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1
Park, Jinhyung. "Pipe-routing algorithm development for a ship engine room design". Thesis, online access from Digital Dissertation Consortium access full-text, 2002. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3062999.
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Holm, Herman. "Ice-Induced Loads on Ship Hulls". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18651.
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The calculation of ice-induced loads on ships is still mainly based on empirical models. In order to gain a better physical understanding of the loading on ice-going vessels, Det Norske Veritas launched an <i>ice load monitoring<i> project involving full scale trials with the coastguard vessel KV Svalbard during the winters 2006, 2007 and 2011. The results from the full scale measurements conducted with KV Svalbard has been topic of several earlier master's thesis at NTNU,The master thesis consists of four parts. The first part is a literature review of the mechanical and physical properties of sea ice.The second part is a review of the rule sets developed by DNV and the IACS regarding vessels operating in ice infested waters. Both design principles and numerical values have been evaluated. The main difference between the designs principles used, is that IACS base their rules on a plastic method of approach, while DNV uses an elastic method. Despite the difference in the design principles, when comparing their numerical values turned out to be quite similar. The DNV rules are in general most conservative for the smaller vessels and the IACS rules the most conservative for large vessels. The third part consists of a finite element study of a part of the bow on KV Svalbard. A systematic load scheme is used, consisting of 102 load cases. For each of the stress factors there where made graphs that showed the stress at the sensor location when moving the patch load. The sensor mounted on the frame were able to measure load that was within the frame loading area and sensor mounted on the stringer could measure stress for all of the load cases in the horizontal directions. One of the explanations for this is that the stringer transfers stress from the load patch area that could be measured by the sensors.The last part consists of a comparison between measurements from the full scale trials and the results from the 102 load cases. This comparison is done through a weighted summation method where 5 different load cases are combined to represent the measured result, and a load factor is calculated for each load case for its contribution of the measured results. The stress component used in this comparison is the shear stress tau xy The load cases were tested against the 11 measurements from the full scale trials. There were in total 11 load cases that gave positive factors for all of the 11 measurements at the same time. A figure was made to show which load cases were likely to contribute in the solution of the load cases. Load cases inside the frame loading area have the largest load factors for the solution of measurements.This load decision scheme is very sensitive to the selection of load cases and boundary conditions. A change of the boundary conditions for the model was tried out for 7 load cases, and with changed boundary conditions, only 5 gave positive load factors.The results of this thesis shows that is possible to find many solution to the measured result by combining many load case, but is it not possible to decide <i>the<i> solution.
3
Yu, Lei. "Fatigue reliability of ship structures". Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/2259/.
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Today we are sitting on a huge wealth of structural reliability theory but its application in ship design and construction is far behind. Researchers and practitioners face a daunting task of dove-tailing the theoretical achievements into the established processes in the industry. The research is aimed to create a computational framework to facilitate fatigue reliability of ship structures. Modeling, transformation and optimization, the three key elements underlying the success of computational mechanics are adopted as the basic methodology through the research. The whole work is presented in a way that is most suitable for software development. The foundation of the framework is constituted of reliability methods at component level. Looking at the second-moment reliability theory from a minimum distance point of view the author derives a generic set of formulations that incorporate all major first and second order reliability methods (FORM, SORM). Practical ways to treat correlation and non- Gaussian variables are discussed in detail. Monte Carlo simulation (MCS) also accounts for significant part of the research with emphasis on variance reduction techniques in a proposed Markov chain kernel method. Existing response surface methods (RSM) are reviewed and improved with much weight given to sampling techniques and determination of the quadratic form. Time-variant problem is touched upon and methods to convert it to nested reliability problems are discussed. In the upper layer of the framework common fatigue damage models are compared. Random process simulation and rain-flow counting are used to study effect of wide-banded non-Gaussian process. At the center of this layer is spectral fatigue analysis based on SN curve and first-principle stress and hydrodynamic analysis. Pseudo-excitation is introduced to get linear equivalent stress RAO in the non-linear ship-wave system. Finally response surface method is applied to this model to calculate probability of failure and design sensitivity in the case studies of a double hull oil tanker and a bulk carrier.
4
Li, Chenxuan. "Risk management in ship finance : a marine insurance perspective". Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/33735.
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The long-standing concept of risk management in the financial sector has attracted more attention after the financial crisis of 2007–2008. In the context of ship finance, marine insurance has proven itself to be an effective tool to transfer certain shipping risks to insurers who are not directly involved in the ship finance projects. This thesis provides original suggestions concerning the role of marine insurance in ship finance, combining a financial perspective, an insurance perspective and a legal perspective. Marine insurance is a key risk management technique that fits into the general risk management process adopted by ship financiers. However, it is not necessarily the most appropriate technique in every particular case due to its limitations and costs. As a result, insurance gaps are identified to assist financiers in optimising the use of marine insurance and to help insurers to spot business opportunities. Marine insurance is a contract which is to be governed by and construed in accordance with the law. At the same time, marine insurance is a contract rather than a guarantee: if something goes wrong in the ship finance package and there is a marine policy, it should not be assumed that the policy represents money in the bank. Things can go wrong under the policy: apart from the legal risks relating to claims under the policy, the law itself may be a risk. In the context of ship finance, the risk transfer is not the only role of marine insurance. Other roles include, inter alia, reducing capital costs, improving the liquidity of shipowners and shipbuilders, and providing peace of mind for ship financiers. Nevertheless, such roles can only be created and sustained if the insurance contracts are carefully drafted and the legal risks are properly managed. The intention has been to state the law as it stands on October 28, 2017.
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Fredriksen, Ørjan. "Ice-Induced Loading on Ship Hull During Ramming". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18423.
