A combination of climate change, due to anthropogenic CO2 emissions and concerns over energy security, due to fluctuating fuel prices, has led to the UK pushing to increase its renewable energy production. Harnessing tidal stream energy is an infant sector in the UK’s renewable energy portfolio, despite the UK’s large tidal stream resource, and is harnessed through deploying tidal stream energy converters. This thesis focuses on the design of a novel vertical axis tidal turbine (VATT) called CarBine which is driven by drag force and therefore has several unique advantages, including slow rotational speed, omni-directionality and a simple design. This research focused on the optimisation of the CarBine design and was split into two areas: physical testing and numerical modelling. A conventional Savonius was also analysed in both of these respects and this enabled a direct comparison of CarBine to a competing drag force driven VATT. Physical testing measured the power of the turbines and was conducted in hydraulic flumes at both Cardiff University (CU) and IFREMER in Northern France for a range of flow conditions. Testing at IFREMER enabled the quantification of the blockage effect in the CU experiments. Physical testing resulted in the optimised design of CarBine being one with a four arm configuration. From physical testing at CU, CarBine showed inferior efficiency performance to that of the conventional Savonius, a Cp of 0.117 compared to 0.225 at U∞=0.72 m/s. As a result a hybrid of both the Savonius and CarBine was tested, namely a Savonius with flaps. However, results from physical testing showed the Savonius with flaps to have inferior performance to both CarBine and the conventional Savonius, with a Cp of 0.103 at U∞=0.72 m/s at CU. Numerical modelling was conducted using the commercial CFD software package, Ansys CFX. Both transient and steady state simulations along with 2D and 3D models were used to model both CarBine and the Savonius. Both the k-ε and SST turbulence models were used for comparison. The two degrees of rotational freedom present in the CarBine design resulted in CarBine being difficult to model precisely. The numerical modelling results were validated against the physical testing results and where available, 3D results showed closer validation than the 2D results.

Hydraulic conductivity is a measurement of the ease of movement of a fluid through a medium and is therefore a key parameter in the design of landfill leachate management systems. Hydraulic conductivity of landfilled wastes may be affected by several factors such as overburden stress from the weight of overlying waste, water content, the type, age and pre-processing of the waste, and the presence of landfill gas. A further factor that may affect leachate movement through wastes is the predominantly horizontal orientated structure of compacted wastes. This anisotropic structure may result in hydraulic conductivity in the horizontal direction being greater than that in the vertical direction. However existing research has been effectively limited to evaluating hydraulic conductivity in a single plane and so the presence of anisotropic flow in waste remains unproven. Consequently, modelling of leachate and contaminant movement in landfills may be compromised by the use of isotropic, or assumed anisotropic, hydraulic conductivity values. The object of this research has been to assess for the first time the inherent anisotropy of two different waste samples by measuring and comparing the vertical and horizontal hydraulic conductivities over a range of stresses typical of landfill conditions. In this thesis, factors affecting the measurement of hydraulic conductivity of wastes are discussed, and details of the samples tested and test methodology are given. The results of the tests are shown and alternative test methods are discussed. The effects of gas accumulation and pore water pressure on waste hydraulic conductivity encountered during testing are also reported as further research has developed from this important finding.

