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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
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Volume & Issues
Volume 28, Issue 8 - Nov 2004
Volume 28, Issue 7 - Nov 2004
Volume 28, Issue 6 - Sep 2004
Volume 28, Issue 5 - Jul 2004
Volume 28, Issue 4 - May 2004
Volume 28, Issue 3 - Mar 2004
Volume 28, Issue 2 - Jan 2004
Volume 28, Issue 1 - Jan 2004
Selecting the target year
Construction of Virtual Images for a Benchmark Test of 3D-PTV Algorithms for Flows
Hwang, Tae-Gyu ; Doh, Deog-Hee ; Hong, Seong-Dae ; Kenneth D. Kihm ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1185~1194
Virtual images for PIV are produced for the construction of a benchmark test tool of PTV systems, Camera parameters obtained by an actual experiment are used to construct the virtual images, LES(Large Eddy Simulation) data sets of a channel flow are used for generation of the virtual images, Using the virtual images and the camera's parameters. three-dimensional velocity vectors are obtained for a channel flow. The capabilities of a 3D-PTV algorithm are investigated by comparing the results obtained by the virtual images and those by an actual measurement for the channel flow.
The Characteristics of Two-Phase Flow Distribution in a Bottom Dividing Header
Im, Yang-Bin ; Kim, Jang-Soo ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1195~1202
In this paper an experimental study was investigated for two-phase flow distribution in compact heat exchanger header. A test section was consisted of the horizontal bottom dividing header(
: 5 mm, L: 80 mm) and 10 upward circular mini channels (
: 1.5 mm, L: 850 mm) using an acrylic tube. Three different types of tube intrusion depth were tested for the mass flux and inlet mass quality ranges of 50 - 200 kg/
s and 0.1 - 0.3, respectively. Air and water were used as the test fluids. The distribution of vapor and liquid is obtained by measurement of the total mass flow rate and the calculation of the quality. Two-phase flow pattern was observed, and pressure drop of each channel was measured. By adjusting the intrusion depth of each channel an uniform liquid flow distribution through the each channel was able to solve the mal-distribution problem.
Air-Water Two-phase Flow Patterns and Pressure Distributions in a Screw-type Centrifugal Pump
Kim, You-Taek ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1203~1210
It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.
Measurements of a Round Jet with High-Definition 3D-PTV
Hwang, Tae-Gyu ; Doh, Deog-Hee ; Saga Tetsuo ; Kenneth D. Kihm ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1211~1224
Two round jets. impinged and pulsed. were measured with high-resolution 3D-PTV technique. The measurement system consists of three CCD cameras, Ar-ion laser, an image grabber and a host computer. Two fitness functions were introduced in a genetic algorithm in order to enhance the correspondences of the particles. One was based on a concept of the continuum theory and the other one was based on a minimum distance error. The velocity profiles of the impinged jet obtained by the constructed 3D-PTV system were compared with those of LDV measurements made in this study. The head vortex of the jet was visualized by LIF and was reconstructed by the constructed high-resolution 3D-PTV system for comparisons.
Melting Heat Transfer Characteristics of Plural Phase Change Microcapsules Slurry Having Different Diameters
Kim, Myoung-Jun ; Kim, Myoung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1225~1238
The present study has been performed for obtaining the melting heat transfer enhancement characteristics of water mixture slurries of plural microcapsules having different diameters encapsulated with solid-liquid phase change material(PCM) flowing in a pipe heated under a constant wall heat flux condition. In the turbulent flow region, the friction factor of the present PCM slurry was to be lower than that of only water flow due to the drag reducing effect of the PCM slurry. The heat transfer coefficient of the PCM slurry flow in the pipe was increased by both effects of latent heat involved in phase change process and microconvection around plural microcapsules with different diameters. The experimental results revealed that the average heat transfer coefficient of the PCM slurry flow was about 2～2.8 times greater than that of a single phase of water.