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As a result of the steadily increasing activities related to marine technology in Arctic regions, Det Norske Veritas has launched an ice load monitoring project to gather knowledge of the ice conditions and prevailing ice-induced actions in the region. The intention of the following thesis is to study different aspects related to design of ice-going vessels, in particular the design scenario where a vessel impacts an ice ridge.The introductory part of the thesis gives an overview of important aspects related to sea ice, including different types of ice features and their physical and mechanical properties. The microstructure of pure ice and formation mechanisms of sea ice are briefly described, and mechanical properties such as elasticity and compressive strength are discussed. Further, a study of existing models for estimation of ice-induced loading on ships is carried out, with focus on local hull plating pressure and global loading due to ice ridge impact.A comparative study of design rules developed by Det Norske Veritas and the International Association of Classification Societies is conducted, and important differences between the two separate rules are identified. The subdivision of class notations is described, and differences in definition of design loads and corresponding requirements are presented. A general conclusion is that the rules developed by Det Norske Veritas are more specific when it comes to governing design scenarios, while rules set forth by the International Association of Classification Societies are more universal in terms of vessel type and prevailing ice conditions.Two separate finite element models based on coastguard vessel KV Svalbard are developed, including a simplified beam element model and a detailed shell element model. Quasi-static and dynamic response analyses for ice ridge impact loading are carried out, where the duration of the load pulse is varied systematically from 0.25~s to 2.0~s. The simplified finite element model is seen to give larger overall maximum response compared with the detailed model, but the difference decreases as the pulse duration is increased.It is observed that quasi-static response is overall larger than dynamic response for both finite element models within the defined pulse duration range. However, the ratio of maximum dynamic to maximum quasi-static response is seen to be positively correlated with the load pulse duration, and a close-to-linear relationship is observed.A study of different parameter variations is performed in order to investigate the importance of various pulse shapes, mass models, damping models and solution methods. Variations are only performed using the simplified beam model. It can be concluded that the shape of the load pulse is of minor importance for dynamic response when the pulse duration is short. However, the pulse shape becomes increasingly important for longer load pulses.An opposite trend is observed when varying the mass model, where a negligible difference in dynamic response is seen for longer load pulses. The difference increases somewhat for shorter load pulses, but can be considered unimportant for dynamic response within the investigated duration interval.It is further observed that the choice of damping model is of significant importance compared with other investigated parameters, and the difference in predicted response remains constant within the investigated pulse duration interval. The choice of solution method is however unimportant for analysis using the simplified beam model.In order to verify the applicability of the finite element models, full scale sea trial measurements of global motions from KV Svalbard are analysed and compared with finite element results. Difference between measured and calculated response during ice ridge impact is seen to be significant, where the calculated maximum response is close to 4 times larger than the maximum measured response. Iterative modifications of the load pulse shape are performed in order to reproduce the measured response history following ice ridge impact, and quite strong agreement is obtained between measured and calculated response.
6
Korkut, Murat. "Nonlinear dynamics of close proximity ship towing". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FKorkut.pdf.
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Matusiak, Jerzy. "Pressure and noise induced by a cavitating marine screw propeller". Espoo : Valtion teknillinen tutkimuskeskus, 1992. http://catalog.hathitrust.org/api/volumes/oclc/25913793.html.
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Miller, Keith McGowan. "A navigation and automatic collision avoidance system for marine vehicles". Thesis, University of Plymouth, 1990. http://hdl.handle.net/10026.1/2503.
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Collisions and groundings at sea still occur, and can result in financial loss, loss of life, and damage to the environment. Due to the size and capacity of moden vessels, damage can be extensive. Statistics indicate that the primary cause of accidents at sea is human error, which is often attributed to misinterpretation of the information presented to the mariner. Until recently, data collected from sensors about the vessel were displayed on the bridge individually, leaving the mariner to assimilate the material, make decisions and alter the vessels controls as appropriate. With the advent of the microprocessor a small amount of integration has taken place, but not to the extent that it has in other industries, for example the aerospace industry. This thesis presents a practical method of integrating all the navigation sensors. Through the use of Kalman filtering, an estimate of the state of the vessel is obtained using all the data available. Previous research in this field has not been implemented due to the complexity of the ship modelling process required, this is overcome by incorporating a system identification proceedure into the filter. The system further reduces the demands on the mariner by applying optimal control theory to guide the vessel on a predetermined track. Hazards such as other vessels are not incorporated into this work but they are specified in further research. Further development work is also required to reduce computation time.
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Betancourt, Michelle K. "A comparison of ship maneuvering characteristics for rudders and podded propulsors". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FBetancourt.pdf.
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Aryawan, Wasis Dwi. "An investigation into the potential of multiple rows ducted propellers for marine applications". Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275427.
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Roddis, Mark Edward. "On the inverse design of marine ducted propulsor blading". Thesis, University College London (University of London), 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265865.
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Salman, Mohammad Ali M. "Adaptive control techniques in ship autopilot design". Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/27227.
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Ship automatic pilot system design has captured the attention of many prominent control engineers with the increasing demand for accurate and more adequate pilots to keep a tighter control in more confined waterways and reduce fuel consumption by improving the course of navigation. Strategies for ship control involving both classical and modern schemes are examined. These include the pole-assignment controller which is an attractive scheme with a simple nature. Modern optimal techniques are also used to reduce the propulsion losses and minimise the travelled distance; the minimum variance controller is implemented for both course-keeping and course-changing requirements. The self-tuning (adaptive) approach which combines the controller design and the identification of system parameters is implemented and various parameter estimation algorithms are examined. Finally a dual-mode adaptive autopilot is designed that can be switched between course-keeping and course-changing with the helmsman taking over if the situation demands.
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Bailey, Philip A. "Manoeuvring of a ship in a seaway". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300887.
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Harrington, K. "Concrete as a fabrication material for simple hulls : A marine innovation study". Thesis, University of Sunderland, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378997.
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Chu, Van Thuy. "Measurement and assessment of ship emissions". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/126390/3/Thuy%20Chu%20Van%20Thesis.pdf.
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This project developed an in-vessel emission measurement system and emission evaluation protocol to aid air quality modellers, government regulators and industry. The work enables characterisation of emissions emitted in different ships using heavy fuel oil and operating under a full range of conditions such as at-berth, manoeuvring and ocean-going. Results from the project will improve the quality of input data to air quality modellers who assess the impact of ship emissions on coastal and port areas.
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Deere, Steven John. "Ship design with the human factor : evacuation and normal operations modelling in the ship design process". Thesis, University of Greenwich, 2012. http://gala.gre.ac.uk/9148/.
