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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 35, Issue 8 - Nov 2011
Volume 35, Issue 7 - Nov 2011
Volume 35, Issue 6 - Sep 2011
Volume 35, Issue 5 - Jul 2011
Volume 35, Issue 4 - May 2011
Volume 35, Issue 3 - May 2011
Volume 35, Issue 2 - Mar 2011
Volume 35, Issue 1 - Jan 2011
Selecting the target year
A Numerical Analysis in Piezoelectric Fan Systems
Park, Ji-Ho ; Kim, Eun-Pil ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 994~1000
DOI : 10.5916/jkosme.2011.35.8.994
In this study, the piezoelectric fan cooling system is investigated. In order to find the proper geometry and configuration, the numerical model for the flow field and heat transfer investigation is used. A simplified nonlinear deformation model is employed for transient solutions of a piezoelectric fan with the dynamic mesh and user defined function capability. The results show that the cooling is most effective when the length of a piezoelectric fan is 5 cm and the cooling plate is 3 cm. The results can be used to develop a new design method of heat sink for piezoelectric fans.
Exergy Analysis of R744-R404A Cascade Refrigeration System
Oh, Hoo-Kyu ; Son, Chang-Hyo ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1001~1008
DOI : 10.5916/jkosme.2011.35.8.1001
This paper describes an analysis on performance and exergy of R744-R404A cascade refrigeration system with internal heat exchanger to optimize the design for the operating parameters of this system. The operating parameters considered in this study include subcooling and superheating degree, internal heat exchanger and compression efficiency, evaporation and condensation temperature in the R744 low- and R404A high- temperature cycle, respectively. The main results are summarized as follows : As the evaporation temperature of cascade heat exchanger increases, the COP of R404A high-temperature cycle increases. But the COP of R744 low-temperature cycle decreases, and the COP of total cascade cycle is almost constant. As cascade evaporation temperature increase, the exergy loss in the R404A condenser and the R744 internal heat exchanger is the largest and the lowest among all components, respectively. Therefore, the exergy loss in the condenser and compressor of R404A must be decreased to enhance the COP of R744-R404A cascade refrigeration system.
A Study on Engine Performance at the Intake Air Compensation by Supercharging in the Low Speed Diesel-Atkinson Cycle
Jang, Tae-Ik ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1009~1015
DOI : 10.5916/jkosme.2011.35.8.1009
In this study, in the high expansion cycle was conduced by variable valve timing system composition to close intake valve late, and in the intake air reduction on the low compression was solved by supercharging pressure. In this wise, by constituting Diesel-Atkinson cycle, this study looked into a possibility of thermal efficiency improvement. As a result, there was improvement in thermal efficiency and output in a whole range of closing timing from ABDC
. However, after ABDC
of closing timing, the thermal efficiency increase was getting smaller. As the result of the study, the optimum intake valve closing timing was about ABDC
, high loading territory of engine was more effective than low loading territory, and engine operation in middle loading territory was stable. At this time, brake thermal efficiency was 12.5% higher than ordinary engine on average.
A Study on Cooling Performance of Aluminium Heat Sink with Pulsating Heat Pipe
Kim, Jong-Soo ; Ha, Soo-Jung ; Kwon, Yong-Ha ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1016~1021
DOI : 10.5916/jkosme.2011.35.8.1016
The enhancement for cooling performance of heat sink is surely necessary to guarantee the performance of electronic products. So in this paper, the cooling performances of the aluminum heat sink with pulsating heat pipe(PHP) were investigated experimentally and numerically. The pulsating heat pipe was used as a heat spreader. Working fluid of PHP was R-22. Heat inputs were 30W, 60W, 80W and 100W, respectively. Heat sink was tested for forced convection conditions with air velocity of 1 ~ 4m/s. And CFD simulations were conducted for two different heat sinks. The results showed that the cooling performance of heat sink with pulsating heat pipe was higher than that of conventional heat sink. Therefore, the pulsating heat pipe can be a good tool to improve cooling performance of heat sink.
The Effect of HHO Gas on the Performance of Industrial Diesel Engine Using Biodiesel Blended Fuel
Park, Kweon-Ha ; Kim, Ju-Youn ; Kim, Chul-Jung ; Lee, Eun-June ; Son, Kwon ; Park, Sung-Hoon ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1022~1027
DOI : 10.5916/jkosme.2011.35.8.1022
A diesel engine works in high compression ratio due to injection of diesel fuel after compression of air. Therefore the engine has a high thermal efficiency, while nitrogen oxide is produced a lot in high flame temperature regions. In order to solve the problem this study HHO gas is added into the intake air of the industrial diesel engine. The test conditions are loads of 0%, 50% and 100% and engine speeds of 700 to 1900 rpm. The results show the maximum torque and pressure is increased, fuel consumption, smoke and CO emissions are decreased and NOx emission is remained at same level.
