Papers
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Numerical and Experimental Modeling of Regular Wave Interacting with Composite Breakwater
Numerical modeling of the interaction between waves and coastal structures is a challenge due to the many nonlinearphenomena involved, such as wave propagation, wave transformation with water depth, interaction between incident andreflected waves, runup/rundown and wave overtopping. For simulating such complex free-surface flows, numerical modelsbased on Lagrangian formulation, such as Smoothed Particle Hydrodynamics (SPH), are on option. Even though validationof these numerical models is essential, comparing numerical results with experimental data is not an easy task. In thepresent paper, an SPH numerical model is validated comparing numerical results of waves interacting with a compositebreakwater with data obtained from physical model tests carried out in one of the LNEC
Year: 2013
Number Pages:
46-54pp.
Author(s): Didier, E.; Martins, R.; Neves, M. G.
: International Journal of Offshore and Polar Engineering
Volume:
Vol. 23, No. 1.
Keywords: Physical modeling; Impact loads; Coastal engineering; Wave-structure interaction; Smoothed particle hydrodynamics (sph)
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Numerical modeling of groin impact on nearshore hydrodynamics
Groins are cross shore structures built to promote shoreline stabilization. However, the specific impact of these structures on the wave conditions and velocity field nearshore (and hence, on sediment transport) is still poorly understood. Therefore, this study wishes to extend this knowledge using a numerical model, COULWAVE, previously validated with field data. For that, a typical bar-trough profile is considered and different groin lengths and orientations are tested, under the influence of different significant incident-wave heights and sea-surface levels.The hydrodynamics factors are found to have a greater impact on the nearshore wave conditions than the groin geometry. The variation of significant incident-wave height imparts the greater changes in wave height nearshore, where the groin would be located. The typical tidal range is also important, since a 2 m change in sea surface level can cause great depth changes over bathymetric features and thus influence wave propagation. Although less important, the geometry of the groin should also be considered. The greater the length, the greater the sheltering effect expected, extending further to the lee-side of the groin. The impact will also reach a broader region. With a smaller impact verified, the best orientation of the groin is hard to unravel.
Year: 2013
Number Pages:
16p.
Author(s): Rocha, M.; Coelho, C.; Fortes, C. J. E. M.
: Ocean Engineering
Keywords: Groins; Coulwave; Numerical modeling; Nearshore hydrodynamics
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Numerical simulation of an oscillating water column device using a code based on NaviereStokes equations
The study of ways of converting ocean wave energy into a useful one and the improvement of theexisting equipment are complex engineering problems and very important issues in today
Year: 2013
Number Pages:
513-530pp.
Author(s): Teixeira, P.; Davyt D.P.; Didier, E.; Ramalhais R.
: Energy
Volume:
Volume 61.
Keywords: Turbine model; Oscillating water column; Wave energy; Finite element method; Numerical simulation
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Preliminary phases of the HIDRALERTA system: Assessment of the flood levels at S. João da Caparica beach, Portugal
The length of the Portuguese coast, the severity of the sea conditions and the concentration of population and economic activities on its coastal zone justify the importance of studying wave-induced risks and, in particular, flooding due to wave action. Indeed, emergency situations caused by adverse sea conditions are frequent and put in danger the safety of people and goods, with negative impacts for society, economy and natural heritage. So, assessing the risk of flooding of coastal and port areas is essential for the proper planning and management of these areas. In this framework, a methodology for the flood risk assessment in coastal and port areas is under development. The methodology is embedded into the HIDRALERTA system, a novel integrated system for port and coastal management, designed to prevent emergency situations, to support their management and to forecast incidental long-term interventions. The present paper describes the methodology, the HIDRALERTA system and a case study, the São João da Caparica beach, on the Lisbon
Year: 2013
Number Pages:
808-813pp.
Author(s): Raposeiro, P.; Fortes, C. J. E. M.; Capitão, R.; Reis, M. T.; Ferreira, J.; Pereira, M.; Guerreiro, J.
: Journal of Coastal Research
Volume:
Special Issue No. 65.
Keywords: Costa da caparica; Flooding; Numerical models; Geographic information system; Coastal planning and management
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REDUCCIÓN DE LA REFLEXIÓN EN EL INTERIOR DEL PUERTO DE VILA DO PORTO, AZORES
Para reducir la agitación en el interior del puerto de Vila do Porto, Azores, se ha proyectado una modificación del muelle interior de atraque de los ferries, con el objetivo de aminorar la reflexión y disminuir el rebase, sin que con eso se reduzca demasiado el área útil de la dársena portuaria. La solución propuesta es una plataforma de forma triangular en planta apoyada en pilares rectangulares, bajo la cual se ha colocado un talud de escollera para disminuir la reflexión. Se presentan los resultados de ensayos en modelo físico 3D y los obtenidos con dos modelos numéricos RANS en lo que se refiere a presiones en la plataforma y reducción de la reflexión (el modelo IH-2VOF y el FLUENT).