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This thesis addresses the modelling of human factors and how they can impact ship design. Two different but related applications areas are considered; passenger ship evacuation analysis and naval vessel normal operations and evacuation analysis. In the first instance, this thesis investigates the impact of the current regulatory specified passenger response time distributions upon evacuation analysis and then recommends a more realistic passenger response time distribution which should be implemented when performing an evacuation analysis of a passenger RO-RO vessel. This realistic passenger response time distribution is based upon the results of sea trials. The results of this analysis have been adopted by the IMO and form part of the new guideline document, IMO MSC 1238. In addition, this thesis addresses the analysis of the human factors’ performance of a naval vessel. Naval vessels are built primarily for undertaking assigned missions in times of war and conflict. While the safety of those on board is important, the ability of the vessel to function and complete its assigned mission is of paramount importance. This thesis utilises an evacuation model, maritimeEXODUS, which was extended to incorporate the functionality of modelling non-evacuation scenarios, to assess the human factors’ performance of a naval vessel during both normal operations and evacuation scenarios. This thesis develops a methodology for simultaneously assessing the human factors’ performance of both a range of normal operation scenarios and evacuation scenario on board a naval vessel. The methodology, called the Human Performance Metric (HPM), is discriminating, diagnostic, systematic, transparent and reproducible in nature. This thesis then implements the HPM methodology into the early stages of the design cycle for a new naval vessel. The thesis presents the software modifications required to implement the methodology in to the design cycle as well as presenting a demonstration of the new system.
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Poor, Christopher A. "SIMULINK modeling of a marine autopilot for TSSE ship designs". Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA319246.
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Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, September 1996.Thesis advisor(s): Robert G. Hutchins. "September 1996." Includes bibliographical references (p. 59). Also available online.
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Källman, Jonas. "Ship Power Estimation for Marine Vessels Based on System Identification". Thesis, Linköpings universitet, Reglerteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-79248.
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Large marine vessels carry their loads all over the world. It can be a container ship carrying over 10 000 containers filled with foods, textiles and electronics or a bulk freighter carrying 400 000 tons of coal. Vessels usually have a ballast system that pumps water into ballast tanks to stabilize the vessel. The ballast system can be used to change the vessel’s trim and list angles. Trim and list are the ship equivalents of pitch and roll. By changing the trim angle the water resistance can be reduced and thus also the fuel consumption. Since the vessel is consuming a couple of hundred tons of fuel per day, a small reduction in fuel consumption can save a considerable amount of money, and it is good for the environment. In this thesis, the ship’s power consumption has been estimated using an artificial neural network, which is a mathematical model based on data. The name refers to certain structural similarities with the neural synapse system in animals. The idea with neural networks has been to create brain-like systems. For applications such as learning to interpret sensor data, artificial neural networks are an effective learning method. The goal is to estimate the ship power using a artificial neural network and then use it to calculate the trim angle, to be able to save fuel. The data used in the artificial neural network come from sensor systems mounted on a container ship sailing between Europe and Asia. The sensor data have been thoroughly preprocessed and this includes for example removing the parts when the ship is docked in harbour, data patching and synchronisation and outlier detection based on a Kalman filter. A physical model of a marine craft including wind, wave, hydrodynamic and hydrostatic effects, has also been introduced to help analyse the performance and behaviour of the artificial neural network. The artificial neural network developed in this thesis could successfully estimate the power consumption of the ship. Based on the developed networks it can be seen that the fuel consumption is reduced by trimming the ship by bow, i.e., the ship is angled so the bow is closer to the water line than the stern. The method introduced here could also be applied on other marine vessels, such as bulk freighters or tank ships.
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Swift, Clare. "Marine environmental monitoring of a ship-based seawater scrubber system". Thesis, University of Newcastle Upon Tyne, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500933.
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The shipping industry is becoming increasingly visible on the global environmental agenda as air emissions from vessels make an increasingly conspicuous contribution to air quality. With the forecast expansion of world trade; scientists are estimating global emissions to increase by 30% to 1.45 billion tonnes in the next decade. This would make shipping responsible for 6% of global emissions by 2020. The International Marine Organisation (IMO) Annex VI entered into force in 2005 and is currently the most important international treaty governing emissions to air from ocean going vessels. It has set strict limits on sulphur dioxide (SO2) and nitrogen oxide (NOx) emissions from ship exhausts, prohibits the deliberate emissions of ozone depleting substances, and places a global cap on the sulphur content of marine fiiel. As an alternative to using low sulphur fliel oils, ships have the option to fit an exhaust gas cleaning system such as a seawater scrubber (SWS) or to use any other feasible technology to limit SO2 emissions. SWS transfers SOx (ca. 95%) and partly NOx (ca. 20%) into aqueous solution, producing acidic solutions which are then buffered with seawater and finally discharged into the sea.
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Antunes, Filipa Alexandra Paiva. "Ship transport of marine invasive species and its stress resistance". Master's thesis, Universidade de Évora, 2014. http://hdl.handle.net/10174/12339.
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In the context of biological invasions, ship transport plays an important role in the transference of species around the world. During this process organisms are exposed to several stressful conditions, which do not prevent them to arrive in areas where they did not occur before. The marine invertebrates Carcinus maenas and Mytilus galloprovincialis natives in Portugal, have already established stable invasive populations in several regions worldwide. This study exposed organisms of both species to stress conditions similar to what occurs in ballast tanks and on ship hulls. Results showed a high survival of pre-stressed Mytilus galloprovincialis individuals when compared to non pre-stressed organisms when exposed to air exposure, hyposalinity and heat events. However when Carcinus maenas was exposed to heat stress, there was no significant difference between groups with a different stress history. These findings suggest that transport on ships is not only a vector of dispersal but also a vector capable to increase the resistance to stress conditions in potential species invaders by selection of resistant individual; Resumo:
"Transporte marítimo de espécies marinhas invasoras e sua resistência ao stress"
No contexto das invasões biológicas, o transporte marítimo desempenha um papel importante contribuindo para a transferência de espécies em todo o mundo. Durante este processo os organismos são expostos a variadas condições de stress que não os impede de chegar a áreas onde não ocorriam anteriormente. Os invertebrados marinhos Carcinus maenas e Mytilus galloprovincialis nativos em Portugal, já estabeleceram populações invasoras estáveis em várias regiões do mundo. Neste estudo, submeteram-se organismos de Carcinus maenas e Mytilus galloprovincialis a condições de stress semelhante ao que ocorre em tanques de água de lastro e em cascos de navios. Os resultados mostram uma maior sobrevivência dos indivíduos Mytilus galloprovincialis pré – expostos a condições de stress quando comparado com organismos sem uma prévia exposição a esses eventos de stress, quando expostos ao ar, baixa salinidade e altas temperaturas. No entanto, quando Carcinus maenas foi exposto a temperaturas mais altas, não houve diferença significativa entre os grupos com diferentes exposições ao stress aplicado. Estes resultados sugerem que o transporte marítimo não é apenas um vetor de dispersão mas também um vector capaz de aumentar a resistência a condições de stress em potenciais espécies invasoras, nomeadamente através da seleção dos indivíduos mais resistentes.
