Part Of Hull Research Articles

Kanne Lobal: A conceptual framework relating education and leadership partnerships in the Marshall Islands

Kanne Lobal: A conceptual framework relating education and leadership partnerships in the Marshall Islands

Methodology for developing the configuration of an ice load monitoring system for an iceresistant self-propelled drifting platform

The ice-resistant self-propelled platform (IRSPP) named North Pole that is currently under construction at the JSC Admiralty Shipyards is designed to carry out year-round scientific research in the Arctic Ocean. The IRSPP will be equipped with a unique ice loads monitoring system (ILMS). The technical requirements for the ILMS were developed in the Department of Ship Performance in Ice of the AARI. The ILMS should ensure a safe operation of the IRSPP in ice conditions (operational function) and serve as a measuring tool for researching of the mechanics of deformation and destruction of ice (scientific function). Analysis of ice conditions at different stages of IRSPP operation showed that the main scenario of ice interaction with the IRSPP hull will be the action of ice under compression on the middle part of the hull during drift. The monitoring of the stress-strain state of the hull is carried out by a complex system of fiber-optic strain sensors placed on different elements of the hull structures. The largest number of sensors are located on the side plating in the middle part of the IRSPP hull. The locations of the sensors were determined by finite element analysis of the stress-strain state of the IRSPP hull under the action of ice load. To monitor the stress-strain state of the surrounding ice field, up to 16 pressure sensors frozen into the ice are provided. Also, the system receives and stores data on the angles of roll, trim, yaw of IRSPP, its longitudinal, lateral and vertical accelerations, and the surrounding hydrometeorological conditions: wind speed and direction, air temperature, atmospheric pressure, and the geographical position of the platform. ILMS will significantly improve the safety of IRSPP operation during prolonged drift in ice conditions. Besides, the ILMS provides the platform hull with the functions of a measuring tool for studying the mechanics of deformation and destruction of sea ice in interaction with the engineering structures. The main purpose of this work is to create a comprehensive system for studying the processes of ice impact on structures in order to obtain new data about the parameters and nature of ice loads.

Exploring Wellbeing and Creativity Through Collaborative Composition as Part of Hull 2017 City of Culture.

Several studies have highlighted the positive effects of group music-making and have suggested that it may be the creative and social aspects of such activities, which have a positive effect on participants’ wellbeing. Collaborative composition offers strong examples of both aspects as participants work together to create new material. However, although it seems likely that participants’ influence over and ownership of the creative material contributes to these positive effects, studies have yet to examine these elements in detail. Through analysis of video observations, pre- and post-project interviews, video recall interviews, and questionnaires, this article aims to: (1) evaluate the impact of participation in collaborative composition workshops on the subjective and psychological wellbeing of older adults and (2) identify skills and approaches employed by the composer-facilitators in order to understand more fully the approach and skills employed to engage participants effectively in the creative process. This second aim is of particular interest given the current movement toward social prescribing and arts and health interventions in the UK. Analysis revealed that all dimensions of the PERMA framework for subjective and psychological wellbeing were present in this collaborative composition project. The specific nature of collaborative composition is considered in comparison with other forms of group musical engagement. For older adults, collaborative composition has much to offer as an activity encouraging social interaction with others with shared interests, increasing positive affect, and enhancing self-esteem. Analysis of workshop videos and interviews with composers identified various facilitation skills employed by the composers to establish safe creative space and to encourage participants to engage in the process of collaborative composition.

