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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Techno-economic assessment of new coating procedures for newbuilding marine production

Baldwin, Laurence James January 2002 (has links)
No description available.
12

The development of an apparatus for the routine measurement of the viscous resistance of ship models

Wynne, J. B. January 1981 (has links)
No description available.
13

Dynamic response of TLPs during tether installation

McLeary, Alwyn January 1998 (has links)
No description available.
14

Dynamics of marine vehicles with aerodynamic surfaces

Collu, Maurizio January 2008 (has links)
An assessment of the relative speeds and payload capacities of airborne and waterborne vehicles highlights a gap which can be usefully filled by a new vehicle concept, utilizing both hydrodynamic and aerodynamic forces. A high speed marine vehicle equipped with aerodynamic surfaces (called an AAMV, 'Aerodynamically Alleviated Marine Vehicle') is one such concept. The development of this type of vehicle requires a mathematical framework to characterize its dynamics taking account of both aerodynamic and hydrodynamic forces. This thesis presents the development of unified and consistent equations of equilibrium and equations of motion to predict the dynamic performance of such AAMV configurations. An overview of the models of dynamics developed for Wing In Ground effect 'WIGe' vehicles and high speed marine vehicles (planing craft) is given first. Starting from these models, a generic AAMV configuration is proposed and a kinematics framework is developed. Then, taking into account the aerodynamic, hydrostatic and hydrodynamic forces acting on the AAMV, equations of equilibrium are derived and solved. This is followed by deriving and solving the full equations of motion, using a small perturbation assumption. A static stability criterion, specific for the AAMV configuration, has been developed. This mathematical framework and its results are implemented in MATLAB and validated against theoretical and experimental data. The resultant capability for analysing novel AAMV configurations is presented through two parametric analysis. The analysis demonstrate that these models offer a powerful AAMV design tool.
15

Aerodynamic forces on high speed multi-hulled marine vehicles

Williams, A. G. W. January 2008 (has links)
The need for high-speed high-payload craft has led to a considerable interest in vehicles capable of bridging the gap between conventional ships and aircraft. One such concept uses the forward motion of the craft to create aerodynamic forces on a wing-like structure, and hence, alleviate the overall drag by reducing the wetted area. This research focuses on the use of suitably shaped multihull geometries to achieve e cient aerodynamic lift for high-speed sea vessels. The problem is rst studied in two dimensions using a simpli ed analytical approach and CFD modeling. The work is then extended into three dimensions and a nal aerodynamic model is produced for a complete hull form, including the e ects of hydrodynamic surfaces above the water. The aerodynamic analysis demonstrates that signi cant e ciency can be achieved through careful shaping of the side hull and cross deck, with lift-to-drag ratios of nearly 50 for a complete aerodynamic hull con guration. Further analysis is carried out using a hybrid vehicle stability model to determine the e ect of such aerodynamic alleviation on a theoretical planing hull vessel. Comparisons are made using the Savitsky planing model, and from this it is found that the resistance can be almost halved for a fty metre, three hundred tonne vehicle with aerodynamic alleviation traveling at 70 knots. A comparative study is made for the hybrid vehicle with regards to size, speed and weight, whilst attempting to match the proportion of aerodynamic lift with speed to a theoretical optimum. From this the likely con gurations for future development are identi ed.
16

