Consideram-se neste trabalho seções bidimensionais oscilando em balanço. Adotam-se modelos representativos do movimento segundo este único grau de liberdade. Estimam-se os parâmetros de inércia e de amortecimento hidrodinâmicos por meio de experimentos de decaimento. Simulações numéricas incorporando os parâmetros estimados experimentalmente, bem como previsões empíricas de resultados da literatura, são confrontadas à registros experimentais para verificação da adequação das previsões, e para avaliação da adequação dos modelos à representação da dinâmica da oscilação. Com a metodologia de análise escolhida, avalia-se a influência de determinados parâmetros sobre as propriedades hidrodinâmicas; consideram-se variações: de proporções da seção, de posição vertical do centro de massa, de inércia própria em balanço, de forma do bojo, e quanto a presença de bolina e suas proporções. Também é considerada a influência do ângulo inicial de banda nas propriedades hidrodinâmicas, bem como a participação da energia irradiada pela onda na energia acumulada pelo sistema anterior ao início do movimento. Os elementos anteriores levam à proposição de orientações para avaliação da influência das propriedades geométricas e inerciais no comportamento do casco em balanço. / The scope of this work is the verification of hydrodynamic properties of two dimensional rolling sections. Analytical models of a single degree-of-freedom movement are adopted. The added inertia and damping are estimated by free decay tests. Numerical simulations with the obtained experimental parameters as well as empirical literature results are compared to the data tests in order to verify the adequacy of the procedures. With the chosen method of analysis, the influence of the hydrodynamic parameters are verified. The following parameters are considered: the beam draft ratio, vertical position of center of gravity, moment inertia, bilge shape and the addition or not of bilge keels. The initial angle of roll is also considered as well as the transport of the energy accumulated before the decay by the wave generated by the movement of the model. These elements lead to the proposition of orientations for the verification of the influence of geometric and inertial properties in the behave of rolling two-dimensional sections.

O presente trabalho propõe um novo modelo hidrodinâmico para avaliação das forças oriundas da ação de correnteza marítima uniforme sobre o casco de navios petroleiros amarrados. A modelagem é válida para qualquer ângulo de incidência de correnteza e sua aplicação é voltada, especialmente, ao estudo dinâmico de sistemas FPSO (Floating Production Storage and Offloading systems), muito embora seu campo de aplicação possa facilmente ser estendido a problemas correlatos em engenharia naval. O modelo ora apresentado depende basicamente das dimensões principais do casco, necessitando de um conjunto bastante pequeno de parâmetros a serem determinados experimentalmente. Essa natureza quase-explícita da modelagem constitui sua principal vantagem face aos demais modelos usualmente empregados, e a mesma advém exatamente do contexto mais restrito para o qual foi formulado. O modelo heurístico estendido foi elaborado com base em um modelo estático previamente desenvolvido por Leite et al. (1998). Foram incorporados os efeitos provenientes do movimento de rotação do casco, tornando o modelo aplicável ao caso geral de movimentos do navio no plano horizontal. A determinação destes efeitos foi fundamentada em uma abordagem heurística, combinando-se estimativas semi-empíricas para as forças decorrentes de diferentes padrões de escoamento fluido no entorno do casco, padrões estes associados a faixas de ângulos de incidência distintas. As estimativas de força e momento em movimento combinado de translação e rotação do casco foram validadas a partir de resultados experimentais obtidos em ensaios de yaw-rotating, conduzidos com modelos de diferentes navios petroleiros, em duas condições de carregamento distintas. ) Posteriormente, a verificação experimental foi ampliada, analisando-se a adequação do modelo hidrodinâmico ao estudo de instabilidade dinâmica de navios atracados por intermédio de um cabo de amarração (hawser), fenômeno conhecido em engenharia naval como fishtailing. Em paralelo ao desenvolvimento do modelo hidrodinâmico e sua validação experimental, objetivos primeiros deste trabalho, procede-se a uma revisão crítica das diferentes abordagens teóricas comumente empregadas, baseada nos principais aspectos hidrodinâmicos envolvidos em aplicações práticas de navios amarrados em sistemas offshore. Assim, face à complexidade do problema em questão e dada a profusão de modelos teóricos existentes na literatura, mais do que a defesa de um ou outro método de análise, procura-se