimes. In a first part, we consider the structural stability of particular viscoelastic flows: 1D shear waves solutions to damped wave equations. We show the convergence toward purely elastic 1D shear waves solutions to standard wave equations, as the relaxation time λ and the viscosity µ grow unboundedly λ ≡ µ/G → ∞ in Maxwell's constitutive equation λ τ +τ = 2 µD(u) for the stress τ of viscoelastic fluids with velocity u. In a second part, we consider the structural stability of general multi-dimensional viscoelastic flows. To that aim, we embed Maxwell’s constitutive equation in a symmetric-hyperbolic system of PDEs which we proposed in our previous publication [ESAIM:M2AN 55 (2021) 807-831] so as to define multi-dimensional viscoelastic flows unequivocally. Next, we show the continuous dependence of multi-dimensional viscoelastic flows on λ ≡ μ/ G using the relative-entropy tool developped for symmetric-hyperbolic systems after C. M. Dafermos. It implies convergence of the viscoelastic flows defined in [ESAIM:M2AN 55 (2021) 807-831] toward compressible neo-Hookean elastodynamics when λ → ∞.
• Étude des processus de submersion de protections côtières par les vagues pour des états de mer complexes
  
  • Villefer Antoine
  , 2022. Près des côtes, dans des conditions de tempête, il est courant d'observer un état de mer bimodal combinant un clapot, caractérisé par des vagues courtes générées localement par le vent, et une houle, caractérisée par des vagues longues générées par des vents lointains en haute mer. Pour dimensionner les protections côtières, la méthodologie actuelle (e.g. guide EurOtop 2018) suggère d'estimer le débit de franchissements pour un état de mer bimodal à l'aide d'un seul jeu de hauteur, période et direction de vagues. Le premier objectif de cette thèse est d'étudier la croissance du clapot en présence d'une houle. Le second objectif vise à étudier les processus de submersion des protections côtières par les vagues dans des conditions d'état de mer bimodales afin d'améliorer la méthode d'estimation du débit de franchissements.Pour répondre au premier objectif, une série d'expériences a été réalisée dans le canal-soufflerie de l'OSU Institut Pythéas à Marseille en profondeur uniforme (i.e. sans structure côtière) afin d'observer la génération du clapot en présence de vagues longues simulées mécaniquement dans la direction du vent. Différentes vitesses de vent et différents types de vagues de batteur ont été testés. Une analyse spectrale a révélé qu'à vitesse de vent constante, la fréquence pic du clapot sans houle est déplacée vers les basses fréquences en présence des vagues de batteur irrégulières.Afin de transposer ces résultats à une échelle côtière, nous avons utilisé le modèle spectral d'états de mer TOMAWAC (Benoit et al. 1996). La précision du modèle numérique quant à la simulation d'états de mer bimodaux a été évaluée à l'aide de deux étapes de validation. La première, à l'échelle du laboratoire, visait à reproduire les résultats obtenus dans le canal-soufflerie. La seconde, à l'échelle côtière, visait à reproduire les observations relevées lors d'un événement de la campagne SHOWEX (Ardhuin et al. 2007, Zhang et al. 2009). Des développements récents permettant la modélisation de la dissipation des vagues (Ardhuin et al. 2010) et des interactions non-linéaires entre quadruplets (Gagnaire-Renou et al. 2010) ont montré de bonnes performances pour la reproduction des observations aux deux échelles.Une seconde campagne d'expériences visait à étudier les processus de franchissements d'une digue par les vagues dans des conditions d'états de mer bimodaux générés uniquement avec le batteur. Une digue à l'échelle 1:25 avec une pente de 3:2 (H:V) a été construite dans le canal-soufflerie. Les débits de franchissements ont été mesurés pour différentes hauteurs de franc-bord, diverses conditions d'états de mer (unimodaux et bimodaux), avec deux types de revêtements : un lisse et un en enrochements. Dans les conditions testées (e.g. états de mer bimodaux), la méthodologie actuelle d'estimation du débit de franchissements est valide pour le cas de la pente lisse. Cependant, en présence d'enrochements, une faible hauteur de franc-bord entraîne une surestimation importante du débit de franchissements pour les états de mer composés d'une forte proportion de clapot. Sur la base des tendances observées avec les différents revêtements, de nouvelles formulations d'estimation des débits de franchissements sont proposées, notamment via une redéfinition des hauteurs de franc-bord et débits adimensionnels.Afin de compléter l'utilisation de modèles réduits dans des configurations complexes, le code multiphasique neptune_cfd (Coste et al. 2007) a été appliqué et comparé aux résultats de laboratoire pour la submersion par des états de mer bimodaux.
• A viscoelastic flow model of maxwell-type with a symmetric-hyperbolic formulation
  
