Publications

In Portugal, emergency situations caused by sea waves are common, and usually have serious consequences for the economy and society. It is thus crucial to implement an early warning system to forecast the occurrence of these situations in relation to wave overtopping and flooding events in coastal/port areas. The European Framework Directive 2007/60/EC of 23 October 2007 recommended the development of risk maps and flood risk management plans, including the establishment of systems for forecasting and early warning. The national and local authorities need to implement short-term/emergency measures to prevent the loss of lives and reduce economic and environmental damage.

Nesta comunicação, descrevem-se os ensaios em modelo físico realizados com o objetivo de caracterizar o campo de ondas em torno de um navio livre, quando sujeito a condições de agitação incidente regular e irregular. Estes dados são especialmente importantes para a validação de modelos numéricos de caracterização da resposta de navios à ação da agitação incidente. Assim, para cada condição de agitação incidente, efetuaram-se medições da elevação da superfície livre e das componentes da velocidade em diversos pontos em redor do navio. Apresentam-se as seguintes análises dos dados experimentais: análise temporal e espetral (espetro de energia e wavelets) dos valores de elevação da superfície livre e análise temporal da velocidade das partículas, a meio da coluna de água. A análise temporal e espetral de cada série de medições obtida permitem a caracterização da agitação nos pontos em redor do navio, em termos de alturas, períodos e velocidade. Avalia-se também a influência do navio nas características da agitação.

Este artigo apresenta os resultados da aplicação do modelo numérico Simulating Waves Nearshore SWAN) com análises comparativas das medidas obtidas a partir dos resultados de modelagem e de edições durante as campanhas de campo em 2010 e 2012 no Litoral Setentrional do Rio Grande do Norte (NE do Brasil). O objetivo principal do presente estudo foi aplicar e validar o modelo numérico SWAN na determinação do clima de ondas, avaliar seus pontos fortes e limitações para a região de interesse. Os dados de campo realizados em dois pontos próximo da costa em profundidades de 3 m (PT_1) e 6 m (PT_2) por meio do uso de dois adcp: AWAC e AQUADOPP. Os dados adquiridos com estes equipamentos foram processados e permitiram a realização de análises espectrais de altura signifi cativa, HS (m), período médio, Tmed (s), e direção média, DIR (º). Para a implementação do modelo SWAN foram empregados para as condições de contorno os dados de agitação a partir do modelo de 3ª geração de escala oceânica Wavewatch III. Para o refi namento e aplicabilidade do modelo, foram introduzidos dados de ventos e maré locais, corrigidos com base no Manual de Engenharia Costeira (CEM), permitindo assim, melhor ajuste dos resultados da modelagem. O domínio de cálculo foi referenciado para as imensões da carta náutica 720, com três malhas regulares de diferentes dimensões e resolução: externa, intermediária e interna, sendo esta última, utilizada para fornecer os parâmetros de propagação da onda ao longo da costa. As confi gurações usadas para o SWAN foram as padrões em modo estacionário, com as formulações KOMEN, a dissipação devido à rebentação induzida pelo fundo com atrito de fundo usando a formulação JONSWAP com coefi ciente de atrito

Wave energy extraction in coastal regions may be an excellent alternative due to the increase in global demand for renewable energy. The viability study of this extraction depends on the evaluation of the wave energy potential that is higher in regions located in high latitudes. Therefore, this study shows evaluation and characterization of wave energy in the south of Brazil. Numerical simulations were carried out by the Mike 21 SW spectral model which was calibrated and validated in the region measurement campaigns. Annual, seasonal and monthly means and the temporal variability of the wave energy potential in a 10-year wave hindcast were analyzed offshore and nearshore. Annual mean fluxes in three points nearshore had similar values; the highest one was 6.7 kW/m, while the wave energy flux offshore was 22.3 kW/m. The refraction and the bottom friction dissipation were responsible for the wave attenuation from offshore to nearshore and, consequently, for the decrease in wave energy. The annual, seasonal and monthly variabilities of wave energy fluxes were moderate offshore and high nearshore. A directional analysis showed that the dominant wave directions were S and NE offshore whereas they were SSE and E nearshore.