fornecer um orientação consistente para que o projetista de sistemas oceânicos possa escolher, com maior confiança, a abordagem mais apropriada para a aplicação em questão, ciente de suas vantagens e eventuais limitações. / A new hydrodynamic model for the analysis of current forces acting on moored tanker ships is proposed. The theoretical model is valid for any angle of attack of the current and is intended, primarily, for the analysis of FPSO (Floating Production Storage and Offloading) systems, although its application may be easily extended to other correlated problems in ocean engineering. The model depends basically on the ship main dimensions and requires few external parameters to be derived. This quasi-explicit nature certainly constitutes the model main advantage and it was only possible due to the more restricted context it was derived for. The extended heuristic model, as it is called, was based on a previous static version presented by Leite et al. (1998). The hydrodynamic effects arising from the ship yaw motion were now incorporated, making the model able to cope with the problem of combined drift-yaw motions. Yaw velocity influence was determined by means of a heuristic combination of semi-empirical formulations of force and moment components, resultant from distinct fluid flow patterns, each one related to a different range of angles of attack. Force predictions were validated through confrontation with yaw-rotating experimental results, obtained for different tanker models in distinct loading conditions. It was also verified experimentally that the model is capable of predicting the hydrodynamic forces involved in the unstable dynamic behavior of asingle-point moored tanker, when subjected to a steady ocean current, known as fisthailing phenomenon. A critical revision of the different theoretical models at hand represents a supplementary purpose of this work. This revision was performed based on the main hydrodynamic aspects involved in common offshore applications of moored tanker ships. ) Therefore, instead of a passionate defense of any particular theoretical procedure, the work aims to provide a consistent orientation in order to help the offshore system designer to choose, between the various hydrodynamic models, the one that is more suitable for the analysis of a specific project, confident on its advantages and aware of its eventual limitations.

O projeto de submarinos é um tema que vem se desenvolvendo há muitos anos. No Brasil, vivemos um momento de pleno avanço na área, sendo encabeçado pela Marinha do Brasil com o desenvolvimento do primeiro submarino de propulsão nuclear brasileiro. No decorrer desse projeto, diversos estudos devem ser desenvolvidos, dentre eles, ensaios com modelos em escala, que serão realizados em um túnel de cavitação. Durante estes experimentos, espera-se que surjam diversas fontes de incerteza, que podem comprometer os resultados obtidos, destacando-se o efeito de blocagem hidrodinâmica. Nesse contexto, esta dissertação apresenta uma investigação do fenômeno de blocagem no modelo de submarino DARPA SUBOFF na seção de testes de um túnel de cavitação. Para isso, simulações tridimensionais de média de Reynolds (RANS) foram realizadas para o modelo de submarino posicionado no túnel (sob blocagem) e sob condição de águas profundas (referência), para diferentes ângulos de ataque e número de Reynolds (Re) constante. Coeficientes de força e momento hidrodinâmicos foram obtidos e os métodos de correção de blocagem clássico e WICS foram empregados para obter fatores que pudessem corrigir esses valores. A eficiência de cada método foi avaliada comparando os valores corrigidos com os de referência. Os resultados mostraram que ambos métodos de correção são eficientes na recuperação de coeficientes de força e momento hidrodinâmicos para razões de blocagem inferiores a 10%, mas ressalvas são feitas quanto à utilização de cada um desses métodos, sendo o método clássico indicado para o estudo de geometrias simples e o método WICS para modelos mais complexos. Paralelamente, a topologia do escoamento ao redor do submarino foi estudada através do método dos pontos críticos, para avaliar se a blocagem hidrodinâmica pode causar alterações nas estruturas presentes no escoamento. A análise topológica permitiu avaliar a evolução nas estruturas do escoamento para os ângulos de ataque e Re simulados. Foram capturadas as linhas de separação no corpo e avaliada sua relação com a tensão de cisalhamento ao longo do casco. A blocagem hidrodinâmica não causou alterações drásticas na topologia do escoamento. / The Project of submarines has been in development for years. In Brazil, we are facing a moment of full progress in this area, leaded by the Brazilian Navy with the development of the first submarine with nuclear