  • Boyaval Sébastien
  , 2022. Maxwell models for viscoelastic flows are famous for their potential to unify elastic motions of solids with viscous motions of liquids in the continuum mechanics perspective. But the usual Maxwell models allow one to define well motions mostly for one-dimensional flows only. To define unequivocal multi-dimensional viscoelastic flows (as solutions to well-posed initial-value problems) we advocated in [ESAIM:M2AN 55 (2021) 807-831] an upper-convected Maxwell model for compressible flows with a symmetrichyperbolic formulation. Here, that model is derived again, with new details.
• The Rance tidal power station: Toward a better understanding of sediment dynamics in response to power generation
  
  • Rtimi Rajae
  • Sottolichio Aldo
  • Tassi Pablo
  Renewable Energy, Elsevier, 2022, 201, pp.323-343. (10.1016/j.renene.2022.10.061)
  DOI : 10.1016/j.renene.2022.10.061
• Wave drag during an unsteady motion
  
  • Dode A.
  • Carmigniani Rémi Arthur
  • Cohen C.
  • Clanet C.
  • Bocquet L.
  Journal of Fluid Mechanics, Cambridge University Press (CUP), 2022, 951, pp.A15. The average wave drag in unsteady motion is studied experimentally with force measurements. Towing hulls of size $L$ at sinusoidal speed, the mean drag is measured for different amplitudes and frequencies of the fluctuating velocity, as well as different Froude numbers $\mathcal {F}_0$ associated with the mean velocity $V_0$ ( $\mathcal {F}_0 = V_0/\sqrt {gL}$ ). The wave drag is reported to be either increased or decreased by velocity fluctuations depending on $\mathcal {F}_0$ . For small fluctuation amplitudes, this drag change is proportional to the square of the amplitude. The effect is maximized for a resonance frequency identified as the Wehausen frequency, which scales as $\sqrt {g/L}$ times the inverse of the Froude number. All these results are rationalized by developing an extension to Havelock's theory. (10.1017/jfm.2022.592)
  DOI : 10.1017/jfm.2022.592
• Drag coefficient Uncertainty for floating wind turbines
  
  • Robaux Fabien
  • Nadal Adria Borras
  • Peyrard Christophe
  • Benoit Michel
  • Benguigui William
  • Guiton Martin
  , 2022.
• Flat plate pressure impact on a still water surface: The effect of surrounding ambient pressure and plate size
  
  • Talioua Abdessamad
  • Berkane Belaïd
  • Batlle Martin Marc
  • Perret Gaële
  • Pinon Grégory
  Ocean Engineering, Elsevier, 2022, 263, pp.111926. The study of the impact between a rigid structure and water has raised the interest of many researchers in these recent years. This problem is relevant to various engineering applications, and particularly in the nautical environment (renewable energy, marine applications...). The present paper details an experimental investigation of rigid circular plates impacts into pure water. The analyses are based on impact pressure temporal signals, pressure impulses and frequency analysis recorded while the plates were impinging the still water surface. The measurement campaigns were carried out at the University Le Havre Normandy’s LOMC laboratory, in a recently developed experimental facility. In the previous experimental and numerical studies, it was observed that the magnitude of the peak slamming pressure is reduced if compared to the theoretical model predicted by von Karman (1929). Similar observations were made here and the decrease was partly attributed to the cushion effect resulting from the presence of an entrapped air layer between the rigid plate and the water free surface. This work aims to study the influence of the cushion effect on the impact pressure by using four rigid circular plates with different diameters in order to modify the volume of the air layer. Initially, the measurements were carried out for an ambient pressure equal to the atmospheric pressure. In a second part of the study, the same measurements were performed for two lower ambient pressures (about 75% and 50% of the atmospheric pressure) in order to minimise the cushion effect. And finally, a frequency analysis is presented with comparisons to theoretical results of Minnaert (1933) in order to correlate the air layer size to the pressure oscillation characteristics. The obtained results were compared with previous experimental and theoretical studies for low impact velocities (10.1016/j.oceaneng.2022.111926)
  DOI : 10.1016/j.oceaneng.2022.111926
• Two-Phase Flow Modeling for Bed Erosion by a Plane Jet Impingement
  