No presente trabalho descreve-se a aplicação de uma metodologia para avaliação das consequências do galgamento no porto de Ponta Delgada, S. Miguel, Açores, recorrendo a uma análise multicritério (Processo de Análise Hierárquica, AHP) do impacto da ocorrência de galgamentos superiores aos limites admissíveis. Esta metodologia permite obter resultados baseados numa análise espacial dos indicadores que caraterizam a zona portuária em estudo, no que diz respeito à sua importância relativa.

This paper describes the analysis of the propagation of regular and irregular waves in a flume by using Fluent® model, which is based on the Navier-Stokes (NS) equations and employs the finite volume method and the Volume of Fluid (VoF) technique to deal with two-phase flows (air and water). At the end of the flume, a numerical beach is used to suppress wave reflections. The methodology consists of adding a damping sink term to the momentum equation. In this study, this term is calibrated for three cases of regular incident waves (H = 1 m, T = 5, 7.5, and 12 s) by varying the linear and quadratic damping coefficients of the formulation. In general, while lower values of damping coefficients cause residuals on the free surface elevation due to wave interactions with the outlet boundary, reflection occurs on the numerical beach when higher values are used. A range of optimal damping coefficients are found considering one of them null. In one of these cases, temporal series of free surface elevation are compared with theoretical ones and very good agreement is reached. Afterwards, an irregular wave propagation, characterized by a JONSWAP spectrum, is investigated. Several gauges along the flume are evaluated and good agreement between the spectrum obtained numerically and the ones imposed at beginning of the flume is verified. This study shows the capacity of NS models, such as Fluent®, to simulate adequately regular and irregular wave propagations in a flume with numerical beach to avoid reflections.

Scale-model tests are usually required to evaluate the hydraulic and structural behavior of proposed rubble-mound breakwater designs. In order to speed up and ease the armor layer damage assessment, we developed a technique based on stereo photogrammetry. A key feature of this technique is its ability to compensate for the refraction in the air-water interface, thus producing a survey of the envelope of the armor layer without the need to empty the wave flume or wave basin where the scale model tests are carried out. This article describes this technique and the tests made to establish confidence in it and in the damage evaluation on a breakwater scale model. Results led to an error estimation of only fractions of a centimeter.

A set of physical model tests was run in to characterize the ship

The ultimate goal of applying SWASH in the present work is to compare SWASH wave height results with laboratory results presented in Løvås (2000) and with field observations of Vo-Luong and Massel (2008) as well. Additionally, SWASH results will be also compared to the ones previously obtained by other empirical and numerical models (Mendez and Losada, 2004; Suzuki et al., 2012).Preliminary SWASH wave height simulations for breaking random waves over vegetation have shown an overall good agreement to the flume data presented in Løvås (2000). The agreement between SWASH and flume results looked worst at the wave breaking zone, which seems to be improved through a better wave breaking parametrization.

Most of the previous studies on wave propagation over vegetation fields estimated drag coefficients (CD) for rigid and flexible plants by the so called calibration method which gave similar CD for both types of plants. However, CD may actually be considerably different when the drag force is directly measured. In order to investigate the wave dissipation and CD further, flume experiments for wave propagation over vegetation are conducted with a special focus on the benchmark single cylinder test that calculates CD by direct measurements in single rigid and flexible artificial plants.