Enhancement of Heat and Mass Transfer by Insert Spring in a Vertical Absorber with Surfactant
Yoon, Jung-In ; Choi, Kwang-Hwan ; Moon, Choon-Geun ; Sarker M.M.A ; Kwon, Oh-Kyung ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1239~1250
This research was concerned with the enhancement of heat transfer by surfactant added to the aqueous solution of LiBr. Different vertical tubes were tested with and without an additive of normal octyl alcohol. The test tubes are a bare inner surface. a groove inner surface, a corrugated inner surface and a spring inserted inner surface tubes. The additive concentration was about 0.08 mass%. The heat transfer coefficient was measured as a function of the film Reynolds number in the range of 20~200. Experiments were carried out at higher cooling water temperature of
to simulate an air cooling condition for several kinds of absorber testing tubes. The experimental results were compared with and without surfactant. The enhancement of heat transfer by Marangoni convection effect which was generated by addition of the surfactant is observed in each test tube. Especially, it is clarified that the tube with an inserted spring has the highest enhancement effect.
Numerical Analysis of an Arc Plasma in a DC Electric Furnace
Lee, Yeon-Won ; Lee, Jong-Hoon ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1251~1257
In order to analyze the heat transfer phenomena in the plasma flames, a mathematical model describing heat and fluid flow in an electric arc has been developed and used to predict heat transfer from the arc to the steel bath in a DC Electric Arc Furnace. The arc model takes the separate contributions to the heat transfer from each involved mechanism onto account, that is radiation, convection and energy transported by electrons. The finite volume method and a SIMPLE algorithm are used for solving the governing MHD equations, that are conservation equations of mass, momentum and energy together with the equations describing a standard k-
model for turbulence. The model predicts heat transfer for different currents and arc lengths. Finally these calculation results can be used as a useful insight into plasma phenomena of the industrial-scale electric arc furnace. From these results, it can be concluded that higher arc current and longer arc length give high heat transfer
Numerical Calculation of Flow Pattern and Fluid Force on a Circular Arc-type Sea Anchor
Ro, Ki-Deok ; Oh, Se-Kyung ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1258~1269
The fluid dynamic characteristics of a circular arc type sea anchor were calculated by a discrete vortex method. The flow for the surface of the sea anchor was represented by arranging bound vortices at adequate intervals. The simulations were performed by assuming that the separations occur at edges. With time, the drag coefficient was almost constant but the lift coefficient oscillated in a cycle due to von Karman's vortex street. As the camber ratios increase, the drag coefficient and Strouhal number were almost constant but the oscillating amplitude of the lift coefficient increased largely.
Effect of Pulse Shapes on Weld Defects in Pulsed Laser Welding of Stainless Steel
Kim, Jong-Do ; Kil, Byung-Lea ; Kim, Young-Sik ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1270~1278
This paper describes the effectiveness of laser pulse shaping in eliminating weld defects such as porosity, cracks and undercuts in pulsed Nd:YAG laser welding. A large porosity was formed in a keyhole mode of deeply penetrated weld metal of any stainless steel. Solidification cracks were present in STS 310S with above 0.017%P and undercuts were formed in STS 303 with about 0.3%S. The conditions for the formation of porosity were determined in further detail in STS 316. With the objectives of obtaining a fundamental knowledge of formation and prevention of weld defects, the fusion and solidification behavior of a molten puddle was observed during laser spot welding of STS 310S through a high speed video photographing technique. It was deduced that cellular dendrite tips grew rapidly from the bottom to the surface, and consequently residual liquid remained at the grain boundaries in wide regions and enhanced the solidification cracking susceptibility. Several laser pulse shapes were investigated and optimum pulse shapes were proposed for the reduction and prevention of porosity and solidification cracking.
Characteristic Simulation of PM-Type Magnetic Circuit Breaker
Park, Han-Seok ; Jung, Hong-Sub ; Woo, Kyung-il ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1279~1285
This paper presents the characteristic simulation of PM-type magnetic circuit breaker with the 2D finite element magnetic field solution including non-linearity of the material and an eddy current. Change of dynamic characteristic of the actuator is quantified from the finite element analysis. The results obtained from a commercial finite element analysis software are compared with those calculated from the developed finite element analysis software. A new modified model to decrease the eddy current is proposed. The characteristics of the two models are compared.