  • Pham-Van-Bang Damien
  • Uh Zapata Miguel
  • Gauthier Georges
  • Gondret Philippe
  • Zhang Wei
  • Nguyen Kim Dan
  Water, MDPI, 2022, 14 (20), pp.3290. This paper presents experimental and numerical studies on the erosion of a horizontal granular bed by a two-dimensional plane vertical impinging jet to predict the eroded craters’ size scaling (depth and width). The simulations help understand the microscopic processes that govern erosion in this complex flow. A modified jet-bed distance, accounting for the plane jet virtual origin, is successfully used to obtain a unique relationship between the crater size and a local Shields parameter. This work develops a two-phase flow numerical model to reproduce the experimental results. The numerical techniques are based on a finite volume formulation to approximate spatial derivatives, a projection technique to calculate the pressure and velocity for each phase, and a staggered grid to avoid spurious oscillations. Different options for the sediment’s solid-to-liquid transition during erosion are proposed, tested, and discussed. One model is based on unified equations of continuum mechanics, others on modified closure equations for viscosity or momentum transfer. A good agreement between the numerical solutions and the experimental measurements is obtained. (10.3390/w14203290)
  DOI : 10.3390/w14203290
• Open water swimming in urban areas E. coli distribution with TELEMAC-3D
  
  • Angelotti Natalia
  • Guillot - Le Goff Arthur
  • Carmigniani Rémi Arthur
  • Brigitte Vinçon-Leite
  , 2022.
• Physical and numerical modelling of overtopping induced fluvial dikes breaching
  
  • Kheloui Lydia
  , 2022. Levees (i.e., fluvial dikes) are important hydraulic structures built along rivers and channel banks to protect surrounding areas from inundations. However, several levee failure events were reported to bring exacerbated damages compared to natural floods. Indeed, these structures may experience several solicitations resulting in breach formation and expansion, overtopping being the most common cause of levee failure.Numerical models can support flood risk management and improve populations' preparedness. However, an accurate prediction of breach dynamics and outflow discharge is essential to simulate possible inundations extent and corresponding flood maps. Nevertheless, levee breach modeling presents significant challenges related to complex physical processes and their poorly understood interactions. In addition, past research efforts were mainly dedicated to developing dam-breach (frontal dikes) failure models, which are not adapted to fluvial dike breaching.The main goals of this research work are to improve the knowledge about the physical processes associated with overtopping induced levee failure on the one hand and increase the accuracy of actual modeling approaches on the other hand. First, experimental investigations were performed at the National Laboratory for Hydraulics and Environment (LNHE) of EDF R&D and aimed to clarify the erosion processes of a non-cohesive homogenous levee in the presence of a movable bed in the main channel, dike foundation, and floodplain. Main channel discharge and geometry were also varied through tests to highlight their influence on breach spacial progression and resulting discharge. Then, numerical investigations were conducted using two different modeling strategies. On the one hand, a simplified two-dimensional breach modeling approach was developed within the hydrodynamic module TELEMAC-2D of the open-source TELEMAC-MASCARET software. Various breach models were implemented in TELEMAC-2D, including simple empirical laws and more sophisticated equations like the Rupro breach model developed at INRAE.On the other hand, a detailed physically-based approach was studied using the hydrodynamic module (TELEMAC-2D) and morphodynamic module (SISYPHE/GAIA). New sediment transport equations were implemented, and slope failure modeling was adjusted to the actual state of the art. Laboratory measurements and field experiment data helped analyze both modeling approaches. Finally, relevant indications and lessons were highlighted to support actual field studies.
• Forecasting sanitary risks for open-water swimming in urban areas
  
