Publications

The availability of clean energy of wind waves is enough to meet current demand of the world, attracting researches to find devices with good performance to extract this type of energy. The oscillating water column converter is a type of device that has been extensively studied for this purpose. This paper describes a numerical analysis of an onshore oscillating water column device taking into account hydrodynamic and aerodynamic coupling, performance curves of the turbine and air pressure control by a relief valve. The numerical analyses are carried out by the Fluinco model, based on slightly compressible flow method to solve the Navier-Stokes equations, and employing the two-step semi-implicit Taylor-Galerkin method. The aerodynamic model is based on the first law of thermodynamics applied to the air column inside the chamber and on turbines similar to Pico

O conhecimento dos esforços resultantes da interacção de uma onda com um quebra-mar verticaltorna-se essencial no dimensionamento deste tipo de estruturas. No presente trabalho, o modelo numérico SPHyCE, baseado numa metodologia de tipo SPH - Smoothed Particle Hydrodynamics, é utilizado para o cálculo das forças num quebra-mar vertical. Para analisar a evolução das forças de impacto foram consideradas várias condições de profundidade no pé da estrutura e de altura de onda incidente abrangendo diferentes regimes de forças. A comparação dos resultados do modelo numérico com os das formulações empíricas permitiu verificar que as forças previstas são semelhantes para os casos de regime de onda parcialmente estacionária. No entanto, para o regime de forças de impacto, existem diferenças que se devem a diversos factores: i) a rebentação da onda no modelo SPHyCE pode não corresponder necessariamente à forma de rebentação prevista nas formulações empíricas; ii) no caso da rebentação com aprisionamento de ar, cuja influência no valor das forças é relevante, o modelo numérico atinge o seu limite de aplicação, pois não integra o ar e não existem formulações aplicáveis; iii) as formulações empíricas aplicáveis com rebentação dão valores claramente por excesso.

Tanto el perfil como la forma en planta de las playas fluviales vienen establecidos por numerosos factoresentre los que cabría destacar las características del sedimento y la dirección y módulo de la velocidad de la corriente en el río. Sin embargo, en ciertos casos, lejos incluso de su estuario o desembocadura, esta morfología puede estar determinada principalmente por la incidencia del oleaje pese a no tratarse de un entorno marítimo.Se presenta aquí una metodología cualitativa que nos permitirá reconocer los aspectos que influyen en la existencia de este tipo de morfologías. Para ello, se estudiará un caso particular, el de la playa de La Concordia ubicada en la margen izquierda del río Uruguay a 70 km de su desembocadura en el estuario del Rio de la Plata. Asimismo se analizará la forma en planta y se verificará que la misma está determinada por la acción del oleaje.

Three submerged coastal structures on the sandy seabed at SantaMaria delMar (SMM) Beach in Southwest Spain were monitored during the sixmonths after installation, starting inNovember of 2005. The monitoring evaluated the self-burial phenomenon of the 40 precast modular concrete elements of the three structures. Assessment included scouring around the structures, their vertical movement, the sinking velocity of the modules and the resulting beach profiles. Pressure sensors and precision topographies permitted continuous monitoring of the self-burial process for the first time in a full-scale case. Comparison of two bathymetries (one performed immediately prior to installation and another performed six months after installation) indicated slight accretion of the seabed,whereas intermediate topographic surveys indicated extensive scouring around the structures. The three structures began sinking into the sandy bottomplatform immediately after placement and continued until they reached the rocky bottom. This study implemented a new methodology using pressure sensors attached to the concrete modules to monitor the structural sinking. Unexpectedly, the average sinking speed was extremely rapid at approximately 3

The effects ofwave steepness andwave breaking on the stability of wave-dissipating blocks placed on caisson breakwaters are examined by hydraulic experiments under conditions with and without wave breaking. It is confirmed that there is a clear dependence of the block stability on the wave steepness through the wave-breaking type, such as plunging and spilling breakers. The stability parameter in thespilling breaker case is larger than that in the plunging breaker case. For non-breaking wave conditions, there is no effect of the wave steepness. An empirical stability formula is proposed taking into account the effects of the wave steepness and the wave-breaking type. Finally, by using the stability formula, failure probabilities of the wave-dissipating blocks having a nominal diameter are evaluated by the first-orderreliability method of the Level II reliability analysis.

This paper describes recent advances on maritime structures

This paper presents the numerical simulations done by using the waves2Foam, an OpenFOAM® library, to simulate the propagation of regular waves without breaking in a three-dimensional flume. The numerical code solves the unsteady Navier-Stokes equations and uses a Volume-of-Fluid (VoF) method to identify the free surface. A regular incident wave with a 1.5s period and 0.1m wave height, was considered. This is one of the conditions from the wide range of wave flume tests conducted at the National Laboratory for Civil Engineering (LNEC) whose objective was to analyze the hydrodynamics of wave transformation and wave breaking for different incident conditions over a variable bathymetry. Comparisons are made between the numerical and the experimental results. These comparisons include time-series of wave-gauges records at several locations along the flume and the corresponding amplitude spectra; significant wave height and average period evolution along the flume; time-series of the velocity components at one section of the flume, measured at the middle of the water column; and hodograph representation of the velocity components, in the middle of the water column, in the xy, xz, and yz planes along the flume. It was found that the numerical results obtained are close to the experimental data. The observed differences are attributable to numerical inaccuracies as well as the differences between the wave generation method in the numerical and experimental tests.

