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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 39, Issue 10 - Dec 2015
Volume 39, Issue 9 - Nov 2015
Volume 39, Issue 8 - Oct 2015
Volume 39, Issue 7 - Sep 2015
Volume 39, Issue 6 - Jul 2015
Volume 39, Issue 5 - Jun 2015
Volume 39, Issue 4 - May 2015
Volume 39, Issue 3 - Mar 2015
Volume 39, Issue 2 - Feb 2015
Volume 39, Issue 1 - Jan 2015
Selecting the target year
A study on the comprehensive resources utilization of seawater by the vacuum heat transfer technology
Shao, Yude ; Mun, Soo-Beom ; Kim, Kyung-geun ; Choi, Bu-Hong ; Lee, Seo-Yeon ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 685~695
DOI : 10.5916/jkosme.2015.39.7.685
Mud, iron oxide, plaster, salt, minerals, and dissolved metals are sequentially deposited in accordance with the increasing concentration of seawater. In this paper, by using the physical characteristics of the seawater, we propose a new vacuum heat-transfer technology to subsequently obtain the proportion of the dissolved components in a cost-effective manner. Based on the vacuum heat-transfer characteristics of seawater, we comprehensively divide the seawater resource processes into the following four processes: (1) the salt concentration process to the saturation concentration, (2) crystallization process for salt formation, (3) mineral precipitation, and (4) remaining of dissolved metals.
Heat transfer characteristic and flow pattern investigation in micro-channels during two-phase flow boiling
Choi, Yong-Seok ; Lim, Tae-Woo ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 696~701
DOI : 10.5916/jkosme.2015.39.7.696
Two-phase flow boiling experiments were conducted in 15 micro-channels with a depth of 0.2 mm, width of 0.45 mm, and length of 60 mm. FC-72 was used as the working fluid, and the mass fluxes ranged from 200 to
. Tests were performed over a heat flux range of
and vapor quality range of 0.1-0.9. The heat transfer coefficient sharply decreased at a lower heat flux and then was kept approximately constant as the heat flux is increased. Based on the measured heat transfer data, the flow pattern was simply classified into bubbly, slug, churn, and wavy/annular flows using the existing method. In addition, these classified results were compared to the transition criterion to wavy/annular regime. However, it was found that the existing transition criterion did not satisfactorily predict the transition criterion to annular regime for the present data.
Study on flow boiling heat transfer in two-phase micro-channels heat sink
Choi, Yong-Seok ; Lim, Tae-Woo ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 702~708
DOI : 10.5916/jkosme.2015.39.7.702
Two-phase flow boiling experiments were conducted using FC-72 as the working fluid. The micro-channels consisted of 15 channels with a depth of 0.2 mm, width of 0.45 mm, and length of 60 mm. Tests were performed over a mass flux range of
, heat flux range of
, and vapor quality range of 0.02-0.93. Based on the results of the experiment, the heat transfer mechanism by nucleate boiling was dominant at a lower vapor quality (x<0.2), whereas that in the region of a vapor quality greater than 0.2 was complexly influenced by nucleate boiling and forced convection boiling. The nucleate boiling and forced convection boiling could be expressed as functions of the boiling number and convection number, respectively. In addition, the heat transfer coefficient obtained by the experiment was compared with the heat transfer coefficient by the existing correlation.
Dynamics modeling and performance analysis for the underwater glider
Nam, Keon-Seok ; Bae, Jae-Hyeon ; Jeong, Sang-Ki ; Lee, Shin-Je ; Kim, Joon-Young ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 709~715
DOI : 10.5916/jkosme.2015.39.7.709
Underwater gliders do not typically have separate propellers for forward motion. They generate propulsive forces based on the difference between their buoyancy and gravity. They can control the volume from the buoyancy engine to adjust the propulsive force. In addition, the attitude of the underwater glider is controlled by a rubberless motion controller. The motion controller can change the mass center and moment of inertia of the inner moving mass. Owing to the change in these parameters, the attitude of the underwater glider is changed. In this study, we derive nonlinear, six degree of freedom (DOF) mathematical models for the motion controller and buoyancy engine. Using these equations, we perform dynamic simulations of the proposed underwater glider, and verify the suitability of the design and dynamic performances of the proposed underwater glider. We then perform the motion control simulation for the pitch and roll angle, and analyze the dynamic performance according to the pitch and roll angles.