The Research of Vibration Power Generation with Two Degree of Freedom Using Ocean Wave
Han, Ki-Bong ; Lee, Hyoung-Woo ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1028~1034
DOI : 10.5916/jkosme.2011.35.8.1028
This paper have been studied that ocean wave power vibration generation system with two D.O.F.(degree of freedom) consists of buoy and vibration generation system with two D.O.F. for using efficiency of ocean wave energy. It selected main frequencies
in frequency with ocean wave and it fitted them to the natural frequencies of vibration system with two D.O.F. in the vibrational power generation system. Then each the relative velocity of between the winding coil and the permanent magnet is faster than the velocity of ocean wave up and down motion by resonance phenomenon. Also the ocean wave power generation with two D.O.F. obtained the more electric energy then the ocean wave power generation with one D.O.F. by coupling effect for two D.O.F. vibration system. Therefore ocean wave power vibration generation system with two degree of freedom that is proposed in this paper has merits which not only using more energy in the ocean wave but also obtaining more electronic energy.
A Study on the Energy Efficiency Operational Indicator for CO
Reduction from Ships
Choi, Jea-Seong ; Rho, Beom-Seok ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1035~1040
DOI : 10.5916/jkosme.2011.35.8.1035
In this study, many researches have been carried out against Energy Efficiency Operational Indicator(EEOI) of existing ships under discussion by IMO. This research is examined the method for the polices about IMO's greenhouse gas reducing emissions among them, we were analyzed the EEOI for existing ships. we have analyzed the result about applying EEOI using the calculation method of the rate of fuel consumption for cargo quantities to the actual existing ships and raised the problem. Based on this research, we were presented the improved EEOI about the engine load using fuel consumption and applied the existing ships. As a result, we concluded that the improved EEOI can define a resonable rate of
A Study on the Diode Laser Surface Hardening Treatment of Cast Iron for Die Material(I) - Characteristics of Surface Hardening by Die Materials -
Kim, Jong-Do ; Song, Moo-Keun ; Hwang, Hyun-Tae ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1041~1047
DOI : 10.5916/jkosme.2011.35.8.1041
In this study, two types of die material cast iron was treated for surface hardening by using high power diode laser to improve mechanical properties of die which is using as essential production technology in the parts manufacturing in virtually all the infrastructure industries now. First of all, the heat treatment characteristics of FCD550 material which is spheroidal graphite cast iron, and through the heat treatment of HCI350 material which is flake graphite cast iron, the heat treatment characteristics of the two materials were compared. The hardness of hardened zone increased over 3 times over base material for both specimens, but as for required heat input, HCI350 was higher than FCD550 material depending on the heat conductivity of the materials by the content amount and shape of graphite contained in the material.
A Study on the Diode Laser Surface Hardening Treatment of Cast Iron for Die Material(II) -Comparison of Hardening Characteristics by the Parts Applied Heat Treatment-
Kim, Jong-Do ; Song, Moo-Keun ; Hwang, Hyun-Tae ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1048~1054
DOI : 10.5916/jkosme.2011.35.8.1048
Laser surface hardening process is the method of hardening surface by inducing rapid self quenching of laser injected area through transfer of surface heat to inside after rapid heating of laser injected area only by high density energy heat source. This surface treatment method does not involve virtually any thermal deformation by heat treatment nor accompanies any other process after surface hardening treatment. In addition, allowing local machining, this method is a surface treatment method suitable for die with complicated shape. In this study, die material cast iron was surface-treated by using high power diode laser with beam profile suitable for heat treatment. Since the shapes of die differ by press die process, specimens were heat-treated separately on plane and corner depending on the applied parts. At this time, corner heat treatment was done with optic head inclined at
. As a result, corner heat treatment easily involves concentration of heat input due to limitation of heat transfer route by the shapes compared with plane part, so the treatment accomplished hardening at faster conveying speed than plane heat treatment.
A Numerical Analysis of the Pressure Drop according to the Shape of TiO
Photocatalyst-coated Module in a HVAC Duct
Hwang, Kwang-Il ; Koo, Jae-Hyoek ; Kim, Da-Hye ; Lee, Hyun-In ; Choi, Young-Guk ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1055~1062
DOI : 10.5916/jkosme.2011.35.8.1055
The purpose of this study is to develop the shape of photocatalyst-coated module for improve the IAQ, which is installed at inside of ductwork and detachable. Including 3 column types(square, circle, diamond) and 2 fin types(diamond and square), totally 5 types are previously declared for numerical analysis and comparison, 5 types are. As the results of numerical analysis, almost the velocity varied at the range of
from the module, except the Type A-3(diamond column type) which is affected to
range and shows the biggest velocity differences. Among the 5 types, the diamond fin type(Type B-1) is analyzed as the most stable in velocity. And the results of local pressure drop show that the difference of pressure coefficient of Type B-1 is computed as 0.59, and that of Type A-3 is 2.44. Meanwhile, from the effect analysis of the number of module, the flow conflict happens and the pressure difference between before and after the module increases if there are over 3 modules inserted.