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Witt, Neil A. J. "Artificial intelligence techniques applied to automatic ship guidance". Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/2592.
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It has been estimated that over eighty per cent of marine accidents have been caused by operator error. The skills of the operator in the handling of the vessel are variable and are subject to external influences. Over the past seventy years many advances have been made in the field of ship control. Early developments on proportional controllers have led to today's modern control systems which have interfacing capabilities with electronic navigation equipment. This research investigates traditional control methodologies and introduces the concept of applying artificial intelligence (AI) methods to the ship guidance problem. Research into AI techniques has been burgeoning over the last fifteen years and the main areas investigated are expert systems, fuzzy logic and neural networks. These areas are compared and the research proposes that it is feasible to design and develop a novel, advanced autopilot that is capable of learning the control functions of the operator as well as the manoeuvring characteristics of the vessel. An assessment is undertaken as to the feasibility of replicating a helmsperson's vessel handling functions with an intelligent neural network control system. This system has the capability of learning the course keeping and track keeping functions for a specific vessel. The research has been carried out under two specific task areas: neural course keeping control utilising simulation methods; and neural track keeping control exploiting the use of simulation and scale model techniques. The use of a scale model has allowed the collection of accurate training data through a integrated navigation and data collection system. The use of such a test bed has permitted the testing of the neural track keeping system. Alternative research has concentrated on the use of mathematical models of vessels and all the training data is created through the use of simulation techniques. Whilst this approach is suitable for the initial design of a neural control system can not fully replicate the disturbances acted upon and the responses of a real vessel. By utilising a scale model containing a navigation, data collection and control system it has been possible to expose the vessel to the real environmental data which is unobtainable when using simulation methods. The results of the neural control strategies implemented on the vessel guidance problem are evaluated against the teacher in terms of performance measures. The results indicate that the performance of the final track keeping system is of the manner desired in that it has learnt the control action of the operator. Areas for further research are presented including the application of alternative AI techniques and the use of more accurate navigation sensors.
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Rebello, De Souza Junior Jesse D'Assuncao. "Geometrical methods of nonlinear dynamics in ship capsize". Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362515.
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Thorsen, Ingvill Bryn. "Estimation and Computation of Ice-Resistance for Ship Hulls". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18757.
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The oil price continues to increase while oil companies search for oil in new areas. There is assumed that 25% of the world’s hydrocarbons are located in the arctic area. Operating in these areas will be a huge challenge due to extreme low temperatures and ice condition Today one can predict with good accuracy how a ship will manage in different ice condition. Research on ship operating in ice the last decades has resulted in many different formulas for predicting ice resistance on a ship hull. Analytical and numerical methods are developed to estimate the resistance working on the ship hull under different ice conditions. Model test will still be the most accurate prediction, but the other methods may give you some guidelines on what to expect. This thesis contain a theoretically study of ice physics and mechanics. The formation and development of sea ice has been reviewed. The Ice Load Monitoring system tested on the Norwegian coast guard vessel KV Svalbard is described. Three different analytical ice resistance calculation methods are described. The three methods are Lindqvist (1989), Keinonen et al. (1996) and Riska et al. (1997). Data obtained from the Ice Load Monitoring system are used to estimate the full scale ice resistance on KV Svalbard. The three analytical methods are calculated with KV Svalbard as a reference ship to be able to compare with the full scale measurements. MATLAB is used for the calculations.
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Rodriguez, Richard Yi. "Characterization of sway forces induced by close proximity ship towing". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Mar%5FRodriguez.pdf.
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Kroondijk, Rinke. "High Energy Ship Collisions With Bottom Supported Offshore Wind Turbines". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19406.
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As the worlds demand for energy is increasing mostly due to the increase in population, and coal, oil and gas deposits are limited, it is desirable to gather energy from renewable energy sources. Wind energy is a form of renewable energy. Wind turbines have been common on land and near shores for some time, but now one wants to take advantage of the wind resources further away from the coast. As the length from the coast increases, so does the water depth making it necessary to use other foundations than the well-known monopile. In this thesis the “Federal Maritime and Hydrographic Agency” in Germany, also known as Bundesamt für Schifffarth und Hydrographie requires in the standard “Design of Offshore Wind Turbines” that an offshore wind turbine needs to be risk evaluated against a ship tanker of more than 500 MJ in collision energy in order to be classified as collision energy. This is to prevent environmental pollution in form of oil spill. Whether the offshore wind turbine models used in this thesis are collision friendly or not relies on different factors. When the given soil properties are used the analyses show in all cases except one that the offshore wind turbine models can be called collision friendly. The case were it could not be called collision friendly was a case with the small jacket at a water depth of 27 m getting hit by a loaded ship at a column of the jacket, but installing a horizontal brace on this jacket would make it also collision friendly. The effects of soil, water depth and a horizontal x-brace are looked further into in this thesis. If the soil had been stronger it is not certain that the outcome would be the same. When the jackets were fixed to the sea bed, several of the models could collapse in the dangerous direction over the ship. A horizontal brace was seen to have a positive effect when installed on the different jacket models. It seems also that it is more favorable to use jackets at deeper water.
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Russell, Matthew Paul. "The drift angle theory applied to ship manoeuvring models". Thesis, University of Plymouth, 1993. http://hdl.handle.net/10026.1/2567.
