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Simulation of sloshing loads on moving tanks
AuthorsMilovan Peric ; Tobias Zorn
Date published2005
AbstractThe aim of this presentation is to demonstrate the possibilities of predicting loads on partially submerged moving structures in particular on tanks in ships and on offshore platforms. After some introductory information the numerical method used to compute fluid flow and motion of floating bodies is briefly presented followed by the results of validation of sloshing simulations. Final sections present results of coupled simulations of flow around the vessel sloshing in tanks inside vessel and vessel motion due to flow-induced forces from all wetted surfaces.
AuthorsMilovan Peric ; Tobias Zorn
Date published2005
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The effects of swimbladder size condition and gonads on the acoustic target strength of mature capelin
AuthorsRoar Jorgensen
Date published2003
AbstractPre- and post-spawning capelin from the Barents Sea stock were observed in a net pen with a calibrated 38 kHz scientific split-beam echosounder. The transducer was positioned vertically or tilted. The acoustic target strength (TS) of capelin depended on swimbladder length. This paper reports recent ex situ TS experiments on Barents Sea capelin and evaluates the possible effects of swimbladder size and condition and of the gonads on the TS of pre- and post-spawning capelin. A look is taken at materials and methods followed by results and discussion.
AuthorsRoar Jorgensen
Date published2003
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The fire performance of cables on warships
AuthorsT R Manley ; D A Harrison
PublisherIMarE Conferences and Symposia
AbstractFollowing problems with the concept that halogens would act as fire retardants without hazard halogen free cables are now used in the construction of warships. Research on fire performance of cables relies heavily on small scale empirically based tests. These tests are not satisfactory for cable behaviour under service conditions. The paper asserts the need for more fundamental work on polymer decomposition in fires.
AuthorsDate publishedT R Manley ; D A Harrison
1987
PublisherIMarE Conferences and Symposia
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Royal Commission on Unseaworthy Ships, Report on Shipwreck 1839
Shelf Location41e
Catalogue number919.84
Shelf Location41e
Catalogue number919.84
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9th International congress on combustion engines A
AuthorsCIMAC
Shelf Location225f
Abstract9th Intl conf held in Stockholm Sweden in 1971 Papers are Developments in control techniques for industrial gas turbines Fluidic injection system for turbochargers and gas turbines Residual oil and gas turbine fuel aspects on corrosion and deposites The application of gas turbines to the propulsion of liquefied natural gas tankers Designing reliability into heavy duty gas turbine controls 12MW industrial three-shaft gas turbine - turbine testing performance prediction and test results The causes of corrosion attack in gas turbines and possible preventive measures Control systems of gas turbine and helper steam turbine units Heat transfer in industrial gas turbine combustion chambers Recent developments in the use of heavy fuels in industrial gas turbines The design of a 3000 HP industrial gas turbine Feasibility and design of a large portable gas turbine facility for natural gas transmission The gas turbine and its influence on pollution of the environment Gas turbine for rail vehicles The development of turbochargers for diesel engines with a high degree of charging A systematic investigation on the corrosion of gas turbine materials at temperatures about 700 deg C by flue gases of impure fuel oils
AuthorsPublisherCIMAC
CIMAC
Shelf LocationDate published225f
1971
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A consideration on use of material grades for hull structural members based on fracture toughness
AuthorsH Yajima ; M Yamamoto ; K Qi et al.
Shelf Location213d
AbstractThe method to estimate allowable crack length is looked at. Next the use of material grades for hull structural members in NK rules and allowable crack length are considered. Assuming of required V-notch Charpy absorbed energy values is touched upon followed by assuming of allowable critical crack length. After this the proposed use of material members for hull structural members with thickness up to 80mm considering fracture toughness is discussed. Lastly a comparison is made between the current use of material grades for hull structural members in NK rules and the proposed one.
AuthorsDate publishedH Yajima ; M Yamamoto ; K Qi et al.
