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A potential flow based flight simulator for an underwater glider ArchiMer
Phoemsapthawee, Surasak; Le Boulluec, Marc; Laurens, Jean-marc; Deniset, Francois.
Underwater gliders are recent innovative types of autonomous underwater vehicles (AUVs) used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of the hydrodynamic behavior and the flight mechanics of the underwater glider is necessary. A 6-DOF motion simulator is coupled with an unsteady potential flow model for this purpose. In some specific cases, the numerical study demonstrates that an inappropriate stabilizer...
Tipo: Text Palavras-chave: Underwater glider; Hydrodynamics; Potential flow; 6DOF; Newton-Euler equation; AUVs.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00171/28227/26480.pdf
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Accumulation des sels nutritifs dans un sédiment lagunaire et environnement hydrodynamique ArchiMer
Gomez, E; Millet, B; Picot, B.
The Mejean-Perols Lagoon is situated on the French Mediterranean coast. It is a small (747 ha) and shallow (70 cm) lagoon. Some treated effluent from Montpellier flows into this hypereutrophic lagoon. The cartography of C, N and P concentrations in the sediment was studied based on 35 bottom samples. The nitrogen and organic carbon concentrations were more or less homogeneous, the highest concentrations being found in the middle of the lagoon. The phosphate was principally bound onto the sediment in the west zone. The observed distribution was independent of grain size, the distribution of which was rather homogeneous. In this lagoon water circulation is wind induced. Four different water flow structures were observed, as functions of the prevailing winds...
Tipo: Text Palavras-chave: Sédiment; Lagune côtière; Hydrodynamique; Sels nutritifs; Carbone; Sediment; Coastal lagoon; Hydrodynamics; Nutrients; Carbon.
Ano: 1998 URL: http://archimer.ifremer.fr/doc/00325/43642/43247.pdf
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An Unstructured Numerical Model to Study Wind-Driven Circulation Patterns in a Managed Coastal Mediterranean Wetland: The Vaccares Lagoon System ArchiMer
Boutron, Olivier; Bertrand, Olivier; Fiandrino, Annie; Hoehener, Patrick; Sandoz, Alain; Cherain, Yves; Coulet, Eric; Chauvelon, Philippe.
The spatiotemporal structure of wind-driven circulation patterns and associated water exchanges can drive important bio-hydrodynamic interactions in shallow lagoons. The Vaccares lagoon system is a complex shallow hydrosystem located in the central part of the Rhone Delta (France). It is internationally recognized as part of a biosphere reserve within the framework of UNESCO's Man and Biosphere Programme, and as a RAMSAR site. Due to its frequent occurrence in this area, and considering the shallowness of the Vaccares lagoon system, wind is assumed to play a major role in the hydrodynamic and biological processes. In this study, a hydrodynamic model was developed to investigate the structure of wind-driven circulations in the Vaccares lagoon system, to...
Tipo: Text Palavras-chave: Coastal lagoon; Mathematical model; Hydrodynamics; Calibration; Validation; Wind-driven circulation.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00303/41382/40558.pdf
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Analysis and visualization of the glass eel behavior (Anguilla anguilla) in the Adour estuary and estimate of its upstream migration speed ArchiMer
Prouzet, Patrick; Odunlami, Marc; Duquesne, Elise; Boussouar, Ahmed.
The studies carried out on the Adour estuary on the migration of glass eels lead to the characterisation of their swimming behavior. Individuals migrate passively with the flood tide current behind the dynamic tide front, and their movements into the water column are linked to the surrounding luminosity and water turbidity. A numerical model was built from observations gathered on glass eel densities during scientific surveys. It uses the outputs of a hydrodynamic model accounting for the variations in the river flow and tide coefficient. It allows the simulation of the displacement of a particle in the longitudinal axis of the estuary. The variation of the vertical movements through the water column takes into account the cloud cover, the moon phases, the...