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A marine vehicle manoeuvring model is concerned with the ability to simulate the status of a vehicle to various demanded controls on a digital computer. Such models have both shore based and sea going applications that are beneficial to the mariner, enhance safety of life at sea and aid in protecting the marine environment The mathematical representation of marine vehicles has generally been conducted by the measurement of the forces and moments that are experienced by a vehicle, in terms of a series of numbers collectively known as hydrodynamic coefficients. This has resulted in the non-linear force modular model which is considered to be the most accurate and versatile mathematical modelling technique. This thesis presents the results from research conducted into the construction of an accurate mathematical model of a patrol craft Picket Boat Nine. The non-linear force modular modelling technique was initially adopted. The required hydrodynamic coefficients were evaluated by the use of full scale sea trials, scale model testing techniques and by semi-empirical methodologies; by the installation of a towing tank, a data monitoring and acquisition system onboard Picket Boat Nine. An alternative new method for mathematically describing marine vehicles has also been developed based upon the drift angle theory. The existence and magnitude of the drift angle has been transformed into a set of hydrodynamic curves that mathematically represent a marine vehicle's manoeuvrability and into a method of determining the track history of a marine vehicle when underway. These two components have been developed into a new form of mathematical model This new approach to mathematical modelling has been tested by full scale sea trials in Picket Boat Nine and with comparison to a force modular model that demonstrates the stature and potential of this method. The results indicate that further research is required to include external disturbances and to prove its validity to other marine vehicles.
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Ye, Quanhuan. "A ship design method involving uncertainties and multiple criteria". Thesis, University of Strathclyde, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263438.
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Tsangaris, Michael. "Ship capsize by broaching-to in severe astern seas". Thesis, University of Strathclyde, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366664.
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Violette, Franck Luc Marcel. "On the fatigue performance prediction of ship structural details". Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388346.
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Kountzeris, Athanasios. "Investigation of ship roll motion by parametric identification techniques". Thesis, University of Sussex, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328345.
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Lin, Tian Ran. "Vibration of finite coupled structures, with applications to ship structures /". Connect to this title, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0093.
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Giziakis, K. "The cost of marine traffic accidents worldwide with particular reference to N.W. European waters". Thesis, London Metropolitan University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382904.
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Anil, Kivanc Ali. "Multi-criteria analysis in Naval Ship Design /". Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Mar%5FAnil.pdf.
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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, March 2005.Thesis Advisor(s): Fotis Papoulias, Roman B. Statnikov. Includes bibliographical references (p. 241). Also available online.
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Alhouli, Yousef Mohammed. "Development of ship maintenance performance measurement framework to assess the decision making process to optimise in ship maintenance planning". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/development-of-ship-maintenance-performance-measurement-framework-to-assess-the-decision-making-process-to-optimise-in-ship-maintenance-planning(3056c2a2-7301-4223-990c-e23432b550bb).html.
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Effective maintenance planning is essential and important in any organisation that is responsible for procuring and managing complex assets. In the marine shipping industry maintenance planning is very significant due to its complexity and the obligations on shipping organisations to comply with certain regulations and requirements. Moreover, improper planning can reduce the ship's availability, which may in turn, be reflected in the revenue of the company. Another issue that requires attention in this field is the cost of maintenance, since improper or inadequate planning could result in breakdowns that could increase the cost of maintenance.This research aims to identify the key factors that affect ship maintenance planning and to provide a framework that can help the decision maker to identify and choose optimum decisions regarding ship maintenance. The research is divided into four stages in order to achieve its objectives and to address the research problem.The first stage is the review of the literature to identify the need for maintenance and to select the key factors that affect maintenance planning. The findings indicate that: maintenance scheduling, selection of maintenance strategy, ship construction, crew compensation, and shipyard selection are the most important factors.The second stage is to evaluate maintenance performance measurements for the marine shipping industry by conducting case study and interviews with professionals involved in the mercantile industry. Semi-structured interviews were conducted with six senior staff experts from three different organisations. The results show that: dry docking scheduling, maintenance costs and budgets, customer satisfaction, employees' satisfaction, classification requirements, and the ship's maintenance requirements are the main factors that have great influence on maintenance planning.The third stage is to develop new methodology to measure the maintenance performance in the marine shipping organisation which is the ship maintenance performance measurement (SMPM) framework. The developed method was validated to assist managers in making the right decisions in ship maintenance planning. The framework was developed based on ten thematic criteria that can be used as indicators for potential organisation growth, i.e., maintenance strategy; dry docking scheduling; budget and costs; the ship's equipment; customer satisfaction; employees; health, safety and environment; learning and growth; classification requirements; and the ship's operation and demands requirements. Interviews were conducted with key personnel from the Kuwait Oil Tanker Company (KOTC) to validate the framework.The fourth stage demonstrates that an optimised schedule for the dry docking of ships for routine maintenance has been constructed. This is accomplished on the basis of one measured criterion, dry docking scheduling, by using an integer programming model to maximise the ship's availability within the company fleet. The model is defined by three constraints: the maintenance window, maintenance completion, and the ship's limit. The model was validated using data from KOTC, and the results depict an optimum solution for maintenance scheduling, maximising the ship's availability to 100% and not less than 92%.
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Welsh, Martin. "A computer-aided conceptual ship design system incorporating expert knowledge". Thesis, University of Newcastle Upon Tyne, 1989. http://hdl.handle.net/10443/398.
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In today's highly competitive shipbuilding market the emphasis is on the production of acceptable design proposals within a very short timescale. A computer-aided conceptual ship design system, which utifises the latest developments in workstation technology, has been developed. It is intended to help reduce the technical and commercial risks associated with the process of tendering for newbuilding contracts. The system as a whole, uses fundamental modeffing techniques to enable areas such as dimensions generation, huilform development, layout design, powering estimation, mass estimation, motions prediction, work content estimation and cost estimation to be considered at a much greater level of detail at the concept design stage than was previously possible. This thesis describes the specification and development of those parts of the overall design system concerned with the generation of vessel dimensions and huliform and layout design. In order to improve the flexibility of the system, a so-called expert system approach has been adopted to provide the mechanism for the control of the design methodology. For this purpose, a unique expert system shell named INCODES (INtelligent COncept DEsign System) was specified and developed. The development of this shell is described in some detail. The application of the INCODES shell to the control of the logic involved in the development of design proposals for containerships is discussed, and the knowledge base developed for the generation of these design proposals is described. The knowledge base is shown to incorporate fundamental procedures for the generation of vessel dimensions and for huliform and layout design, as well as a comprehensive suite of analysis routines to assist in the verification of the design proposals. The knowledge base is also considered to be unique in its treatment of the investigation of the loading arrangements of containership design proposals. The flexibility of the procedures developed is demonstrated by their application to the generation and examination of containership design proposals which possess a range of physical and operational characteristics.
