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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 34, Issue 8 - Nov 2010
Volume 34, Issue 7 - Nov 2010
Volume 34, Issue 6 - Sep 2010
Volume 34, Issue 5 - Jul 2010
Volume 34, Issue 4 - May 2010
Volume 34, Issue 3 - May 2010
Volume 34, Issue 2 - Mar 2010
Volume 34, Issue 1 - Jan 2010
Selecting the target year
Failure and Repair of the Propeller
Lee, Woon-Ho ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 608~616
DOI : 10.5916/jkosme.2010.34.5.608
Study on Temperature Distribution for Various Conditions of Moving Heating Source During Line Heating Process
Choi, Yoon-Hwan ; Lee, Yeon-Won ; Choi, Kwang ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 617~624
DOI : 10.5916/jkosme.2010.34.5.617
Line heating is a manufacture method, which was widely used to machining a curved surface in the ship construction. The qualities using by line heating are very difference compare to the proficiency level of the engineer. So it's mainly depend on the automation equipment instead of the proficiency level engineer. In this study, it would be investigate the temperature distribution of the heating plate, which was used by the automation equipment according to line heating. The main factors are the moving velocity of the heating source, strength and the heating method separately, in temperature distribution while line heating. In this paper, it was investigated the temperature change with the vary of each three variables. The numerical result showed that peak temperature decrease if the moving velocity of the heating source increased. It can also calculate the change quantitatively that the peak temperature and temperature distribution changed linearly with the vary of the heating source.
Relationships between Electric Power Generation of PV System and Heat Transfer which has Free Air Ventilation Duct
Kim, Myoung-Jun ; Chea, Gyu-Hoon ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 625~631
DOI : 10.5916/jkosme.2010.34.5.625
Recently, the fossil energy and its related environmental problems (increase in PPM of
) have been increased. Therefore, the interests on new and renewable energy have been increased as the one of the future industrial leading items. Among the renewable energy, the PV (Photo-Volatic) systems has particular merit at the electricity can be directly acquired from the sun. Usually in PV systems, the ambient temperature and air velocity have strongly related on the effect of power generation of PV panel. So the purpose of this study is to clarify relationships between power generation of PV panel and outer environmental factors like temperature and air velocity. And these types of applications using natural energy are strongly affected by the climate conditions. Therefore the data of this study were re-arranged in terms of non-dimensional correlations.
A Development of Converting Technology for the Marine Gasoline/CNG Bi-fuel Engine
Park, Myung-Ho ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 632~637
DOI : 10.5916/jkosme.2010.34.5.632
Natural gas, a fossil fuel contained mostly of methane, is one of the cleanest alternative fuels. It can be used in the form of compressed gas(CNG) or liquefied natural gas(LNG) to cars and trucks. And, dedicated natural gas vehicles are designed to run on natural gas only, while Bi-fuel vehicles can also run on gasoline or CNG, especially, bi-fuel can be defined as the simultaneous combustion of two fuels. In this study, converted gasoline marine system to CNG Bi-fuel system which is made up of injector, regulator, tank and ECU is converted. And estimated the fuel system and engine power compared the result with gasoline engine is estimated. As a result, CNG engine shows low exhaust emissions but maxium power is 7% reduced compared to gasoline engine.
Numerical Analysis of Heat Transfer in the Ribbed Channel Inserted with Tape
Kang, Ho-Keun ; Ahn, Soo-Whan ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 638~644
DOI : 10.5916/jkosme.2010.34.5.638
Numerical predictions of a fully developed turbulent flow through a square duct (
) with twisted tape inserts and with twisted tape plus interrupted ribs are respectively conducted to investigate regionally averaged heat transfer and flow patterns. A rib height-to-channel hydraulic diameter(e/
) of 0.067 and a lengthto-hydraulic diameter(L/
) of 30 are considered at Reynolds number ranging 8,900 to 29,000. The interrupted ribs are axially arranged on the bottom wall. The twisted tape is 0.1 mm thick carbon steel sheet with diameter of 28 mm, length of 900 mm, and 2.5 turns. Each wall of the square channel is composed of isolated aluminum sections. Two heating conditions are investigated for test channels with twisted tape inserts and rib turbulators: (1) electric heat uniformly applied to four side walls of the square duct, and (2) electric heat uniformly applied to two opposite walls of the square channel. The results show that uneven surface heating enhances the heat transfer coefficient over uniform heating conditions, and significant improvements can be achieved with twisted tape inserts plus interrupted ribs.