Анализ полного сопротивления корпуса судна на различных скоростях хода

The paper shows method for analyzing total resistance of ship which calculated on Froude numbers from 0.14 to 0.41. To this method the hull surface divides into its component surfaces to the ship length. This approach allows to calculate the distribution of resistance forces along the ship length. Based on this data hull zones for correcting can be selected, and a better comparison of several hull can be made. First of all mathematical scheme of total resistance calculating develops and validates in the OpenFOAM software. The standard solver interDyMFoam and DTMB 5415 hull data uses. Three grids uses for mesh convergence. To implement the proposed method the DTMB 5415 hull divides into 22 surfaces along the length. According to the results of numerical simulations the curves of distribution of resistance force along the hull length for the different ship speeds obtain. Due to analysis of curves two versions of hull develops based on DTMB 5415 hull: without bulb and with streamlined bulb. Both hulls have lower resistance at all speeds compared to the DTMB 5415 base hull. Due to analysis of resistance force distribution curves of new hulls distributed resistance force on middle and stern parts of hull does not depend on ship speed and stem part lines. Stem part of hull has the most important influence on total resistance.

CFD Simulation of the Moonpool on the Total Resistance of a Drillship at Low Forward Speed

A moonpool is meant to access the underwater part of hull from onboard ship. Moonpools are openings right through the hull from deck to bottom, allowing equipments, ROVs, etc. to be put into the water at a location on the vessel under permissible ship motion condition. Open moonpools in a drillship are causing additional resistance when the ship is in forward speed. It was shown that the water inside the moonpool started to oscillate at forward speed. The drillship is mainly subjected to two types of motions of water mass inside the column namely, piston mode and sloshing mode. The later mode will be dominant in longer moonpools and piston mode in shorter. The amplitude of water particles inside the moonpool is correlated with the forward speed such that increased forward speed leads to increased amplitudes. The main objective of this study is to find the total resistance and the free surface flow caused by the moonpool when the drillship is at low forward speed condition. Drillship with and without moonpool are considered for the study. Proven packages are used to calculate the calm water resistance of the drillship with moonpool. The incremental change in resistance caused by the moonpool in forward motion is a measure of water motion inside the moonpool for that particular field.

Design and analysis of composite panel for impact loads in marine environment

Impact loads from incoming waves always challenge the strength of structural parts of a ship. Modern high-speed crafts including naval vessels are subjected to impact loads during high speed and sudden manoeuvre. Wave slamming may damage structural parts and cause flooding of compartments due to impact. Hydrodynamic impact load results in structural damage in conventional marine vehicles. Loads during cargo loading, unloading, shipping of green water, impact with icebergs etc. come under low-velocity impact loads. The structural parts of a ship can also be damaged due to the impact of collision with icebergs as in the case of the Titanic accident. Weapon discharge, flight operation, bulk cargo operation and collision with other structures are other examples of impact load acting on marine vehicles. Severe hydrodynamic impact load may cause damage of shell plating, collapse of bow part, damage of hatch covers, collapse of hull girder etc. Such structural parts should possess sufficient impact strength. Composite shells can be used for hull, deck or hatch covers of bulk carriers to reduce the weight of vehicle and to indirectly increase the pay load capacity. In the present work, cost-effective composites are prepared by adding fillers to improve impact strengths and tested to verify the same. The main objective of the study is to develop a cost-effective composite to be used as part of hull, deck and hatch cover of bulk carrier. Feasibility and selection of fillers to improve impact strength are established. Prior to this, different sizes of fillers and the chemical treatment of filler with acid were considered. Calcium carbonate (CaCO3), silicon carbide (SiC) and alumina (Al2O3) are considered with glass epoxy composite for the above analysis. The additional impact strength due to the application of fillers is determined using Izod impact strength tests. Contact force is considered as a scale parameter for the impact response for composite laminates. Contact force is the force against impact load on composite structures. Contact force and deflection history of composite panels are affected by a number of parameters such as fibres angle, laminate geometry, impactor energy, stiffeners, surface area of impactor and loading eccentricity. Effects of all possible parameters are included and their influence on the response is determined using the well-known package based on finite element method (FEM), ABAQUS. The FEM analysis of Khalili et al. (2011 Compos Struct 93:1363–1375) is used for comparison of results of the present numerical analysis. The study leads to many new insights to designers of cost-effective composite structures.