propulsion in the country. During this project, many studies will be developed, among them, experiments with scaled models, that will be performed in a cavitation tunnel. Throughout these experiments, many sources of uncertainty are expected to arise that may compromise the results obtained, one effect that stands out is the hydrodinamic blockage. In this context, this master\'s thesis presents an investigation of the blockage phenomenon in the submarine model DARPA SUBOFF placed in the test section of a cavitation tunnel. To accomplish this, tridimensional simulations of Reynolds-Averaged Navier Stokes equations (RANS) were performed to the submarine model placed in the tunnel (under blockage) and in deep water condition (reference), to a variety of angles of attack and a constant Reynolds Number (Re). Cofficients of hydrodynamic forces and moment were measured and the classic and WICS correction methods were used to obtain factors that could correct these values. The efficiency of these methods were evaluated comparing the corrected values with the reference ones.The results showed that both correction methods are efficients in the recovery of hydrodynamic forces and moment to blockage ratios below 10%, but reservations are made about the use of each method. The classic method is suggested when simple geometries are tested and the WICS method when more complex models are used. At the same time, the flow topology around the submarine was studied, using the critical point theory, to evaluate if the hydrodynamic blockage can cause changes in the structures in the flow. The topology analysis permited to assess the evolution of structures in the flow to the conditions of angle of attack and Re simulated. Separation lines were captured in the body and their relationship with the shear stress in the hull was evaluated. The hydrodynamic blockage did not cause drastic changes in the flow topology.

The effect of acoustic and hydrodynamic cavitation on the precipitation of inorganic catalytic materials was investigated. The overall objective was to understand the fundamental factors involved in synthesizing nanometer-size catalytic materials in the 1-10 nm range in a cavitating field. Materials with grain sizes in this range have been associated with enhanced catalytic activity compared to larger grain size materials. A new chemical approach was used to produce titania supported gold by coprecipitation with higher gold yields compared to other synthesis methods. Using this approach, it was determined that acoustic cavitation was unable to influence the gold mean crystallite size compared to non-sonicated catalysts. However, gold concentration on the catalysts was found to be very important for CO oxidation activity. By decreasing the gold concentration from a weight loading of 0.50% down to approximately 0.05%, the rate of reaction per mole of gold was found to increase by a factor of 19. Hydrodynamic cavitation at low pressures (6.9-48 bar) was determined to have no effect on gold crystallite size at a fixed gold content for the same precipitation technique used in the acoustic cavitation studies. By changing the chemistry of the precipitation system, however, it was found that a synergy existed between the dilution of the gold precursor solution, the orifice diameter, and the reducing agent addition rate. Individually, these factors were found to have little effect and only their interaction allowed gold grain size control in the range of 8-80 nm. Further modification of the system chemistry and the use of hydrodynamic cavitation at pressures in excess of 690 bar allowed the systematic control of gold crystallite size in the range of 2-9 nm for catalysts containing (2.27 ± 0.17)% gold. In addition, it was shown that the enhanced mixing due to cavitation led to larger gold yields compared to classical syntheses. The control of gold grain size was gained at the loss of CO activity, which was attributed to the formation of non-removable sodium titanate species. The increased mixing associated with cavitation contributed to the activity loss by partially burying the gold and incorporating more of the sodium titanate species into the catalysts. This work produced the first evidence of hydrodynamic cavitation influencing the gold crystallite size on titania supported gold catalysts and is the only study reporting the control of grain size by simple mechanical adjustment of the experimental parameters. Despite the low activity observed due to sodium titanate, the methodology of adjusting the chemistry of a precipitating system could be used to eliminate such species. The approach of modifying the chemical precipitation kinetics relative to the dynamics of cavitation offers a general scheme for future research on cavitational processing effects.

