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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 37, Issue 8 - Nov 2013
Volume 37, Issue 7 - Nov 2013
Volume 37, Issue 6 - Sep 2013
Volume 37, Issue 5 - Jul 2013
Volume 37, Issue 4 - May 2013
Volume 37, Issue 3 - May 2013
Volume 37, Issue 2 - Mar 2013
Volume 37, Issue 1 - Jan 2013
Selecting the target year
Velocity and temperature profiles of Al/water micro fluid in a circular tube with swirl
Chang, Tae-Hyun ; Lee, Kwon Soo ; Lee, Chang-Hoan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 677~684
DOI : 10.5916/jkosme.2013.37.7.677
A lot study of convection heat transfer on internal flow has been extensively conducted in the past decades using of high specific surface area, increasing heat transfer coefficient, swirling flow and improving the transport properties. This study concerned with the application of a tangential slot swirl generator for improving heat transfer in a horizontal circular copper tube. The Al particles(about
) was employed for this experimental work. 3D PIV(particle image velocimetry) technique has employed to measure velocity profiles of Al particles with and without swirl flow. The copper tube is heated uniformly by winding of a heating coil for heat transfer work, having a resistance of 9 ohm per meter. Experiments are performed in the Reynolds number range of 6,800~12,100 with swirl and without swirl using Al particles. Experimental data for comparison of Nusselt number is presented that of with swirl and without swirl along the test tube for the Reynolds numbers. The Nusselt number is improved with increasing of Reynolds numbers or swirl intensities along the test tube. The Nusselt number with swirl flow is about 60.0% to 119.0% higher than that obtained by the Dittus-Boelter equation.
A study on the use of pure palm oil (biodiesel-DO) as an alternative fuel on the fuel supply system of marine diesel engines
Uy, Dang Van ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 685~693
DOI : 10.5916/jkosme.2013.37.7.685
The biodiesel used as an alternative fuel for diesel engines is well- known, however the price of the bio-diesel is still higher than conventional diesel oil (DO) by 10% to 15% depending on a kind of bio-oil and a country producing the bio-diesel. One of idea to reduce the price of bio-diesel is to use the pure bio-oil as fuel for marine diesel engines, because to use the pure bio-oil as fuel without the esteritification process can reduce the price of bio-fuel. At present time, some experts in some countries who have been carrying out experiments on the use of pure bio-oil produced from rape seeds, sunflower seeds... as fuel for marine diesel engines have achieved important results. In recent years, at Vietnam Maritime University we also have been using the pure palm oil and its blended fuel (Palm oil and DO) as fuel for marine diesel engines in laboratory and on board of ships. The blended fuel is a mixing fuel of the pure palm oil and diesel oil with content of pure palm oil by 5%, 10%, 15%, 20% and 35%. In this paper, we would like to present some results from our experiments to investigate the impacts of using the palm oil and its blended fuel on the important technical features of the fuel supply system of marine diesel engines such as the fuel supply amount for one cycle, fuel supplying pressure, ignition delay time and so on. The results from the research will be good fundamental parameters to support proper operation of marine diesel engines using bio-oil and blended fuels as alternative fuel in near future.
Design of exhaust manifold for pulse converters considering fatigue strength due to vibration
Cho, Kyung-Sang ; Son, Kyung-Bin ; Kim, Ue-Kan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 694~700
DOI : 10.5916/jkosme.2013.37.7.694
The design of the exhaust manifold for the pulse converters of a 4 strokes high power medium-speed diesel engine is presented in terms of fatigue analysis. The said system undergoes thermal expansion due to high temperature of exhaust gas and is exposed to intrinsic vibration of the internal combustion engine. Moreover, the exhaust pulse generates pressure pulsating along the runner inside manifold. Under such circumstances, the design and construction of exhaust manifold must be carried out in a way to prevent early failure due to fracture. To validate the design concept, a test rig was developed to simulate the combination of thermal and vibrational movements, simultaneously. Experimental results showed that a certain sense of reliability can be achieved by considering a field factor obtained from the results of engine bench tests.