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Kattan, Mohamed Raouf. "The development and application of quality chains to ship production". Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240688.
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Zeinoddini, Mostafa. "Dynamic behaviour of offshore structure members subjected to ship collision". Thesis, University of Surrey, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298154.
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Kato, Ryoji. "Modelling of Ship Superstructure Icing : Application to Ice Bridge Simulators". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18655.
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Increasing activities on high north regions bring about a demand of safety ship navigation. Under severe weather condition considerable amounts of ice may accumulate on marine structures. Ice bridge simulator is of importance in terms of training for qualified maritime personal. The new ice module to fit for additional problem for the ship icing is introduced with low reality into bridge simulator. Regarding this our aim is to develop ice model that calculate ice load on the ship structure and stability change include parameters of air temperature, relative wind speed, wave height etc. As a result of literature survey theoretical and empirical method with its algorithm is studied. The ice thickness on cylinder and plate as a representative element of the structures are calculated as a function of liquid water content, relative wind speed and freezing fraction for simplified ship superstructures to include the effect of trapped water on deck. Since we have to deal with several thousand of element to be calculated every seconds including iteration process, computer should be used, hence new ice model is proposed by using computer language C++. In case study 300 tonnage size coast guard vessel is selected as a model ship. Under assumptions that those external parameters are stable in the duration of simulation, proposed model is validated. As a result proposed model could simulate total ice load and following stability change, with error of rolling period after 20 hours simulation being 0.14 sec compared to full scale measurement.
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Park, Jong Jin. "Modelling trailing vortices from a slender ship hull for manoeuvring calculations". Thesis, University of Newcastle Upon Tyne, 2001. http://hdl.handle.net/10443/895.
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A particular problem that has been encountered in modelling the forces and moment acting on a manoeuvring ship, has been the correct estimation of the distribution of side force along its length. If traditional slender body theory is used, reasonable agreement can be obtained between theoretical and experimental result over the forebody of the ship. However, moving aft, the two increasingly diverge until there are significant differences at the stem. For this reason manoeuvring coefficients cannot be accurately predicted by this approach. In a number of studies, the reason for the discrepanciesh as been attributed to the influence of trailing vortices that develop along the hull. The conclusion is consistent with sensitivity analyses carried out with augmented slender body theory incorporating vortices of specified location and strength along the ship. The present thesis is concerned with modelling trailing vortices along a ship in drift motion so that they can be used in the calculation of the associated distribution of forces and manoeuvring coefficients. A numerical model based on the Discrete Vortex Method has been developed for the analysis of vortex flow around the ship which is representedb y slender body approximation. The trailing vortices are modelled by a series of transverse two-dimensional multi-vortex solutions marching longitudinally down the hull. Results are presented for six different hull types; a flat plate, the Wigley hull, a block hull, a Series 60 hull, the British Bombardier and the British Bombardier with a pram stem. The effects of varying drift angles are also investigated for each hull types. Good qualitative agreement is shown between the predicted velocity and vorticity fields and results from experimental studies. The distribution of side forces and yaw moments along the hull is also well predicted. The results explain manoeuvring phenomena occurring for the hull forms considered that have been observed experimentally and at full scale.
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Kim, J. J. "Development of ship production planning system using a cost-based approach". Thesis, University of Strathclyde, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372106.
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Mohammed, Abuu Khalifa. "Nonlinear Shell Finite Elements for Ultimate Strength and Collapse Analysis of Ship Structures". Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-79.
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The present thesis deals with ultimate strength and collapse analysis of ship structures. Within this are, the attention is directed towards simple and efficient nonlinear finite element models for stiffened plate panels in ship structures. Several types of Morley elements are investigated and two are selected for further development. These triangular elements assume constant stress distribution over the element area.
The first element considered is a nonlinear facet shell element which is valid within moderate rotations. Its elastic formulation has been proposed earlier. In this work, the element matrices are extended to account for material plasticity. The second element, is a displacement-based curved element which undergoes arbitrary large displacements and rotations. The discrete equilibrium equations for this element are re-derived so as to make them more efficient with standard Newton-Raphson solution procedures.
Material plasticity formulation using through-the thickness integration as well as resultants plasticity is presented. The evolution laws are derived from the natural laws of thermodynamics, and a return mapping algorithm with a backward Euler difference scheme is used for a solution of the evolution equations. The plasticity computations involve a solution of a single scalar yield surface for the plasticity multiplier. By performing the matrix algebra analytically, simple and explicit expressions are derived. These equations reduce the computational costs remarkably.
Numerical examples, mostly selected from well-know benchmark problems, are presented to demonstrate the performance of the proposed formulations. Very good agreement is obtained when compared with published results. In addition, typical problems for ultimate strength and collapse analysis of ship hull-girder are analyzed. These include plate girders, stiffened plate panels, as well as a cruciform element. The results show good agreement not only with those obtained from commercial finite element programs, but also from the experimental observations. For stiffened plate panels, comparison is made with DNV design rules, which is found to give non-conservative estimates for some load conditions.
Finally, a study on multi-span stiffened panels is performed so as to compare the estimates provided by the conventional single span model. It is observed that the conventional model provides conservative estimates, and the effect of transverse frames is especially significant on the finite element model of stiffened panels.
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Merrett-Jones, Michaela. "The effect of sewage enrichment upon the integrity of the fabric of marine sites of archaeological importance". Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/770239/.