O projeto BSafe4Sea visa desenvolver, testar e comprovar o conceito de previsão do comportamento estrutural de quebra-mares de talude como a base de um sistema inovador de apoio à decisão. A utilização de fotografias aéreas obtidas com veículos aéreos não tripulados, de vídeo e de posicionamento com GNSS, juntamente com a avaliação probabilística do comportamento dos quebra-mares baseada em modelos físicos e numéricos, apoiarão o planeamento e a priorização de trabalhos de manutenção e reparação, aumentando a segurança, funcionalidade e resiliência destas obras. Este sistema é urgente devido à sua relevância para as modernas redes de transporte de mercadorias e passageiros e às condições extremas a que os quebra-mares estão sujeitos, e que se poderão agravar devido às alterações climáticas.

This paper describes a programme under the responsibility of LNEC for the systematic observation and monitoring of maritime works that has successfully been applied to an extensive number of maritime structures on the Portuguese mainland coast and abroad.The now-called OSOM+ programme comprises the following four main components for each structure: periodic visual inspections by an experienced technician; periodic aerial inspections with a UAV/drone; a ANOSOM-GIS database, to store and/or query obtained information on the observation campaigns, as well as to diagnose present, evolution and risk conditions of the structure; a mobile, portable, application, for real-time input and visualization of the database information.This recently updated methodology encompasses a number of tools and functionalities that are illustrated in this paper with applications to a real case, the Faro-Olhão

In this paper, the development of such system, called SWAMS ALERT, is detailed and an illustration on how it applies to a real port is presented, namely the port of S. Roque do Pico. SWAMS ALERT is as risk forecast and management system for the safety of transiting ships and moored ships in ports and harbors. This system can be fine-tuned to a specific port, thus becoming a valuable tool to help in the selection of docking and mooring devices. SWAMS ALERT extends the functionality of the wave overtopping events forecast system HIDRALERTA to include the ship

Since 1986, the National Laboratory for Civil Engineering (LNEC) has developed a program for Systematic Observation of Maritime Works (OSOM) for the structures under the responsibility of the former Port and Maritime Transport Institute (IPTM).The objective of this program is to monitor the behavior of the structures and recommend timely interventions for their maintenance and/or repair. Recently, with the acquisition by LNEC of an unmanned aerial vehicle (UAV, or drone), a number of structural surveys have been carried out to complement the information obtained in above mentioned visual observation campaigns. The UAV provides more detailed and accurate information on the state of the structures. It also allows the assessment of the evolution of structures

Neste artigo descreve-se o trabalho desenvolvido, até ao presente na construção, desenvolvimento e implementação dos 2 novos protótipos do sistema HIDRALERTA para os portos da Madalena do Pico e de S. Roque do Pico, ambos na Ilha do Pico, Açores. Este sistema permite a previsão e alerta de situações de emergência relacionadas com agitação marítima, galgamentos, inundações.

The recent acquisition of an UAV (Unmanned Aerial Vehicle), or drone, has enriched ongoing LNEC

Nesta comunicação analisa-se a influência da variação da profundidade na interação hidrodinâmica entre dois navios, um estacionário e outro navegando na vizinhança, com recurso à modelação física e numérica. O navio em movimento é um modelo autopropulsionado à escala do navio de transporte de produtos químicos

O conhecimento das forças devido à ação das ondas que atuam nos emissários submarinos compostos por uma conduta e anéis de estabilização de betão, para agitação com direção de propagação próxima da direção do emissário, é essencial para o seu dimensionamento. Esta é uma configuração complexa, para a qual a modelação numérica, utilizando modelos 3D de tipo RANS-VoF (Reynolds-Average-Navier-Stokes Volume-of-Fluid), é especialmente adequada para obter uma estimativa das forças na conduta e nos anéis. O presente estudo consiste na simulação de um emissário submarino com anéis de estabilização à escala 1:15 que foi ensaiado num tanque de ondas tridimensional, nas instalações do Danish Hydraulics Institute (DHI), para estudar a influência da direção da agitação incidente e da distância da conduta ao fundo nas forças que atuam no emissário. Foram realizados ensaios sem e com anéis (2 tipos de anéis), para diferentes condições de agitação e direções de agitação incidente (90º, i.e., perpendicular à conduta, 30º e 10º) e para três distâncias da conduta ao fundo (0.0, 0.020 e 0.033m). Os resultados numéricos são comparados aos experimentais para agitação com direcção de propagação perpendicular ao emissário, para 3 alturas de onda incidente. Verificou-se que o modelo de turbulência k-

