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Discussion on ship machinery maintenance based on oil monitoring
AuthorsX P Yan ; H L Xiao ; R S Burns
PublisherComputational Mechanics Publications
AbstractThe principles methods and programs of oil monitoring are discussed. Old techniques of marine machinery maintenance are reviewed. From the monitored experiences of diesel engines mounted in tugboats a suitable maintenance system is suggested based on oil monitoring. Applications are carried out. It is concluded that oil monitoring methods applied to ship machinery monitoring are helpful in reforming the old maintenance techniques and developing predictive maintenance in ships.
AuthorsDate publishedX P Yan ; H L Xiao ; R S Burns
1995
PublisherComputational Mechanics Publications
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Experimental study on profile change of rubble mound breakwater and wave force on rubble stone
AuthorsS Araki ; I Deguchi
PublisherInternational Society of Offshore and Polar Engineers
AbstractDeformation of rubble mound breakwater wave force on a rubble stone and run-up height were measured in experiments to obtain fundamental data for establishing a design method. The process of breakwater profile change resulting from the movement of rubble stone by waves was studied. Characteristics of profile change response of rubble stone to waves and change in the hydraulic function of rubble mound breakwater with development of profile change were investigated.
AuthorsDate publishedS Araki ; I Deguchi
1998
PublisherInternational Society of Offshore and Polar Engineers
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Experimental study on vertical ice loads acting on pile structures with a circular cross-section
AuthorsT Terashima ; A Nishihata ; H Honda et al.
PublisherInternational Society of Offshore and Polar Engineers
AbstractWhen ice sheets adfreeze to structures with a circular cross-section vertical ice loads act on them as the water level changes due to tides. At a certain water level the ice sheets fracture. Modes of failure are classified as bending failure and adfreeze bond failure. Theoretical equations have been developed to estimate vertical ice loads which correspond to each mode of failure. Equations were verified by field experiments.
AuthorsDate publishedT Terashima ; A Nishihata ; H Honda et al.
1998
PublisherInternational Society of Offshore and Polar Engineers
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General design theory and its influence on design of ships
AuthorsK Hoset ; S Erichsen
PublisherUniversity of Newcastle
AbstractPapers on design theory in general and on the practical design of ships are compared in an attempt to trace the influence of design theory on ship design. About 30 papers and books published between 1951 and 1995 are reviewed. The influence of design theory seems to be limited to the application of computer programmes introduction of economic measures of merit and designing of design tasks. It is suggested that literature on design theory should reach the design engineers more effectively.
AuthorsDate publishedK Hoset ; S Erichsen
1997
PublisherUniversity of Newcastle
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Influence of bubble size on micro-bubble drag reduction
AuthorsXiaochun Shen ; Eric S Winkel ; Steven L Ceccio et al.
Date published2005
AbstractExperiments were conducted on micro-bubble drag reduction (MBDR) by injecting compressed nitrogen from a cross-stream slot into the wall turbulent boundary layer (TBL) of a high speed water tunnel. Nitrogen was injected at volumetric flow-rates from 30 to 180 standard litres per second with the tunnel operating at a free-stream velocity of 11m/s. In this paper preliminary experimental results focusing on the influence of bubble size on the effectiveness of MBDR are presented. The results in this study suggest that density modification is the primary mechanism for MBDR. The influence of bubble size on the efficiency of MBDR is very small.
AuthorsXiaochun Shen ; Eric S Winkel ; Steven L Ceccio et al.
Date published2005
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Measurement of pressure distribution on a full scale propeller - measurement on a conventional propeller
AuthorsY Ukon
Date published1991
AbstractThis paper describes the first development of sophisticated pressure measurement techniques for a full scale propeller and its success. Excellent agreements with theory were found at most of the measurement points especially at the fore part of the blades. The present measurement has provided a number of invaluable standard data to validate the numerical computational techniques on marine propellers at high Reynolds number.
AuthorsY Ukon
Date published1991
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Measuring ice loading on podded propellers systems
AuthorsAyhan Akinturk ; Stephen Jones ; Corwyn Moores et al.
Date published2003
AbstractIn this paper an experimental system to measure contact ice loads on a podded propeller in different operating conditions is described. The system is capable of measuring loads on different parts of the system in different ice thicknesses and azimuthing angles. There is a lack of information as to the loads occurring on podded propeller systems operating in ice. Hence this study aims to close the knowledge gap for this type of propulsion system. This paper describes the experimental setup designed and built at the National Research Council of Canada Institute for Marine Dynamics (NRC-IMD) for measuring ice loads on such a system.
AuthorsAyhan Akinturk ; Stephen Jones ; Corwyn Moores et al.