Neste artigo, apresenta-se uma breve descrição do papel da modelação física no apoio ao projeto de obras marítimas, seguida de um exemplo de ensaios realizados no âmbito da ampliação do porto de pesca de Rabo de Peixe, São Miguel

Descrevem-se os procedimentos para avaliar o caudal médio galgado sobre um trecho de um quebra-mar de taludesa partir das caraterísticas da agitação marítima incidente no mesmo trecho. Apresenta-se uma metodologia paraestimação de valores extremos daquele caudal, partindo das séries temporais da mesma variável, e ilustram-se essesprocedimentos num trecho do molhe oeste do porto de Sines que protege o posto 2 do terminal de granéis líquidos daação da agitação marítima. Este regime de extremos do caudal médio galgado é fundamental para a avaliação do riscode ocorrência de galgamentos não admissíveis no posto 2.

An aerial monitoring system was developed for the maritime structures protecting the foundation columns of the airport infrastructure of the Madeira Island Airport, in the scope of research project MEGE, to complement the already existing monitoring program of visual observations. For the aerial monitoring of the berm breakwater, with about 770 m in length, a fast data acquisition system was envisaged. Imaging techniques acquired through a high-resolution camera coupled to an unmanned aerial vehicle (UAV) were used, which allowed for a very fast and efficient automated procedure, compatible with the difficult accessibility to the structure on the seaside. Point clouds corresponding to the breakwater geometry were obtained from the set of aerial images from the camera on board of the UAV, using photogrammetric techniques. In this paper, the two complementary parts of the monitoring of this structure are described and corresponding results are shown.

This paper aims to evaluate the impact of ships on fenders during the berthing process. Physical tests and numerical simulations with MOORNAV tool were performed with versions of the GulfStream ship in still water and under a set of different conditions. A comparative analysis was made between outputs of the two models considering specific conditions. The MOORNAV application resulted in a standard deviation from the physical model of 3% to 6% in relation to the maximum force exerted on each fender.

This paper aims to evaluate the impact of ships on fenders during the berthing process. Physical tests and numerical simulations with MOORNAV tool were performed with versions of the GulfStream ship in still water and under a set of different conditions. A comparative analysis was made between outputs of the two models considering specific conditions. The MOORNAV application resulted in a standard deviation from the physical model of 3% to 6% in relation to the maximum force exerted on each fender.

Neste trabalho, descreve-se a aplicação do programa OSOM+ às obras marítimas do Porto de Sines, em especial ao quebra-mar oeste. Assim, serão apresentados resultados de comparação entre as situações observadas em 2018 e 2020 no âmbito de inspeções visuais e com drone, mediante apreciação e análise de fotografias georreferenciadas, ortomosaicos, nuvens de pontos, modelos numéricos de superfície e perfis selecionados. É também ilustrada a forma como a aplicação e base de dados ANOSOM-WEB pode ser empregue quer durante as campanhas de observação, quer em gabinete. Conclui-se este trabalho com a apresentação das vantagens da recente atualização da metodologia e do que se julga ser a sua importância na tomada de decisões sobre a necessidade ou não de realizar obras de manutenção e/ou reparação nestas estruturas, ou similares.

Os mapas de risco costeiro, integrados em modelos de risco, são excelentes ferramentas de apoio à tomada de decisão no âmbito da gestão e proteção costeira em situações normais e de emergência [1], ajudando aproteger as populações e infraestruturas em risco de inundação costeira e galgamento oceânico proteger as populações e infraestruturas em risco de inundação costeira e galgamento oceânico.

SAFEPORT safety system aims at forecasting and alerting, on a regular basis, emergency situations regarding ships operation in port areas caused by extreme weather-oceanographic conditions. It uses forecasts provided offshore of the area under study of sea agitation, wind and tide. The characterization of the response of the free and moored ships at a berth is performed using the numerical package SWAMS. The system issue alerts, through danger levels associated with risk levels of exceedance of recommended values for movements and forces imposed on ship mooring systems. SAFEPORT can be adapted to any port. So far, it has been developed and adapted to three terminals of the port of Sines, where three different ships were simulated. This paper presents the developments made to date of the safety system, which includes tests performed in storm situations. The numerical models run every day, in real-time mode, in a computer cluster and the system provide forecast results for the next 72 hours. The results are disseminated on a web page and a mobile application in a variety of formats. It was concluded that the SAFEPORT safety system issued alerts according to the observed reality during the storm Dora. It has also been shown to be a computer tool for the optimization of ship mooring systems. The system is currently in testing and validation phase therefore, forecasts should be interpreted as indicative.