CFD Study on Aerodynamic Power Output of 6 MW Offshore Wind Farm According to the Wind Turbine Separation Distance
Choi, Nak-Joon ; Nam, Sang-Hyun ; Jeong, Jong-Hyun ; Kim, Kyung-Chun ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1063~1069
DOI : 10.5916/jkosme.2011.35.8.1063
This paper presents aerodynamic power outputs of wind turbine of 6 MW wind farm composed of 3 sets of 2 MW wind turbine according to the separation distance by using CFD. Layout design including offshore wind farm and onshore wind farm is key factor for the initial investment cost, annual energy production and maintenance cost. For each wind turbine rotor, not actuator disc model with momentum source but full 3-dimensional model is used for CFD and it has a great technical meaning. The results of this study can be applied to the offshore wind farm layout design effectively.
Field Test for Performance Evaluation of a Tubular Turbine in Marine Small Hydro Power Plant
Hwang, Yeong-Ho ; Lee, Young-Ho ; Choi, Young-Do ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1070~1077
DOI : 10.5916/jkosme.2011.35.8.1070
This study includes field test results for performance evaluation of a tubular turbine in marine small hydro power plant. Minimum output power of the tested turbine generator is examined with using of the measured effective head, output power and efficiency. For the rated and maximum output power tests, corrected values from the result of turbine model test are used for the performance evaluation, because experimental conditions of field test at the rated and maximum output powers are restricted correctly. Performance of the test turbine shows good conformance with the suggested guarantee values of output power and efficiency at the measured points of minimum, rated and maximum output power.
Temperature and Sound Noise Control for LED lamp
Yoon, Jong-Su ; Choi, Hyeung-Sik ; Shin, Hee-Young ; Lim, Tae-Woo ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1078~1084
DOI : 10.5916/jkosme.2011.35.8.1078
In this paper, a temperature control for LED(Light Emitting Diode) lamp using a cooling fan is studied. An efficient temperature control scheme for the LED lamp using the fan wind at the lowest sound noise is studied. Also, for minimization study of sound noise and temperature control of an LED lamp, a sequential control algorithm using the cooling fan at the lowest sound noise is presented. For the study, after measurement of the minimum sound noise of the fan and related temperature of the LED lamp through tests, experiments on temperature control of the LED lamp using the fan was performed.
A Design and Implementation of Monitoring Applications using Shipboard Integration Network Communication Library
Kim, Tae-Jong ; Hwang, Hun-Gyu ; Lee, Seong-Dae ; Lee, Jang-Se ; Jang, Kil-Woong ; Park, Hyu-Chan ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1085~1091
DOI : 10.5916/jkosme.2011.35.8.1085
This paper describes a design and implementation of monitoring applications on shipboard integration network. A wrapping module is designed to reuse pre-developed communication library of shipboard integration network. By using the wrapping module, monitoring applications are also designed to display several kinds of shipboard data. They are implemented and tested on general PC and embedded PC to verify that they can be applicable to different platforms.
A Routing Scheme by Normalized Transmission Characteristics (NTCR) for Multi-Carrier MANETs at Sea
Son, Joo-Young ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1092~1097
DOI : 10.5916/jkosme.2011.35.8.1092
Data communications at sea are done by the traditional radio and satellite carriers. Because of the restrictions on the data rate and cost of the carriers, a novel data communication system at sea is needed. Nowadays the efforts to make use of the broadband land carriers at sea have been pursued. This paper proposes a routing scheme (NTCR) using the various carriers on land for a MANET model at sea. The NTCR scheme optimizes the route using a chosen carrier by taking considerations of normalized transmission characteristics (NTC) of applications and carriers. The NTCR scheme is compared with the MWR (max-win based routing) scheme.
A Carrier Preference-based Routing Scheme(CPR) for Multi-Layered Maritime Data Communications Networks
Son, Joo-Young ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1098~1104
DOI : 10.5916/jkosme.2011.35.8.1098
Data communications networks at sea can be modelled by multi-layered networks with traditional carriers (RF, satellites), and BWA (wireless LAN, WiBro, LTE), which partially makes it possible the high speed communication services (WWW, VoIP) at sea. In this paper, a novel routing scheme (CPR) is proposed which selects an optimal carrier for each hop in routes based on carrier preferences (CP). The carrier preferences are measured proactively depending on the feasibility of transmission characteristics (transmission rate, cost, and latency time) of the carriers for each application. Performance was compared with that of the OMH-MW (Optimal Medium per Hop based on Max-Win) routing scheme.