  • Vinçon-Leite Brigitte
  • de Moura Contente Helena
  • Angelotti Rodrigues Natalia
  • Clercin N
  • Bezerra F
  • Piccioni F
  • Lemaire Bruno J.
  • Lucas F S
  • Paz I
  • Carmigniani R
  , 2022. Urban water bodies are increasingly used for recreational activities, including swimming. The practice of open water swim requires a good water quality, complying with sanitary regulations based on the concentration of faecal indicator bacteria. To forecast a possible sanitary risk, a monitoring station can be implemented upstream of the bathing area. Then the transfer time of the microbiological contaminant must be accurately modelled in order to derive the contamination level in the bathing area. A hydrodynamic model is a useful tool for achieving this goal. In La Villette basin (Paris, France), as part of Paris-Plage programme, a bathing area has been implemented since summer 2017. We present in this paper results of a 3D hydrodynamic model of La Villette basin, the transport of E.coli towards the swimming area and the advantages of this modelling approach.
• On the Physics of Kayaking
  
  • Prétot Charlie
  • Carmigniani Rémi Arthur
  • Hasbroucq Loup
  • Labbé Romain
  • Boucher Jean-Philippe
  • Clanet Christophe
  Applied Sciences, Multidisciplinary digital publishing institute (MDPI), 2022, 12 (18), pp.8925. The propulsion force of a kayaker can be measured thanks to sensors placed on the paddle. This article aims at linking this force to the evolution of the velocity of the boat. A general model is proposed to describe the motion of a K1 kayak. To validate the model and evaluate the relevant physics parameters, three on-water kayaking trials are proposed: a pure deceleration, a standing start, and 10 × 50 m with two athletes at the national level. These trials were performed with a force sensor on the paddle and video recording. We used the deceleration to evaluate the drag of the boat. Then the standing start showed that there was an active drag coefficient while kayaking. Finally, the 10 × 50 m exhibited a power law of one-third between the velocity and the stroke rate. The acceleration during the standing start together with the relationship between the velocity and stroke rate were well captured theoretically. This approach enabled us to evaluate the important parameters to describe a kayak race: the drag of the boat, an active drag coefficient, the mean propulsive force, and a propulsive length. It can be used to characterize athletes and monitor their performances. (10.3390/app12188925)
  DOI : 10.3390/app12188925
• L’hydrogéographie, sa place dans l’analyse systémique, du bassin-versant au bassin déversant
  
  • Viel Vincent
  • Lavie Emilie
  • Brousse Guillaume
  • Carlier Benoit
  • Michler Luc
  • Resch Mathilde
  • Shahsavari Gashin
  • Arnaud-Fassetta Gilles
  , 2022.
• Hydrodynamics, sediment transport, and morphodynamics in the Vietnamese Mekong Delta: Field study and numerical modelling
  
  • Binh Doan Van
  • Kantoush Sameh
  • Ata Riadh
  • Tassi Pablo
  • Nguyen Tam
  • Lepesqueur Jérémy
  • Abderrezzak Kamal El Kadi
  • Bourban Sébastien
  • Nguyen Quoc Hung
  • Phuong Doan Nguyen Luyen
  • Trung La Vinh
  • Tran Dang An
  • Letrung Thanh
  • Sumi Tetsuya
  Geomorphology, Elsevier, 2022, 413, pp.108368. (10.1016/j.geomorph.2022.108368)
  DOI : 10.1016/j.geomorph.2022.108368
• Three-dimensional hydrodynamic-biogeochemical modelling of a small urban lake
  
