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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Society of Naval Architects of Korea
Journal Basic Information
Journal DOI :
The Society of Naval Architects of Korea
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Volume & Issues
Volume 50, Issue 6 - Dec 2013
Volume 50, Issue 5 - Oct 2013
Volume 50, Issue 4 - Aug 2013
Volume 50, Issue 3 - Jun 2013
Volume 50, Issue 2 - Apr 2013
Volume 50, Issue 1 - Feb 2013
Selecting the target year
Hull Maintenance Management System Development for Semi-Submersible Drilling Rig
Oh, Eun-Sung ; Choi, Woo-Young ; Kim, Hyeong-Cheol ; Bae, Si-Hoon ; Byeon, Ji-Ha ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 129~137
DOI : 10.3744/SNAK.2013.50.3.129
Each owner or operator of offshore products uses a maintenance management system like CMMS(Computerized Maintenance Management System) in order to manage their assets effectively and efficiently for a long time. But most of maintenance management systems have been focused on machinery items, not on 'Hull' until now. On the other hand, classifications like ABS, DNV, GL are having a sale on hull inspection and maintenance system for ships and an interest in hull maintenance system is increasing because of the application of EDD(Extended Dry Docking). This paper discusses the concept, inspection process and the practical application of Hull maintenance for Semi-submersible drilling rig to extend the service life and run a stable operation.
Development of New Experimental Devices and Methods to Measure Shaft Forces of Ships
Lee, Young-Jin ; Rhyu, Seong-Sun ; Lee, Kyung-Jun ; Seo, Jong-Soo ; Lew, Jae-Moon ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 138~144
DOI : 10.3744/SNAK.2013.50.3.138
New experimental devices and methods to measure shaft forces of ships are proposed in this paper. The strain gauge type six-component load cell was newly designed and installed to the end of the propeller shaft. The signals generated from the sensor in the propeller rotating are transferred to the new data amplifying and processing board on the shaft and the data is transmitted to the self-made wireless receiver. To find out the characteristics of shaft forces during port and starboard turning motions in sea trial, oblique and combined yaw maneuvering tests at straight, transient, maximum yaw rate, steady conditions were performed with the model ship installed the shaft forces measuring device using circular motion tester of Samsung Ship Model Basin. Characteristics of the measured shaft forces in model tests show quantitatively good agreement with the computed values obtained by the CFD programs using the measured wake data in oblique towing conditions. In the near future, It is hoped that the estimated shaft forces for a ship from this experimental method could be validated through comparison with directly measured values of a ship.
Pre-Swirl Duct of Fuel Oil Saving Device Design and Analysis for Ship
Shin, Hyun-Joon ; Lee, Kang-Hoon ; Han, Myung-Ryun ; Lee, Chang-Yul ; Shin, Sung-Chul ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 145~152
DOI : 10.3744/SNAK.2013.50.3.145
Recently, with oil price jumping and environmental issues, Green ship is paid deep attention to by ship owner, operator, builder, class and government. Fuel efficiency and reduction of
emissions are expected to have a strong influence on the design and operation of merchant ships. Many ship owners and operators are seeking the more economic method by the best operating route and the application of reliable and effective energy saving devices. With the Energy Efficiency Design Index (EEDI) in 2013 attention will more than ever be focused at achieving maximum fuel economy in the hydrodynamic design of hull forms, their appendages and propellers. IMO requirements for
emission for ships will now be implemented for vessels ordered from 1st January 2013. So far, a lot of new idea and patents have been proposed, tested, claimed and applied for various kinds of ship type. This paper shows numerical and experimental work related to a study on a energy saving devices particularly for fuller ship such as merchant vessel of Tanker and Bulker. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction.
Design of Power Transmission System of a Water Bike
Choi, Jung-Kyu ; Kim, Hyoung-Tae ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 153~159
DOI : 10.3744/SNAK.2013.50.3.153
The power transmission system has always been considered critical for a human powered boat(or water bike) since it first showed up at Human Powered Vessel Festival. Mechanical problems, such as abrasions and other damages of the gear system for the power transmission, lead to poor durability and low efficiency of a boat. This paper described mechanical problems and a design process of power transmission system and then suggested the method to solve the problems. It is selected a module and a type of gears that are structurally stable thus can transmit the power durable. Especially the lower gear box is applied to CRP(contra rotating propeller) system for improving the structural stability and the propeller efficiency as well. As the results, the upper and lower gear box are designed and manufactured. And from the trial test, it is confirmed that the power transmission system is reliable.