A study on performance and smoke emission characteristics by blending low purity methanol in a DI diesel engine with the EGR rates of 0, 12.8 and 16.5%
Syaiful, Syaiful ; Bae, Myung-Whan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 701~710
DOI : 10.5916/jkosme.2013.37.7.701
The purpose of this study is to investigate experimentally the effect of low purity methanol (LPM) on performance and smoke emission characteristics by using a four-cycle, four-cylinder, water-cooled, direct injection diesel engine with EGR system. The experiments are performed by the change of engine load in the engine load ranges of 25 to 100% with an interval of 25% under the constant engine speed of 2000 rpm. The LPM in the fuel blends contained 24.88% water by volume. The blended fuel ratios of diesel oil to LPM are maintained at 100/0, 95/5, 90/10 and 85/15% on the volume basis. In this paper, EGR rates are varied in three conditions of 0, 12.8 and 16.5%. The result shows that the brake power of a blended fuel with 15% LPM is reduced more 11.1% than that of the neat diesel oil at the full load with the EGR rate of 16.5%. At this condition, also, the brake specific fuel consumption (BSFC) is increased by 3.2%, the exhaust gas temperature is decreased by 10.7%, the smoke opacity is decreased by 18.7% and the brake thermal efficiency is increased by 7.3%. The sharp reduction of smoke opacity for a blended fuel with the LPM content of 15% at the full load without EGR system is observed by 68.4% compared with that of the neat diesel oil due to the high oxygen content of LPM.
Microstructural behavior on weld fusion zone of Al-Ti and Ti-Al dissimilar lap welding using single-mode fiber laser
Lee, Su-Jin ; Kawahito, Yousuke ; Kim, Jong-Do ; Katayama, Seiji ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 711~717
DOI : 10.5916/jkosme.2013.37.7.711
Titanium (Ti) metal and its alloys are desirable materials for ship hulls and other structures because of their high strength, light weight and corrosion-resistance. And light weight and corrosion-resistant aluminum (Al) is the ideal metal for shipbuilding. The joining of Ti and Al dissimilar metals is one of the effective measures to reduce weight of the structures or to save rare metals. Ti and Al have great differences in materials properties, and intermetallic compounds such as Ti3Al, TiAl, TiAl3 are easily formed at the contacting surface between Ti and Al. Thus, welding or joining of Ti and Al is considered to be extremely difficult. However, it was clarified that ultra-high speed welding could suppress the formation of intermetallic compounds in the previous study. Results of tensile shear strength increases with an increase in the welding speed, and therefore extremely high welding speed (50m/min in this study) is good to dissimilar weldability for Ti and Al. In this study, therefore, full penetration dissimilar lap welding of Ti (upper) - Al (lower) and Al (upper) - Ti (lower) with single-mode fiber laser was tried at ultra-high welding speed, and the microstructure of the interface zones in the dissimilar Al and Ti weld beads was investigated.
Study of Specific energy of mechanical destruction of ice for calculation of ice load on ships and offshore structures
Tsuprik, V.G. ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 718~728
DOI : 10.5916/jkosme.2013.37.7.718
Analysis of scenarios of transportation oil and gas which produced in the Arctic and others cold seas shows that in the near-term there will be a significant increase of tonnage of tankers for oil and gas and number of ships which should be exploited in difficult ice conditions. For the construction of ice-resistant structures (IRS) intended for production of oil and gas and transportation of these products at ice-class vessels, calculating the load from ice to board the ship and on surface of supports of the platforms are the actuality and urgent tasks. These tasks have one basis in both cases: at beginning of the contact occurs fracture of edge of ice, then occurs compressing of rubble shattered of ice, then they extruding from contact area, after this next layer of ice begin to destruct. At calculating the strength of plating and elements construct of vessels, icebreakers and ice-resistant platforms the specific energy of mechanical destruction ice
is an important parameter. For the whole period of study of physical and mechanical characteristics of sea ice have been not many experimental studies various researchers to obtain numerical values of this energetic characteristic of the strength of ice by a method called Ball Drop Test. This study shows that the destruction of the ice from dynamic loading in zone of contact occurs in several cycles, and the ice destructed with a minimum numerical values of
. The author offer this energy characteristic to take as a base value for the calculation of ice load on ships and offshore structures.
Turbulent properties in a mixed statistically stationary flow
Baek, Tae-Sil ; Doh, Deog-Hee ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 729~736
DOI : 10.5916/jkosme.2013.37.7.729
The turbulent properties in a mixed statistically stationary flow were investigated experimentally by a pseudo stereoscopic PIV. In order to validate the experimental results, the profiles of the turbulent kinetic energy were evaluated with the flow features. A mechanical agitator having 6 blades was installed at the bottom of the mixing tank (D=60cm, H=60cm). The agitator was rotated with 80rpm clockwise and counter-clockwise. For the measurements, three cameras were used and all were synchronized. The images captured by one of the three cameras was used for the measurement of rotational speed, and the images captured by the other two cameras were used to measure three dimensional components of velocity vectors. All vectors captured at the same rotational angle were phase averaged to construct three-dimensional vector fields to reconstruct the spatial distribution of the flow properties. It was seen that the jet scrolling along the tank was the main source of mixing.