Multiphase flow is the simultaneous flow of two or more phases, in direct contact, and is important in the oil industry, e.g. in production wells, in sub-sea pipelines and during the drilling of wells. The behaviour of the flow will depend on the properties of the constituent phases, the flow velocities and volume fractions of the phases and the geometry of the system. In solids-in-liquid flows, measurement of the local solids volume fraction distribution and the local axial solids velocity distribution in the flow cross section is important for many reasons including health and safety and economic reasons, particularly in oil well drilling operations. However upward inclined solidsliquid flows which are frequently encountered during oil well drilling operations are not well understood. Inclined solids-liquid flows result in non- uniform profiles of the solids volume fraction and axial solids velocity in the flow cross- section. In order to measure the solids volumetric flow rate in these situations it is necessary to measure the distributions of the local solids volume fraction and the local axial solids velocity and then to integrate the product of these local properties in the flow cross section. This thesis describes the development of a non-intrusive Impedance Cross-Correlation (ICC) device to measure the local solids volume fraction distribution and the local solids axial solids velocity distribution in upward inclined solids-water flows in which these distributions are highly non-uniform. The ICC device comprises a non-conductive pipe section of 80mm internal diameter fitted with two arrays of electrodes, denoted „array A‟ and „array B‟, separated by an axial distance of 50mm. At each array, eight electrodes are equispaced over the internal circumference of the pipe. A control system consisting of a microcontroller and analogue switches is used such that, for arrays A and B, any of the eight electrodes can be configured as an "excitation electrode" (V+), a "virtual earth measurement electrode" (Ve) or an "earth electrode" (E) thus enabling the local mixture conductance in different regions of the flow cross-section to be measured and thereby allowing the local solids volume fraction in each region to be deduced. The conductance signals from arrays A and B are also cross-correlated to yield the local solids axial velocity in the regions of flow under interrogation. A number of experiments were carried out in solids-in-water flows in a flow loop with an 80 mm inner diameter, 1.68m long Perspex test section which was inclined at three different inclination angle to the vertical ( o 0 , o 15 and o 30 ). The obtained results show good quantitative agreement with previous work carried out using intrusive local probes. Integration of the flow profiles in the cross section also yielded excellent quantitative agreement with reference measurements of the mean solids volume fraction, the mean solids velocity and the solids volumetric flow rate. Furthermore, this study also showed good qualitative agreement with high speed film of the flow. It is believed that the method of velocity and volume fraction profile measurement described in this thesis is much simpler to implement, more accurate and less expensive than the currently very popular technique of dual-plane Electrical Resistance Tomography (ERT). Finally, the thesis describes a mathematical model for predicting the axial velocity distribution of inclined solids-water flows using the solids volume fraction profiles measured by the ICC device. Good agreement was obtained between the predicted velocity profiles and the velocity profiles measured using the ICC device.

Optimal cut plans for cutter suction dredgers aim to maximize operational efficiency. Maximizing operational efficiency involves minimization of stoppage time resulting from non-productive dredger movements. To automate a systematic search for optimal twodimensional cut plans for cutter suction dredgers two models with an adaptive simulated annealing-based solution approach were developed. The first model, the dredge cut nesting model, optimizes irregular stock cutting problems where stencils represent dredge cuts and sheets represent dredging areas. Stencils are collections of unit dredge cuts with dimensions related to an effective cutting width which can be achieved with the cutter suction dredger considered. The objectives of the dredge cut nesting model are to maximize sheet coverage and to minimize stencil overlap. Centroids of unit dredge cuts of final nest layouts are extracted and used as grid nodes in the second model. The second model, the dredger routing model, optimizes asymmetric travelling salesperson problems with turning costs. The objectives of the dredger routing model are to minimize total route length and sum of turning angles, and to maximize average link length. A link consists of two or more route edges which are aligned with each other to within specified limits. A significant result of this research is that an engineering application of both models showed that two-dimensional cut plans for cutter suction dredgers can be systematically optimized and that dredger routes with minimum turning costs can be found. However, results also showed that the dredger routing model is not yet sophisticated enough to find cut plans for cutter suction dredgers for which overall project execution time is minimal.