  • Piccioni Francesco
  • Casenave Céline
  • Hoang Le Minh
  • Vinçon Leite Brigitte
  , 2022. The ecological state of lake ecosystems worldwide has deteriorated over the past decades. Eutrophication and climate change contribute to the increase of algal blooms, in particular of toxic cyanobacteria blooms, which currently constitute a main concern in the management of water resources. Modelling tools are of central importance to better understand the impact of climate change on the thermal regime of small and shallow lakes and its relation to phytoplankton growth. The recognized three-dimensional hydrodynamic model TELEMAC3D was recently coupled with the biogeochemical library Aquatic EcoDynamics (AED). Here, the coupled model is applied on Lake Champs-sur-Marne, a small and shallow lake (Great Paris), which suffers from recurrent cyanobacterial blooms.The available data set includes high-frequency data. Water temperature, oxygen, nitrate, chlorophyll and phycocyanin are measured at a 10mn time step. The results of a simulation run from February to November 2019 are presented.The model performance is assessed thoroughly against multiple variables and at different time scales. Regarding the thermal regime of this polymictic lake, the simulated water temperature is in very good agreement with observations. Moreover, the alternation of mixing and stratification is well captured by the model. The seasonal evolution of the phytoplankton biomass is correctly reproduced as well as its distribution between the main phytoplankton groups. Furthermore, the dynamics of dissolved oxygen and nitrate is well captured. This fully coupled 3D hydrodynamic-biogeochemical model provides a new robust tool for modelling the interplay between hydrodynamics and biogeochemistry in small polymictic lakes which represent the majority of global lakes.
• Finite-Volume approximation of the invariant measure of a viscous stochastic scalar conservation law
  
  • Boyaval Sébastien
  • Martel Sofiane
  • Reygner Julien
  IMA Journal of Numerical Analysis, Oxford University Press (OUP), 2022, 42 (3), pp.2710-2770. We study the numerical approximation of the invariant measure of a viscous scalar conservation law, one-dimensional and periodic in the space variable, and stochastically forced with a white-in-time but spatially correlated noise. The flux function is assumed to be locally Lipschitz continuous and to have at most polynomial growth. The numerical scheme we employ discretises the SPDE according to a finite-volume method in space, and a split-step backward Euler method in time. As a first result, we prove the well-posedness as well as the existence and uniqueness of an invariant measure for both the semi-discrete and the split-step scheme. Our main result is then the convergence of the invariant measures of the discrete approximations, as the space and time steps go to zero, towards the invariant measure of the SPDE, with respect to the second-order Wasserstein distance. We investigate rates of convergence theoretically, in the case where the flux function is globally Lipschitz continuous with a small Lipschitz constant, and numerically for the Burgers equation. (10.1093/imanum/drab049)
  DOI : 10.1093/imanum/drab049
• aero-elastic modeling of floating wind turbines with vortex methods
  
  • Corniglion Rémi
  , 2022. Floating offshore wind turbines are set on a foundation free to move under the effect of the winds and waves. This induces a relative motion between the wind turbine rotor and the incoming wind. The Blade Element Momentum Theory, widely used to study the aerodynamics of wind turbines relies on empirical corrections to model these unsteady conditions. In this thesis, medium fidelity aerodynamic models are used to provide more insight into the unsteady aerodynamic loads on a moving wind turbine rotor. The phenomenon of dynamic inflow is studied with regard to floating wind turbines. Imposed surge motions are first explored with a lifting line free vortex wake model and an actuator line model. The aerodynamics of a wind turbine after three perturbations are studied: a blade pitch step; a rotor speed step and a surge velocity step. The Free Vortex Wake method and an analytical helical vortex model based on the Joukowsky rotor model are used to study the dynamic behavior of the induced velocity at the blades. To improve upon the imposed motions cases, a Free Vortex wake code is coupled to a hydro-servo-elastic code to study floating wind turbines in real metocean conditions. A wake simplification model is proposed to enable long simulations at a reasonable computational cost. The coupled code is validated against experimental and numerical data. The aero-hydro-servo-elastic code is used to evaluate the influence of the aerodynamic models on the computed damage of an industrial scale floating wind turbine.
• Psychiatric symptoms and mortality in older adults with major psychiatric disorders: results from a multicenter study
  