Tipo: Text Palavras-chave: Numerical modeling; Fish behavior; Migration; Estuary; Hydrodynamics; Exploitation rate; Glass eel; Anguilla anguilla; Atlantic Ocean.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/00000/11171/7531.pdf
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Assessment of an environmental barrier to transport of ichthyoplankton from the southern to OceanDocs
Lett, Christophe; Veitch, Jennifer; Van der Lingen, Carl D.; Hutchings, Larry.
The Lüderitz upwelling cell and Orange River cone (LUCORC) area, a transboundary region between South Africa and Namibia, is considered to be an environmental barrier to transport of ichthyoplankton from the southern to the northern Benguela upwelling ecosystems. We use environmental data and modelling to assess the potential mechanisms responsible for this barrier: environmental data were extracted from the 1 × 1° World Ocean Atlas 2001 database and used to build maps of annual mean salinity, temperature, chlorophyll, dissolved oxygen and nutrient concentrations; outputs of a regional circulation model were used in an individual-based model to assess the transport of passive particles from the southern to the northern Benguela. The data show no clear...
Tipo: Journal Contribution Palavras-chave: Ichthyoplankton; Upwelling; Modelling; Coastal oceanography; Trade winds; Salinity; Hydrodynamics; Cartesian coordinates; Chlorophylls.
Ano: 2007 URL: http://hdl.handle.net/1834/4667
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Atlas thématique de l'environnement marin en baie de Saint-Brieuc (Côtes-d'Armor) ArchiMer
Augris, Claude; Hamon, Dominique.
This atlas presents in a synthetic form the hydrodynamical, geological and biological characteristics of one of the most studied region of the French littoral. Geologic and geophysical data of the Saint-Brieuc Bay show that the deep basement consists of pre-palaeozoic or palaeozoic sedimentary series in the centre of the Bay, whereas metamorphic and magmatic formations are dominant in coastal regions. The location of superficial sediments in the Bay, is mainly due to marine currents. A granulometric gradient, from very fine to coarse sediments, appears in two directions: from the coast towards the high sea, and from the west to the east. Rocky substrates disrupt the sediment distribution, with, most of the time, a concentration of coarse sediments near the...
Tipo: Text Palavras-chave: Atlas; Bathymetry; Bottom topography; Commercial species; Geomorphology; Hydrodynamics; Marine resources; Sediment analysis; Sedimentary basins; Zoobenthos.
Ano: 1996 URL: http://archimer.ifremer.fr/doc/00031/14246/11527.pdf
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Bridging molecular and continuous descriptions: the case of dynamics in clays Anais da ABC (AABC)
Dufrêche,Jean-François; Rotenberg,Benjamin; Marry,Virginie; Turq,Pierre.
The theory of transport in porous media such as clays depends on the level of description. On the macroscopic scale,hydrodynamics equations are used. These continuous descriptions are convenient to model the fluid motion in a confined system. Nevertheless, they are valid only if the pores of the material are much larger than the molecular size of the components of the system. Another approach consists in using molecular descriptions. These two methods which correspond to different levels of description are complementary. The link between them can be clarified by using a coarse-graining procedure where the microscopic laws are averaged over fast variables to get the long time macroscopic laws. We present such an approach in the case of clays. Firstly, we...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Clays; Multi-scale modelling; Molecular dynamics; Hydrodynamics; Brownian model.
Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000100006
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Can north american fish passage tools work for South american migratory fishes? Neotropical Ichthyology
Baigún,Claudio Rafael Mariano; Nestler,John Michael; Oldani,Norberto Oscar; Goodwin,R. Andrew; Weber,Larry J..