Gravel filters are potentially a low cost, low maintenance water treatment solution. They require no mechanical or electrical parts and can operate without the addition of chemicals or the need for close supervision. As such, they are an appropriate technology for treating road runoff as a component of Sustainable urban Drainage Systems (SuDS) and as an initial stage of drinking water treatment in rural areas. However, the processes by which pollutant particles are removed in gravel filters are poorly understood and practical experience shows that many filters fail long before their expected design life is reached. For this reason gravel filters are little used for drinking water treatment and, when they are incorporated into SuDS, their removal efficiency and maintenance requirements are unpredictable. The aim of this thesis was to better understand particle removal processes and the implications for gravel filter design. This was achieved through a combination of lab-based experiments and numerical modelling. • The change in conservative tracer transport characteristics with pollutant particle accumulation was assessed through column experiments. • The spatial heterogeneity of particle accumulation was measured by collecting 3D data with magnetic resonance imaging (MRI). Multiple scans of filters allowed the temporal evolution of particle accumulation to be assessed. A method for processing the raw MRI data to yield the change in 3D pore geometry was developed, assessed and applied. • A simple method for extracting and comparing pore network characteristics at different stages of particle accumulation was applied to the MRI derived geometry. • Direct modelling of the 3D MRI pore geometry with the open source software OpenFOAM allowed correlation of flow velocities with particle accumulation at each point in the pore network. Lagrangian particle tracking was used to simulate the transport of a conservative tracer through the filter. Key findings were that spatial heterogeneity in particle accumulation was influenced by both initial pore geometry and the temporal evolution of the pore network with accumulation. This was attributed to the formation of high velocity preferential flow paths that were evident in both the 3D MRI data and the numerical model of that data. Pore networks exhibited a decrease in connectivity with accumulation and this was mirrored by a decrease in the volume of the filter that was accessible to a conservative tracer. Conclusions of this thesis are that MRI is a useful tool for non-invasively assessing the spatial variability of clogging in gravel filters and, when combined with numerical modelling of the pore geometry, for establishing the link between pore velocity and particle removal. The formation of preferential flow paths is detrimental to the pollutant removal efficiency of a filter and could explain why many filters fail to produce good quality effluent well before their physical pollutant storage capacity is reached.

The work presented here is a research thesis of the Ph. D programme in The School of Computing, Science & Engineering at The University of Salford UK. The work presents the evaluation of using explicit finite element techniques for structural non-linear dynamic analysis of a floating offshore wind turbine used for harnessing wind kinetic energy and converting it to electricity. The LS-DYNA3D explicit finite element analysis programme is used in performing the evaluation of the analysis and in creating a full scale model typical to the one evaluated. The developed model (case study) is a 1.4MW power rated floating 3 blades turbine elevated at 46.5 m above main sea level a top a tripod lattice steel tower firmly resting on a moored floating concrete hull buoy, positioned on a concrete circular disk. The mooring cables supporting the floating units in the multi unit farm are designed to share seabed anchoring piles for economic reasons. The model is intended for use in moderately deep waters of up to 500m. The State-of-the-art report is presented concerning wind energy technology, floating offshore wind structures and important features of the LS-DYNA3D code. The theoretical basics for service loads experienced by the floating wind turbine are explored and the loads are quantified. The Verification and validation work on developed small models is presented to ensure confidence in the developed full scale model and the evaluation of the finite element techniques which may be applied to such structures. Development of full scale model, material properties, loads and boundary conditions are presented. Recommendations both for this model and future development are accordingly made.