Year: 2013
Number Pages:
139-148pp.
Author(s): Neves, M. G.; Didier, E.; Robert, M.; Losada, I.
: Revista Iberoamericana de Ingeniería Mecánica
Volume:
Vol. 17, N.º 2,.
Keywords: Modelos rans; Modelado físico; Puerto; Reflexión
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Risk assessment in submarine outfall projects: The case of Portugal
Submarine outfalls need to be evaluated as part of an integrated environmental protection system forcoastal areas. Although outfalls are tight with the diversity of economic activities along a denselypopulated coastline being effluent treatment and effluent reuse a sign of economic prosperity, precautionsmust be taken in the construction of these structures. They must be designed so as to have the leastpossible impact on the environment and at the same time be economically viable. This paper outlines theinitial phases of a risk assessment procedure for submarine outfall projects. This approach includesa cost-benefit analysis in which risks are systematically minimized or eliminated. The methods used inthis study also allow for randomness and uncertainty. The input for the analysis is a wide range ofinformation and data concerning the failure probability of outfalls and the consequences of an operationalstoppage or failure.As part of this risk assessment, target design levels of reliability, functionality, and operationality weredefined for the outfalls. These levels were based on an inventory of risks associated with suchconstruction projects, and thus afforded the possibility of identifying possible failure modes. Thisassessment procedure was then applied to four case studies in Portugal. The results obtained were thevalues concerning the useful life of the outfalls at the four sites and their joint probability of failureagainst the principal failure modes assigned to ultimate and serviceability limit states. Also defined werethe minimum operationality of these outfalls, the average number of admissible technical breakdowns,and the maximum allowed duration of a stoppage mode. It was found that these values were inconsonance with the nature of the effluent (tourist-related, industrial, or mixed) as well as its importancefor the local economy. Even more important, this risk assessment procedure was able to measure theimpact of the outfalls on human health and the environment.
Year: 2013
Number Pages:
186-195pp.
Author(s): Mendonça, A. C.; Losada, M. A.; Reis, M. T.; Neves, M. G.
: Journal of Environmental Management
Volume:
116.
Keywords: Failure modes; Limit states; Risk assessment; Submarine outfalls
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SIMULAÇÃO NUMÉRICA DO COMPORTAMENTO DE NAVIOS AMARRADOS EM BACIAS ABRIGADAS
Neste artigo descreve-se a ferramenta numérica SWAMS que se baseia nos modelosnuméricos DREAMS, BOUSS-WMH e MOORNAV para caracterizar a resposta dum navioamarrado no interior dum porto sujeito à acção da agitação marítima. Os dois primeirosmodelos simulam a propagação de ondas lineares e não lineares em zonas abrigadas deprofundidade variável, tendo em conta os fenómenos da refracção, difracção, reflexãoparcial, dissipação de energia devida ao atrito de fundo e rebentação das ondas. Enquantoo modelo DREAMS é um modelo linear baseado na equação de declive suave, o modelonão linear BOUSS-WMH é baseado nas equações de Boussinesq. O comportamento donavio amarrado é simulado com o pacote numérico MOORNAV que engloba um modelonumérico para resolver, no domínio da frequência, os problemas de radiação e de difraçãoda interacção de corpos flutuantes com ondas e um modelo que converte os resultadosdaqueles problemas do domínio do tempo para o domínio da frequência e que monta eresolve as equações do movimento do navio amarrado, BAS.Apresentam-se asmodificações introduzidas no modelo WAMIT para calcular as forças de difracção com basenas relações apresentadas em Haskind. Tais relações, porque utilizam o potencial develocidades obtido com o modelo DREAMS ou com o modelo BOUSS-WMH, permitemlevar em conta a refracção, difracção ou reflexão que podem ocorrer na propagação dasondas para o interior de uma bacia abrigada. Para além da descrição dos modelosnuméricos na ferramenta SWAMS, apresenta-se a forma como os resultados sãotransferidos entre eles bem como aplicações da mesma para ilustrar as suas capacidades.
Year: 2013
Number Pages:
85-103pp.
Author(s): Pinheiro, L.; Santos, J. A.; Fortes, C. J. E. M.
: VETOR - Revista de Ciências Exatas e Engenharias
Volume:
v.23, n.1.
Keywords: Swams; Portos; Modelos numéricos; Navio amarrado; Agitação marítima
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Wave Runup and Overtopping at Seawalls Built on Land and in Very Shallow Water
The current study proposes prediction formulas both for random wave runup and mean overtopping discharge at seawalls constructedon land or in very shallow water. Although several existing formulas for runup and overtopping use the incident wave characteristicsat the toes of seawalls, this study adopts the equivalent deepwater wave characteristics and an imaginary seawall slope for easy application of theformulas, especially in relation to seawalls constructed on land. The prediction formulas for overtopping use the predicted runup values. For thewave runup prediction formulas two sets of experimental data are used; i.e., a new set of data and the data obtained in a previous study. For thewave overtopping prediction formulas, the experimental data measured in a previous study are used. Comparisons with measurements showgood performances of both new prediction methods.