  • Chene Margaux
  • Sánchez-Rico Marina
  • Blanco Carlos
  • de Raykeer Rachel Pascal
  • Hanon Cécile
  • Vandel Pierre
  • Limosin Frédéric
  • Hoertel Nicolas
  • Adès Jean
  • Alezrah Charles
  • Amado Isabelle
  • Amar Gilles
  • Andréi Ovidiu
  • Arbault Denis
  • Archambault Georges
  • Aurifeuille Gilles
  • Barrière Sarah
  • Béra-Potelle Céline
  • Blumenstock Yvonne
  • Bardou Hervé
  • Bareil-Guérin Michèle
  • Barrau Pierre
  • Barrouillet Claudine
  • Baup Emilie
  • Bazin Nadine
  • Beaufils Béatrice
  • Ayed Jalel Ben
  • Benoit Michel
  • Benyacoub Kader
  • Bichet Thérèse
  • Blanadet Françoise
  • Blanc Olivier
  • Blanc-Comiti Julien
  • Boussiron Didier
  • Bouysse Anne-Marie
  • Brochard Alain
  • Brochart Olivier
  • Bucheron Bastien
  • Cabot Marion
  • Camus Vincent
  • Chabannes Jean-Marc
  • Charlot Véronique
  • Charpeaud Thomas
  • Clad-Mor Cateline
  • Combes Colette
  • Comisu Maricela
  • Cordier Sylvain
  • Costi François
  • Courcelles Jean-Paul
  • Creixell Mercedes
  • Cuche Henry
  • Cuervo-Lombard Christine
  • Dammak Anis
  • Rin David
  • Denis Jean-Bernard
  • Denizot Hélène
  • Deperthuis Anne
  • Diers Eric
  • Dirami Smail
  • Donneau Didier
  • Dreano Pierre
  • Dubertret Caroline
  • Duprat Eric
  • Duthoit Didier
  • Fernandez Christian
  • Fonfrede Philippe
  • Freitas Nelly
  • Gasnier Philippe
  • Gauillard Jacques
  • Getten Fabien
  • Gierski Fabien
  • Godart Fabien
  • Gourevitch Raphaël
  • Delyle Aude Grassin
  • Gremion Juliette
  • Gres Hélène
  • Griner Véronique
  • Guerin-Langlois Christophe
  • Guggiari Christian
  • Guillin Olivier
  • Hadaoui Hamadi
  • Haffen Emmanuel
  • Hanon Cécile
  • Haouzir Sadeq
  • Hazif-Thomas Cyril
  • Heron Anne
  • Hubsch Bérengère
  • Jalenques Isabelle
  • Januel Dominique
  • Kaladjian Arthur
  • Karnycheff Jean-François
  • Kebir Oussama
  • Krebs Marie-Odile
  • Lajugie Christine
  • Leboyer Marion
  • Legrand Pierre
  • Lejoyeux Michel
  • Lemaire Vincent
  • Leroy Evelyne
  • Levy-Chavagnat Diane
  • Leydier Antoine
  • Liling Chantal
  • Llorca Pierre-Michel
  • Loeffel Philippe
  • Louville Patrice
  • Navarro Stéphane Lucas
  • Mages Nicolas
  • Mahi Mohamed
  • Maillet Odile
  • Manetti Aude
  • Martelli Catherine
  • Martin Pascal
  • Masson Marc
  • Maurs-Ferrer Isabelle
  • Mauvieux Joelle
  • Mazmanian Sylvain
  • Mechin Emmanuelle
  • Mekaoui Lila
  • Meniai Mostéfa
  • Metton Agnès
  • Mihoubi Amine
  • Miron Maria
  • Mora Geneviève
  • Adès Valérie Niro
  • Nubukpo Philippe
  • Omnes Cécile
  • Papin Stéphanie
  • Paris Pierre
  • Passerieux Christine
  • Pellerin Jérôme
  • Perlbarg Julie
  • Perron Sylvie
  • Petit Annie
  • Petitjean François
  • Portefaix Christophe
  • Pringuey Dominique
  • Radtchenko Andrei
  • Rahiou Hassan
  • Raucher-Chéné Delphine
  • Rauzy Anne
  • Reinheimer Lionel
  • Renard Michel
  • René Margaux
  • Rengade Charles-Edouard
  • Reynaud Paul
  • Robin Didier
  • Rodrigues Christelle
  • Rollet Aurélie
  • Rondepierre Fabien
  • Rousselot Bernard
  • Rubingher Sarah
  • Saba Ghassen
  • Salvarelli Jean-Pierre
  • Samuelian Jean-Claude
  • Scemama-Ammar Corinne
  • Schurhoff Franck
  • Schuster Jean-Pierre
  • Sechter Daniel
  • Segalas Béatrice
  • Seguret Tiphaine
  • Seigneurie Anne-Sophie
  • Semmak Amina
  • Slama Frédéric
  • Taisne Sophie
  • Taleb Mohamed
  • Terra Jean-Louis
  • Thefenne Dominique
  • Tran Eric
  • Tourtauchaux Rémi
  • Vacheron Marie-Noëlle
  • Vandel Pierre
  • Vanhoucke Valérie
  • Venet Emmanuel
  • Verdoux Hélène
  • Viala Anne
  • Vidon Gilles
  • Vitre Murielle
  • Vurpas Jean-Luc
  • Wagermez Carole
  • Walter Michel
  • Yon Liova
  • Zendjidjian Xavier
  European Archives of Psychiatry and Clinical Neuroscience, Springer Verlag, 2022, 273 (3), pp.627-638. (10.1007/s00406-022-01426-4)
  DOI : 10.1007/s00406-022-01426-4
• Floods in housing estate : some experimental data
  