Date published2003
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"Multimedia" on the ship's bridge - alleviating the impact of new technology on the mariner
AuthorsK P Dickens ; M J Dove
PublisherIMarE Conferences and Symposia
AbstractThe proposed development of a prototype multimedia training package to facilitate the introduction of new technology onboard ship is based on the findings of a questionnaire/survey (with supporting interviews) carried out to assess the attitudes of individual mariners to the introduction of specific items of equipment (GMDSS electronic charts combined radar/chart displays navigation systems) and to the learning aids provided (manuals software packages teachers experience).
AuthorsDate publishedK P Dickens ; M J Dove
1995
PublisherIMarE Conferences and Symposia
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On the effects of the slip stream on the mathematical representation of open propellers
AuthorsA Koumbis
Date published1984
AbstractA mathematical method for calculating the salient features of open propellers with an irregular balanced slipstream (with or without finite core tip vortex) is presented and compared with other published methods in worked examples. The method is based on approximations of the wake geometry. A propeller design procedure is outlined.
AuthorsA Koumbis
Date published1984
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On the influence of speed on the manoeuvring behaviour of a container carrier
AuthorsP Oltmann ; M S Chislett
Shelf Location213c
AbstractExtensive manoeuvring model tests for a modern post-Panamax container carrier are described examining whether the vessel will fulfill the interim IMO standards and considering the influence of speed on the manoeuvring performance. The model tests (zig-zag manoeuvres) were performed together with supplementary numerical simulations of turning circles and reverse spiral tests. The model tests and numerical simulations are discussed.
AuthorsDate publishedP Oltmann ; M S Chislett
1996
Shelf Location213c
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Precipitate effects on CGHAZ toughness of underwater weld on pipeline steels
AuthorsG Wang ; Y Shi
Date published1999
AbstractThe behaviour of the carbides and nitrides in X60 X65 and X70 pipeline steels (Ti-V-Nb microalloyed) during underwater welding and their effects on the coarse-grained heat-affected zone (CGHAZ) toughness are looked into. In-air welds are also produced for comparison purposes. After some background information the materials and the experimental procedure are considered. This is followed by discussion of the results.
AuthorsG Wang ; Y Shi
Date published1999
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Statistical analysis of two probabilistic models of ice accretion on overhead line conductors
AuthorsK Savadjiev ; M Farzaneh
PublisherInternational Society of Offshore and Polar Engineers
AbstractTwo probabilistic models of atmospheric icing on overhead transmission line conductors involving the combined wind-on-ice loads and the specification of radial ice thickness versus linear ice weight were analysed. A method for determining the combined wind- on-ice loads is proposed using the largest extreme distribution for icing and the Weibull distribution for wind speed. The specification of ice linear weight on conductors instead of ice radial thickness was proposed for probability based line design.
AuthorsDate publishedK Savadjiev ; M Farzaneh
1998
PublisherInternational Society of Offshore and Polar Engineers
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Symposium on the shaft driven generator system - on the high harmonies of thyrister type shaft driven AC generator system
AuthorsS Itano
Date published1982
AbstractThe generation of high harmonics associated with thyristor type shaft driven AC generators are discussed with consideration of - effects on rotating machinery radio equipment measuring instruments; the phenomena of electrostatic electromagnetic radio and conduction noise; and anti-noise countermeasures the converter and inverter systems.
AuthorsS Itano
Date published1982
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The effect of variation in hydrodynamic coefficients on the loading on jacket structures and the implications for tank testing
AuthorsM Abdelradi ; N S Miller
Date published1986
AbstractProcedures for the experimental and theoretical determination of wave loading on offshore structures composed of cylindrical members (such as jackets) are explained and relevant literature examined. Problems in obtaining satisfactory valves for the hydrodynamic coefficients of inertia drag and lift in scaling and in constructing adequate facilities for tank testing are discussed and recommendations made.
AuthorsM Abdelradi ; N S Miller
Date published1986
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Developments on exhaust emission modelling for large two-stroke diesel engines - some comparisons with measured data and an update on the latest emission reduction techniques
AuthorsNiels Kjemtrup ; Kjeld Aabo ; Thomas Knudsen
Date published2007
AbstractThe continuous development of the MAN B&W Diesel two-stroke engines within the field of exhaust gas emission reduction methods is presented. A variety of approaches used towards a better description of emission formation inside the combustion chamber are discussed. The modelling tools described cover a range from simple 0D and 1D formulations to complex state of the art 3D CFD models with advanced sub-models for spray combustion and pollutant formation. And on the experimental side details are given on extensive parametric studies with the in-house two-stroke test engine. Further a novel study on large engine fuel injection is presented using latest technology high-speed imaging techniques. In addition to the in-house tests all major engine test results from production sites since year 2000 have been recorded in a database allowing the statistical analysis of engine test data across engine type engine configuration and of course engine operating conditions. Major results from an extensive ongoing data-mining activity on the basis of this database are given. In particular the results confirm the full potential of the electronic-controlled engine with variable injection-rate profiling. Finally status on development issues such as SAM (Scavenging Air Moistening) TES (Thermo Efficiency System) and use of turbochargers with VTA (Variable Turbine Area) are outlined.
