Propagation of water waves in shallow water with emphasis on fluid-seabed interactions: advantages and imitations of 2DH Numerical Techniques

Propagation of water waves in shallow water with emphasis on fluid-seabed interactions: advantages and imitations of 2DH Numerical Techniques

Διάδοση κυμάτων σε ρηχά νερά και αλληλεπίδραση ρευστού - θαλάσσιου πυθμένα: πλεονεκτήματα και περιορισμοί υπολογιστικών προσομοιώσεων με Μοντέλα Μέσου Βάθους (EL)

Αφεντούλης, Βασίλειος (EL)

Afentoulis, Vasileios (EN)

ntua (EL)

Τσουκαλά, Βασιλική (EL)

Mohammadi, Bijan (EN)

Stamou, Anastasios (EN)

Belibassakis, Kostas (EN)

Samaras, Achilleas (EN)

Karambas, Theofanis (EN)

Tsoukala, Vasiliki (EN)

Benoit, Michel (EN)

doctoralThesis

2023-02-16T08:04:28Z

2022-11-28

This study seeks to assist in better understanding of non-cohesive sediments movement under wave-current actions. The core aim of the present dissertation is to develop novel, advanced 2DH numerical modelling techniques, and evaluate the advantages limitations of the existing ones, with the purpose of precisely simulating morphodynamic mechanisms over a variety of complex and irregular bathymetries, considering wave unsteady phenomena and several small-scale physical processes in the inner surf and swash zone. In addition, the advanced compound models, which were tailored within the context of the present research, served to assess the hydrodynamic and morphodynamic effects of a number of coastal defence types, such as submerged and emerged offshore-detached breakwaters, groynes and jetties. To analyse general sediment phenomena in erosion-dominated and high-energy coasts, numerical assessments, based on available existing devices, were carried out in selected case studies in Greece. Furthermore, laboratory experimental data analysis and advanced coupled models were used to study the incipient motion of fine-sand and morphological evolution from dissipative to intermediate and reflective beach state. Finally, inspired by the capacities and limitations of the existing numerical devices, the development of a novel and robust numerical model was achieved in purpose of practical applications. In particular, a process-based newly developed sediment transport model, with a quasi-3D approach for the assessment of suspended sediment transport, was utilized in tandem with a fully non-linear Boussinesq model to evaluate wave-current-sediment transport interactions in wave-dominated conditions, with and without the presence of coastal defences. In this context, novel 3D and 2D laboratory experimental investigations were exploited to corroborate the numerical predictions. The model validation against experimental measurements revealed that the main scope of the thesis was fulfilled satisfactorily. In summary, this work unveils several fundamental aspects of fine sediment motion under the combined and unsteady action of waves and currents. It is believed that this research will help to further enhance our understanding of how 2DH modelling techniques can be applied in an extended range of coastal engineering problems, while it can be a valuable asset for engineers and scientists desiring to obtain accurate bed level evolution predictions. (EN)

Διάδοση κυμάτων (EL)

Παράκτιες κατασκευές (EL)

Ακτομηχανική (EL)

Θαλάσσια υδροδυναμική (EL)

Παράκτια έργα (EL)

Αριθμητική μοντελοποίηση (EL)

Numerical modeling, (EN)

Coastal morphodynamics (EN)

Hydrodynamics (EN)

Coastal structures (EN)

Sediment transport (EN)

English

Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Πολιτικών Μηχανικών. Τομέας Υδατικών Πόρων και Περιβάλλοντος. Εργαστήριο Λιμενικών Έργων (EL)

Αναφορά Δημιουργού-Μη Εμπορική Χρήση 3.0 Ελλάδα

http://creativecommons.org/licenses/by-nc/3.0/gr/

National Technical University of Athens

Digital Library of National Technical University of Athens | Dspace@NTUA

Κεντρική Βιβλιοθήκη Ε.Μ.Π.

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