  • Larrarte Frédérique
  • Doumic Augustin
  • Goutal Nicole
  , 2022, pp.6 p., photos, graph.. The water cycle can be affected by violent events such as earthquakes, tsunamis, floods, ... In France, 17 millions of inhabitants are exposed to flood risk. One challenge during floods is to be able to access to people refugee over buildings. In order to investigate the hydraulic context generated by the grouped obstacles representative of a submerged housing estate, a preliminary experimental study was conducted. We experimentally study the flow in the presence of rows of macro-roughnesses representative of a submerged housing estate, and this for situations representing both current and more intense floods. After presenting the experimental configurations, the experimental results are given and discussed. The first conclusions are completed by the perspectives. (10.3850/iahr-39wc2521716x2022577)
  DOI : 10.3850/iahr-39wc2521716x2022577
• Structure of open-channel flows through an array of square cylinders
  
  • Oukacine Marina
  • Larrarte Frédérique
  • Goutal Nicola
  Urban Water Journal, Taylor & Francis, 2022, 19 (7), pp.12 p.. The impact of obstacles on the hydrodynamic flow structure is of major interest since such flows are representative of flooded urban areas. This study focuses on a pattern depicting a single-family home and garden area, as found in recent suburban development. The purpose herein is to analyze the evolution of the velocity distribution for a densely built area as well as for emerged to slightly submerged situations, which represent various flood situations ranging from commonplace to extreme. Free-surface flows through an in-line distribution of square cylinders were investigated in a laboratory flume, in the aim of assessing the effect of relative submergence on the flow structure within the cylinder array. The results show that the lines of square cylinders channelize the flow. Moreover, the submerged case generated similar flow characteristics below the top of the cylinders, which drastically changed once the water flowed above the square cylinder level. (10.1080/1573062X.2022.2075771)
  DOI : 10.1080/1573062X.2022.2075771
• Numerical investigation of slamming loads on floating offshore wind turbines
  
  • Batlle Martin Marc
  • Harris Jeffrey
  • Renaud Paul
  • Hulin Florian
  • Filipot Jean-François
  , 2022, pp.ISOPE-I-22-031. This paper presents the results of ongoing work regarding numerical simulations of breaking wave impacts on a surface-piercing cylinder. The computational fluid dynamics solver, Code Saturne, using the volume of fluid approach, is presented and utilised for offshore hydrodynamics. Phase-focused waves are employed to recreate singular breaking events under relatively controlled conditions. The fluid shape and kinematics are described during the breaking process and the load produced by a plunging breaker on a rigid cylinder is investigated.
• Effects of Vegetation Patch Patterns on Channel Morphology: A Numerical Study
  
