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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
International Journal of Naval Architecture and Ocean Engineering
Journal Basic Information
Journal DOI :
The Society of Naval Architects of Korea
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Volume & Issues
Volume 4, Issue 4 - Dec 2012
Volume 4, Issue 3 - Sep 2012
Volume 4, Issue 2 - Jun 2012
Volume 4, Issue 1 - Mar 2012
Selecting the target year
Hydrodynamic design of an underwater hull cleaning robot and its evaluation
Lee, Man Hyung ; Park, Yu Dark ; Park, Hyung Gyu ; Park, Won Chul ; Hong, Sinpyo ; Lee, Kil Soo ; Chun, Ho Hwan ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 335~352
DOI : 10.3744/JNAOE.2012.4.4.335
An underwater hull cleaning robot can be a desirable choice for the cleaning of large ships. It can make the cleaning process safe and economical. This paper presents a hydrodynamic design of an underwater cleaning robot and its evaluation for an underwater ship hull cleaning robot. The hydrodynamic design process of the robot body is described in detail. Optimal body design process with compromises among conflicting design requirements is given. Experimental results on the hydrodynamic performance of the robot are given.
The implementation of the integrated design process in the hole-plan system
Ruy, Won-Sun ; Ko, Dae-Eun ; Yang, Young-Soon ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 353~361
DOI : 10.3744/JNAOE.2012.4.4.353
All current shipyards are using the customized CAD/CAM programs in order to improve the design quality and increase the design efficiency. Even though the data structures for ship design and construction are almost completed, the implementation related to the ship design processes are still in progress so that it has been the main causes of the bottleneck and delay during the middle of design process. In this study, we thought that the hole-plan system would be a good example which is remained to be improved. The people of outfitting division who don't have direct authority to edit the structural panels, should request the hull design division to install the holes for the outfitting equipment. For acceptance, they should calculate the hole position, determine the hole type, and find the intersected contour of panel. After consideration of the hull people, the requested holes are manually installed on the hull structure. As the above, many processes are needed such as communication and discussion between the divisions, drawings for hole-plan, and the consideration for the structural or production compatibility. However this iterative process takes a lot of working time and requires mental pressure to the related people and cross-division conflict. This paper will handle the hole-plan system in detail to automate the series of process and minimize the human efforts and time-consumption.
Technological and economic study of ship recycling in Egypt
Welaya, Yousri M.A. ; Abdel Naby, Maged M. ; Tadros, Mina Y. ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 362~373
DOI : 10.3744/JNAOE.2012.4.4.362
The ship recycling industry is growing rapidly. It is estimated that the International Maritime Organization's (IMO) decision to phase-out single hull tankers by 2015 will result in hundreds of ships requiring disposal. At present, the ship recycling industry is predominantly based in South Asia. Due to the bad practice of current scrapping procedure, the paper will highlight the harm occurring to health, safety and environment. The efforts of the Marine Environment Protection Committee (MEPC) which led to the signing of the Hong Kong International Convention are also reviewed. The criteria and standards required to reduce the risk and damage to the environment are discussed and a proposed plan for the safe scrapping of ships is then presented. A technological and economic study for the ship recycling in Egypt is carried out as a case study. This includes the ship recycling facility size and layout. The equipment and staff required to operate the facility are also evaluated. A cost analysis is then carried out. This includes site development, human resources, machineries and equipment. A fuzzy logic approach is used to assess the benefits of the ship breaking yard. The use of the fuzzy logic approach is found suitable to make decisions for the ship breaking industry. Based on given constraints, the proposed model has proved capable of assessing the profit and the internal rate of return.
Psycho-acoustic evaluation of the indoor noise in cabins of a naval vessel using a back-propagation neural network algorithm
Han, Hyung-Suk ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 374~385
DOI : 10.3744/JNAOE.2012.4.4.374
The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.
Suggestion of a design load equation for ice-ship impacts
Choi, Yun-Hyuk ; Choi, Hye-Yeon ; Lee, Chi-Seung ; Kim, Myung-Hyun ; Lee, Jae-Myung ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 386~402
DOI : 10.3744/JNAOE.2012.4.4.386
In this paper, a method to estimate ice loads as a function of the buttock angle of an icebreaker is presented with respect to polycrystalline freshwater ice. Ice model tests for different buttock angles and impact velocities are carried out to investigate ice pressure loads and tendencies of ice pressure loads in terms of failure modes. Experimental devices were fabricated with an idealized icebreaker bow shape, and medium-scale ice specimens were used. A dry-drop machine with a freefall system was used, and four pressure sensors were installed at the bottom to estimate ice pressure loads. An estimation equation was suggested on the basis of the test results. We analyzed the estimation equation for design ice loads of the International Association of Classification Societies (IACS) classification rules. We suggest an estimation equation considering the relation between ice load, buttock angle, and velocity by modifying the equations given in the IACS classification rules.