1998
Shelf Location213d
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Air quality and ventilation on ro-ro ferry vehicle decks - research recommendations and guidelines
AuthorsG L Reynolds
Date published1996
AbstractA programme of research undertaken by Lloyd's Register (LR) into air quality and ventilation on ro-ro ferry vehicle decks was designed to evaluate levels of nitric oxide (NO) nitrogen dioxide (NO2) hydrocarbons (HC) carbon monoxide (CO) particulates and polynuclear aromatic hydrocarbons (PAH). The performance of the mechanical ventilation systems and air flow distributions was also assessed and relationships between ventilation and air quality evaluated. Distinct air pollution patterns characterised discharge and loading profiles for particular cargo types but there was no consistent differences in overall air quality between summer and winter. Hand held CO monitors provided a good indication of spatial variability in exhaust fumes on passenger vehicle decks but not freight vehicle decks. The IMO Guidelines on the Design of Ventilation Systems in Ro-Ro Cargo Spaces and Operational Recommendations for Minimising Air Pollution in Ro-Ro Cargo Spaces are outlined.
AuthorsG L Reynolds
Date published1996
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An approach to calculate the probability of wave impact on an FPSO bow
AuthorsC Guedes Soares ; R Pascoal ; E M Antao et al.
Date published2004
AbstractThis work aims at characterizing the probability of wave impact and expected impact load on the bow geometry of an FPSO. In order to determine the instant when impact occurs an experimental program was performed on a specific bow shape. The bow was instrumented with pressure transducers and the test program also making use of video recordings was designed such that it was possible to determine the correlation between undisturbed wave shape and the impact pressure time traces. A comparison between the probability distributions of local wave steepness of the experimental undisturbed wave time trace and numerical simulations of second order wave theory is provided. The experimental results were further used to determine how the probability of impact varies with free surface vertical velocity. The proposed model for determining the probability of impact load is based on combining both models.
AuthorsC Guedes Soares ; R Pascoal ; E M Antao et al.
Date published2004
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An experimental study on flooding into the car deck of a ro-ro ferry through damaged bow door
AuthorsN Shimizu ; R Kambisseri ; Y Ikeda
PublisherElsevier
AbstractExperiments were carried out on a model ro-ro car ferry with a bow opening instead of a bow door. The model was run into regular head waves allowing only heave and pitch motions. The flooding of the car deck increased with the increase of bow opening size wave height and Froude number. The motions changed with the flooding. Theoretical calculations showed a heavy loss of (static) righting moment due to the shift of water on deck. The study suggests that a ship should be slowed down or stopped on damage to reduce or avoid further flooding. The experiment is detailed the results and analysis are presented and conclusions are drawn.
AuthorsDate publishedN Shimizu ; R Kambisseri ; Y Ikeda
2000
PublisherElsevier
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Analysis of hydrodynamic forces on a propeller blade of tunnel thrusters in bollard conditions
AuthorsIsao Funeno
Date published2006
AbstractTunnel thrusters comprise a propeller mounted inside a tunnel which is attached to vessels such as ferries container ships passenger vessels etc. In the past theoretical analysis of hydrodynamic performance of tunnel thrusters has been extremely difficult. In designing propeller blades of tunnel thrusters for hydrodynamics and strength it is necessary to accurately estimate hydrodynamic forces on the blades as external forces. In order to overcome these problems a new analysis method has been developed using CFD (computational fluid dynamics) based on RANS (Reynolds averaged Navier-Stokes') equations. An outline of this analysis method is described and computed results are verified by comparing them with measured data. Force-acting points on a blade during one revolution are also discussed. This method is shown to be a very useful and reasonable design tool for the propeller blades. Results are presented and discussed and conclusions are drawn.
AuthorsIsao Funeno
Date published2006
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Analysis of wave run-up measurements on a mini-TLP
AuthorsI A Sibetheros ; J M Niedzwecki ; P Teigen
Date published2005
AbstractWave run-up on deepwater offshore structures may contribute to wave overtopping of the platform deck. It may also cause undesirable loads including impact loads on the underside of the deck when combined with other hydrodynamic phenomena beneath the platform deck. In this study a 1:40 scale model of an unmanned mini-TLP design was subjected to a series of design sea environments for the Gulf of Mexico. Complimentary testing of compliant and fixed hull configurations was performed and the wave run-up was measured at several locations around the hull in both head and quartering sea orientations of the platform. The wave elevation data reported here was obtained at three critical points on the hull and a reference wave gage well upstream of the model. Analysis of the data was performed using an orthogonal third order Volterra series system analysis technique. The wave run-up measurements were compared and correlated to the incident wave elevation measurements.
