Abstract

Abstract

The objective of this thesis is the research on numerical algorithms to develop numerical tools to simulate seakeeping problems as well as wave resistance problems of ships and floating structures.
The first tool developed is a wave diffraction-radiation solver. It is based on the finite element method (FEM) in order to solve the Laplace equation, as well as numerical schemes based on FEM, streamline integration, and finite difference method tailored for solving the free surface boundary condition.
It has been developed numerical tools to solve solid body dynamics of multibody systems with body links across them. This tool has been integrated with the wave diffraction-radiation solver to solve wave-body interaction problems.
Also it has been tailored coupling algorithms with other numerical tools in order to solve multi-physics problems. In particular, it has been performed coupling with a MEF structural solver to solve fluid-structure interaction problems, with a mooring solver, and with a solver capable of simulating internal flows in tanks to solve couple seakeeping-sloshing problems.
Numerical simulations have been carried out to validate and verify the developed algorithms, as well as to analyze case studies in the areas of marine engineering, offshore engineering, and offshore renewable energy.

Abstract

eaports’ energy strategy should rely on the use of renewable energy. Presently, the share of renewable energy used by many of the ports worldwide is negligible. Some initiatives are in the process of implementation to produce some of the energy used by the Port of Valencia, one the largest ports in the Mediterranean Basin. Among these initiatives, a photovoltaic plant with an installed capacity of 5.5 MW is under a tendering process and the assessment studies for the deployment of three to five windmills are close to being finished. However, this is not enough to make it a “zero emissions port” as some of the energy demand would still be covered by fossil fuels. Therefore, we should consider clean alternative energy sources. This article analyses the wave energy resources in the surroundings of the Port of Valencia using a 7-year series of data obtained from numerical modelling (forecast). The spatial distribution of wave power is analysed using data from 3 SIMAR points at Valencia Bay and is compared to the data obtained by the Valencia Buoy I (removed in 2005). The obtained results are used to estimate the power matrices and the average energy output of two wave energy converters suitable to be integrated into the port’s infrastructure. Finally, the wave energy converters’ production is compared to the average amount of energy that is forecast to be obtained from other renewable sources such as solar and wind. Due to the nature of the Gulf’s wave climate (mostly low waves), the main conclusion is that the energy obtainable from the waves in the Valencia Gulf will be in correlation with such climate. However, when dealing with great energy consumers every source of production is worthwhile and further research is needed to optimize the production of energy from renewable sources and its use in an industrial environment such as ports.

Abstract

Nearly 40% of the world’s population lives within 100 kilometres of the coast with the risk that this implies in terms of exposure to the effects of climate change. Ocean energy, according to the IPCC (Intergovernmental Panel on Climate Change) in 2019, has been identified as one of the measures for mitigating these effects. In addition, ocean energy can play an essential role in achiev‐ ing some of the SDGs (Sustainable Development Goals) set at the Paris Climate Summit in 2015, namely SDG 7 (clean and affordable energy) and SDG 13 (climate action) and could have a substan‐ tial impact on others such as SDG 1 (poverty eradication), SDG 2 (end hunger), SDG 5 (gender equality), SDG 6 (universal energy access), SDG 8 (promote sustainable economic growth), SDG 9 (build resilient infrastructure), SDG 14 (sustainable conservation of oceans and seas) and SDG 17 (promote sustainable development cooperation). There are several projects under development around the world aimed at extracting energy from waves. However, to date, no technology has been found that, in general terms, is superior to others. There are several conditioning factors that prevent this type of energy from reaching the level of maturity of other marine renewable energies. These are mainly economic, technological, environmental, and regulatory, to mention the most important. This article aims to analyse the approaches that other researchers have adopted to evaluate wave energy projects and, through a prospective method of expert consultation such as the Delphi meth‐ odology, will present the most generally accepted criteria for successful wave energy projects. Sub‐ sequently, the validity of these results will be analysed for the case of the use of the energy produced for self‐consumption in ports.