En esta Tesis, se ha desarrollado el Modelo MEDiNA, que simula la circulación oceánica tridimensional del Atlántico Norte y del Mar Mediterráneo y da como resultado series temporales de salinidad, temperatura y componente u, v y w de la velocidad. Mediante la ejecución de dicho modelo, se han generado 46 años de datos que se han validado mediante la comparación de los mismos con una base de datos de climatologías (GDP), además de mediante el cálculo del transporte en los principales canales y estrechos de la cuenca occidental mediterránea y del Golfo de México. Una vez que se han validado los resultados se ha demostrado además, la capacidad que tiene el modelo MEDiNA para simular la formación y la propagación de la masa de agua MOW (Mediterranean Overflow Water) y se ha conseguido demostrar que los modelos-z, como el modelo MEDiNA, son capaces de simular adecuadamente las corrientes de densidad, como por ejemplo la MOW (Dietrich et al., 2008). Por último se han aplicado dos herramientas estadísticas para el análisis de los resultados; la primera de ellas es la técnica estadística estándar, análisis de Componentes Principales, también denominada análisis de Funciones Ortogonales Empíricas (Empirical Orthogonal Function, EOF), y la segunda son las Redes Neuronales Auto-Organizativas (Self Organizing Maps, SOM). Se ha demostrado que tanto los EOF como las SOM, además de ser potentes herramientas estadísticas, son adecuadas para estudiar en este caso, las series temporales de variables oceanográficas obtenidas a partir del modelo MEDiNA, con el fin de obtener patrones de circulación, así como la relación de éstos con los patrones atmosféricos. / In this thesis, it has developed the MEDiNA model, which simulates three-dimensional ocean circulation in the North Atlantic and the Mediterranean Sea and results time series of salinity, temperature and component u, v and w of the velocity. By implementing this model it has generated 46 years of data that it has been validated by comparing with a climatology database (GDP), and by calculating the main transport in the narrow channels Western Mediterranean basin and the Gulf of Mexico. Once it has validated the results also demonstrated the ability of the Medina model to simulate the formation and spread of the water body MOW (Mediterranean Overflow Water) and has succeeded in demonstrating that the z-models, as MEDINA model, are able to adequately simulate density currents, such as the MOW (Dietrich et al., 2008). Finally, it has applied two statistical tools for analyzing the results, the first of these is the standard statistical technique, principal component analysis, also called Empirical Orthogonal Function analysis (Empirical Orthogonal Function, EOF) and the second is Self-Organizing Neural Networks (Self Organizing Maps, SOM). Its have been shown that both, SOM and EOF, as well as being powerful statistical tools are adequate to study in this case, the time series of oceanographic variables of the model obtained from Medina, to obtain ocean patterns and their relationship to atmospheric patterns.

[ES] A través de la evolución y el desarrollo de la humanidad, la historia del individuo, de su comunidad y de la cultura, ha estado marcada por muchos esfuerzos focalizados en la creación de buenas prácticas, herramientas y tecnologías dirigidas hacia la reducción de la vulnerabilidad ante distintos tipos de riesgos. En el ámbito de la calidad, la seguridad alimentaria, la seguridad y la salud ocupacional, la gestión ambiental y la eficiencia energética, estos esfuerzos se han consolidado e integrado en instrumentos para el aseguramiento, la mejora en el desempeño y la garantía en términos de certificación de Sistemas de Gestión, conocidos internacionalmente como Normas ISO, que en la actualidad tienen un amplio abanico de posibilidades y modelos, donde los de mayor utilización corresponden al acrónimo en inglés QHSE3+: ISO 9001:2015 "Quality management systems Requirements", para la Q de calidad; ISO 45001:2018 ISO 45001, "Occupational health and safety management systems - Requirements", para la HS de seguridad y salud en el trabajo; ISO 14001:2015 Environmental management systems Requirements with guidance for use, para la E de medio ambiente; ISO 50001:2018. Energy Management Systems - Requirements with guidance for use, para la E2 de eficiencia energética. El acrónimo considera al final el signo (+), que corresponde a cualquier otro referencial que pueda ser exigido a la organización en función de la naturaleza de sus operaciones y del mercado, o que tenga relevancia en función de la naturaleza de los riesgos de la organización, como, por ejemplo, las normas ISO 21500:2012. Guidance on Project management, ISO 22000:2018. International Organization for Standardization. Food safety management systems - Requirements for any organization