A Study on the Non-evaporating Diesel Spray Characteristics as a Function of Ambient Pressure in Constant Volume Combustion Chamber
Jeon, Chung-Hwan ; Jeong, Jeong-Hoon ; Kim, Hyun-Kyu ; Song, Ju-Hun ; Chang, Young-June ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 645~652
DOI : 10.5916/jkosme.2010.34.5.645
The aim of this investigation was study on the non-evaporation diesel spray characteristics injected through a common-rail diesel injector under various ambient pressure. The diesel spray was investigated with observation of macroscopic characteristics such as spray tip penetration and spray cone angle by the shadowgraph and the image processing method. The numerical study was conducted using a computational fluid dynamics code, AVL-FIRE. The breakup models used were WAVE model and standard
turbulence model was applied. The numerical study used input data which spray cone angle and fuel injection rate was achieved by Zeuch's method. Comparison with experimental result such as spray tip penetration was good agreement. Distribution of droplet diameter were conducted on four planes where the axial distances were 5, 15, 39 and 49mm respectively downstream from the orifice exit.
A Study on the Forced Fitting Method of Stern Tube Bearing for Propulsion Shafting in Ships
Cho, Kwon-Hae ; Lee, Jae-Hyun ; Kim, Yang-Gon ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 653~660
DOI : 10.5916/jkosme.2010.34.5.653
The stern tube bearing is installed to the stern tube and stern boss casting by using the method of the force pressured fitting. The adequate value of the interference between the stern tube bearing and casting should be considered owing to the slip. In this study, to review and compare the fitting force and the contact pressure, the theory of thick walled cylinder is considered to clarify the formula which received from the maker. Also the fitting force and contact pressure are calculated by using the standard value of interference, Young's modulus, Poisson's ratio and friction coefficient.
Laser Peening: A Novel Tool to Reduce SCC Susceptibility and Prolong Fatigue Life of Metallic Components
Sano, Yuji ; Kim, Jong-Do ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 661~669
DOI : 10.5916/jkosme.2010.34.5.661
The effects of laser peening on metallic materials have been investigated with water-penetrable frequency-doubled Nd:YAG laser. Laser pulses of 200 mJ energy and 8 ns duration focused on samples underwater with 0.8 mm spot diameter. X-ray study showed that compressive residual stress was imparted on SKD61 from the surface to nearly 2 mm depth. Stress corrosion cracking (SCC) was prohibited for sensitized SUS304 even in a severely corrosive environment fatigue lives of SUS316L and SM490A welded samples were prolonged significantly in the high-cycle regime. Since 1999, laser peening has been applied to prevent SCC in operating nuclear power plants in Japan.
An Electrochemical Evaluation on the Corrosion Property of Metallizing Film
Moon, Kyung-Man ; Shin, Joong-Ha ; Lee, Myung-Hoon ; Lee, Sung-Yul ; Kim, Yun-Hae ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 670~677
DOI : 10.5916/jkosme.2010.34.5.670
There are many surface protection methods for numerous steel structures being used under severely corrosive environment, one of them, metallizing(thermal spray) is a available protection method which is comparatively and recently developed for surrface protection of various steel structures. However coating film obtained by spraying is to be needed increasingly more good corrosion resistance due to accelerating of environmental contamination. In this study, coating films(DFT:
) are performed with arc spray by wire metal and their types of films are pure zinc, pure aluminum, alloy film(Al:Zn=85:15) and alloy film(Al:Zn=95:5). And corrosion resistance of their films was investigated with electrochemical methods in seawater solution. Pure aluminum film showed a relatively somewhat good corrosion resistance compared to among those of other films and alloy films also showed a good corrosion resistance compared to pure zinc film. Especially it was observed that pure aluminum film showed a comparatively good corrosion resistance than that of alloy film named as galvarium spray(Al:Zn=85:15) in seawater solution. Morphology of corroded surface of pure zinc film appeared the pattern like intergranlar corrosion, however films of pure aluminum and alloy metal showed a general corrosion pattern.