A Numerical Analysis of the Supercavitating Flow around Three-Dimensional Axisymmetric Cavitators
Kim, Ji-Hye ; Jang, Hyun-Gill ; Ahn, Byoung-Kwon ; Lee, Chang-Sup ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 160~166
DOI : 10.3744/SNAK.2013.50.3.160
Recently submerged objects moving at high speed such as a supercavitating torpedo have been studied for their practical advantage of the dramatic drag reduction. In this study, we are focusing our attention on supercavitating flows around axisymmetric cavitators; a numerical method based on inviscid flow is developed and predicted supercavities around several shapes of 2D and 3D cavitators are presented. The results are validated by comparison of existing theoretical and empirical results. In addition, characteristic features of supercavity shapes and drag forces acting on a real scale torpedo are evaluated according to practically appropriate operating conditions.
Computational Analysis for Effects of Cooling System on Homogeneity of Ice Thickness and Temperature on Water Surface
Lee, Sungsu ; Kim, Young-Min ; Lee, Chun-Ju ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 167~174
DOI : 10.3744/SNAK.2013.50.3.167
Model ice forming process in ice tank needs several steps of seeding, freezing, tempering. In those process, one of the most important factors to affect the accuracy of experiment is the homogeneity of the ice thickness and the temperature. This paper investigated a computational and statistical method to assess the uniformity of the model ice. In addition, the different configurations of freezing systems were considered to improve the uniformity. Qualitative assessment using streamlines from the cooling units was carried out by computational fluid dynamics (CFD) and the quantitative evaluations of the homogeneity were compared using the temperature distribution on the ice surface. In addition, multi species transport analysis is introduced to understand the circulation efficiency of cold air from the cooling units. As the results, optimized configurations were determined by adjusting the angles of vane in the cooling units.
Passenger Ship Evacuation Simulation Considering External Forces due to the Inclination of Damaged Ship
Ha, Sol ; Cho, Yoon-Ok ; Ku, Namkug ; Lee, Kyu-Yeul ; Roh, Myung-Il ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 175~181
DOI : 10.3744/SNAK.2013.50.3.175
This paper presents a simulation for passenger ship evacuation considering the inclination of a ship. In order to describe a passenger's behavior in an evacuation situation, a passenger is modeled as a rigid body which translates in the horizontal plane and rotates along the vertical axis. The position and rotation angle of a passenger are calculated by solving the dynamic equations of motions at each time step. To calculate inclined angle of damaged ship, static equilibrium equations of damaged ship are derived using "added weight method". Using these equations, physical external forces due to the inclination of a ship act on the body of each passenger. The crowd behavior of the passenger is considered as the flock behavior, a form of collective behavior of a large number of interacting passengers with a common group objective. Passengers can also avoid an obstacle due to penalty forces acting on their body. With the passenger model and forces acting on its body, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) are implemented and the effects of ship's inclination on the evacuation time are confirmed.
A Study on the Management Methods of the Ship Infrared Signature
Cho, Yong-Jin ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 182~189
DOI : 10.3744/SNAK.2013.50.3.182
In the development process of new naval ships, it is necessary to make the effort of the signature management and reduction of ship infrared(IR) signature to increase the ship survivability(susceptibility). So far the ship's contrast radiant intensity is used as a ship IR signature design criteria during the naval ship design stages. However, nowaday it is in a state of disorder at the basic design stage because of the lack of any related studies and methods. In this study, the IR signature management methods for improving the signature reduction and ship survivability are suggested by the comparison analysis of the advantages and disadvantages of signature management techniques. And also the criteria for the ship signature management are suggested when considering the infrared signature measuring assets and sea trial environments of the Korean peninsula.
Development of Received Acoustic Pressure Analysis Program of CHA using Beam Tracing Method
Kwon, Hyun-Wung ; Hong, Suk-Yoon ; Song, Jee-Hun ; Jeon, Jae Jin ; Seo, Young-Soo ;
Journal of the Society of Naval Architects of Korea, volume 50, issue 3, 2013, Pages 190~198
DOI : 10.3744/SNAK.2013.50.3.190
In order to predict acoustic pressure distributions by exterior incident wave at Cylindrical Hydrophone Array (CHA) sensor's positions, acoustic pressure analysis is performed by using beam tracing method. Beam tracing method is well-known of reliable pressure analysis methods at high-frequency range. When an acoustic noise source is located at the center of rectangular room, acoustic pressure analysis is performed by using both beam tracing method and Power Flow Boundary Element Method (PFBEM). By comparing with results of beam tracing method and those of PFBEM, the accuracy of beam tracing method is verified. We develop the CHA pressure analysis program by verified beam tracing method. The developed software is composed of model input, sensor array creator, analysis option, solver and post-processor. We can choose a model option of 2D or 3D. The sensor array generator is connected to a sonar which is composed of center position, bottom, top and angle between sensors. We also can choose an analysis option such as analysis frequency, beam number, reflect number, etc. The solver module calculates the ray paths, acoustic pressure and result of generating beams. We apply the program to 2D and 3D CHA models, and their results are reliable.