The effect of dynamic operating conditions on nano-particle emissions from a light-duty diesel engine applicable to prime and auxiliary machines on marine vessels
Lee, Hyungmin ; Jeong, Yeonhwan ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 403~411
DOI : 10.3744/JNAOE.2012.4.4.403
This study presents the nano-sized particle emission characteristics from a small turbocharged common rail diesel engine applicable to prime and auxiliary machines on marine vessels. The experiments were conducted under dynamic engine operating conditions, such as steady-state, cold start, and transient conditions. The particle number and size distributions were analyzed with a high resolution PM analyzer. The diesel oxidation catalyst (DOC) had an insignificant effect on the reduction in particle number, but particle number emissions were drastically reduced by 3 to 4 orders of magnitude downstream of the diesel particulate filter (DPF) at various steady conditions. Under high speed and load conditions, the particle filtering efficiency was decreased by the partial combustion of trapped particles inside the DPF because of the high exhaust temperature caused by the increased particle number concentration. Retarded fuel injection timing and higher EGR rates led to increased particle number emissions. As the temperature inside the DPF increased from
, the peak particle number level was reduced by 70% compared to cold start conditions. High levels of nucleation mode particle generation were found in the deceleration phases during the transient tests.
On the energy economics of air lubrication drag reduction
Makiharju, Simo A. ; Perlin, Marc ; Ceccio, Steven L. ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 412~422
DOI : 10.3744/JNAOE.2012.4.4.412
Air lubrication techniques for frictional drag reduction on ships have been proposed by numerous researchers since the 19th century. However, these techniques have not been widely adopted as questions persist about their drag reduction performance beyond the laboratory, as well as energy and economic cost-benefit. This paper draws on data from the literature to consider the suitability of air lubrication for large ocean going and U.S. Great Lakes ships, by establishing the basic energy economic calculations and presenting results for a hypothetical air lubricated ship. All the assumptions made in the course of the analysis are clearly stated so that they can be refined when considering application of air lubrication to a specific ship. The analysis suggests that, if successfully implemented, both air layer and partial cavity drag reduction could lead to net energy savings of 10 to 20%, with corresponding reductions in emissions.
Ultimate strength of simply supported plate with opening under uniaxial compression
Yu, Chang-Li ; Lee, Joo-Sung ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 423~436
DOI : 10.3744/JNAOE.2012.4.4.423
Unstiffened plates are integral part of all kinds of structures such as ship and offshore oil platforms. Openings are unavoidable and absolutely reduce the ultimate strength of structures. In this study, the finite element analysis package, ABAQUS, is used to analyze the behavior of unstiffened plate with rectangular opening. The rectangular opening form is divided into two cases. In case1, opening depth is constant, but opening width is varied. Meanwhile, in case2 opening width is fixed and opening depth is varied. Besides, for the two different form opening, the effect of plate slenderness parameter (
), opening area ratio (AR) and opening position ratio (PR) on the ultimate strength of plate with opening under axial compression are presented. It has been found that the ultimate strength of plate ofcase1is much more sensitive to the plate slenderness parameter (
) and opening area ratio (AR) than that of case2. However, for case1, opening position (PR) almost has no effect on the ultimate strength, whereas, regardingcase2, the influence of opening position (PR) depends on the plate slenderness parameter (
). Based on nonlinear regression analysis, three design formulae are not only developed but also approved reasonably for the practical engineering design.
An array effect of wave energy farm buoys
Kweon, Hyuck-Min ; Lee, Jung-Lyul ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 437~446
DOI : 10.3744/JNAOE.2012.4.4.437
An ocean buoy energy farm is considered for Green energy generation and delivery to small towns along the Korean coast. The present study presents that the floating buoy-type energy farm appears to be sufficiently feasible for trapping more energy compared to affixed cylinder duck array. It is also seen from the numerical results that the resonated waves between spaced buoys are further trapped by floating buoy motion.Our numerical study is analyzed by a plane-wave approximation, in which evanescent mode effects are included in a modified mild-slope equation based on the scattering characteristics for a single buoy.
