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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 36, Issue 8 - Nov 2012
Volume 36, Issue 7 - Nov 2012
Volume 36, Issue 6 - Sep 2012
Volume 36, Issue 5 - Jul 2012
Volume 36, Issue 4 - May 2012
Volume 36, Issue 3 - May 2012
Volume 36, Issue 2 - Mar 2012
Volume 36, Issue 1 - Jan 2012
Selecting the target year
Characteristics of Cryogenic Cascade Refrigeration Cycle for Liquefaction of Natural Gas with the Pressure Drop of Heat Exchanger
Yoon, Jung-In ; Choi, Kwang-Hwan ; Son, Chang-Hyo ; Kwag, Jin-Woo ; Baek, Seung-Moon ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 756~761
DOI : 10.5916/jkosme.2012.36.6.756
Natural gas is converted in to LNG by chilling and liquefying the gas to the temperature of
, when liquefied, the volume of natural gas is reduced to 1/600 of its standard volume. This gives LNG the advantage in transportation. In this study, the effects of the pressure drop of refrigerant and natural gas in the LNG heat exchanger of cryogenic cascade refrigeration cycle were investigated and then the design criteria for the pressure drop of refrigerant and natural gas of the LNG heat exchanger were proposed. The pressure drop of the cascade liquefaction cycle was investigated and simulated using HYSYS software. The simulation results showed that the pressure drop in the LNG heat exchanger is set to 50 kPa considering the increase in the compressor work and COP of cryogenic cascade liquefaction cycle.
A Study of Performance Characteristics on Portable Air Conditioner by Using Condensation Water
Kim, Jae-Dol ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 762~767
DOI : 10.5916/jkosme.2012.36.6.762
This study presents the effect which the condensation water affects on performance characteristics of apparatus when the condensation water injects to the condenser. The experimental results are the following. The inlet outlet refrigerant temperature in condenser and outlet air temperature showed a little lower than that of the existing method. Also, the refrigeration capacity and COP(coefficient of performance) increased about 3%, 13~16% and the compressor work decreased about 27% than that of the conventional method. So, these results contribute not only the performance improvement of apparatus but also the solution of problem according to the discharge of periodic condensation water.
Performance Comparison of R134a Organic Rankine Cycle (ORC) Using Hot Wastewater and Surface Seawater
Yoon, Jung-In ; Son, Chang-Hyo ; Baek, Seung-Moon ; Kim, Hyeon-Ju ; Lee, Ho-Saeng ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 768~773
DOI : 10.5916/jkosme.2012.36.6.768
This study was performed to find out the possibility that hot waste water from a thermoelectric power plant can be applied to Organic Rankine Cycle (ORC) by comparing the performance characteristics for use of the ocean surface water (
) and hot waste water (
) as a secondary fluid. The parameters considered in this study are four; superheating temperature, subcooling temperature, turbine efficiency, and pump efficiency. Main results of this study are summarized as follows : Overall efficiency of applying hot waste water to ORC is 87% higher than that of surface water. Thus it could be confirmed that hot waste water of the thermoelectric power plant can be applied to ORC.
MILD Combustion Characteristics with Inlet Air Velocity in a Conical Combustor
Kim, Tae-Kwon ; Ha, Ji-Soo ; Jo, A-Ron ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 774~779
DOI : 10.5916/jkosme.2012.36.6.774
MILD (Moderate and Intense Low Oxygen Dilution) combustion is a technology that uses the recirculation of combustion gas to increase thermal efficiency not only by keeping down the concentration of Nitric Oxides and temperature but also by uniformizing the internal temperature of the combustion furnace. This study is a trial to obtain MILD combustion characteristics by adjusting the equivalence ratio with the air flow rate in the conical combustor while keeping the fuel flow rate and measuring the exhaust gas of the combustion furnace.
Study on the Buoy and Vibration System in Broadband Ocean Wave Power Generator
Lee, Hong-Chan ; Yea, Kyung-Soo ; Hwang, Sung-Il ; Han, Ki-Bong ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 780~787
DOI : 10.5916/jkosme.2012.36.6.780
In general, the ocean wave vibration power generator consists of buoy, vibration system and linear generation system. It maximized energy efficiency by using resonance phenomenon that turned to the natural frequency of vibration system and frequency of ocean wave energy. But it is difficult to obtain efficiently energy from ocean wave because the frequency of ocean wave changes from moment to moment. In this paper, we study the buoy and vibration system of ocean wave power generator to solve these problem. Firstly, we designed the buoy that gives rise to resonance between ocean wave and buoy. Secondly, we designed vibration system that is occurred to resonance between buoy and vibration system. And then the relative velocity between the buoy and magnetic of ocean wave vibration generator increases and the relative displacement between buoy and ocean wave decreases at the same time. As a result, the method which is proposed in this paper has merits not only securing its stability from harsh ocean wave environment but also obtaining more kinetic energy from ever-changing ocean wave.