in the food chain, e ISO 27001:2013 Information technology - Security techniques -Information security management systems - Requirements. La presente Investigación Doctoral, desarrolla un Modelo Conceptual para los Sistemas de Gestión que cubren los referenciales "QHSE3+", bajo un enfoque integral de riesgos que incluye la perspectiva energética y otras componentes que se puedan requerir, en función de la naturaleza y particularidades del negocio. El enfoque propuesto se basa en el Diseño Sistémico, y en el desarrollo y la aplicación de herramientas dirigidas a facilitar su aplicación e implementación en las diferentes empresas, bajo aplicaciones sencillas en Excel. La estructura de la presente Tesis Doctoral se resume en seis capítulos: El capítulo 1 contiene la introducción y la presentación de los principios y elementos de la gestión integral, la administración de riesgos y el enfoque asociado al acrónimo "QHSE3+", considerando la gestión integral de riesgos y los planteamientos de ISO 31000:2018. En el capítulo 2 se describe la metodología general empleada para el desarrollo de la investigación, el estudio del estado del arte, los principios y las fuentes que enmarcan la investigación, el modelo conceptual, los requisitos, el diagnóstico, y la metodología para la planificación y el desarrollo del proyecto. El capítulo 3, los resultados del diseño del Modelo Conceptual. En el capítulo 4, la presentación de la secuencia de aplicación del modelo. El capítulo 5 contiene el Balance de Resultados cuali-cuantitativos de la aplicación preliminar del modelo. Finalmente, el capítulo 6 resume las conclusiones obtenidas en cada uno de los anteriores capítulos y presenta las posibles líneas futuras de investigación. En los Anexos, se ha incluido la referencia a las ilustraciones utilizadas en el Informe de Tesis, la referencia a los archivos de soporte, Herramientas y Plantillas Generadas, los Ejemplos de Aplicación, las Guías, y finalmente, la referencia al archivo "Una voz desde el TC 176. Entrevista a Leopoldo Colombo". / [CA] A través de tota l'evolució i el desenrotllament de la humanitat, la història de l'individu, de la seua comunitat i de la cultura ha estat marcada per molts esforços focalitzats en la creació de bones pràctiques, ferramentes i tecnologies dirigides cap a la reducció de la vulnerabilitat davant de distints tipus de riscos. En l'àmbit de la qualitat, la seguretat alimentària, la seguretat i la salut ocupacional, la gestió ambiental i l'eficiència energètica, estos esforços s'han consolidat i integrat en instruments per a l'assegurament, la millora en l'exercici i la garantia en termes de certificació de Sistemes de Gestió, coneguts internacionalment com a Normes ISO, que en l'actualitat tenen un ampli palmito de possibilitats i models, on els de major utilització corresponen a l'acrònim en anglés QHSE3+: ISO 9001:2015 "Quality management systems ¿ Requirements", per a la Q de Qualitat. ISO 45001:2018 ISO 45001, "Occupational health and safety management systems - Requirements", per a la HS de seguretat i salut en el treball. ISO 14001:2015 Environmental management systems ¿ Requirements with guidance for use, per a la E de medi ambient. ISO 50001:2018. Energy Management Systems - Requirements with guidance for use, per a la E2 de eficiència energètica. L'acrònim considera al final el signe (+), que correspon a qualsevol altre referent que pot ser exigit a l'organització en funció de la naturalesa de les seues operacions i del mercat, o la importància que té en la funció de la naturalesa dels riscos de l'Organització, com per exemple, la norma ISO 21500: 2012. Orientació sobre gestió de projectes, la norma ISO 22000: 2018. Sistemes de gestió de la innocuïtat dels aliments: requisits per a qualsevol organització de la cadena alimentària i ISO 27001: 2013 Tecnologia de la informació - Tècniques de seguretat - Sistemes de gestió de la seguretat de la informació - Requisits. La present Investigació Doctoral, desenvolupa un Model Conceptual per als Sistemes de Gestió que cobreixen els referencials "QHSE3+", sota un enfocament integral de riscos que inclou la perspectiva energètica i altres components que es puguen requerir, en funció de la naturalesa i particularitats del negoci. L'enfocament proposat es basa en el Disseny Sistèmic, i en el desenvolupament i l'aplicació d'eines dirigides a facilitar la seua aplicació i implementació en les diferents empreses, sota aplicacions senzilles en Excel. L'estructura de la present Tesi Doctoral es resumeix en sis capítols: El capítol 1 conté la introducció i la presentació dels principis i elements de la gestió integral, l'administració de riscos i l'enfocament associat a l'acrònim "QHSE3+", considerant la gestió integral de riscos i els plantejaments d'ISO 31000:2018. En el capítol 2 es descriu la metodologia general empleada