In North America, the Numerical Fish Surrogate (NFS) is used to design fish bypass systems for emigrating juvenile salmon as they migrate from hatchery outfalls and rearing habitats to adult habitat in the oceans. The NFS is constructed of three linked modules: 1) a computational fluid dynamics model describes the complex flow fields upstream of dams at a scale sufficiently resolved to analyze, understand and forecast fish movement, 2) a particle tracking model interpolates hydraulic information from the fixed nodes of the computational fluid model mesh to multiple locations relevant to migrating fish, and 3) a behavior model simulates the cognition and behavior of individual fish in response to the fluid dynamics predicted by the computational fluid...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Hydraulic strain; Hydrodynamics; Numerical Fish Surrogate; Eulerian-Lagrangian-agent method.
Ano: 2007 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000200004
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Circulation and suspended sediment transport in a coral reef lagoon: The south-west lagoon of New Caledonia ArchiMer
Ouillon, S.; Douillet, Pascal; Lefebvre, J. P.; Le Gendre, Romain; Jouon, Aymeric; Bonneton, P.; Fernandez,; Chevillon, C.; Magand, O.; Lefevre, J.; Le Hir, Pierre; Laganier, R.; Dumas, Franck; Marchesiello, P.; Madani, A. Bel; Andrefouet, S.; Panche, J. Y.; Fichez, R..
The south-west lagoon of New Caledonia is a wide semi-open coral reef lagoon bounded by an intertidal barrier reef and bisected by numerous deep inlets. This paper synthesizes findings from the 2000-2008 French National Program EC2CO-PNEC relative to the circulation and the transport of suspended particles in this lagoon. Numerical model development (hydrodynamic, fine suspended sediment transport, wind-wave, small-scale atmospheric circulation) allowed the determination of circulation patterns in the lagoon and the charting of residence time, the later of which has been recently used in a series of ecological studies. Topical studies based on field measurements permitted the parameterisation of wave set-up induced by the swell breaking on the reef barrier...
Tipo: Text Palavras-chave: Hydrodynamics; Suspended sediment; New Caledonia; Coral reef lagoon; Sediment; Turbidity; Resuspension.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00014/12526/9401.pdf
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Coastal hydrodynamics in a windy lagoon ArchiMer
Alekseenko, Elena; Roux, Bernard; Sukhinov, A.; Kotarba, R.; Fougere, D..
The nonlinear hydrodynamics (3D RANS model) in a wide semi-enclosed windy lagoonal ecosystem is accurately investigated in the context of analyzing the limiting conditions of the recovery of submerged aquatic vegetation (SAV). Among the main natural hydrodynamical forcings, we consider the wind effect. We mainly focus attention to characteristic velocities (free surface and bottom) and to free surface elevation in the nearshore regions (with shallow water) where SAV were severely damaged in the past decades. Our main result relates to wind effects that form downwind coastal jets, alongshore, in shallow water areas, due to Berre bathymetry. Such coastal jets, which were never described previously in Berre lagoon literature, give rise to substantial bottom...
Tipo: Text Palavras-chave: Hydrodynamics; Berre lagoon; Current structures; Zostera noltii; Seagrass protection.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00144/25511/24704.pdf
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Coastal phytoplankton community dynamics and coexistence driven by intragroup density-dependence, light and hydrodynamics ArchiMer
Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle.
Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic...
Tipo: Text Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf
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Contribution de l''etude des suspensions a la comprehension des mecanismes hydrosedimentaires estuariens et littoraux en Manche centrale et orientale ArchiMer
Dupont, J; Lafite, R; Lamboy, M.
Satellite imagery shows the turbid and thermal plume of the Seine River and littoral zone of Picardie and Haute-Normandie. The suspensions have been analysed in conformity with a strategy elaborated in 1985 by the authors. In this macrotidal coastal environment they have attempted to draw the dynamic specificities and the material characteristics.
Tipo: Text Palavras-chave: Estuarine front; Harbours; Coastal zone; Estuaries; Marine environment; Composition; Particle concentration; Granulometry; Hydrodynamics; River plumes; Suspended particulate matter.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1277.pdf
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Dynamique des eaux (en Baie de Seine): Synthese des discussions ArchiMer
Chabertd'Hieres, G.