A study on characteristics of combustion and exhaust emissions on bio-diesel fuel in marine diesel generator engine (Low load centering)
Cho, Sang-Gon ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 716~721
DOI : 10.5916/jkosme.2015.39.7.716
As the severity of environmental pollution has increased, restrictions on air pollution have been strengthened. Stringent regulations have been imposed, not only on marine diesel engines but also on automotive and industrial power plants. Thus, biofuels have been directly applied in practical engines and used in training ships for basic research. Even though a high biofuel percentage cannot be used in a training ship engine for safety reasons, because this type of engine is larger than those used in institutional laboratories, the results will provide important basic information that will allow organizations to determine the status of a large output. Biodiesel fuel was studied to determine how it would affect the combustion characteristics and exhaust emissions of a marine diesel generator engine. The main results can be summarized as follows. Because the physical and chemical compositions of biofuels are similar to those of diesel fuel, it was found that their practical use was possible in a training ship. The specific fuel consumption and NOx increased, whereas a tendency was found for carbon monoxide and soot to decrease. In addition, no significant pressure change difference was found between the diesel fuel and biofuels.
A study on an instantaneous angular velocity and torque fluctuation for marine diesel engine
Jung, Gyun-sik ; Lee, Ji-woong ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 722~728
DOI : 10.5916/jkosme.2015.39.7.722
The demand for shipboard energy management is expected to gradually increase based on ship energy efficiency management plans (SEEMPs), which have been in use since January 1, 2013. Therefore, the fuel consumption of the main engine, which occupies the greatest portion of the energy used, along with elements related to the engine power, should be strictly monitored. There are many different methods for indicating the engine power. However, this study performed an experiment to monitor the status of a ship`s engine power in real time using an encoder and a proximate switch, which are economical to purchase and easy to install. In the experiment, the angular velocity during one cycle of a two-stroke low-speed engine was measured, and the measured data were converted to the torque fluctuation. The angular velocity during an abnormal firing condition in the cylinder was also measured, and the torque fluctuation as a result of a misfire was considered. The results were compared with sea trial data to determine the reliability. In this study, the status of the engine power was determined using the torque fluctuation of the main engine in an operating ship.
Forging process design of cup shaped large forging using finite element method
Kang, Jong Hun ; Kim, Hyun Jun ; Lee, Hyoung Woo ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 729~734
DOI : 10.5916/jkosme.2015.39.7.729
This research developed a new deep-bore, cup-shape, large forging process by combining die forging and free forging methods. In the proposed process, a preform for cup-shape large forging is produced by die forging, and a product with a deep bore is finally manufactured using an open die forging method, which is generally produced using a backward extrusion process. Finite element analysis results showed a higher effective strain distribution with a smaller forging load using the proposed method compared to the backward extrusion method. The production of a prototype with good internal quality using a small press capacity verified the proposed method.
Preliminary design and performance analysis of a radial inflow turbine
Kim, Do-Yeop ; Kang, Ho-Keun ; Kim, You-Taek ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 735~743
DOI : 10.5916/jkosme.2015.39.7.735
The major component with a significant impact on the thermodynamic efficiency of the organic Rankine cycle is the turbine. Many difficulties occur in the turbine design of an organic Rankine cycle because the expansion process in an organic Rankine cycle is generally accompanied by a dramatic change in the working fluid properties. A precise preliminary design for a radial inflow turbine is hard to obtain using the classic method for selecting the loading and flow coefficients from the existing performance chart. Therefore, this study proposed a method to calculate the loading and flow coefficient based on the number of rotor vanes and thermodynamic design requirements. Preliminary design results using the proposed models were in fairly good agreement with the credible results using the commercial preliminary design software. Furthermore, a numerical analysis of the preliminary design results was carried out to verify the accuracy of the proposed preliminary design models, and most of the dependent variables, with the exception of the efficiency, were analyzed to meet the preliminary design conditions.
