Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 38, Issue 10 - Dec 2014
Volume 38, Issue 9 - Nov 2014
Volume 38, Issue 8 - Oct 2014
Volume 38, Issue 7 - Sep 2014
Volume 38, Issue 6 - Jul 2014
Volume 38, Issue 5 - Jun 2014
Volume 38, Issue 4 - May 2014
Volume 38, Issue 3 - Mar 2014
Volume 38, Issue 2 - Feb 2014
Volume 38, Issue 1 - Jan 2014
Selecting the target year
An analysis on the characteristics of regasification system for gas fuelled ship depending on the mixing ratio of eglycol and water
Lee, Yoon-Ho ; Kim, You-Taek ; Kang, Ho-Keun ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 799~805
DOI : 10.5916/jkosme.2014.38.7.799
Recently, the regulations of the Local and Global for a variety of air pollution prevention has been enhanced by the steep rise in fuel oil prices. So, the appearance of Gas Fuelled Ships became necessary. In this study, we configured a regasification system which uses Eglycol water as a heating medium to evaporate before being supply fuel to the DF engine, then we analysed the system properties according to the Eglycol water mixing ratio. The results were as follows. When pressure, temperature, and flux of natural gas(NG) which are supplied to DF engines are uniformly kept, the higher mixing ratio of Eglycol is, the lower mixing specific heat of Eglycol water. And the cycle flux and electric power were 1.65 and 1.54 times more required. respectively, than water was used as the heating medium. Basic variables including mass flux according to the mixing ratio of Eglycol water, required electric power of operating fluid pumps, the temperature of natural gas which is supplied to the engine, and the heat exchanger's capacity were drawn from the gotten results.
An usefulness study on estimation and control method of EGR ratio using intake manifold pressure in an gasoline engine
Park, Hyeong-Seon ; Yoon, Jun-Kyu ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 806~813
DOI : 10.5916/jkosme.2014.38.7.806
The EGR system being reburned the part of the exhaust gas through intake system indicates more favorable emission characteristics to reduce NOx in a gasoline engine, but the case of inappropriate exhaust gas quantity induced from engine is fallen engine power caused by unstable combustion. In this study, we examined a method to predict EGR ratio according to various engine operation condition based by intake manifold pressure and confirmed such a prediction data through an experimental method. And after having constituted feedback EGR control algorithm in a base with such a prediction data, we acquired qualitatively similar results by having compared data provided through an EGR feedback control experiment with the data which calculated quantity of residual gas for the engine operation condition. Therefore, the applied algorithm and the system for feedback EGR control showed feasibility applied to real electronic control EGR technology.
Performance analysis simulation for domestic application of heat pump by using sea water heat source
Lim, Seungtaek ; Kim, Jungsik ; Oh, Cheol ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 814~820
DOI : 10.5916/jkosme.2014.38.7.814
Due to the development of human civilization, industrialization and urbanization, the human race demanded the food, clothing and shelter as well as a comfortable living environment. For the purpose of this, the refrigeration and air conditioning part was carried out research and development. However, high oil prices and environmental pollution having problems in the 21st century cannot be overlooked. As an alternative, thermal system was designed using the heat pump to applied sea water heat source. In this paper, outside and sea temperatures are analysed in 2010 and carried out the performance analysis simulation at All water and All Air heat pump system by HYSYS program for domestic use. As a result, total average COP of the system is 3.37 from All Water system and All Air is 3.48. It showed that high performance confirmed in both system.
Prediction methods for two-phase flow frictional pressure drop of FC-72 in parallel micro-channels
Choi, Yong-Seok ; Lim, Tae-Woo ; You, Sam-Sang ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 821~827
DOI : 10.5916/jkosme.2014.38.7.821
In this study, an experimental study was performed to predict the two-phase frictional pressure drop of FC-72 in parallel micro-channels. The parallel micro-channels consist of 15 channels with depth 0.2 mm, width 0.45 mm and length 60 mm. And tests were performed in the ranges of mass fluxes from 152.2 to
and heat fluxes from 7.5 to
. The experimental data was compared and analyzed with existing correlations to predict the pressure drop. The existing methods to predict the pressure drop used the homogeneous model and the separated model. In this study, the new correlation was proposed by modified existing correlation using the separated model, and the new correlation predicted consequently with the experimental data within MAE of 9.6%.