A Study on the Sensorless Speed Control of Induction Motor by New Direct Torque Control
Kim, Jong-Su ; Seo, Dong-Hoan ; Kim, Seung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1105~1110
DOI : 10.5916/jkosme.2011.35.8.1105
This paper presents an improved direct torque control based on artificial neural networks technique. The major problem that is usually associated with DTC drive is the high torque(speed) ripple. To overcome this problem a torque hysteresis band with variable amplitude is proposed based on artificial neural networks. The artificial neural networks proposed controller is shown to be able to reducing the torque(speed) ripple and dependency on motor parameter and to improve performance DTC especially at high speed and reversal running.
Configuration of a Module for Monitoring Voltages Between Power Lines and Hull Onboard Vessels Based on the Vector Diagram at 3 Phase Ungrounded Power Distribution System
Choi, Soon-Man ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1111~1116
DOI : 10.5916/jkosme.2011.35.8.1111
Power distribution systems onboard vessels are typically configured without any live line connected to hulls for earthing purpose, where the line to hull voltages are affected and deformed depending on the impedances consisting of insulation resistances and distributed capacitances between power lines and hull. An insulation fault at power lines causes the line to hull voltages to increase to a higher level which brings more possibilities to electric shock and deterioration of insulation material. This study focuses on how to configure a module which enables to continuously monitor the voltages between power line and hull based on the vector diagram by analyzing the neutral point of 3 phase voltages and the algorithm for plotting method on the PC monitors.
Characteristics of Neutral Point Loci on Line Voltages to Hull When Insulation Resistance Collapses by Earthing Faults at 3 Phase Power Distribution Systems Onboard Vessels
Choi, Soon-Man ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1117~1123
DOI : 10.5916/jkosme.2011.35.8.1117
Ungrounded power systems are adopted onboard vessels which enable more stabilized power supply even in case of electric leakage to hull. If earthing faults happen at these systems, they make grounding impedances of power lines unbalanced each other on the three phases, resulting in high voltages to hull which can bring more possibilities of electric shocks and electric fires. This study focuses on how to configure a calculation module for transferring a grounded condition by lowered insulation resistance into a vector diagram of the voltages to hull. By using the module, the loci of neutral points were acquired to analyze how voltages to hull are affected by earthing faults and the distributed capacitances between power lines and hull. The suggested module was simulated and compared to the measured values from a test power system in good results.
A Prediction on Indoor Contaminant Diffusion Characteristics of a Training Ship by Mechanical Ventilation System
Hwang, Kwang-Il ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1124~1131
DOI : 10.5916/jkosme.2011.35.8.1124
This study performed the prediction about the indoor contaminant's diffusion characteristics which can be affected by the mechanical ventilation system on a training ship. The results are as followings. It is clear that the contaminants are spread to most of the indoors, regardless of the contamination beginning zone. About 65~100 minutes later, the contaminant densities of whole indoor zones are evaluated as clean. Comparing the contamination beginning zone being located at higher deck(scenario A) to the contamination beginning zone being located at lower deck(scenario B), although the contaminant density by scenario A is 10 times higher than that by scenario B, the number of contaminated zones are 50% less. The contaminant densities are evaluated as to be rapidly decreased when the outside air induction ratio against design volume is over 75%.
Estimation of Distribution of the Weak Soil Layer for Using Geostatistics
Jeong, Jin ; Jang, Won-Il ;
Journal of the Korean Society of Marine Engineering, volume 35, issue 8, 2011, Pages 1132~1140
DOI : 10.5916/jkosme.2011.35.8.1132
When the offshore wind power plant is planned to construct, it is important for the wind farm site to figure out the distribution of the weak soil layers that might cause subsidence by the impact of the external moment from the wind plant's load and an oscillating wind load. Coring test is the optimistic method to figure out weak soil layers, but this method have some problem such as condition of the in-situ or economical limitation. In order to make up for the weak points in coring test, the researches using the geostatistics methods is actually done. In this study, setting a fixed coastal area that offshore wind plants construct firstly and Estimation of distribution on the thickness of the weak soil layer through the geostatistic method is conducted. The weak soil layer is sorted by result of the Standard penetration test, geostatistic method is used to ordinary kring and sequential gaussian simulation and compared to both method's result. As a results of study, we found that both methods show similar estimations of deep weak soil layer and we could evaluate quantitatively the uncertainty of the result.