AuthorsI A Sibetheros ; J M Niedzwecki ; P Teigen
Date published2005
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Automated knuckle detection in ship hull forms
AuthorsRobert Bronsart ; Gernot Kneiling
Date published2006
AbstractIn the early design stages of ship hulls computer-based methods are used to check improve and compare multiple design alternatives. In the field of fluid dynamics increasing ship speeds place emphasis on the reduction of resistance. Codes based on potential flow theory are used to estimate and analyse the flow around the ship's hull and to determine the wave-induced resistance. The distribution of panels on the hull has a significant impact on the accuracy of the overall power prediction. Creating the panels on the hull surface especially for modern hull forms is a resource intensive non- or semi-automated task requiring a profound experience-based knowledge. The time needed for the manual definition of the mesh is high. No methods are known at present for automatically creating panel discretisations of ship hull forms. Mesh generation methods for potential flow calculations require appropriate descriptions of the ship hull surface. The IGES standard is a widely used format in the shipbuilding industry for the exchanges of ship hull forms. Methods are presented here to prepare ship hull form descriptions based on IGES files which are later used for potential flow calculations. Two major problems are solved: topology recovery and knuckle detection.
AuthorsRobert Bronsart ; Gernot Kneiling
Date published2006
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Benchmarking of truss spar vortex induced motions derived from CFD with experiments
AuthorsJohn Halkyard ; Senu Sirnivas ; Samuel Holmes et al.
Date published2005
AbstractThe authors have been investigating the use of CFD as a means for predicting full scale vortex induced motions (VIM) performance and for facilitating the design of spars for reduced VIM. This paper reports on the results of a study to benchmark the CFD results for a truss spar with a set of model experiments carried out in a towing tank. The focus is on the effect of current direction reduced velocity and strake pitch on the VIM response. The tests were carried out on a 1:40 scale model of an actual truss spar design and all computations were carried out at model scale. Future study will consider the effect of external appurtenances on the hull and scale-up to full scale Reynolds' numbers on the results.
AuthorsJohn Halkyard ; Senu Sirnivas ; Samuel Holmes et al.
Date published2005
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Cargo securing manual : A guide to owners
AuthorsLloyd's Register
Shelf Location230d
AbstractThis example Cargo Securing Manual is based on the Draft Guidelines for the Preparation of the Cargo Securing Manual, MSC/Circ.745. The purpose of this example is to provide guidance to those involved in the preparation of Cargo Securing Manuals, i.e. guidance to the master and crew on board the vessel with respect to the proper stowage and securing of cargo units, suggesting appropriate wording and highlighting the details and information to be included. Contents Securing devices and arrangements, with specifications for fixed and portable cargo securing devices and inspection and maintenance schemes; and Stowage and securing of non-standardised and semi-standardised cargo, with parts on handling and safety instructions, evaluation of forces acting on cargo units, and application of portable securing devices on various cargo units, vehicles and stowage blocks. There is a floppy disk in a pouch on the inside of the front cover which contains the IMO Guidelines for the Preparation of the Cargo Securing Manual, and the Lloyd's Register Example Cargo Securing Manual.
AuthorsPublisherLloyd's Register
Lloyd's Register
Shelf LocationDate published230d
1996
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Case study: effects of wind loading on structural reliability
AuthorsEmmanuel Fakas ; Suhartodjo Tuty ; Beverley F Ronalds et al.
Date published2001
AbstractThe effect of wind loading on structural reliability under storm overload is investigated for a number of minimum facility platforms on the North West Shelf. The long term distribution of environmental loading and consequently the structural reliability is seen to be highly sensitive to wind loading for platforms in very shallow water where the high return period wave heights are limited by breaking waves. The wind loading contribution to the total platform loading is further investigated for a typical minimum facility platform for a range of water depths topsides weights and substructure effective diameters. Critical design conditions are thus highlighted for which a realistic assessment of structural reliability is highly dependent on the accuracy of the wind loading estimation.
AuthorsEmmanuel Fakas ; Suhartodjo Tuty ; Beverley F Ronalds et al.
Date published2001
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Comparison of results of impact tests on laboratory and natural freshwater ice with hydrodynamic model predictions
AuthorsV Likhomanov ; I Stepanov ; R Frederking et al.