per al desenvolupament de la investigació, l'estudi de l'estat de l'art, els principis i les fonts que emmarquen la investigació, el model conceptual, els requisits, el diagnòstic, i la metodologia per a la planificació i el desenvolupament del projecte. El capítol 3, els resultats del disseny del Model Conceptual. En el capítol 4, la presentació de la seqüència d'aplicació del model. El capítol 5 conté el Balanç de Resultats cuali-quantitatius de l'aplicació preliminar del model. Finalment, el capítol 6 resumeix les conclusions obtingudes en cadascun dels anteriors capítols i presenta les possibles línies futures d'investigació. En els Annexos, s'ha inclòs la referència a les il·lustracions utilitzades en l'Informe de Tesi, la referència als arxius de suport, Eines i Plantilles Generades, els Exemples d'Aplicació, les Guies, i finalment, la referència a l'arxiu "Una veu des del TC 176. Entrevista a Leopoldo Colombo". / [EN] Throughout the evolution and development of humanity, the history of the individual, their community and their culture has been characterized by many efforts focused on the creation of good practices, tools and technologies aimed at reducing vulnerability related to different types of risks. In the field of quality, food safety, occupational safety and health, environmental management and energy efficiency, these efforts have been consolidated and integrated into instruments for insurance, improvement in performance, and guarantee in terms of requirements for the certification of Management Systems. These instruments are known internationally as ISO Standards, and currently have a wide range of possibilities and models, where the most commonly used correspond to the acronym in English QHSE3+: ISO 9001:2015 "Quality management systems ¿ Requirements", for the Q of Quality. ISO 45001:2018 ISO 45001, "Occupational health and safety management systems - Requirements", for the HS of the Health and Safety. ISO 14001:2015 Environmental management systems ¿ Requirements with guidance for use, for the E of Environment. ISO 50001:2018. Energy Management Systems - Requirements with guidance for use, for the E2 of Energy Efficiency. The acronym considers at the end the sign (+), which corresponds to any other referential that may be required from the organization depending on the nature of its operations and the market, or that has relevance according to the nature of the risks of the organization, such as the ISO 21500: 2012 Standards. Guidance on project management, ISO 22000: 2018. International Organization for Standardization. Food safety management systems - Requirements for any organization in the food chain, and ISO 27001: 2013 Information technology - Security techniques - Information security management systems - Requirements. This Doctoral Research develops a Conceptual Model for Management Systems that cover the references "QHSE3+", under a comprehensive risk approach that includes the energy perspective and other components that may be required, depending on the nature and particularities of the business. The proposed approach is based on the Systemic Design, and the development and application of tools aimed at facilitating its application and implementation in different companies, under simple applications in Excel. The structure of this Doctoral Thesis is summarized in six chapters, configured as described below: Chapter 1 contains the introduction and presentation of the principles and elements of comprehensive management, risk management and the approach associated with the acronym "QHSE3 +", considering comprehensive risk management and the approaches of ISO 31000: 2018. Chapter 2 describes the general methodology used for the development of the research, the study of the state of the art, the principles and sources that frame the research, the conceptual model, the requirements, the diagnosis, and the methodology for planning. and the development of the project. Chapter 3, the results of the Conceptual Model design. In Chapter 4, the presentation of the model application sequence. Chapter 5 contains the Qualitative and Quantitative Results Balance of the preliminary application of the model. Finally, Chapter 6 summarizes the conclusions obtained in each of the previous chapters and presents the possible future lines of research. In the Annexes, the reference to the illustrations used in the Thesis Report, the reference to the support files, Generated Tools and Templates, the Application Examples, the Guides, and finally, the reference to the file "A voice from TC 176. Interview with Leopoldo Colombo ". / Poveda Orjuela, PP. (2021). Configuración de un modelo conceptual para los sistemas de gestión "qhse3+", con perspectiva de rendimiento energético y administración integral de riesgos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171277 / TESIS