On the Sedimentary Structure in Some Portions of the Pacific Ocean from data on Seismic Reflected Waves

1. During 1957-1958 the Institute for Physics of the Earth of the Ac. Sci. USSR carried out investigations by deep seismic sounding (DSS) of the earth's crust in the north-western part of the Pacific ocean and in the adjoining aquatoria (l-2). The investigation technique consisted mainly in following on the seismograms the seismic waves coming from the deep boundaries in the crust. At the same tune data were -also collected on the structure of the upper layer consisting of ocean sediments. 2. Simultaneously with the seismic waves coming from the deep crustal layers, vertical reflections from the bottom surface and from the boundaries in the sediments were also observed in order to investigate the structure of the sediments. The observations of the reflected waves were carried out by two methods. When heavy charges (above 100 kgr) were fired for DSS observations, a unichannel set on the moving ship was used for recording reflected waves. A piezocrystal secured to the underwater part of the ship's hull served as a receiver. The preamplified signal was recorded in a wide frequency range and then passed through a narrow band-pass filter. The frequency band was so chosen as to increase the effective sensitivity of the channel. It was known from experience that good records of reflected waves were obtained in the 50-70 c/sec frequency range. A sample seismogram is shown in fig. 1. On this and similar seismograms not only reflections from subbottom boundaries are seen, but also pulses due to secondary shocks and possibly also to reflections from the water surface at the shooting point.

Electrochemical oil/water demulsification and purification of bilge water using Pt/Ir electrodes

The electrochemical oil/water demulsification and purification of bilge water were investigated using Pt/Ir electrodes in a batch electrochemical reactor. Bilge water is a corrosive mixture of seawater containing a variety of constituents including cleaning agents, solvents, fuel, lubricating oils and hydraulic oils. It is resulted mainly by the leakage from the machinery and fresh water washdowns, which are allowed to drain to the lowest inner part of the ship's hull. In this study, the influence of operating parameters as bilge water composition, seawater/fresh water composition, current density, and reaction temperature on the removal efficiency of COD, oil/grease and turbidity was analyzed. Experimental results were optimized using response surface methodology in order to maximize the removal rates while minimizing current density and mean energy consumption. The optimized conditions under specified constraints were obtained for the highest desirability at 100% bilge water composition (COD o = 3080 mg/L), 50/50% seawater/fresh water composition, 12.8 mA/cm 2 current density and 32 °C reaction temperature. Kinetic studies resulted in first order overall electrochemical conversion rate of pollutants based on COD concentration with the activation energy of 26.2 kJ/mol.

A universal method for calculating isobaric-isothermal sections of ternary system phase diagrams

A method for calculating and constructing isobaric-isothermal sections of ternary system phase diagrams with the use of convex hulls was developed. The method is based on the projection of the singularities of the lower part of the Gibbs energy convex hull onto the plane of component mole fractions followed by a geometric analysis of the properties of this projection. The method is applicable to a wide range of ternary systems, it can be used to find tie-line coordinates and determine the phase compositions of all the diagram regions. The quality of the suggested algorithm was estimated, and examples of the construction of several phase diagrams are given.

Numerical analysis of effect of asymmetric stern of ship on its screw propeller efficiency

Numerical analysis of effect of asymmetric stern of ship on its screw propeller efficiency During designing the ship its designer tends to achieve as-high-as possible efficiency of ship's propulsion system. The greatest impact on the efficiency is introduced by ship's screw propeller whose efficiency depends not only on its geometry but also distribution of wake current velocity. To change wake current distribution and improve propeller efficiency an asymmetric form is usually applied to stern part of ship hull. This paper presents results of numerical analysis of wake current velocity distribution, performed by using a CFD method for a B 573 ship of symmetric stern and the same ship of an asymmetric stern. Next, the mean values of screw propeller efficiency in non-homogenous water velocity field were calculated for both the hull versions of B 573 ship.