This is a phd thesis

Localizados na interface entre a terra e o mar, sistemas estuarinos estão propensos a grandes influências de substâncias que são introduzidas por diversas fontes, incluindo rios, deposição atmosférica, efluentes e escoamento de água superficial. Estas áreas, em geral, possuem um forte gradiente de concentração de substâncias químicas, onde essas são transformadas, retidas ou eliminadas. O Canal de Piaçaguera está inserido no Sistema Estuarino de Santos e São Vicente (SESS), localizado na Bacia Hidrográfica da Baixada Santista, situada na região Região Metropolitana da Baixada Santista (RMBS), que compreende os municípios de Cubatão, Santos, São Vicente, Guarujá e Praia Grande. No SESS foram implantadas, na década de 50, diversas indústrias de base (siderurgia, petroquímica e de fertilizantes), que assim como o Porto de Santos, maior da América Latina, detém alto potencial poluidor, o que fez desse estuário um grande receptor de resíduos tóxicos e efluentes líquidos contaminados. A região do Canal de Piaçaguera, área considerada mais crítica em termos de poluição desse estuário, recebe efluentes de diversas indústrias e tem como outras importantes fontes poluidoras as atividades de dragagem, deposição atmosférica, águas provenientes de drenagem superficial, esgotos clandestinos e o Porto de Santos. O presente trabalho buscou ampliar o conhecimento da poluição das águas superficiais do Canal de Piaçaguera e verificar a influência da hidrodinâmica na contaminação dessa área e em outras áreas do estuário. Primeiramente foi realizada uma avaliação dos dados de qualidade das águas superficiais da Companhia Ambiental do Estado de São Paulo (Cetesb) medidos em pontos dos rios Mogi, Piaçaguera e Cubatão, os quais despejam suas águas no canal, dos anos de 2000 a 2010. Para estimar as concentrações e área atingidas foram realizadas simulações da dispersão de poluentes em pontos dentro e fora do canal, a partir da modelagem numérica acoplada, de hidrodinâmica e dispersão. O diagnóstico de qualidade da água indica comprometimento da qualidade ambiental dos corpos dágua estudados, visto que apresentam teores acentuados de poluentes diversos e de fontes difusas, destacando-se as industriais e dos terminais portuários. O rio Piaçaguera contribuiu com o maior número de poluentes e mais elevada concentração deles. A modelagem demonstrou que o Canal de Piaçaguera apresenta circulação com energia bem menor que outras áreas do estuário, sendo notório o menor espalhamento de poluentes nessa área, de modo que a baixa velocidade das correntes no Canal é associada a menor dispersão de partículas. Considerando o lançamento contínuo de poluentes e fatores agravantes como, baixa hidrodinâmica, a bioacumulação e resuspensão dos sedimentos contaminados, é evidente que essa área necessita de maior controle e rigidez na disposição dos materiais com alto potencial poluidor. / Located at the interface between land and sea, estuarine systems are prone to large influences of substances that are introduced by various sources, including rivers, atmospheric deposition, wastewater and surface water runoff. These areas generally have a strong concentration gradient of chemicals where these are transformed, retained or eliminated. The Piaçaguera\'s channel is inserted at the estuarine system of Santos and São Vicente (SESS), located in the Santos Basin, located in the metropolitan area of Santos (RMBS), which includes the cities of Cubatao, Santos, Sao Vicente, Guaruja and Praia Grande. At the SESS were implanted, in the 1950s, several basic industries (steel, petrochemicals and fertilizers), that as the Port of Santos, Latin America\'s largest, has high pollution potential as well as the Port of Santos, what made this a great receiver estuary of toxic waste and contaminated wastewater. The region Piaçagueras channel, an area considered most critical in terms of pollution of the estuary receives effluents from various industries and its other major pollution sources of dredging activities, atmospheric deposition, water from surface drainage, underground running down and the Port of Santos . This study aimed to expand knowledge of the pollution of surface waters of the Channel Piaçaguera and the influence of hydrodynamics on the contamination of the area. We first carried out an evaluation of the data quality of surface waters of the State Environmental Company of São Paulo (Cetesb) at the points measured in the river Mogi, Piaçaguera and Cubatão, which discharge their waters into the canal, of the years 2000 to 2010. To estimate the concentrations and area affected were carried