Development of unified communication for marine VoIP service
Kang, Nam-seon ; Yim, Geun-wan ; Lee, Seong-haeng ; Kim, Sang-yong ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 744~753
DOI : 10.5916/jkosme.2015.39.7.744
This paper presents the results of research on developing marine unified communications to provide VoIP service based on marine satellites. With the recent popularity of smart-phones and other mobile devices, the demand for Internet-based wired and wireless unified technology has been growing in marine environments, and increasing interest is being directed to VoIP products and service models with high price competitiveness and the ability to deliver a variety of services. In this regard, this research designed three instruments, developed their unit modules, and verified their performances. These three instruments included the following: (1) a marine VoIP module equipped with an analogue gateway that can be linked to the existing devices used in vessels, which is more than 80% smaller than that of a land system; (2) a text/voice/video engine for marine satellite communications that runs on technology that minimizes communication data usage, which is a core technology for a marine VoIP service; and (3) a unified communication service that can support multilateral cloud-based message conversations, telephone number-based call functions, and voice/video calling between a private space in a ship and shore.
Lifetime test of batteries for BLE modules for site identification of vessel`s crews and passengers (SIVCP)
Kwon, Hyuk-joo ; Kim, Min-Gwon ; Kim, Yoon-Sik ; Lee, Sung-Geun ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 754~759
DOI : 10.5916/jkosme.2015.39.7.754
Nowadays, short distance communication systems with low power energy (LPE) are developed for identification and monitoring of site identification of vessel crews and passengers (SIVCP). LPE communication modules, such as Bluetooth low energy (BLE) and Zigbee, are used for short distance communications with LPE. These modules enable 1:N communications and their popularity is growing since the modules can be mounted on movable objects, such as mobile devices and human body. When these modules are used, the important factor that affects their operation time and design are the capacity and size of battery. Therefore, they must be made as small as possible, and the battery should be selected to be slightly smaller than the module. In this study, we calculate the theoretical life of batteries used in SIVCP BLE modules using data sheet and discharge characteristic graph under the condition of a 1/250 transmission-ratio (TR). We thus calculate experimental life by measuring transmission current for the same TR, and low speed mode current for a 1/5000 TR and measure long-term experimental life using 1/25 TR for days. Through these experiments, we verify experimental methods for the prediction and extension of battery life that would enable us to select appropriate sizes of batteries based on vessel usage and passenger types. The selections of the module TR and battery size are important factors affecting the cost reduction of module design, the battery maintenance, and passenger convenience.
Protocol implementation for simultaneous signal continuation acquisition of industrial plant machine condition in wireless sensor networks
Lee, Hoo-Rock ; Chung, Kyung-Yul ; Rhyu, Keel-Soo ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 760~764
DOI : 10.5916/jkosme.2015.39.7.760
Wireless sensors, installed on machinery, and Time Division Multiple Access (TDMA) transmission make an ideal system for monitoring machine conditions in industrial plants because there is no need for electronic wiring. However, there has not yet been a successful field application of such a system, capable of continuously transmitting data at sample rates greater than 100 Hz. In this research, a TDMA network protocol capable of acquiring data from multiple sensors at sample rates greater than 100 Hz was developed for field application. The protocol was implemented in a single cluster-star topology network, and the system was evaluated based on the node number and transmission distance. Network simulator 2 (ns-2) was used for a real field simulation. Non-TDMA and TDMA protocol cases were compared using four sensor nodes. In the cases of 20-s and 40-s transmission times, there was little difference between the reception rates of the non-TDMA and TDMA systems. However, the difference was much greater when using a 60-s transmission time.