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This research programme was instigated in response to concerns regarding the potential impact of sewage contamination from a long sea-outfall commissioned in 1991 in Portsmouth, Hampshire, on the long-term quality of local, historic wreck timbers. Information pertaining to the quality of seawater and the degradation of sacrificial wood samples, with particular emphasis on the action of the wood-boring crustacean, Limnoria spp, was collected and is presented in this thesis. The data was collected from three wreck sites in the Solent and surrounding waters: the Mary Rose (1509 - 1545), HMS Invincible (1744 - 1758) and HMS Hazardous (1698 - 1706). Both the Mary Rose and HMS Invincible sites are situated in an area of the Solent that was contaminated by sewage discharge. The site of HMS Hazardous is in cleaner water at Bracklesham Bay and was therefore designated as the control. Limnoriid activity was found to be higher at the HMS Invincible site than at the Mary Rose site - the HMS Invincible site also recorded the highest levels of sewage contamination. However, limnoriid activity was greater still at the "clean" control site of HMS Hazardous, thereby ruling out a conclusive link with sewage contamination. Water quality analyses showed the existence of vertical layering in the water column for many of the parameters determined. L. quadripunctata dominated the limnoriid population at the three sites but there was a significant presence of L. lignorum at the deeper Mary Rose site. On one occasion (winter 93/94), L. lignorum dominated the limnoriid population at the Mary Rose site. At the same time, the affinity for Scots pine wood observed during the rest of the study was not apparent. Faecal indicator bacteria were isolated from the biofouling layer of the wood blocks at both the Mary Rose and HMS Invincible sites and microbiological activity appeared to be greatest at the Mary Rose site. Fouling barnacles on the wood samples appeared to offer some protection from limnoriid activity in the short-term but had no long-term protective effect.
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Streett, Andrew R. "Preliminary finite element modeling of a piezoelectric actuated marine propulsion fin /". Electronic version of thesis, 2006. https://ritdml.rit.edu/dspace/handle/1850/2630.
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Raspa, Paolo. "Advanced strategies for control and fault diagnosis of marine surface vessels". Doctoral thesis, Università Politecnica delle Marche, 2013. http://hdl.handle.net/11566/242729.
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Il moto di vascelli superficiali è pesantemente influenzato dalla presenza di onde
e altri disturbi ambientali. Il moto di rollio indotto dalle onde provoca accellerazioni
verticali che possono incrementare le possibilità di danni al carico
e l’incidenza di malori per passeggeri ed equipaggio, mentre i moti orizzontali
indotti da correnti, onde e vento influiscono sul preciso posizionamento della
nave nelle operazioni di ancoraggio o di accostamento della nave. E’ di grande
importanza per la sicurezza e il comfort di equipaggio ed eventuali passeggeri,
nonchè sicurezza del carico, affidabilità e operabilità della nave che il vascello
sia predisposto con opportuni sistemi di controllo in grado di smorzare il moto
di rollio o garantire un corretto posizionamento della nave in maniera affidabile,
quindi anche in caso di guasti alle appendici di controllo. Per questi aspetti il
problema principale risiede nel trovare il giusto trade-off tra le prestazioni e la
complessità del sistema di controllo in rapporto alle condizioni operative, dovute
agli accoppiamenti tra I gradi di libertà del sistema. Questa tesi presenta dei
contributi innovativi per la quantificazione delle limitazioni insite nei sistemi di
controllo per lo smorzamento del rollio attraverso lo studio delle caratteristiche
proprie del modello idrodinamico e propone un innovativo sistema controllo a
struttura variabile focalizzato sulla robustezza in risposta a incertezze sul modello,
ai disturbi esterni e a possibili guasti nel sistema di attuazione della nave
nei sistemi di controllo per la stabilizzazione del moto di rollio e per il posizionamento
dinamico della nave. Le soluzioni proposte sono state validati tramite
tool e software per la simulazione, nonchè tramite test condotti in vasca con un
modello in scala di un vascello di superficie.The motion of surface vessels due to waves is significantly affected by environmental disturbances, like waves, currents and wind. The roll-induced high vertical accelerations increase the possibility of cargo damage and the incidence of seasickness development, while horizontal motion due to waves, currents, waves and wind affects the ship offloading and dynamic positioning operation. Thus the design of control systems to damp the induced roll motion and to guarantee a reliable stabilization to fixed or dynamic position, also in case of thruster failure, as prescribed from certification agencies. The main issue is reaching a proper trade-off between the achievable performances and the complexity of the control system in relation to the operating condition and the coupling between the ship degree of freedom. This thesis presents some novel contributions to the quantification of fundamental limitation in roll stabilisers and a novel variable structure control system focused on the robustness respect to model uncertainties, environmental disturbances and thruster failures specific for rudder-fin-roll-stabilers and dynamic positioning. The proposed solutions are validated using simulation tools and software and experimental tests conducted at the Marine Cybernetics Laboratory of the Norwegian University of Science and Technologies with a scaled model vessel.
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Rubin, Ewelina. "Scleractinian Coral Recruitment to Reefs Physically Damaged by Ship Groundings". NSUWorks, 2009. http://nsuworks.nova.edu/occ_stuetd/227.
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Southeast Florida reefs are impacted by a number of stress factors, among which ship groundings are one of the most physically damaging. In particular, portion of Florida reef tract located near Port Everglades in Broward County has been severely damaged by ship groundings. In 2004, extensive physical damage of more than 30,000 m2 was caused by the groundings of two large cargo ships, the MV Eastwind and MV Federal Pescadores. The present study was designed to examine differences in the recruitment patterns of scleractinian corals and pioneering benthic communities settling to these physically impacted sites compared to undamaged reef sites. Coral recruitment and non-coral benthic settlers were measured on unglazed terracotta tiles deployed for a period of one year from February 2007 to February 2008 at five different locations: three control sites (including a high coral cover site) and the two ship grounding sites. Colony morphology and two genetic markers: mitochondrial cytochrome oxidase subunit I and cytochrome b were used to identify the coral recruits. A whole genome amplification kit (REPLI-g, Qiagen) was used to obtain sufficient amounts of DNA from small coral spat. The image analysis software Coral Point Count with the Excel extension was used to quantify the percent cover of major benthic invertebrate and algal functional groups. Results revealed very low diversity of coral recruits and low recruitment rates (0.5-2.7 recruits m-2 yr-1), suggesting a low potential for recovery of the damaged areas. Other non-coral benthic groups, including turf algae, barnacles, sponges, tunicates and bryzoans, were found to proliferate and occupy almost the entire tile substrate, suggesting possible coral recruitment inhibition by space preemption or coral recruit mortality by overgrowth. Turf algae which comprised up to 50% of the total cover were the most dominant group settling to the tiles. This dominance of algae on the tiles reflects a similar pattern of algal dominance present on the reef system along the Florida coast.