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A major objective of TRA LISBON 2022 Conference is to boost research and innovation capacity for the transport sector, throughout a full innovation cycle, from idea to market. Having this in view, the project

The demonstration area will be one of the main focus points of TRA LISBON 2022, presenting multifunctional spaces and being prepared to receive a large number of different types of on-site demonstrations (indoor and outdoor). On-line demonstrations will also be an option, allowing for the widest possible coverage of access for all the participants.The dedicated areas will allow for interactive demonstrations of technological innovations to be carried out by and for industry partners, researchers, and other stakeholders. Demonstrations are an excellent opportunity to introduce conference attendees in an engaging way, as well as to promote new contacts and promising business.

According to the CSA project plan, WP5.2 task objective is to organize technical tours that feature attractive and interactive showcases aiming at engaging participants into novel technologies for all transport modes and enabling stakeholders and their companies to disseminate and even sell their products and applications to all interested parties.

This report is part of HYDRALAB+ Work Package 10, which seeks to strengthen the coherence of experimental hydraulic and hydrodynamic research undertaken by the HYDRALAB+ partner organisations. It outlines the work carried out by Samui Design & Management Ltd, supported by HR Wallingford, in relation to the development of a data repository structure that can be adopted by participants of the HYDRALAB+ project.

Reliable prediction of wave run-up/overtopping and structure damage is a key task in the design and safety assessment of coastal and harbor structures. Run-up/overtopping and damage must be below acceptable limits, both in extreme and in normal operating conditions, to guarantee the stability of the structure and the safety of people and assets on and behind the structure. The mean-sea-level rise caused by climate change and its effects on wave climate may increase the number and intensity of run-up/overtopping events and make the existing coastal/harbor structures more vulnerable to damage.Accurate estimates, through physical modelling, of the statistics of overtopping waves for a set of climate change conditions, are needed. The research project HYDRALAB+ (H2020-INFRAIA-2014-2015) gathers an advanced network of environmental hydraulic institutes in Europe, which provides access to a suite of environmental hydraulic facilities. They play a vital role in the development of climate change adaptation strategies, by allowing the direct testing of adaptation measures and by providing data for numerical model calibration and validation. The use of physical (scale) models allows the simulation of extreme events as they are now, and as they are projected to be under different climate change scenarios.The enclosed dataset refers to the experimental work developed at LNEC within HYDRALAB+ and considers 2D damage and overtopping tests for a rock armor slope, with four different approaches to represent storms. Data of free surface elevation, overtopping and damage is presented.

The HYDRALAB+ project is aimed at strengthening the coherence of experimental hydraulic and hydrodynamic research undertaken across its partner organisations. This report is D10.2 of the HYDRALAB+ project, entitled

The HYDRALAB+ project is aimed at strengthening the coherence of experimental hydraulic and hydrodynamic research undertaken across its partner organisations. This report is D10.3 of the HYDRALAB+ project, entitled

This deliverable is related to task 8.2

Neste relatório inicial são apresentadas a arquitetura e as caraterísticas gerais dos protótipos do sistema de previsão, alerta e gestão de riscos causados pela agitação marítima para os portos de Madalena do Pico, São Roque do Pico e Praia da Vitória. Os três protótipos em desenvolvimento têm por base uma arquitetura semelhante, com características distintas, nomeadamente no que respeita à localização dos dados de base, às malhas computacionais utilizadas e às características físicas das fronteiras, tanto no plano horizontal (interface terra-mar), como no vertical (batimetria dos fundos). Caracteriza-se o layout geral dos portos, bem como a sua morfologia e operabilidade.

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