Numerical analysis of influence of streamline rudder on screw propeller efficiency

Numerical analysis of influence of streamline rudder on screw propeller efficiencyDuring designing the ship its designer tends to obtain as high as possible efficiency of ship propulsion system. To this end on certain ships additional elements such as: nozzles, half-nozzles or suitably profiled fins attached to underwater part of ship's hull before screw propeller, are applied (sometimes they are intended for the mitigating of vibration resulting from operation of screw propeller). Another device which affects operation of screw propeller is streamline rudder capable of improving its efficiency (most of the transport ships is fitted with single screw propeller and streamline rudder placed behind it). In this paper the influence of streamline rudder on screw propeller efficiency has been examined with the use of numerical methods of fluid dynamics (CFD). The obtained results indicate a very favourable influence of the rudder on screw propeller efficiency. Research in this area is continued and its results concerning impact of particular geometrical parameters of rudder on screw propeller efficiency, will be presented in the future.

Investigations of influence of screw propeller operation on water flow around stern part of ship hull

Investigations of influence of screw propeller operation on water flow around stern part of ship hull This paper presents results of measurements of velocity field in before- the - propeller flow in presence of a ship model hull of two configurations, as well as comparative calculations of velocity field on a full-scale ship. Analysis of the research results showed that input data to Biot-Savart formula should be modified in the case of calculations of propeller-induced velocities on ship hull surface.

POD형 물분사 추진장치의 설계 및 성능해석

A study of design and analysis for the POD type waterjet is conducted. The analysis and design of waterjet system are more difficult than that of conventional propulsor because waterjet is complicatedly composed of many parts which are impeller, stator, inlet, nozzle, etc. The streamline method is traditionally used in the design of pump whose characteristics are similar to those of waterjet. This streamline method, however, has some limitation in analysis of a viscous flow as well as the interaction of inlet part of hull. In the present study, the developed CFD program is applied to the analysis of POD type waterjet. The developed program is first validated by comparing the existed experimental results. The designed waterjet system is also analyzed by the developed CFD program and analyzed results show that the performance of the present POD type waterjet is above the requirement.

『입당구법순례행기』 에 기록된 선체구성재 ‘누아’에 대한 소고

Ennin was a Japanese buddhist monk who stayed in Tang from Jun. 13, 838 A.D. to Dec. 14, 847 A.D. in lunar`s calender and wrote lengthy diary through the travel. This diary contained lots of information on the politics, economy, social culture, religion, diplomatic policies, militaries, geography, transportations and administrations of Tang China. Especially the beginning of his diary dated from Jun. 13, to July 3, 838 A. D. was recorded in the manner of ship`s logbook entries. Many terms of navigation and naval architecture appeared on it. It is very important to understand them for studying ancient ship and its navigation skill. This paper aims to investigate the meaning of ‘Nu-A’ obviously referring to some part of hull of the ship as the first step to annotate the terms of navigation and naval architecture which were appeared in the diary.

To be or not to be a cog: the Bremen Cog in perspective

Following on from Thijs Maarleveld's paper in 1995 on type-names for archaeological finds of ships, the use of the term cog has been questioned by Timm Weski, who suggested the archaeological term Ijsselmeer-type instead. The present paper surveys a total of 18 ship-finds of this type with respect to date, origin and year of investigation, without finding support for the proposed change in terminology. Instead, the archaeological term cog should be restricted to seagoing vessels of the 12th–15th centuries which share the structural features of the lower part of hull with the Bremen Cog. Recent results of dendroanalysis point to the root of the Jutland peninsula as a more likely area than the former Zuiderzee for the transformation of a hypothetical older‘proto-cog'-type for navigation on rivers and in the Waddensee into the proper seagoing medieval cog-type. Impulses for this transformation were found, most likely, in the need to circumnavigate Cape Skagen already in the 12th century, and technical features were probably taken over from large Scandinavian cargo ships of that period. © 2000 The Nautical Archaeology Society