Emission Prediction from Naval Ship Main Propulsive Diesel Engine under Steady Navigation
Lee, Hyung-Min ; Park, Rang-Eun ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 788~793
DOI : 10.5916/jkosme.2012.36.6.788
This study was focused on the estimations of air pollutants, such as PM(Particulate matters), SOx(Sulfur Oxides),
(Carbon diOxides) and NOx(Nitrogen Oxides), from a diesel propulsion engine installed on a naval vessel. Legislative and regulatory actions for exhaust emissions from ships are being strengthened in international communities and national governments to protect human health and the environment. In this context, various technologies have been developed from all of the nations of the world to meet strict standards. These regulations are based on commercial ship applications and according to size, but are not suitable for military naval vessels, which have much different engine operating conditions and hull architectures. Additionally, there is no international emission control system for military ships. Emission factors have been updated for commercial ship types from work at various research institutes; however, it is difficult to develop emission factors for military vessels because of their characteristics. In this paper, exhaust emissions from diesel engines installed on naval vessels under steady navigation condition were estimated with emission inventory methodology applied to ocean going vessels using fuel-based methods and fuel sulfur content analysis.
A Study on the Improvement of FEM model in Plate Vibration by Modification of Young's Modulus and Shape
Park, Sok-Chu ; Oh, Chang-Guen ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 794~801
DOI : 10.5916/jkosme.2012.36.6.794
Finite Element Method is a strong tool to analyse static and dynamic problem of a structure. FEM is a good method for static problem, but for dynamic problem there are some differences between real phenomena and analyzed phenomena. Therefore some modifications are needed to identify two results. In this paper authors propose a genetic algorithm method 1) to adjust dimensions of plate for identifying natural frequencies, 2) to fit amplitude of FEM Frequency Response Function(FRF) onto it of real FRF. Analysis by raw FEM data gave questions if the results were for the same object. By only adjusting Young's modulus much better accordances were obtained, but limitation existed still. Very good agreements were achieved by shape modification and damping coefficient identification.
Forging Process Design of Self-Piercing Rivet for Joining dissimilar Sheet Metals
Kim, Dong-Bum ; Lee, Mun-Yong ; Park, Byung-Joon ; Park, Jong-Kweon ; Cho, Hae-Yong ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 802~807
DOI : 10.5916/jkosme.2012.36.6.802
Self-piercing rivet is sheet joining method. It is being used more to join aluminum alloy sheets. Self-piercing riveting is a large-deformation process that involves piercing. The self-piercing rivet, under the press from the punch, pierces the top sheet and forms a mechanical interlock with the bottom sheet. In this study, forging process was designed for manufacturing self-piercing rivet. The forging process has been simulated by using commercial FEM code DEFORM-2D. In simulation of forging process for manufacturing rivet, process sequence, formability, forging load, and distributions of stress and strain were investigated. The suitable forging process could be designed by comparisons of simulation results. The developed process consists of four stages: upsetting, first chamfering, back extrusion, and second chamfering. The simulated results for forging process were confirmed by experimental trials with the same conditions.
Drag Reduction on a Square Prism Using a Detached Splitter Plate
Ro, Ki-Deok ; Yoon, Seong-Min ; Choi, Dong-Hyeon ; Kim, Jae-Hyeon ; Sim, Eun-Chong ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 808~813
DOI : 10.5916/jkosme.2012.36.6.808
The Characteristics of the drag reduction of a square prism having a detached splitter plate at the wake side were investigated by measuring of lift and drag on the square prism. The experimental parameters were the width ratios(H/B=0.5~1.5) of splitters to the prism width and the gap ratios (G/B=0~2) between the prism and the splitter plate. As the results the amplitude of the lift on the square prism having a detached splitter plate was remarkably decreased by comparison with the prototypical square prism. The drag reduction rate of the square prism was increased with H/B in case of the same G/B, and was increased and decreased with G/B in case of the same H/B. The maximum drag reduction rate was represented by 24.2% at H/B=1.5 and G/B=0.5.