AuthorsNiels Kjemtrup ; Kjeld Aabo ; Thomas Knudsen
Date published2007
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Bureau of Maritime Affairs Republic of Liberia Decision of the Commissioner of Maritime Affairs R.L and Report of the Investigation into the Matter of the Loss by Grounding of the Motor Tanker Braer ON 7703 on the South Coast of Shetland Island 5 January
AuthorsBureau of Maritime Affairs
PublisherBureau of Maritime Affairs
AbstractItems include - Interviews Findings of Fact Recommendation on Fuel Tank Venting and Conclusions.
AuthorsDate publishedBureau of Maritime Affairs
1994
PublisherBureau of Maritime Affairs
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Comprehensive study on two-stage combustion for the reduction of soot and NOx emissions from DI diesel engines
AuthorsT Chikahisa
Date published2000
AbstractResults are presented of a series of works on two-stage combustion. The effect of turbulent jet on smoke reduction is investigated - it is found that turbulence induced during the main combustion reduces smoke without increasing NOx. Next experimental results are discussed of several trials with two-stage combustion for NOx reduction. Then to see the NOx reduction potential of the two-stage combustion and to identify the effective control-factors for the reduction NOx formation kinetics are analysed together with the jet momentum on smoke reduction. Finally jet impingement on flame is observed to find out the condition that will give the maximum mixing with the same energy of CCD jets. Results are listed as a conclusion.
AuthorsT Chikahisa
Date published2000
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Effects of slip-stick on top tensioned riser fatigue
AuthorsJohn J Murray ; Djoni E Sidarta ; Xiaohua Lu et al.
Date published2002
AbstractThis paper compares and discusses the results of coupled and uncoupled models to compute the damage in the risers due to slip-stick. The two models are based on identical finite-element models of the riser system. The main difference is how the motion input to each model is computed. In the coupled model the effects of the riser on the motions are integrated in to the time-domain solution of the motion. In the uncoupled model motions that are computed assuming only horizontal restoring forces from the risers are imposed on the contacts between the riser and the hull. In general the coupling effects showed that the risers dampen motion in surge sway roll pitch and yaw but have an insignificant effect on the natural periods. The heave comparison showed a reduction in heave due to damping from the risers sliding as well as from the constraints of the risers while they are stuck. Results of the coupled analysis showed lower fatigue damage than those predicted by the uncoupled model and these results are used to show the level of conservatism introduced by the uncoupled model.
AuthorsJohn J Murray ; Djoni E Sidarta ; Xiaohua Lu et al.
Date published2002
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Effects of Wave Intermittency and Nonlinearity on Wave Loads
AuthorsJ Yang ; J Zhang
Date published2000
AbstractTwo methods Hybrid Wave Model (HWM) and Mode-Coupling Method (MCM) are respectively used to simulate ambient wave kinematics of a Single Degree of Freedom (SDOF) cylindrical structure and in turn to predict wave forces on it by using the Morison equation. The statistics of the simulated results reveal the effects of surface intermittency and nonlinear wave kinematics on the wave forces. It is shown that the combination of surface intermittency and nonlinear wave kinematics greatly increase the wave forces on a bottom fixed cylinder with the increase in the spectral steepness in comparison with the results given by linear wave theory (LWT). Hence both nonlinear wave kinematics and surface intermittency should be considered in predicting the wave forces. It is also shown that their effects depend on the characteristics of sea states. The effects are stronger in sea states of a spectrum of broader band than in a narrow-band spectrum.
AuthorsJ Yang ; J Zhang
Date published2000
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Evaluating the design of passenger and crew accommodation on ships
AuthorsDuncan A Joiner
Date published2006
AbstractThe designers of accommodation on ships like the designers of buildings rely heavily on experience and tradition. They have few opportunities to test spaces and fittings as prototypes in use before committing to final construction. They also have little opportunity to know the expectations of users - passengers and crew - and to be able to balance those expectations with the requirements of maintenance staff and ship owners or with engineering and physical environmental constraints. It is suggested that POE (post occupancy evaluation) methods developed for evaluating buildings in use could also be used to evaluate and inform the design of passenger and crew accommodation on ships. POE has been developed and used in architecture during the last 20 years. It is a technique that enables designers to optimise the expectations of all interested parties associated with the building. It is a process of negotiation which can be used to inform the fine-tuning or re-fit of an existing building and provides a sound database about users' expectations for the design of new buildings. It has been used on a wide range of building applications including courthouses retail stores scientific research laboratories banks
AuthorsDuncan A Joiner
Date published2006