  • Li Jiaze
  • Claude Nicolas
  • Tassi Pablo
  • Cordier Florian
  • Vargas-Luna Andrés
  • Crosato Alessandra
  • Rodrigues Stéphane
  Journal of Geophysical Research: Earth Surface, American Geophysical Union/Wiley, 2022, 127 (5). Abstract This study investigates the effects of vegetation patch patterns on the morphological evolution of alluvial river channels at the reach‐scale. For this, a new two‐dimensional numerical biomorphodynamic model has been developed using the Telemac‐Mascaret system. Considering the newest development in the topic, the effects of vegetation on bedload transport are included by extending Einstein's parameters for the sediment transport formula. The model was subsequently validated by published laboratory experiments reproducing alternate bar dynamics with different vegetation establishment scenarios. The validated model was then used to study the influence of vegetation patch patterns on the channel morphological evolution considering the two most observed ones: (a) the filled pattern with plants well distributed within the patch, and (b) the stripe pattern with plants established only along the patch edges. 14 scenarios were simulated in total, including sensitivity analyses on the coefficients of vegetation characteristics. The results indicate that the morphological responses of an alternate bar system to the stripe pattern consist of channel widening, steeper slope and reduced water depth, with increased sediment transport rates. The effects of the filled pattern are similar but weaker. The results also show that with the stripe pattern, the alternate bars tend to migrate toward the centerline forming center bars. Besides, the scroll bars forming downstream are shorter, corresponding to less visible chute channels, compared to the filled pattern. Despite much less vegetation coverage, the stripe pattern decreases the bar elongation rates in a way similar to the filled pattern. (10.1029/2021JF006529)
  DOI : 10.1029/2021JF006529
• Morphodynamic Evolution and Sustainable Development of Coastal Systems
  
  • Dissanayake Pushpa
  • Brown Jennifer
  • Yates Marissa L.
  Journal of Marine Science and Engineering, MDPI, 2022, 10 (5), pp.647. Coastal systems are highly dynamic morphological environments due to erosion and sedimentation at different spatio-temporal scales as a result of natural forcing [...] (10.3390/jmse10050647)
  DOI : 10.3390/jmse10050647
• Spatial variability of the erodibility of fine sediments deposited in two alpine gravel-bed rivers: The Isère and Galabre
  
  • Haddad Hanna
  • Jodeau Magali
  • Legout Cédric
  • Antoine Germain
  • Droppo Ian
  CATENA, Elsevier, 2022, 212, pp.106084. In mountainous environments, high suspended sediment load during runoff or dam flushing events can lead to important amounts of fine deposits in gravel bed rivers. Fine sediment deposits may contribute to bar elevation, riparian vegetation growth and consequently to bar stabilization. Despite their contribution to the morphodynamic of mountain rivers, the erosion properties of fine sediments in this context is not fully understood.In order to investigate the dynamics of re-suspension of these deposits, field monitoring campaigns were performed to explore both the spatial variability and the controlling factors of the erodibility of fine deposits. A cohesive strength-meter (CSM), along with moisture, grain sizes, geographical position and elevation were used to evaluate both the critical bed shear stress for erosion and erosion rate of fine sediment deposits in two rivers of the French Alps: the Isère and Galabre.The results highlight a large variety of fine sediment deposition areas, which are discontinuous compared to those in estuaries and lowland rivers. A high spatial variability of erodibility was observed on the reach, the bar and the metric scale. While no upstream–downstream trend was observed at the scale of both studied reaches, the locations of the deposits, elevation from the river surface and their moisture were inter-related variables and with the highest correlations to erodibility. Measurements showed that both dry and humid deposits located at the highest and lowest elevation from the river surface respectively, were more easily eroded than intermediate deposits with medium moisture. (10.1016/j.catena.2022.106084)
  DOI : 10.1016/j.catena.2022.106084