Hydrodynamic characteristics for flow around wavy wings with different wave lengths
Kim, Mi Jeong ; Yoon, Hyun Sik ; Jung, Jae Hwan ; Chun, Ho Hwan ; Park, Dong Woo ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 447~459
DOI : 10.3744/JNAOE.2012.4.4.447
The present study numerically investigates the effect of the wavy leading edge on hydrodynamic characteristics for the flow of rectangular wings with the low aspect ratio of 1.5. Five different wave lengths at fixed wavy amplitude have been considered. Numerical simulations are performed at a wide range of the angle of attack (
) at one Reynolds number of
. The wavy wings considered in this study did not experience enough lift drop to be defined as the stall, comparing with the smooth wing. However, in the pre-stall region, the wavy wings reveal the considerable loss of the lift, compared to the smooth wing. In the post-stall, the lift coefficients of the smooth wing and the wavy wings are not much different. The pressure coefficient, limiting streamlines and the iso-surface of the spanwise vorticity are also highlighted to examine the effect of the wave length on the flow structures.
Thermo-economic approach for absorption air condition onboard high-speed crafts
Seddiek, Ibrahim S. ; Mosleh, Mosaad ; Banawan, Adel A. ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 460~476
DOI : 10.3744/JNAOE.2012.4.4.460
High-speed crafts suffer from losing a huge amount of their machinery energy in the form of heat loss with the exhaust gases. This will surely increase the annual operating cost of this type of ships and an adverse effect on the environment. This paper introduces a suggestion that may contribute to overcoming such problems. It presents the possibility of reusing the energy lost by the ships' exhaust gases as heating source for an absorption air condition unit onboard high-speed crafts. As a numerical example; the proposed method was investigated at a high-speed craft operating in Red Sea between Egypt and the Kingdom of Saudi Arabia. The results obtained are very satisfactory. It showed the possibility of providing the required ship's air condition cooling load during sailing and in port. Economically, this will reduce the annual ship's operating cost. Moreover, it will achieve a valuable reduction of ship's emissions.
Endplate effect on aerodynamic characteristics of three-dimensional wings in close free surface proximity
Jung, Jae Hwan ; Kim, Mi Jeong ; Yoon, Hyun Sik ; Hung, Pham Anh ; Chun, Ho Hwan ; Park, Dong Woo ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 477~487
DOI : 10.3744/JNAOE.2012.4.4.477
We investigated the aerodynamic characteristics of a three-dimensional (3D) wing with an endplate in the vicinity of the free surface by solving incompressible Navier-Stokes equations with the turbulence closure model. The endplate causes a blockage effect on the flow, and an additional viscous effect especially near the endplate. These combined effects of the endplate significantly reduce the magnitudes of the velocities under the lower surface of the wing, thereby enhancing aerodynamic performance in terms of the force coefficients. The maximum lift-to-drag ratio of a wing with an endplate is increased 46% compared to that of wing without an endplate at the lowest clearance. The tip vortex of a wing-with-endplate (WWE) moved laterally to a greater extent than that of a wing-without-endplate (WOE). This causes a decrease in the induced drag, resulting in a reduction in the total drag.
Experimental investigation on stern-boat deployment system and operability for Korean coast guard ship
Chun, Ho Hwan ; Kim, Moon Chan ; Lee, Inwon ; Kim, Kookhyun ; Lee, Jung Kwan ; Jung, Kwang Hyo ;
International Journal of Naval Architecture and Ocean Engineering, volume 4, issue 4, 2012, Pages 488~503
DOI : 10.3744/JNAOE.2012.4.4.488
The stern boat deployment system was investigated to evaluate the capability of launching and recovering rigid hull inflatable boat (RHIB) via the stern ramp. The main parameters to launch and recover RHIB were tested at the design stage. The combined hydrodynamic effect of the stern wake and the water jet flow made it difficult to maintain the maneuvering and sea-keeping ability of RHIB approaching to the stern ramp. The safe recovery course was proposed to maintain the directional control of RHIB and to reduce the combined hydrodynamic effect in the transom zone. To evaluate the feasibility of RHIB recovery, the stern sill depth was measured in various conditions and the ramp availability time was obtained. Also, the experimental percent time operability (PTO) test was performed by the number of successive launching and recovering operations.