Theoretical study on the performance improvement of refrigeration system installed with ejector entraining expansion gases after expansion process
Yun, Sangkook ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 828~833
DOI : 10.5916/jkosme.2014.38.7.828
In this paper, the performance characteristics for newly developed ejector refrigeration system, which is that the part of saturated vapor from liquid-vapor separator after ejector expansion process is entrained in ejector, and the saturated liquid flows in the evaporator and compressed with the rest of vapor in separator, is studied. The reasons of the performance improvement of refrigeration system are that the refrigeration capacity is increased due to quality reduction after iso-entropic expansion process by ejector and the compression work is reduced because of the relatively high pressure of vapor refrigerant before compression process. The comparison results of the ejector system entraining expansion gases with the present residential freezer show that the COP increases to 27.8% maximum in case of the pressure drop to 65% of high pressure of freezer, and to 40.1% for 75% pressure drop of refrigerant R401A. The COP improvement rate with 20%~60% pressure lift in diffuser of ejector is only 2.6%~3%.
A study on particle collection efficiency of a low power consumption two-stage electrostatic precipitator for oil mists collection
Song, Chi-Sung ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 834~843
DOI : 10.5916/jkosme.2014.38.7.834
A two-stage electrostatic precipitator (ESP) using a carbon brush charger and a plate-plate parallel aluminum collector was developed and its application for removal of oil mist aerosols was investigated. Charge number per particle and particle collection efficiency at different applied voltage to the carbon brush charger were measured and compared to those obtained by theoretical calculations. A long-term operation of the ESP during 9 weeks was also performed to evaluate its performance durability for oil mists. Average charge number per mist particle increased with the applied voltage to the charger, and thus the collection efficiency of the mist particles also increased overall at the particle size range of 0.26 - 3 mm. The tendencies of the average charge number per particle and particle collection efficiency obtained from theoretical calculations were considerably consistent with those of the experimental results. Particle collection efficiency of ~99 % at 0.3 mm could be achieved by power consumption of only 0.0033 W/(
) at the face velocity of 1 m/s and its collection performance maintained stably during every 8 hr operation per day for 9 weeks with little increase of pressure drop.
Variation of the structural stability for the sonar dome window in a naval vessel according to the state of the drain valve
Han, HyungSuk ; Lee, KyungHyun ; Park, SeongHo ; Lim, YongSoo ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 844~853
DOI : 10.5916/jkosme.2014.38.7.844
Since the active sonar for a naval vessel is usually installed in a bulbous bow, GRP(Glass reinforced plastic) material with low density and high strength is used for the material of the sonar dome window in order to prohibit impact by slamming wave or foreign material in the sea. The structural safety of the sonar dome is varied according to the interior and exterior distributed pressure on the sonar dome. Therefore, the variation of the structural safety according to the pressure variation of the sonar dome window caused by the drain valve state is studied by CAE.
Root cause analysis of the abnormal wear on diesel engine crankpin and lubricant contamination
Seo, Jeongwoo ; Park, Donghee ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 854~867
DOI : 10.5916/jkosme.2014.38.7.854
In the circumstance that high oil price state is continued over the world, the investment in crude oil development by oil major is a trend of increasing. Recently the number of delivered drill-ship for 5 years has been sharply increased all over the world and about twice than that of past 30 years. As addition to the increase of the drill-ship demand, the operation of drill-ships which is delivered recently is about 3,000 meters, ultra deep sea, on average and the work area is expending. Accordingly the drilling system including the size and length of pipe for drilling has been bigger and bigger and the power supply equipment for operation system also has large capacity. Unlike merchant vessel, high power and high voltage of diesel generators are required for drill-ship for which the demand for V-type 320 bore of diesel generator has increased. It is on the raised that the importance of lubrication oil cleaning for diesel generator on drill-ship which has longer time for construction, and also long term low load operation is unavoidable during commissioning of equipments. Recently it was reported that engine crankpin was damaged due to the hard contact caused by the abnormal wear down(Cam wear) on crankpin and bearing. The same pattern of wear down was found through the inspection on series vessels and the other vessel under commissioning. The purpose of this paper is to analyze of the wear mechanism based on the observation and theories and objective research from actual cases and to prepare the counter measures to avoid foreseeable damage when the lubricating oil is not properly cleaned.
Effect of pre-post injection timing of diesel fuel for naval vessel on the combustion and emission characteristics in an optically-accessible single cylinder diesel engine
Lee, Hyungmin ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 868~876
DOI : 10.5916/jkosme.2014.38.7.868
The objective of this study is focused on the analyzing combustion, carbon monoxide and hydrocarbon emission characteristics of marine diesel oil, utilized for naval propulsion engine, with varying pre-post injection timing of an optically accessible single cylinder engine. And also the combustion process is analyzed by means of a high speed camera visualization. On the result of retarding pre-injection timing toward main injection timing, the mean effective pressure and maximum pressure of combustion chamber are increased; however, the heat release rate is decreased. Furthermore, the emission rates of carbon monoxide and hydrocarbon are reduced in this case. In hence, when a post-injection timing is advanced, the mean effective pressure and maximum pressure are increased, because the combustion has been performed under the high temperature and high pressurized environment during main injection time, and the emission rates of carbon monoxide and hydrocarbon are increased. From the experimental results, it considered that retarding of pre-injection timing affects to shorten the ignition delay of main injection clearly, and to raise the flame intensity comparing to the advanced state. The ignition delay during post-injection is not appeared at any post-injection time, but the flame intensity has been weakened gradually according to the retarding of post-injection timing.