out simulations of pollutant dispersion in points inside and outside the channel from the coupled numerical modeling of hydrodynamics and dispersion. The diagnosis of water quality indicates impairment of environmental quality of the water bodies studied, since they exhibit high values concentration of various pollutants and diffuse sources, especially the industrial and port terminals. The river Piaçaguera contributed the largest number of pollutants and the higher their concentration theirs. The modeling demonstrated that the Piaçagueras channel has circulation with far less energy than other areas of the estuary, being remarkable the lowest spread of pollutants in this area, so that the low kinetic energy of currents in the channel is associated with a lower dispersion of particles. Considering the continuous discharge of pollutants and aggravating factors such as low hydrodynamics, bioaccumulation and resuspension of contaminated sediments, it is clear that this area needs greater rigidity in the control and disposal of materials with high pollution potential.

Subsea pipelines are subjected to wave and steady current loads which cause pipeline stability problems. Current knowledge and understanding on the pipeline on-bottom stability is based on the research programmes from the 1980’s such as the Pipeline Stability Design Project (PIPESTAB) and American Gas Association (AGA) in Joint Industry Project. These projects have mainly provided information regarding hydrodynamic loads on pipeline and soil resistance in isolation. In reality, the pipeline stability problem is much more complex involving hydrodynamic loadings, pipeline response, soil resistance, embedment and pipe-soil-fluid interaction. In this thesis Computational Fluid Dynamics (CFD) modelling is used to investigate and establish the interrelationship between fluid (hydrodynamics), pipe (subsea pipeline), and soil (seabed). The effect of soil types, soil resistance, soil porosity and soil unit weight on embedment was examined. The overall pipeline stability alongside pipeline diameter and weight and hydrodynamic effect on both soil (resulting in scouring) and pipeline was also investigated. The use of CFD provided a better understanding of the complex physical processes of fluid-pipe-soil interaction. The results show that the magnitude of passive resistance is on the average eight times that of lateral resistance. Thus passive resistance is of greater significance for subsea pipeline stability design hence the reason why Coulomb’s friction theory is considered as conservative for stability design analysis, as it ignores passive resistance and underestimates lateral resistance. Previous works (such as that carried out by Lyons and DNV) concluded that soil resistance should be determined by considering Coulomb’s friction based on lateral resistance and passive resistance due to pipeline embedment, but the significance of passive resistance in pipeline stability and its variation in sand and clay soils have not be established as shown in this thesis. The results for soil porosity show that increase in pipeline stability with increasing porosity is due to increased soil liquefaction which increases soil resistance. The pipe-soil interaction model by Wagner et al. established the effect of soil porosity on lateral soil resistance but did not attribute it to soil liquefaction. Results showed that the effect of pipeline diameter and weight vary with soil type; for sand, pipeline diameter showed a greater influence on embedment with a 110% increase in embedment (considering combined effect of diameter and weight) and a 65% decrease in embedment when normalised with diameter. While pipeline weight showed a greater influence on embedment in clay with a 410% increase. The work of Gao et al. did not completely establish the combined effect of pipeline diameter and weight and soil type on stability. Results also show that pipeline instability is due to a combination of pipeline displacement due to vortex shedding and scouring effect with increasing velocity. As scoring progresses, maximum embedment is reached at the point of highest velocity. The conclusion of this thesis is that designing for optimum subsea pipeline stability without adopting an overly conservative approach requires taking into consideration the following; combined effect of hydrodynamics of fluid flow on soil type and properties, and the pipeline, and the resultant scour effect leading to pipeline embedment. These results were validated against previous experimental and analytical work of Gao et al, Brennodden et al and Griffiths.