A autoridade portuária do arquipélago dos Açores, Portos dos Açores, SA, identificou a necessidade de dispor de um sistema de alerta precoce para os riscos associados à agitação marítima, nomeadamente os relacionados com os galgamentos costeiros e com os navios amarrados. No âmbito do Projeto ECOMARPORT, associaram-se com a Universidade dos Açores e o LNEC para o desenvolvimento de três novos protótipos do sistema HIDRALERTApara os portos de S. Roque do Pico, Madalena do Pico e Praia da Vitória. Os novos protótipos têm, para além da previsão de eventos de galgamento das proteções portuárias, a capacidade de prever esforços e movimentos de navios amarrados. As situações de emergência podem ser previstas, permitindo que as autoridades portuárias possam tomar medidas de mitigação para evitar a perda de vidas e minimizar os danos.

Early warning systems (EWS) are fundamental tool to reduce risks in coastal areas since they provide in advance the necessary information for the responsible authorities to mitigate the effects of possible emergency situation due to storms.

The case studies are Costa da Caparica coastal area and Ericeira port, both on the West Portuguese Coast.

The To-SEAlert project (Fortes et al. 2019) aims to include a set of tools/methodologies into the Early Warning Systems (EWS) HIDRALERTA, (Poseiro, 2019, Fortes et al., 2021, Santos et al., 2020, Zózimo et al., 2021, Ferreira, et al. 2021a) to make it more efficient reliable and robust.

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Realização de ensaios em modelo físico reduzido 3D para a avaliação da estabilidade do quebra-mar destacado do Porto Inlgês, Maio, Cabo-Verde

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Adverse sea conditions can cause emergency situations associated to wave overtopping, which endanger the safety of people and goods, with negative impacts for society, the economy and the environment. Therefore, a methodology to assess the overtopping risk in port and coastal areas is essential for a proper planning and management of these areas.The Portuguese National Laboratory for Civil Engineering (LNEC) has been developing the HIDRALERTA system, an integrated decision-support tool for port and coastal management, which focus in preventing and supporting the management of emergency situations and the long-term planning of interventions in the study areas. It enables the user to calculate the risk for various port and coastal activities, starting with the characterization of sea-waves, wind field and tide levels at the study regions.HIDRALERTA was already tested at different places in Portugal: Costa da Caparica beach, in Almada, and port of Praia da Vitória, in the Azores. However, in both cases, the evaluation of wave overtopping / flooding consequences was carried out using a quite simple approach. In fact, such consequences were assessed only at a global and qualitative level, based on information provided by the responsible authorities.This paper aims at testing a quantitative methodology to evaluate overtopping consequences: the Analytic Network Process (ANP). This methodology was proposed to solve complex decision-making problems and its objective is to calculate the priorities among decision elements which will define their final weights on the consequences. The ANP approach can produce interdependencies between criteria and compute the respective weight of each criterion. Such a network model with dependence and feedback improves the priorities derived from judgements and makes prediction more accurate. So, the ANP allows comparison among clusters of elements. Furthermore, in this methodology we take into account the impacts of alternatives on the importance of criteria, by normalizing the comparison matrix. Thus, the given alternatives can influence the ranking of criteria.Application of the ANP methodology to the case study of Praia da Vitória port is presented and a consequences level map is obtained.

Apresenta-se um novo sistema de alerta para navios amarrados em portos que se encontra em desenvolvimento no Laboratório Nacional de Engenharia Civil. O sistema SWAMS_ALERTA é um sistema de previsão e alerta baseado na avaliação do risco associado ao comportamento de navios amarrados em zonas portuárias.Os riscos associados a navios amarrados decorrem de movimentos excessivos, quer no plano horizontal, quer no plano vertical. Estes movimentos podem condicionar as atividades portuárias, nomeadamente cargas e descargas, mas em casos extremos podem levar à ocorrência de situações de emergência, tais como rotura de cabos, rotura de cabeços de amarração ou até colisões com o cais. As consequências deste tipo de situações envolvem sempre grandes prejuízos materiais e por vezes humanos.O sistema SWAMS_ALERTA utiliza as medições e previsões de agitação marítima para a determinação dos seus efeitos em termos de movimentos nos seis graus de liberdade e forças nas amarras e defensas quando o navio se encontra estacionado no cais. Para tal, o sistema recorre a uma série de modelos numéricos, interligados entre si. A comparação destes valores com valores máximos admissíveis pré-estabelecidos permite a avaliação, em tempo real, de situações de emergência e a emissão de alertas dirigidos às entidades portuárias.O sistema é constituído por 4 módulos:I

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