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Maneepan, Komsan. "Genetic algorithm based optimisation of FRP composite plates in ship structures". Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/52012/.
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Composite materials (herein means Fibre Reinforced Plastic, FRP) are increasingly usedin the construction of marine vehicles because of their outstanding strength, stiffness and light weight properties. However, the use of FRP comes with difficulties in the design process as a result of the large number of design variables involved: composite material design, topologies and laminate schemes. All variables are related to each other leading to a high dimensional and flexible design space. It is hard to use traditional design methods in order to gain solutions for an initial design stage in a short time. Hence, this thesis deals with the presentation of a structural synthesis (optimisation framework) for plate components of composite ship structures. The framework broadly consists of an optimisation technique and structural analytical methods. To make the framework compatible with the nature of composite ship structural design problems, the Genetic Algorithm (GA) is selected as the optimisation tool because of its robustness, its ability in dealing with both continuous and discrete variables and its excellent searching for a global optimum. The typical plate types in a ship structure are the stiffened and unstiffened plates. For a stiffened plate, the combination of the grillage analysis of energy method based on Navier solution and an equivalent elastic properties approach are introduced. Using this, it is possible to produce layer by layer optimisation results for the base plate, web and crown of the stiffened plate. Unfortunately, solutions of the adopted grillage analysis do not cover the mechanical behaviour of the plate between stiffeners so the Higher-Order Shear Deformation Theory (HSDT) must be employed. This method provides accurate solutions for thin to moderately thick plates with a compromised computational time. Then stiffness, strength and stability can be considered in the design problem. In addition, to achieve the program of the structural synthesis, various computational modules are implemented according to the evaluation of composite micromechanics properties, maximum stress failure criteria and structural weight function. Then the main modules are validated with available resources. The usefulness of the program has been proved by comparing it with the optimal solutions from finite element software. Finally, many application examples of secondary and tertiary composite ship structures are presented. The optimal results prove the success of the optimisation framework. This could be evidence for further improvement to obtain a valuable structural optimisation tool.
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Mercer, Robert M. "Attitudes and perceptions of instructors operating marine simulator courses". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/MQ36155.pdf.
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Baar, J. M. "A three-dimensional linear analysis of steady ship motion in deep water". Thesis, Brunel University, 1986. http://bura.brunel.ac.uk/handle/2438/6527.
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The investigation of steady ship motion in calm water is a classic problem in ship hydrodynamics, where ship waves and wave resistance are subjects of unquestionable importance. Despite considerable efforts in the past a satisfactory solution of the steady ship motion problem has not been achieved so far. The application of three-dimensional potential flow theory results in an essentially nonlinear problem formulation due to the unknown position of the disturbed free surface. In this thesis consistent linearisation schemes are discarded in favour of the inconsistent Neumann-Kelvin theory. This approximation implies that nonlinear free surface effects are neglected entirely, but the three-dimensional features of the fluid flow and hull geometry are otherwise fully retained. The Kelvin wave source potential, otherwise known as the wave resistance Green's function, is analysed in great detail. Solutions to the disturbance potential of the steady perturbed ship flow are obtained by means of a Kelvin wave source distribution method. The exact source strength is the solution of a Fredholm integral-equation of the second kind. An explicit source strength approximation, valid for sufficiently slender ships operating at fairly low speeds, is investigated. Particular emphasis is placed on computational aspects. Highly accurate and efficient methods for the evaluation of the Kelvin wave source potential are proposed. The developed theory is applied to five different ship forms, viz. a submerged prolate spheroid, Wigley's parabolic ship, a tanker, a fast destroyer and a cruiser. Over a wide range of ship speeds experimental data are compared with theoretical predictions of the steady flow parameters such as wave resistance, wave profiles, pressure signatures and lift force distributions.
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Tan, Kok Thong. "Defining and developing an efficient design tool for ship and yacht design". Thesis, University of Cambridge, 2001. https://www.repository.cam.ac.uk/handle/1810/272437.
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Demirel, Yigit Kemal. "Modelling the roughness effects of marine coatings and biofouling on ship frictional resistance". Thesis, University of Strathclyde, 2015. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26005.
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The answers to the question, “How might the roughness of coatings and biofouling be related to full-scale ship resistance and powering?” were sought in this research, and novel contributions were made to the state-of-the-art knowledge. The current techniques used for predicting the roughness effects of marine coatings and biofouling on the resistance of full-scale ships rely on assumptions from similarity law scaling and boundary layer theory. Although this is a reasonable method, it may be difficult for less experienced users to carry out such an analysis since similarity law scaling includes several numerical procedures which may cause numerical errors and requires deep knowledge of the subject. It would also be beneficial to propose alternative methods with which to accurately predict these effects using fully-nonlinear Computational Fluid Dynamics (CFD) models, since current technological advances offer computational power which can be utilised to perform simulations based on Reynolds-Averaged Navier-Stokes (RANS) approaches. This work mainly aims to model the roughness effects of marine coatings and biofouling on ship resistance and powering, and to develop and propose alternative models for this purpose. Firstly, drag characterisation of several marine coatings, including the novel paints developed within the EU FP7 FOUL-X-SPEL Project, as well as control surfaces, was made through towing tests of flat plates coated with such coatings. An in-house code based on the similarity law scaling was then developed. This was used to assess the roughness effects of different marine coatings, including FOUL-X-SPEL Paints, and different fouling conditions on the frictional resistances of flat plates of ship lengths. Added resistance diagrams were generated using these predictions. Following this, two separate CFD models were developed and proposed for the prediction of the roughness effects of marine coatings and biofouling using flat plates of both model-scale and full-scale. These models were validated against an experiment and compared with the similarity law scaling, respectively. Afterwards, unsteady RANS CFD simulations of the roughness effects of marine coatings and biofouling on the full-scale KCS hull appended with a rudder were performed, using the roughness models proposed earlier, in order to arrive at a final conclusion. Finally, some discussions and conclusions on the outcomes of the work performed within this thesis are presented. This author believes that this study has shown the applicability of the CFD-based method to investigate the roughness effects of marine coatings and biofouling on ship frictional resistance. The CFD methods and added resistance diagrams proposed in this thesis stand as practical prediction methods for both academia and industry.