The Performance of Cathodic Protection with ICCP
Oh, Jin-Seok ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1286~1290
This paper describes the anti-corrosion system on underwater structures of ships. Metals and alloys have several positions in the series such as immunity, corrosion and passivity. The iron potential has to change from the corrosion position to the anodic protection or cathodic protection for preventing corrosion by providing corrosion protection system such as ICCP(Impressed Current Cathodic Protection). The purpose of ICCP system is to eliminate the rusting or corrosion, which occurs on metal immersed in water. The system includes a power supply unit, which consists of a transformer, a converter. a controller, etc. This paper presents the protection performance of ICCP under dynamic condition such as velocity. The variation of potential and current density with time and environment factors are also described Finally, the experimental results will be explained and analysed.
Communication Redundancy for Reliability Improvement in an Industrial Monitoring and Control System
Rhyu, Keel-Soo ; Chung, Kyung-Yul ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1291~1298
In development of monitoring and control systems, one of the most important points is to consider a redundancy so that the system can be operated normally although hardware faults are partly occurred. The purpose of this paper is to introduce a monitoring and control system with a redundancy function for I/O servers and communication networks. I/O servers composed with an active server and a standby server. Each server also has 3 communication ports, 2 ports of them were connected to field units and the other 1 port was connected to the other server. Field units have to be constructed to 2 communication ports connected I/O servers through communication lines. Also, server communication module was implemented for analyzing and handling fault elements. and was submodularized for linking easily with a monitoring and control module. An experiment with 2 servers and 2 field units was constructed to demonstrate its effectiveness.
Stability Analysis and Proposal of a Simple Form of a Fuzzy PID Controller
Lee, Byung-Kyul ; Kim, In-Hwan ; Kim, Jong-Hwa ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1299~1312
This paper suggests the simple form of a fuzzy PID controller and describes the design principle, tracking performance, stability analysis and changes of parameters of a suggested fuzzy PID controller. A fuzzy PID controller is derived from the design procedure of fuzzy control. It is well known that a fuzzy PID controller has a simple structure of the conventional PID controller but posses its self-tuning control capability and the gains of a fuzzy PID controller become nonlinear functions of the inputs. Nonlinear calculation during fuzzification, defuzzification and the fuzzy inference require more time in computation. To increase the applicability of a fuzzy PID controller to digital computer, a simple form of a fuzzy PID controller is introduced by the backward difference mapping and the analysis of the fuzzy input space. To guarantee the BIBO stability of a suggested fuzzy PID controller, ‘small gain theorem’ which proves the BIBO stability of a fuzzy PI and a fuzzy PD controller is used. After a detailed stability analysis using ‘small gain theorem’, from which a simple and practical method to decide the parameters of a fuzzy PID controller is derived. Through the computer simulations for the linear and nonlinear plants, the performance of a suggested fuzzy PID controller will be assured and the variation of the gains of a fuzzy PID controller will be investigated.
A Study of the Technical Treatment within an Environmental Appetency for the Ballast Water
Nam, Chung-Do ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 8, 2004, Pages 1313~1323
In accordance with adoption of new convention for the control of ship's ballast water at the diplomatic conference held in London Feb, 2004, every country has to regulate the ballast water and deposit matters. When this Resolution comes into effect in 2009, all vessels engaged in international voyage must have ballast water control program, ballast water records, equipments which are suitable to the standard of exchange and performance for the ballast water. This study estimates objectively their performances, merits and demerits of the ballast water treatment technique and exchanging techniques for safe operation of ships. It is desirable to design an equipment to control the ballast water using the brush-type vacuum suction nonstop reverse cleaning system to overcome the clogging phenomenon and the direct disc filtering to maximize filtering area for the optimum process considering biological availabilities. It will be expected to protect against marine pollution and to maintain clean sea if it is secured to develop new ballast water treatment techniques. And it will also be expected to cope with the Resolution and each regulation of the developed countries from the ballast water.