Nosso trabalho considera o processo de exclusão simples do vizinho mais próximo evoluindo com taxas de salto aleatórias . Demonstramos o limite hidrodinâmico deste processo. Este resultado è obtido através do limite hidrodinâmico do processo de exclusão onde as taxas de salto iniciais são substituidas pelas taxas cx,N que tem a mesma distribuição para cada N maior ou igal a 1. Fazemos algumas suposições no meio c_N e consideramos que as partículas estão inicialmente distribuidas de acordo à medida produto de Bernoulli associada a um perfil inicial. / Consider a Poisson process with rate equal to 1 in IR. Consider the nearest neighbor simple exclusion process with random jump rates § where §x =\\lambda, \\lambda > 0 if there is a Poisson mark between (x, x + 1) and §x = 1 otherwise. We prove the hydrodynamic limit of this process. This result follows from the hydrodynamic limit in the case that the jump rates {§x : x inteiro} are replaced by an array {cx,N : x inteiro} having the same distribution for each N >=1.

O uso de modelos de manobras representa um auxilio importante no projeto de veículos marinhos, permitindo a verificação do desempenho destes veículos, desenvolver o sistema de piloto automático, dentre outras aplicações durante a fase de projeto. Na área de veículos submarinos, seus modelos são tradicionalmente baseados em equações de movimento que incluem expressões polinomiais para representar os esforços hidrodinâmicos. Estes modelos são derivados de uma expansão em série de Taylor de forças e momentos, sendo representados em função das variáveis de movimento. Entretanto, estes modelos limitam a representatividade dos esforços hidrodinâmicos, e, especialmente para os termos de segunda ou mais altas ordens, eles requerem ensaios custosos em tanque de provas para identificar corretamente cada um dos coeficientes polinomiais. Esta dependência em ensaios de tanque de provas tem um impacto critico, ou até mesmo não realístico, durante o desenvolvimento de veículos autônomos submarinos, AUVs, de baixo ou médio custo. Utilizando métodos atuais da fluidodinâmica computacional (CFD), este trabalho propõe um roteiro alternativo para definir os modelos de manobras não lineares para uma classe de AUVs. As simulações de CFD, verificados e validados por normas rigorosas, são utilizados como base para derivar as funções não lineares que representam os esforços hidrodinâmicos, devido variações na velocidade lateral, velocidade angular e deflexão dos lemes. A abordagem numérica é complementada pelo uso de modelos analíticos e semi-empíricos oriundos da indústria de mísseis, que tiveram que ser melhorados com informações retiradas das simulações de CFD. Ajustes adicionais e derivações nos intervalos de confiança para as estimativas produzidas por métodos numéricos também são fornecidos pelo uso de modelos analíticos e semi-empíricos. Adotando o AUV Pirajuba como caso de estudo, a validação dos modelos de manobra foi realizada em duas etapas. Primeiro, são comparadas as estimativas dos esforços hidrodinâmicos com as medições em tanque de provas de um modelo cativo, e em seguida a resposta dinâmica dos modelos de manobras são comparadas com aquelas obtidas por ensaios em mar, sempre utilizando critérios de verificação e validação. Este tipo de análise indicou uma validação dos esforços hidrodinâmicos e do movimento para grande parte dos ensaios, sendo que nos demais casos o AUV teve seu comportamento dinâmico bem reproduzido. Este resultado demonstra que a metodologia proposta pode ser utilizada para estimar o modelo de manobra de um AUV típico, gerando uma solução de menor custo para a fase de desenvolvimento destes veículos. / The use of maneuvering models represents an important assistance in the project of marine vessels, allowing for the evaluation of the vehicle performance, the autopilot system development, among other tasks during the design phase. In the field of underwater vehicles, those models commonly are based on equations of motion that include polynomial expressions for representing the hydrodynamic efforts. They are derived from Taylor series expansion of forces and moments represented as functions of the motion variables. However, those models limit the representativeness of the hydrodynamic