To be or not to be a cog: the Bremen Cog in perspective

Following on from Thijs Maarleveld's paper in 1995 on type-names for archaeological finds of ships, the use of the term cog has been questioned by Timm Weski, who suggested the archaeological term Ijsselmeer-type instead. The present paper surveys a total of 18 ship-finds of this type with respect to date, origin and year of investigation, without finding support for the proposed change in terminology. Instead, the archaeological term cog should be restricted to seagoing vessels of the 12th–15th centuries which share the structural features of the lower part of hull with the Bremen Cog.Recent results of dendroanalysis point to the root of the Jutland peninsula as a more likely area than the former Zuiderzee for the transformation of a hypothetical older ‘proto-cog’-type for navigation on rivers and in the Waddensee into the proper seagoing medieval cog-type. Impulses for this transformation were found, most likely, in the need to circumnavigate Cape Skagen already in the 12th century, and technical features were probably taken over from large Scandinavian cargo ships of that period.

Idealisation of ships with large hatch openings by a thin-walled rod of open section on many elastic supports

The open part of the ship's hull with large hatch openings is considered as a prismatic thin-walled rod of open section on many elastic supports subjected to torsion. The stiffness of deck strips and the ship's sides in the deck plane is taken into account by elastic supports. Internal forces and displacements of the open part of the hull and deck strips are obtained in an analytical form, using the method of initial parameters. Stresses and displacements can be presented numerically and graphically, in a form suitable for preliminary calculations. A numerical example is given.

他船視覚情報の収集自動化に関する研究

In case of collision avoidance, information about targets is obtained from a radar system or through the sense of vision and hearing. Especially, the information through the sense of vision is very wealthy. However, the study of machine perception concerned with the sense of vision is delayed, it is the present condition that the practical collection of visual information is leaved entirely to persons under the actual navigation system. In this paper, first, we classified the information required the estimation of encounter conditions with other vessels. Next, by using of image processing techniques, we tried to get out of the picture related to a part of hull from a color photograph which had a scene of a vessel on the sea, and extracted some features from the processed image. After then, we attempted presumption of the visual information in accordance with the extracted features.

A solution method for three-dimensional turbulent boundary layers on bodies of arbitrary shapes

Abstract This paper is concerned with the prediction of the three-dimensional turbulent flows around bodies of irregular but basically cylindrical shape. Examples of such bodies are: ship or submarine hulls or an aircraft fuselage. The solution method described uses a non-orthogonal coordinate system in which the surface of the body is arranged to coincide with a coordinate surface. The velocity components solved for are the axial, radial and circumferential components of the cylindrical system from which the coordinates are derived. The equations are solved by the finite difference method of [1] for three-dimensional, parabolic flows. Turbulence is accounted for via a two-equation model of turbulence developed in [2] and modelled in [3]. Some preliminary solutions are presented for flow around the rear part of a ship's hull. The results seem to be qualitatively correct. However, no comparison with experimental data has yet been made. The present method can be easily extended to handle partially parabolic effects as described in [4].

A Study on the Hull Girder Strength of Container Ships with Large Hatch Openings

This paper presents the investigated resuts of numerical simulation pertaining to the hull girder strength of container ships in irregular sea.Using the so-called total system of hull girder strength analysis developed by the authors, the analysis of the long-term prediction of structural response of three container ships is carried out.And the wave-induced stresses in longitudinal strength members, distortion of hatch openings and the torsional deformation of hull girder are studied from the point of view of the long-term prediction.As a result of this simulation, the following conclusions are obtained.(1) In the middle part of ship, the wave-induced normal stress in the upper deck at the side edge of hatch opening is in the stress range of 89.5kg/mm2 and the wave-induced shearing stress in the outer hull at the load water line is below 10kg/mm2 with probability level 10-6.The normal stress of outer hull at the bilge part is in the same level with that of the upper deck.(2) In the fore hold structure, the normal stress of the upper deck is almost in the same level with that of the middle part of ship.Furthermore the torsional deformation of hull girder is considerably large compared with that of the middle part of hull because of the decrease in the torsional rigidities.(3) As to the distortion of hatch openings, the elongation Δl of the diagonal length of them is largest in the hatch of the middle part, but there are small differences in the ratio Δl/l with same probability level.