The discussions about "water dynamics" have dealt with the knowledge of long-term water mass circulation (from several days to several months), by the effects of three parameters: tides near limits and in the Seine Bay, turbid freshwater discharge (Seine river) and winds. This communication gives information about Eulerian and Lagrangian drift, used for residual current exhibition.
Tipo: Text Palavras-chave: Lagrangian current measurement; Eulerian current measurement; Mathematical models; Coastal zone; Residual flow; Hydrodynamics.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1271.pdf
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Dynamique des sédiments fins et mixtes des zones intertidales de la baie de Marennes-Oléron ArchiMer
Kervella, Stephane.
This thesis aims at increasing the general knowledge on sediment dynamics of intertidal flats in the Marennes-Oléron Bay, according to physical, biological and anthropogenic factors. The conducted research is compound of three complementary studies: (1) a study of sediment behaviour through applied rheophysics on intertidal superficial sediments; (2) a hydro-sedimentary study based on identification of the forcing action (physical, biological or anthropogenic) on the intertidal flat stability over several time scales (from the event to several months); (3) a specific application of the model SiAM-2DH to the Marennes-Oléron Bay. The surface sediments shows a mechanical behaviour that mainly depends on the fine fraction for a composition that contains up...
Tipo: Text Palavras-chave: Rhéophysique; Seuil d’écoulement; Sédiments cohésifs et mixtes; Sédimentation; Érosion; Hydrodynamique; Vasière; Zone intertidale; Conchyliculture; ALTUS; SiAM-2DH; Baie de Marennes-Oléron; Rhéophysics; Shear strenght; Cohesive and mixed sediment; Sédimentation; Erosion; Hydrodynamics; Mudflat; Intertidal area; Oyster; ALTUS; SiAM-2DH; Marennes-Oléron Bay..
Ano: 2009 URL: http://archimer.ifremer.fr/doc/00004/11534/8117.pdf
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Environmental factors controlling biomass development of seagrass meadows of Zostera noltei after a drastic decline (Arcachon Bay, France) ArchiMer
Cognat, Mathis; Ganthy, Florian; Auby, Isabelle; Barraquand, Frederic; Rigouin, Loic; Sottolichio, Aldo.
The relative impact of light, depth, hydrology, hydrodynamics, sediment and nutrients on growth of the seagrass Zostera noltei was investigated in Arcachon Bay, where the extent of seagrass beds has been decreasing for 20 years. A comprehensive multi-parameter survey of 9 sites was conducted monthly over one year. A three-parameter logistic growth model was fitted to biomass data to unravel the relative contributions of environmental factors on seagrass growth. The present study highlights the fact that, in addition to the dominant positive effect of light on plant growth, the hydrological and hydrodynamic parameters were important drivers for Z. noltei growth at the scale of the whole Bay. At the scale of individual sites, other factors such as macroalgal...
Tipo: Text Palavras-chave: Physical parameters; Light; Hydrodynamics; Adaptation; Statistical growth model.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00451/56229/57789.pdf
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Estudios de la circulación forzada por el viento en el estuario del Río de la Plata y sus implicancias en la estratificación: resultados del análisis de datos y simulaciones numéricas OceanDocs
Meccia, V.L..
For the first time, the analysis of historical salinity data and new current series is combined with high resolution numerical simulations, with the aim of understanding the processes that occur in the active and important Río de la Plata estuary (South America). With that objective, the first relatively long ADCP current series collected in two points of the estuary are analyzed. Only 25% of the currents variance is accounted by the tide. Approximately another 25% is associated with internal wave activity at the sampling locations, where a strong stratification exists. These waves are forced by land-sea breeze and tide and are very frequent during spring and summer. The remaining 50% of the energy is wind driven and occurs in synoptic to intra-seasonal...