A study on characteristics of SOFC/GT system for the supply gas flow rates
Park, Sang-Kyun ; Lee, Joo-Hee ; Park, Geong-Dae ; Choi, Jae-Hyuk ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 765~772
DOI : 10.5916/jkosme.2015.39.7.765
In this research, the characteristics of SOFC/GT (Solid Oxide Fuel Cell/Gas Turbine) system temperature, stack power and system efficiency for flow rates of air, CH4 and water supplied to SOFC stack have been investigated. The temperature of the gas supplied to cathode and anode of SOFC stack in the SOFC/GT system are maintained by utilizing exhaust gas without the addition of external heat source. As a result, within the scope of this study, temperatures of gas supplied to cathode and anode of SOFC stack were maintained at 1000 (K) by utilizing the exhaust gas of the SOFC/GT system without the addition of external heat source. The system efficiency is increased with increase of air flow rate supplied to the stack and with decrease of
flow rate supplied to the stack. In addition, it can be found that the flow rate of the exhaust gas supplied to the turbine had a significant effect on the system efficiency. And the efficiencies of SOFC stack and SOFC/GT system depending upon various operating conditions of the SOFC/GT system is 51~57% and 57~73%, respectively.
Designation of fuel oil scrubber nozzle positioning using CFD analysis and PIV methods
Kim, In-Cheol ; Kim, Chang-Goo ; Park, Sung-Jin ; Cho, Dong-Yeon ; Lee, Young-Ho ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 773~778
DOI : 10.5916/jkosme.2015.39.7.773
Global warming has recently become an issue that has resulted in a growing trend to minimize environmental pollution. The International Maritime Organization (IMO) has shown that the majority of marine atmospheric pollution occurs as a result of emissions from marine vessels. Therefore, the environmental regulations and emission standards regarding marine vessels have gradually become stricter, and the research and development in this area is experiencing significant progress. In this study, a nozzle for a fuel oil scrubber was investigated using computational fluid dynamics (CFD) and particle imaging velocimetry (PIV). Experiments were conducted on scaled-down model of the scrubber to determine its performance, which was then compared with CFD results. Based on the experimental results, it was found that at a spray angle of
, the spray velocity at the nozzle was 20.1 m/s. From this comparison, a full-scale scrubber model was analyzed using CFD, and the effect of the positioning of the nozzle was studied.
Properties analysis of environment friendly calcareous deposit films electrodeposited at various temperature conditions in natural seawater
Lee, Chan-Sik ; Kang, Jun ; Lee, Myeong-Hoon ;
Journal of the Korean Society of Marine Engineering, volume 39, issue 7, 2015, Pages 779~785
DOI : 10.5916/jkosme.2015.39.7.779
Cathodic protection is recognized as the most cost-effective and technically appropriate corrosion prevention method for the submerged zone of offshore structures, ships, and deep-sea facilities. When cathodic protection is applied, the cathodic currents cause dissolved oxygen reduction, generating hydroxyl ions near the polarized surface that increase the interfacial pH and result in enhanced carbonate ion concentration and precipitation of an inorganic layer whose principal component is calcium carbonate. Depending on the potential, magnesium hydroxide can also precipitate. This mixed deposit is generally called "calcareous deposit." This layer functions as a barrier against the corrosive environment, leading to a decrease in current demand. Hence, the importance of calcareous deposits for the effective, efficient operation of marine cathodic protection systems is recognized by engineers and scientists concerned with cathodic protection in submerged marine environments. Calcareous deposit formation on a marine structure depends on the potential, current, pH, temperature, pressure, sea-water chemistry, flow, and time; deposit quality is significantly influenced by these factors. This study determines how calcareous deposits form in sea water, and assesses the interrelationship of formation conditions (such as the sea water temperature and surface condition of steel), deposited structure, and properties and the effectiveness of the cathodic protection.