Manufacture, repair and recycling of thermoplastic composite boats

Otheguy, Mariano E. January 2010 (has links)
The design and construction of boats using thermoplastic composites (TPCs) is an emerging industry derived from the advantages these materials offer. Short manufacturing cycle times, virtually infinite shelf life, increased toughness, no volatiles emission, and the ability to be re‐processed and recycled, lead to improved processes and open new and more sustainable manufacturing possibilities for boats and other structures. However, the manufacture, repair and actual recycling of TPCs still present a number of technical challenges. This thesis addresses the five most important of these challenges, from both the academic and industrial points of view. The manufacturing of TPC structures involves the impregnation of reinforcing fibres with melted resin. This process, known as consolidation, is still to be fully understood. In order to contribute to this understanding, a consolidation model based on existing and newly developed sub‐models was developed and applied to experimental data. The results obtained proved that the non‐isothermal consolidation of laminates of a thickness typical of boatbuilding, can be approached by applying this model locally on a discretised laminate, fitting well experimental data. The choice of a cost‐effective moulding material is one of the factors currently preventing the widespread use of TPCs in boatbuilding. The vacuum forming of TPCs requires moulds which have considerable strength, and allow high service temperatures and the shape freedom which is typical of boat moulds. A review of commercial and experimental materials and laboratory experimentation on a novel glass‐reinforced ceramic composite was carried out, showing that a range of metals and composites are useful for TPC‐capable moulds, and that a cost‐effective free‐shape mould capable of processing any TPC is achievable. After hull shell manufacturing stiffeners and other internal structure are often required. The manufacturing of such a reinforced and subdivided hull involves the use of a joining technology. Adhesive joining, widely used in thermosetting resin composite boats, cannot be easily used on TPCs due to their low energy surfaces. However, the re‐melting ability of thermoplastic resins enables the use of welding, fusion bonding and other joining methods involving molecular diffusion at the bond line. Experiments carried out on lap and T‐joints showed that vacuum‐assisted local heating can be used for structural assemblies such as reinforced boat hulls, obtaining strengths that are comparable to existing thermosetting designs. A TPC boat manufactured and assembled in such way would still require a suitable repair technique that provides a long product life. An emergency repair method capable to return the boat to the water in less than 24 hours without using any mould was devised and tested on a prototype TPC rigid inflatable boat. This was achieved by fusion bonding the edges of a pre‐manufactured flat panel to the hull. The flat panel adapted to the hull double curvature by means of vacuum pressure, delivering the required bond quality and strength. Finally, the disposal of a TPC boat must be addressed after the end of its service life. Current policies and innovative business thinking are leading companies into reusing and recycling instead of landfilling materials. While the mechanical recycling of TPCs, achieved by means of resin re‐melting, has been largely studied, the recycling of a real boat containing paint and core material raise questions on how these materials would affect the recyclate. An experimental study on the recycling of a TPC real boat was carried out to answer these questions, revealing that despite the deleterious effect of core and paint, the final properties of injection moulded samples were in the region of those of virgin materials.
17

AIS operation for effective bridge lookout

Hua-Zhi, Hsu January 2008 (has links)
No description available.
18

The ferry service offer : an analysis of ferry services operating from and within the United Kingdom

Heijveld, Harmanus January 1998 (has links)
The objective of this study is to investigate the market offer of passenger-car ferry services within and from the United Kingdom. The study is approached from the pomt of view of the provider of the ferry service offer. Initially, it seeks to analyse the existing ferry services offered within and from the United Kingdom by the various operators, and subsequently undertakes an empirical investigation based on the appropriate marketing and management theory. The role of the consumer is, of course, crucial to an understanding of the marketing of ferry services. However, this particular study focuses on the supply of the ferry offer, and may be seen as complementary to earUer studies of ferry consumers and benefits sought. A comparison of on-board facilities and services on 70 ferries operating in the UK in 1994 resulted in the development of a basehne model explaining differences between services according to a wide range of criteria. This led to the development of a conceptual model of the ferry service offer using concepts from services marketing and corporate culture theory. Using cluster analysis it was concluded that the ferry service offer can be described in terms of core, augmented, and inter-product levels. In addition to these three ferry service offer levels the preferred service provider of each particular ferry service element has been identified. Using multiple discriminant analysis it was concluded that the augmented ferry service offer can be explained by differences among Miles & Snow corporate culture types (prospectors, analysers, and defenders). Combining these results, this study provides an explanation of the ferry service offer in terms of product level, preferred provider, and dominant corporate culture, which should prove of both practical and theoretical value.
19

Reliability assessment and risk analysis of submarine blowout preventers

Moura Jorge, Nilo de January 2000 (has links)
No description available.
20

Turbulent shear-flows near irregularly rough surfaces with particular references to ships' hulls

Musker, Anthony Joseph January 1977 (has links)
No description available.

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