Effect of Mixer Structure on Turbulence and Mixing with Urea-water Solution in Marine SCR System
Kim, Tae-Kyoung ; Sung, Yon-Mo ; Han, Seung-Han ; Ha, Sang-Jun ; Choi, Gyung-Min ; Kim, Duck-Jool ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 814~822
DOI : 10.5916/jkosme.2012.36.6.814
To improve the flow and mixing characteristics of marine SCR system, two different mixer including up-down and swirl type mixer were considered. The purpose of this study is to analyse turbulence intensity and uniformity index in detail and to improve the performance of SCR with respect to the mixer structure. The results showed that, the concentration uniformity index is improved by about 5% with the utilization of both mixers in the front of catalyst part. Although the RMS value and relative turbulence intensity increased after the up-down type mixer, it could observed that the value of two parameters decreased with the flow proceeding forward to the downstream. For the case of swirl type mixer, the decrease of RMS value and relative turbulence intensity were relatively smaller than that of up-down type mixer, and uniform distribution of relative turbulence intensity was observed. As a results, it could be concluded that the mixing effects and the distance of the two kinds of mixer were different.
A Carrier Preference and Location-based Routing Scheme(CPLR) at Multi-carrier Maritime Data Communications Networks
Son, Joo-Young ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 823~829
DOI : 10.5916/jkosme.2012.36.6.823
Data communications networks at sea in the future can be modelled by overlapped MANET networks with Broadband Wireless Access carriers. A novel routing scheme (CPLR) is proposed in this paper, which finds out an optimal route by selecting an optimal carrier for each hop in routes based on carrier preferences of each application, and locations of ships as well. As distances between each ships and destination ships are considered in this scheme, routing can be done much faster. Performance is compared with that of the CPR (only Carrier Preference-based Routing Scheme), and it shows some improvements.
Sensorless Speed Control of Induction Motor by Direct Torque Control with Numerical Model
Yoon, Kyoung-Kuk ; Kim, Sung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 830~836
DOI : 10.5916/jkosme.2012.36.6.830
Various control algorithms have been proposed for the speed-sensorless control for an induction motor. These control schemes are mainly based on the speed feedback with the flux and speed estimations. This paper proposes another method for the speed-sensorless control for an induction motor. The proposed scheme is based on the torque and flux compensation without speed estimations, in which the same controlled stator voltage is applied to both the induction motor and the numerical model so that the differences between torques and fluxes of the model and the induction motor may be compelled to give access to zero. The results of experiment show the effectiveness of the scheme.
Simulation for the Calculation of Switching Time when Asynchronous Motors are Starting
Bae, Cherl-O ; Vuong, Duc-Phuc ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 837~843
DOI : 10.5916/jkosme.2012.36.6.837
Asynchronous motors are widely used in many fields. The various starting methods have been developed for the asynchronous motors which have large power compared to source power. The most popular ways to start the motors are to reduce the voltage of motor's stator or change the resistance fed rotor. It is needed to the specific time to reduce the voltage and change the resistance at a specific step. We call it the switching time. It is very difficult to know the switching time exactly. It varies with different types of motors as well as load characteristics. Thus, this paper focuses on the design and development for the mathematical models of motor and load. And then it is implemented in SIMULINK in order to calculate this time. The simulation results are both compared and discussed in detail so that it can be applied for new system with various motors and loads.
Bidirectional Zeta-Flyback Converter for Improved Efficiency
Jung, Mun-Kyu ; Kwon, Young-Ahn ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 844~849
DOI : 10.5916/jkosme.2012.36.6.844
In this paper, a bidirectional Zeta-Flyback converter is proposed. The topology of the proposed converter is analyzed, which is superposition of bidirectional Flyback converter mode and bidirectional Zeta converter mode in a cycle. The proposed converter allows power flow in either a forward direction or a backward direction. Bidirectional power flow is obtained by a transformer and components. The proposed converter's output is controlled by duty of constant frequency PWM of switch. Compared to conventional bidirectional isolated DC-DC converters, the proposed isolated bidirectional DC-DC converter has high power density and high transformer utilization. To confirm the proposed converter, the simulation and experimental results are presented.
Real time indoor positioning system using IEEE 802.15.4a and sensors
Cho, Hyun-Jong ; Hwang, Kwang-Il ; Noh, Duck-Soo ; Seo, Dong-Hoan ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 6, 2012, Pages 850~856
DOI : 10.5916/jkosme.2012.36.6.850
Bilateration using two fixed nodes has been used in the field of the real time indoor location system in the narrow space such as building or ship passage. However, as the distance between the fixed nodes increases or any obstructions exist in their zone, it is difficult to detect the location of mobile node(user) due to the degradation of its reception ratio. In order to compensate for these problems, this paper presents, based on IEEE 802.15.4a chirp signal, a new real time indoor location system using stride measurement algorithm which can calculate the location through sensors attached to user. The proposed system consists of an ultrasonic sensor to measure the leg length, a geomagnetic sensor to recognize the user's orientation, and an inertial sensor to obtain the angle between the legs. The experimental results are shown that the proposed system has twice or more accurate output compared with conventional indoor location method in the section which is partially out of communication reachability.