Energy efficiency improvements in part load for a marine auxiliary diesel engine
Jung, Kyun-Sik ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 877~882
DOI : 10.5916/jkosme.2014.38.7.877
The reduction of CO2 emission has been discussed in the Marine Environment Protection committee in the International Maritime Organization as the biggest causes of GHG for the purpose of indexing CO2 amounts released into the atmosphere from ships. Accordingly, various methods including the change in the hull design to improve energy efficiency, the coating development to reduce friction resistances, the additives development for improving thermal efficiency in an engine, the low-speed operation to reduce fuel consumptions, and etc. have been applied. The main engine of a ship is an electronic engine for improving the efficiency of the whole load area. However, marine generator engines still use mechanical drive engines in intake, exhaust, and fuel injection valve drive cams. In addition, most of marine generator engines in ships apply a part-load operation of less then 80% due to an overload protection system. Therefore, marine auxiliary diesel engine set at 100% load is necessary to readjust in order to efficient operation because of part-load operation. The objective of this study is to report the results of the part-load fuel consumption improvement by injection timing readjust to identifying the operational characteristics of a marine generator engine currently operated in a ship.
Characteristics of surface damage with applied current density and cavitation time variables for 431 stainless steel in seawater
Kim, Seong-Jong ; Chong, Sang-Ok ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 883~889
DOI : 10.5916/jkosme.2014.38.7.883
It is generated for cavitation erosion due to the local static boiling by pressure differentials in high speed rotating fluid environment. The cavitation is influenced by various elements such as pressure, velocity, temperature, pH of fluid and medium. In particular, the damage of material is accelerated due to the electrochemical corrosion by
and cavitation erosion due to cavities in seawater. In this paper, hence, it investigated for martensite stainless steel the damage behavior with applied current density and cavitation time in natural seawater solution. Less damage depth at the cavitation condition was observed than static condition as a result of galvanostatic experiment. Furthermore, it was shown that dramatic increase of weightloss, damage rate and damage depth after 3 hour of cavitation test.
Effects of alloy elements on electrochemical characteristics improvement of stainless steel in sea water
Lee, Jung-Hyung ; Choi, Yong-Won ; Jang, Seok-Ki ; Kim, Seong-Jong ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 890~899
DOI : 10.5916/jkosme.2014.38.7.890
Austenitic stainless steel is widely used in various industries due to its excellent corrosion resistance. However, Cr carbides precipitation along the grain boundaries after heat treatment or welding may develop Cr depleted zone, which acts as a preferential site for intergranular corrosion attack. To resolve this, carbon stabilizing element such as Ti or Nb are added to suppress formation of Cr carbides. However, there are few reports on corrosion characteristics under seawater environment of the stabilized stainless steel. This study investigated the effects of alloying contents on the electrochemical characteristics in seawater of stainless steel containing stabilizing element(Ti and Nb). To achieve this, the changes on the microstructure due to alloying were observed with microscope, and the electrochemical characteristics were determined by measurement of natural potential and potentiodynamic polarization experiments. The microscopic observation revealed that all specimens had inclusions other than the austenite matrix phase due to the addition of alloying elements. Such inclusions are considered to have different electrochemical characteristics from those of the matrix, and thus a clear distinction was found according to the type of stabilizers and the contents. The results of this study suggest that it is important to consider the effects of alloying contents on the electrochemical characteristics in seawater with the addition of Ti or Nb into austenitic stainless steel.
Experiments of flowfield of a square prism having a front vertical plate
Ro, Ki-Deok ; Jo, Dong-Bae ; Yoon, Young-Jun ; Park, Seo-Jin ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 900~908
DOI : 10.5916/jkosme.2014.38.7.900
The Characteristics of the flowfields of a square prism having a small vertical plate at the upstream side was investigated by measuring of fluid force on the square prism and by visualization of the flow fields using PIV. The experimental parameters were the width ratios(H/B=0.2~0.6) of vertical plates to the prism width and the gap ratios (G/B=0~3) between the prism and the vertical plate. The drag reduction rate of the square prism was increased with H/B in case of the same G/B, and was increased and then decreased with G/B in case of the same H/B. The lift reduction rate of the square prism was hardly not affected by the width and gaps ratios, the average value was about 48.1%. In case of a square prism having a small vertical plate, the stagnation regions were represented in the upstream and downstream sides of the square prism.