efforts, and, especially for the second order or higher terms, they require expensive trials in towing tank facilities to correctly identify each polynomic coefficient. This dependence on intensive tank tests has a critical impact, or is even unrealistic during the development of middle or low cost autonomous underwater vehicles, AUVs. Using current methods of computational fluid dynamics (CFD), this work proposes an alternative roadmap to construct nonlinear manoeuvring models, which can be applied to a class of AUVs. CFD simulations, verified and validated by rigorous standards, are used as basis to derive nonlinear functions that represent the hydrodynamic efforts due to variations in lateral velocity, angular rate and rudder deflection. The numerical approach is complemented by the use of analytical and semi-empirical models derived from missile industry, which have been improved according to the information taken from the CFD simulations. Further adjustments and derivation of confidence intervals to the estimates produced by the numerical method are also provided by the use of analytical and semi-empirical models. Adopting the Pirajuba AUV as a test bed, the manoeuvring model validation was carried out in two stages. Firstly, estimates of hydrodynamic efforts are compared with measurements obtained from experiments using a captive model in a towing tank. In the second step, the dynamic response predicted by the maneuvering model was compared with the output measured during free model trials. This type of analysis validated the hydrodynamic efforts and motion in most of the experiments, whereas for the remaining cases the AUV had its dynamic behavior well reproduced. This result demonstrates that the proposed methodology can be used to estimate the maneuvering model of a typical type AUV, generating a lower cost solution for the development phase of the vehicle.

Ce travail de thèse s’inscrit dans le contexte général de l’étude de la dynamique de la frangelittorale. Le but de ce travail de thèse était l’étude des couplages entre les ondes de surface (vagues, ondeslongues dont les ondes infra-gravitaires), les variations du niveau marin et les courants ainsi que les variationsà haute-fréquence du niveau d’eau sur la plage et les déplacements de la nappe phréatique au sein de la plagesableuse. L’approche retenue est essentiellement expérimentale in-situ.La campagne de mesure ROUSTY201412 a permis de récolter un jeu de données hydro- morphodynamiquesconsidérable, qui viendra alimenter l’étude des plages sableuses dans de nombreux domaines. Elle permeten particulier de décrire l’ensemble d’une saison hivernale sur un même site soumis à une grande variété declimats de houles et de vents, ce qui en fait un jeu de données unique dans le contexte méditerranéen.Dans cette thèse nous nous intéressons à trois domaines d’étude : la dynamique de la surface libre avecl’analyse des relations existantes entre les différentes échelles (vagues, variations du niveau marin, ondeslongues, wave-setup, ...), la structure et l’évolution du courant ainsi que le lien avec la dynamique de surface,et la circulation souterraine dans la nappe de plage et en particulier sous la zone de swash. / This PhD work is part of the general context of littoral dynamic study. The purpose of this workwas to study couplings between surface waves (waves and long waves including infra-gravity waves), sea waterlevel variations and currents, as well as high-frequence water level variations on shoreline and groundwatermovements within sandy beaches. The approach is mostly experimental in-situ.The field campaign ROUSTY201412 allowed the collection of a substantial hydro- morphodynamic dataset,supplying sandy beaches studies in several fields. In particular, it will allow, on a same site, the descriptionof a full winter season under various waves and winds climates, making it a unique dataset in Mediterraneancontext.In this PhD, we are interested in three fields : free surface dynamics, including multi scale relations analysis(waves, water level variations, long waves, wave-setup, ...), currents structure and evolution linked withsurface dynamics, and groundwater circulation within the coastal aquifer and particularly under the swashzone.