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Organization → DHA → NPE → R&D projects → Non-linear Wave Transformations in Coastal Zones

> Non-linear Wave Transformations in Coastal Zones

(2000-2006).

 

OBJECTIVES

The aim of this project was to perform a comprehensive validation of wave propagation models (models based upon the linear or non-linear formulations) with classical and with real test cases.
This validation contributed to improve our knowledge on the phenomena occurring during the wave propagation in coastal zones, which, in turn, will enable a better modelling of these phenomena.

The application of wave models to classical and real test cases allowed the study of the models`behaviour in different situations of wave propagation.

This work contributed:

  1. to evaluate the advantages and disadvantages of the models;
  2. to extend the range of applicability of both types of models in coastal engineering studies;
  3. to get the background needed to the application of the model; and to the definition of model` s operational conditions.

METODOLOGY

The work to be carried out within the scope of the project, consisted of the validation of wave propagation models (models based upon the linear or non-linear formulations) with classical and real test cases. The wave propagation models studied were:

  • finite element numerical model, code-named DREAMS_CC_CR. This model is based on the elliptic version of the mild-slope equation of Kirby (1984), which was modified by adding a term corresponding to wave breaking. This numerical model includes the combined effects of refraction, diffraction and reflection of waves propagating over mild-sloping bottoms, the effects of currents and wave breaking;
  • three non-linear finite element numerical models, based on the unidirectional, one-dimensional and two-dimensional versions of the time dependent non linear mild slope equation, Nadaoka et al. (1994);
  • Two linear finite element numerical models based on the one and two-dimensional linear versions of the time dependent mild slope equation, Nadaoka et al. (1994).

The work consisted of the following tasks and sub-tasks:

  • Task 1 - Validation of the numerical finite element model DREAMS_CC_CR, for wave propagation in the presence of currents and including wave-breaking:
    1. Application of the model to practical cases for validation purposes, in order to acquire sensitivity to the harbour entrance problem and in general to the problem of sheltered zones where there currents can be present;
    2. Application of the model to practical cases for validation purposes, in order to gain a better understanding on the wave breaking problem;
    3. Establishment of the model operational conditions;
    4. Evaluation of the advantages and disadvantages of the model when applied to real test cases.
  • Task 2 - Validation of the unidirectional and one-dimensional (linear and non-linear) numerical models with literature test cases;
    1. Application of the numerical models to classical test cases;
    2. Establishment of the model operational conditions;
    3. Evaluation of the limitations of each model;
    4. Assessment of the main improvements of the nonlinear model over the fully linear approach.
  • Task 3 - Validation of the two-dimensional non-linear numerical model with test cases:
    1. Application of the numerical model to classical test cases;
    2. Application of the numerical model to real test cases;
    3. Establishment of the model operational conditions;
    4. Evaluation of the advantages and disadvantages of model when applied to real test cases;
    5. Assessment of the main improvements of the nonlinear model over the fully linear approach.
  • Task 4 - Preparation of the PhD. thesis.

 

RESULTS

Results of DREAMS_CC_CR model
Results of DREAMS_CC_CR model

 

Results of FUNWAVE (Boussinesq type model)
Results of FUNWAVE (Boussinesq type model)

 

Results of time dependent nonlinear finte element mild slope model
Results of time dependent nonlinear finte element mild slope model

 

MAIN PUBLICATIONS

FORTES, C.J.E.M. (2002) - Transformações Não-Lineares de Ondas Marítimas em Zonas Portuárias. Análise pelo Método dos Elementos Finitos. Tese de doutoramento em Eng. Mecânica, IST. Janeiro de 2002.

MIL-HOMENS, J. (2005) - Modelação Numérica da Propagação da Agitação Marítima com Modelos de Resolução de Fase. Tese de mestrado em Eng. Civil submetida ao IST, 2005.

TEAM

Coordinator : Juana Fortes

The team involved 3 research officers and two trainee researchers
Participation of : IST (DEM) and Universidade Nova de Lisboa

última modificação: 2012-04-23 16:49