A study on improvement of the control performance of the automatic voltage regulator of a brushless synchronous generator
Lee, Youngchan ; Kim, Jongsu ; Jung, Byung-Gun ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 909~915
DOI : 10.5916/jkosme.2014.38.7.909
Terminal voltage of the Automatic Voltage Regulator(AVR) of brushless synchronous generator is generally being controlled by PID Control way in shore and ship field. However, in case of changeable large load on power system, PID control method is deficiency to respond output voltage with settling time. Hence, taking into consideration this situation, it is required new control method. In this thesis, we propose Fuzzy Logic Control(FLC) which has more optimal robust control way in order to respond varying values of terminal voltage to the brushless synchronous generator through simulation of MATLAB/SIMULINK and prove Fuzzy logic control more optimal compared with PID control.
A harmonic reduction scheme for 12-pulse diode rectifiers by auxiliary voltage supply
Kim, Sung-Hwan ; Kim, Jong-Su ; Oh, Sae-Gin ; Yoon, Kyoung-Kuk ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 916~922
DOI : 10.5916/jkosme.2014.38.7.916
Diode rectifiers have been widely used for an AC to DC converter. But a big problem is that they include large harmonics components in the input currents. A 12-pulse configuration with phase shifting transformer is useful for reducing them. however, it still includes the (
)th (m; integer) harmonics in the input currents. In this paper, we propose a single-phase square wave auxiliary voltage supply which is inserted in the middle DC bus. It reduces harmonics especially the 11th and 13th and the harmonic characteristic becomes almost equivalent to a 24-pulse rectifier. Theoretical analysis of the combined 12-pulse diode rectifier with the auxiliary supply is presented and a control method of the auxiliary supply is proposed. The reduction in the input current harmonics is verified by simulation using software PSIM.
Implementation of underwater visible light communication system interlinked with bluetooth
Kim, Min-Soo ; Sohn, Kyung-Rak ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 923~928
DOI : 10.5916/jkosme.2014.38.7.923
Communication underwater is severely limited when compared to communications in air because water is essentially opaque to electromagnetic radiation except in visible range. Acoustic systems are capable of long range communication, but offer limited data rates and significant latency due to the speed of sound in water. On the other hand, optical wireless communication has been proposed as one of the best alternatives to meet the requirements of the underwater observation and subsea monitoring systems. It will help In this study, we are developing an underwater optical communication system that integrates with a depot ship floating on the water. An interface between LED lighting communication system and Bluetooth module is presented to support the underwater-to-air communications. Error free image and text transmission at 3 m of water were achieved at bit rates of 230.4 kbps. This development effort will enhance infrastructure to efficiently interconnect between underwater wireless systems and command ship networks for underwater monitoring.
Implementation of pressure monitoring system(PMS) for ship's engine performance analysis(SEPA) based on the web
Yang, Hyun-Suk ; Kwon, Hyuk-Joo ; Lee, Sung-Geun ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 929~935
DOI : 10.5916/jkosme.2014.38.7.929
This paper is study on the pressure monitoring system(PMS) for ship's engine performance analysis( SEPA) based on web, with high speed and accuracy. This system is composed of pressure sensor, monitoring module with multi channel A/D converter, TCP/IP and satellite internet communication system. Existing domestic products measure cylinder pressure when piston of first explosive cylinder reached TDC(the top dead center) point and then measure next cylinder pressure manually each angle divided by a constant rotating interval. But presented system monitors in the local and web computer, using pressure information transmitted from pressure sensor installed on each engine. In this system, it is possible to increase the accuracy of the engine performance analysis because not only each TDC points but cylinder pressures synchronized with the TDC points could be measured in real time, accurately. And therefore, it may be used in a various diagnosis of main engines, such as deviations of each cylinder maximum pressures(Pmax) and the TDC firing positions and combustion conditions.
A study for electric power of float-counterweight wave energy converter
Lee, Sung-Bum ; Hadano, Kesayoshi ; Moon, Byung-Young ;
Journal of the Korean Society of Marine Engineering, volume 38, issue 7, 2014, Pages 936~942
DOI : 10.5916/jkosme.2014.38.7.936
As a result of the exhaustion of fossil fuel, interest about renewable energy is increasing day by day. Inter alia, study for wave power energy of which the calculability is high and the available amount is abundant is going along actively. As a float-countweight wave energy converter is equivalent improved structural strength compared with oscillating body type. we made the wave only in order to up and down motion by setting up bulkhead which is called wave camber at the outside of float. This paper mainly focuses on generation amount of plural connected float-counterweight wave energy converter and we calculate the amount. The result, we confirmed that the more a numerical value of nl/L increases, the more amount of electricity rises and also when it is over nl/L=0.40, it is possible to get continuous generation. Through this study, we can use as basic data for design of wave chamber on advantageous condition at the real seas and by way of estimation for generation amount.