Year: 2013
Number Pages:
346-357pp.
Author(s): Mase, H.; Tamada, T.; Yasuda, T.; Hedges, T.; Reis, M. T.
: JOURNAL OF WATERWAY, PORT, COASTAL, AND OCEAN ENGINEERING
Volume:
Vol. 139(5).
Keywords: Imaginary seawall slope; Seawalls near shoreline; Wave overtopping; Wave runup
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A Semi-Infinite Numerical Wave Flume using Smoothed Particle Hydrodynamics
This paper presents the new boundary condition implemented in the LNEC SPH numerical model based on theSPHysics model and on a standard Smoothed Particle Hydrodynamic formulation: the piston-type wave maker includesnow dynamic wave absorption and allows simulating a semi-infinite flume. Verification of the active wave makerabsorption is carried out through the simulation of the interaction between a regular incident wave and an impermeablevertical breakwater. Results show that the active wave-maker allows outgoing waves to be absorbed and reflection at thewave-maker to be avoided
Year: 2012
Number Pages:
193
Author(s): Didier, E.; Neves, M. G.
: International Journal of Offshore and Polar Engineering
Volume:
22, No. 3.
Keywords: Coastal engineering; Wave dynamic absorption; Smoothed particle hydrodynamics (sph)
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Análise comparativa entre medições in situ e estimativas numéricas na Praia da Cornélia, Costa da Caparica, Portugal
Este artigo aborda a análise comparativa entre as medições de agitação marítima efectuadas na Praia da Cornélia (Costa da Caparica, Portugal), durante os dias 12 a 14 de Maio de 2010, e os resultados numéricos da aplicação do modelo não-linear do tipo Boussinesq, COULWAVE. Esta análise tem como principal objectivo a avaliação do desempenho deste modelo numérico na simulação da propagação de ondas em condições reais, pretendendo evidenciar, deste modo, as suas potencialidades e limitações.As condições de fronteira do modelo foram geradas com base em séries temporais de elevação medidas a uma profundidade aproximada de 7.6 m (relativa ao zero hidrográfico
Year: 2012
Number Pages:
147-157pp.
Author(s): Rocha, M.; Moura, T.; Fortes, C. J. E. M.; Capitão, R.; Bezerra, M.; Sancho, F. E.
: Revista da Gestão Costeira Integrada/ Journal of Integrated Coastal Zone Management
Volume:
12(2).
Keywords: Praia da cornélia; Modelação numérica; Rebentação; Propagação das ondas
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Integrated Harbour Navigation Control System NATO PO-NAVIGATION - The Port of Sines VTS/VTMIS
N/A
Year: 2000
Number Pages:
31 p.
Author(s): Covas, J. A.
Editor: ******
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A numerical model for wave propagation under current effects
N/A
Year: 1999
Number Pages:
10 p.
Author(s): Fortes, C. J. E. M.; Santos, A. V.; Fernandes, J. L. M.
Editor: ******
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Análise do colapso de uma estrutura flutuante amarrada
N/A
Year: 1999
Number Pages:
18 p.
Author(s): Santos, J. A.; Marcos Rita, M.
Editor: ******
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Definição de Regimes de Agitação Marítima - Casos de Estudo
N/A
Year: 1999
Number Pages:
15 p.
Author(s): Capitão, R.; Fortes, C. J. E. M.; Carvalho, M. M.; Covas, J. A.
Editor: ******
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Estudo de ressonância do porto de Sines
N/A
Year: 1999
Number Pages:
11 p.
Author(s): Neves, M. G.; Losada, M. A.; Losada, I.
Editor: ******
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Experimental study on the functionality of a submerged horizontal porous plate
N/A
Year: 1999
Number Pages:
5 p.
Author(s): Neves, M. G.; Losada, M. A.; Losada, I.
Editor: ******
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Long-wave interaction with coastal structures
N/A
Year: 1999
Number Pages:
9 p.
Author(s): Santos, J. A.; Peregrine, D. H.
Editor: ******
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Modelling of 3D currents around a detached breakwater
N/A
Year: 1999
Number Pages:
5 p.
Author(s): Sancho, F. E.; Fortes, C. J. E. M.; Fernandes, J. L. M.; Svendsen, I. A.
Editor: ******
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On the wave field and wave induced current field around a datached breakwater
N/A
Year: 1999
Number Pages:
10 p.
Author(s): Sancho, F. E.; Fortes, C. J. E. M.; Fernandes, J. L. M.; Svendsen, I. A.
Editor: ******
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Perfil de equilíbrio de uma praia com barra-fossa (Equilibrium profile of barred beaches)
N/A
Year: 1999
Number Pages:
19 p.
Author(s): Sancho, F. E.
Editor: ******
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