An Electrochemical Evaluation on Corrosion Properties of Welding Zone of Stainless Steel by GTAW
Moon, Kyung-Man ; Lee, Kyu-Hwan ; Kim, Jin-Gyeong ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 678~685
DOI : 10.5916/jkosme.2010.34.5.678
GTAW was carried out to the austenitic 304(STS 304) and 22 APU stainless steels. In this case, difference of the corrosion characteristics of welded zone with STS 304 and 22APU mentioned above was investigated with electrochemical methods. Vickers hardness of weld metal in case of STS 304 (Hv-250) showed a relatively higher value than this of 22 APU(Hv-217). The corrosion current densities of weld metal of 22APU and heat affected zone of STS 304 were observed at the highest value compared to those of other welding zone respectively. This is probably because chromium depletion field due to chromium carbide formed to weld metal of 22APU and to heat affected zone of STS 304 can preferentially easily be corroded with more active anode than other fields. Consequently it is thought that application of the other welding methods like as laser welding or using of the optimum filler metals is necessary to improve the corrosion resistance of welding parts of these steels.
Evaluation of the Damage Mechanism in CFRP Composite Using Computer Vision
Kwon, Oh-Heon ; Xu, Shaowen ; Sutton, Michael ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 686~694
DOI : 10.5916/jkosme.2010.34.5.686
Continuing progress in high technology has created numerous industrial applications for new advanced composite materials. Among these materials, carbon fiber-reinforced plastic (CFRP) laminate composite is typically used for low-weight carrying structures that require high specific strength. In this study, the damage mechanism of a compact tension (CT) specimen of woven CFRP laminates is described in terms of strain and displacement changes and crack growth behavior. The digital image correlation (DIC) method (which is employed here as a computer vision technique) is analyzed. Acoustic emission (AE) characteristics are also acquired during fracture tests. The results demonstrate the usefulness of these methods in evaluating the damage mechanism for woven CFRP laminate composites. From the results, we show these methods are so useful in order to evaluate the damage mechanism for woven CFRP laminate composites.
CFD Analysis on the 2nd Cylinder Discharge line in Hydrogen Reciprocating Compressor
Lee, Gyeong-Hwan ; Woo, Ju-Sik ; Shin, Yong-Han ; Jeong, Hyo-Min ; Chung, Han-Shik ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 695~702
DOI : 10.5916/jkosme.2010.34.5.695
Numerical analysis information will be very useful to improve fluid system. General information about an internal gas flow is presented by numerical analysis approach. Relating with hydrogen compressing system, which have an important role in hydrogen energy utilization, this should be a useful tool to observe the flow quickly and clearly. Flow characteristic analysis, including pressure and turbulence kinetic energy distribution of hydrogen gas coming to the cylinder of a reciprocating compressor are presented in this paper. Suction-passage model is designed based on real model of hydrogen compressor. Pressure boundary conditions are applied considering the real condition of operating system. The result shows pressure and turbulence kinetic energy are not distributed uniformly along the passage of the Hydrogen system. Path line or particles tracks help to demonstrate flow characteristics inside the passage. The existence of vortices and flow direction can be precisely predicted. Based on this result, the design improvement, such as reducing the varying flow parameters and flow reorientation should be done. Consequently, development of the better hydrogen compressing system will be achieved.
Performance and Internal Flow Analysis on the 80kW-Class Cross-Flow Hydro Turbine with the Variation of Effective Head
Choi, Young-Do ; Lim, Jae-Ik ; Lee, Young-Ho ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 703~710
DOI : 10.5916/jkosme.2010.34.5.703
Recently, small hydropower attracts attention because of its clean, renewable and abundant energy resources to develop. However, suitable turbine type is not determined yet in the range of small hydropower and it is necessary to study for the effective turbine type. Therefore, a 80kW-Class cross-flow turbine is adopted in this study because of its simple structure and high possibility of applying to small hydropower. The result shows that as effective head increases, tangential and radial flow velocities increase and thus, the increased tangential velocity contributes to the increase of angular momentum and output torque.