Tipo: Theses and Dissertations Palavras-chave: Estuaries; Estuarine dynamics; Circulation; Winds; Salt wedges; Hydrodynamics; Estuaries; Winds; Hydrodynamics; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_8401; Http://aims.fao.org/aos/agrovoc/c_3723.
Ano: 2008 URL: http://hdl.handle.net/1834/2830
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Etude expérimentale pour l'optimisation des performances d'une plage d'amortissement parabolique ArchiMer
Le Boulluec, Marc; Kimmoun, Olivier; Molin, Bernard.
An optimisation study was run before rebuilding the damping beach of the Ifremer Ocean Engineering Basin. Trials were conducted at a ¼ geometrical scale at Ecole Centrale de Marseille in a wave tank reproducing the original performance of the beach. A series of modifications was studied : incidence, device between the beach and the adjacent wall, porosity. Porosity was shown as the most efficient tool to enhance the beach absorption and full scale measurements revealed that the resulting damping coefficient was less than 10 % for all usual periods and amplitudes.
Tipo: Text Palavras-chave: Hydrodynamique; Essais en bassin; Houle; Réflexion; Amortissement; Plage; Hydrodynamics; Wave tank testing; Reflection; Damping beach.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/00170/28170/26404.pdf
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General hydrodynamical features in the ligurian sea inferred from the dyome experiment ArchiMer
Taupier-letage, Isabelle; Millot, Claude.
Tipo: Text Palavras-chave: Hydrodynamique; Mer Ligure; Circulation générale; Moyenne échelle; Variabilité; Hydrodynamics; Ligurian Sea; General circulation; Mesoscale; Variability.
Ano: 1986 URL: http://archimer.ifremer.fr/doc/00110/22125/19761.pdf
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How do microalgae perceive light in a high-rate pond? Towards more realistic Lagrangian experiments ArchiMer
Demory, David; Combe, Charlotte; Hartmann, Philipp; Talec, Amelle; Pruvost, Eric; Hamouda, Raouf; Souille, Fabien; Lamarea, Pierre-olivier; Bristeau, Marie-odile; Sainte-marie, Jacques; Rabouille, Sophie; Mairet, Francis; Sciandra, Antoine; Bernard, Olivier.
Hydrodynamics in a high-rate production reactor for microalgae cultivation affects the light history perceived by cells. The interplay between cell movement and medium turbidity leads to a complex light pattern, whose forcing effects on photosynthesis and photoacclimation dynamics are nontrivial. Hydrodynamics of high density algal ponds mixed by a paddle wheel has been studied recently, although the focus has never been on describing its impact on photosynthetic growth efficiency. In this multidisciplinary downscaling study, we first reconstructed single cell trajectories in an open raceway using an original hydrodynamical model offering a powerful discretization of the Navier-Stokes equations tailored to systems with free surfaces. The trajectory of a...
Tipo: Text Palavras-chave: Photosynthesis; Hydrodynamics; Modelling; Photoacclimation; Dunaliella salina; Non-photochemical quenching.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00445/55692/57352.pdf
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Hydrodynamic Aspects at Vitória Bay Mouth, ES Anais da ABC (AABC)
GARONCE,FLÁVIA A.A.; QUARESMA,VALÉRIA S..
Understading the hydrodynamic behavior and suspended particulated matter (SPM) transport are of great importance in port regions such as Vitória Harbor, which is located at Vitória Bay, Vitória – ES, Brazil. Vitória Bay is an estuary that has not been systematically assessed through a temporal analysis in order to identify its hydrodynamics characteristics and SPM exchange. This study aims to investigate salt and suspended particulate matter flux at the estuarine mouth of Vitória Bay by understanding the temporal variation of salinity, temperature and tidal currents within the water column and at the channel crosssection. Results showed that the estuarine mouth tended to present partial stratification periods during neap tides and little stratification in...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Estuary; Hydrodynamics; Suspended particulate matter; Vitória Bay.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000200555
Registros recuperados: 48
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