PublisherInternational Society of Offshore and Polar Engineers
AbstractAn extensive series of drop impact tests were carried out previously by the Arctic and Antarctic Research Institute on natural ice and by the National Research Council of Canada on laboratory ice. The data from both test locations were analysed by a hydrodynamic model of impact of a rigid body on ice. The ice impact crushing strength showed consistency and similar trends. Impact strength decreased with increasing temperature. Further development of the model is considered.
AuthorsDate publishedV Likhomanov ; I Stepanov ; R Frederking et al.
1998
PublisherInternational Society of Offshore and Polar Engineers
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Contract designs for ballast water treatment systems on containership 'R J Pfeiffer' and tanker 'Polar Endeavor'
AuthorsW L Hurley ; S S Schilling ; T P Mackay
Date published2001
AbstractThe Great Lakes Ballast Technology Demonstration Project recently funded three six-month full-scale design studies of promising ballast water treatment systems. The aim of each study is to fully develop for a specified 'target' vessel the contract design and life-cycle cost of a reliable optimised flow-through on-board treatment system that effectively removes living organisms from a ship's ballast water before it is discharged into an ecosystem other than its original source. Two of these three studies are examined and two different kinds of target vessels are selected. This is one of the first efforts devoted to developing contract design level technical solutions quantifying life-cycle costs and assessing actual vessel operational impacts on effective ecosystem maintenance. Diagrams appear on pages 19-21.
AuthorsW L Hurley ; S S Schilling ; T P Mackay
Date published2001
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Effect of Plate Thickness on Fatigue Strength of Base Material and Butt Welded Specimens Made from EH40 Steel Thick Plates: Phase 1
AuthorsHelena Polezhayeva; Clive Badger
PublisherThe International Society of Offshore and Polar Engineers (ISOPE); 2009
AbstractIn large vessels, the thickness of deck plating has increased significantly during the last decade. Hence, it is not possible to ignore the effect of plate thickness on fatigue strength for these structures. To complement existing data and to establish the effect of plate thickness on fatigue strength, constant amplitude fatigue tests were carried out under tensile and bending loads for base material and butt welded specimens of various thicknesses made from high-tensile EH40 steel. Based on the fatigue test results and available literature, the thickness exponent was derived.
AuthorsDate publishedHelena Polezhayeva; Clive Badger
2009
PublisherThe International Society of Offshore and Polar Engineers (ISOPE); 2009
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Effects of lateral stability on the design of HT/HP flowlines
AuthorsWei Ma ; Olivier Andrieux ; Pierrick Sauvage et al.
Date published2002
AbstractThis paper discusses key effects of the lateral stability on pipeline design and especially on axial creeping under thermal and pressure cyclic loading when connected through catenary risers to large offset floating platforms. The paper demonstrates that the flowlines may have much larger net axial displacement under repeated production shut-downs if they are laterally unstable. The paper provides sufficient details and results for the deepwater pipeline ratcheting phenomenon through extensive finite element analyses. The models mainly cover production flowlines in both elevation profile and plan layout. The results are also compared with theoretical calculations. Some important considerations on deepwater pipeline design are described.
AuthorsWei Ma ; Olivier Andrieux ; Pierrick Sauvage et al.
Date published2002
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Encouraging attitude behaviour and cognitive change in ships' officers: as simple as ABC?
AuthorsClaire H Pekcan
Date published2005
AbstractOn the full mission simulator courses run at Warsash Maritime Centre a team of researchers and lecturers is working together to ensure three things: (1) that students learn and learn the types of attitudes behaviours and cognitions that have deep significance for their effectiveness on board ship; (2) that the course lecturers concentrate more on what the students do and less on what they do by designing learning sessions that get the students engaged; and (3) that the students learn more than the lecturers do through observation of reflection on and critical analysis of their own behaviour. Accordingly the philosophical underpinnings and the behavioural change process upon which the delivery of these novel courses depends are discussed. In the course of this exposition particular attention is paid to explaining the ABC (antecedent-behaviour-consequence) mechanism of learning by which the adoption of the new behaviours is encouraged and transferred to the shipboard environment. Further it is explained why the development of technical competence in shiphandling or engine management while still important is no longer the primary learning objective of these courses and why the emphasis is on developing the skills of communication
AuthorsClaire H Pekcan
Date published2005