Study on an Automatic Punching System for a LED Display using Flexible Plates
Choi, Hyeung-Sik ; Kang, Jin-Il ; Her, Jae-Gwan ; Han, Jong-Suk ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 711~717
DOI : 10.5916/jkosme.2010.34.5.711
In this paper, a new automatic punching system that generates pinholes expressing texts or images on a plastic plate is developed. The pin-holed plate is used as a new glamorous display board reflecting colourful lights from the light emitting diode (LED) installed on the edge side of the plate. The punching system has four actuators which work together to make multiple holes with accurate position and depth on the plastic plate. For even reflection of the lights from texts or images on the board and fast production of the pin-holed boards, we developed an accurate actuating structure of the system cooperating with a PID control algorithm. We also built a GUI-based integrated control system to help users easily design luminous texts or images on the plastic plate. Also, we conducted a performance test of the system to verify the punching speed and depth control of the pin holes on the plastic plate.
Study on the Wall Effect Correction for Propeller Open Water Characteristics in the Medium Size Cavitation Tunnel
Suh, Sung-Bu ; Kim, Ki-Sup ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 718~724
DOI : 10.5916/jkosme.2010.34.5.718
This paper studies the differences due to the wall effect in propeller open water(POW) characteristics tested in a towing tank and in a medium size cavitation tunnel(CT). When the advanced velocity of the propeller is defined as the flow velocity measured in the plane of propeller, POW characteristics resulting from CT has a better relationship with them of towing tank. To obtain the wall effect in the propeller plane, numerical computation using the lifting panel theory is performed with and without the wall around a propeller. Then, POW results in CT are corrected based on the wall effect from numerical results. The POW results obtained from this procedure show a better agreement with the experimental results in the towing tank.
Hydraulic Characteristics of Two Types of Pyramid-Shaped Artificial Reefs
Sohn, Byung-Kyu ; Lee, Jeong-Woo ; Yi, Byung-Ho ; Yoon, Han-Sam ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 725~734
DOI : 10.5916/jkosme.2010.34.5.725
This study conducted hydraulic testing to assess the stability of two types of pyramid-shaped artificial reefs (ARs) constructed to promote the growth of shellfish and seaweed. Previous theoretical and hydraulic experimental studies have clearly demonstrated Froude similitude. The results of this study revealed that some dimensionless design parameters affected the stability of both types of artificial reefs under various wave and current field conditions (e.g., surf similarity parameters, water particle velocity, wave pressure). In the fixed bed condition, the dimensionless water particle velocity based on the surf similarity parameter was large (about 0.4), and in the moveable bed condition, the relative water depth based on the dimensionless wave pressure was low (about 0.11). In addition, horizontal wave pressure and uplift pressure varied by relative water depth, demonstrating the tendency for wave pressure to decrease linearly with increased relative depth. These findings indicate that the development of more stable design technology forartificial reefs should be based on long-term data and additional study of sliding due to wave action. The findings also highlight the importance of hydraulic experiments in solving problems that have emerged in the design and construction of artificial reefs.
A Study on the Diving Standards for Underwater Work in Hostile Environment
Kang, Sin-Young ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 735~742
DOI : 10.5916/jkosme.2010.34.5.735
This paper reviewed the diving standards for underwater work in hostile environment and analyzed applied Navy diving technique, diving equipments and procedure for rescue operation of Navy ship Cheonan's missing crew occurred near Bak Ryung Do in March 2010. The operation was done beyond the international standards and safety practice, and by considering the nature of the mission, urgency and effectiveness as well as the detailed facts such as duration and depth of the dive, type of work to be performed, environmental conditions, time constraints of early rescue operation, it is analyzed that using air scuba diving system was adequate.
Submerging Performances of Automatic Submersible Buoy Operated by Air Control
Kim, Tae-Ho ; Hur, Jung-Gyu ; Yang, Kyong-Uk ;
Journal of the Korean Society of Marine Engineering, volume 34, issue 5, 2010, Pages 743~749
DOI : 10.5916/jkosme.2010.34.5.743
The primary object of this study was to develop the control algorithm and program for automatic submersible buoy which is free to move vertically within the water column by adjusting weight and buoyancy forces by air control. The experiment was performed to validate the usefulness of the program in the indoor water tank. In the experiment, the automatic submerging and surfacing of the buoy were controlled by water-pressure gauge and air control system. The buoy is raised by injecting compressed air from a compressor and then is lowered by releasing the air. The submerging and surfacing characteristics of the buoy calculated with the numerical model were similar to measurements obtained with the experiment. It was concluded that the algorithm and program could be useful in analyzing various parameters and submerging mechanisms required to design new type of automatic submersible fish cage system.