An obstacle avoidance system of an unmanned aerial vehicle using a laser range finder
Kim, Hyun ; Miwa, Masafumi ; Shim, Joonhwan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 737~742
DOI : 10.5916/jkosme.2013.37.7.737
Recently, unmanned aircrafts for safe measurement in hazardous locations have been developed. In a method of operation of unmanned aircraft vehicles (UAV), there are two methods of manual control and automatic control. Small UAVs are used for low altitude surveillance flights where unknown obstacles can be encountered. Obstacle avoidance is one of the most challenging tasks which the UAV has to perform with high level of accuracy. In this study, we used a laser range finder as an obstacle detector in automatic navigation of unmanned aircraft to patrol the destination automatically. We proposed a system to avoid obstacles automatically by measuring the angle and distance of the obstacle using the laser range finder.
Optimal iterative learning control with model uncertainty
Le, Dang Khanh ; Nam, Taek-Kun ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 743~751
DOI : 10.5916/jkosme.2013.37.7.743
In this paper, an approach to deal with model uncertainty using norm-optimal iterative learning control (ILC) is mentioned. Model uncertainty generally degrades the convergence and performance of conventional learning algorithms. To deal with model uncertainty, a worst-case norm-optimal ILC is introduced. The problem is then reformulated as a convex minimization problem, which can be solved efficiently to generate the control signal. The paper also investigates the relationship between the proposed approach and conventional norm-optimal ILC; where it is found that the suggested design method is equivalent to conventional norm-optimal ILC with trial-varying parameters. Finally, simulation results of the presented technique are given.
Design of an extremely miniaturized planar ring hybrid
Kang, In Ho ; Sun, Shu Zhong ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 752~759
DOI : 10.5916/jkosme.2013.37.7.752
This paper presents a method for analyzing and designing an extremely miniaturized planar ring hybrid, using the combination of parallel and diagonally shorted coupled lines. In contrast to conventional miniaturized coupled line filters, it is proven that the required electrical length of transmission line can be largely reduced to even a few degrees, not only effectively suppressing the spurious passband but also approximately maintaining the same characteristic around the stable center frequency. A ring hybrid filter at center frequency of 1 GHz was fabricated on the FR4 epoxy glass cloth copper-clad plat (CCL) PCB substrate. The insertion loss of a ring hybrid filter with the die area of
is -4.68 dB. Simulated results are well agreed with the measurements.
A comparison of grammatical error detection techniques for an automated english scoring system
Lee, Songwook ; Lee, Kong Joo ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 760~770
DOI : 10.5916/jkosme.2013.37.7.760
Detecting grammatical errors from a text is a long-history application. In this paper, we compare the performance of two grammatical error detection techniques, which are implemented as a sub-module of an automated English scoring system. One is to use a full syntactic parser, which has not only grammatical rules but also extra-grammatical rules in order to detect syntactic errors while paring. The other one is to use a finite state machine which can identify an error covering a small range of an input. In order to compare the two approaches, grammatical errors are divided into three parts; the first one is grammatical error that can be handled by both approaches, and the second one is errors that can be handled by only a full parser, and the last one is errors that can be done only in a finite state machine. By doing this, we can figure out the strength and the weakness of each approach. The evaluation results show that a full parsing approach can detect more errors than a finite state machine can, while the accuracy of the former is lower than that of the latter. We can conclude that a full parser is suitable for detecting grammatical errors with a long distance dependency, whereas a finite state machine works well on sentences with multiple grammatical errors.
Shore power to ships and offshore plants with flywheel energy storage system
Jeong, Hyun-Woo ; Ha, Yun-Su ; Kim, Yoon-Sik ; Kim, Chul-Ho ; Yoon, Kyoung-Kuk ; Seo, Dong-Hoan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 771~777
DOI : 10.5916/jkosme.2013.37.7.771
This paper describes a study of major shipyard's electrical network and simulation of applying flywheel energy storage system on the electrical network at shipyard for shore-power to ships and offshore plants in order to save fuel consumption on engines, mitigate voltage sags, and prevent blackout due to pulsed load and fault, resulting in reduction of air emission into atmosphere. The proposed energy recycling method with FESS (Flywheel Energy Storage System) can be applied for electrical power system design of heavy cranes at shipyards.
Liquid level measurement system using capacitive sensor and optical sensor
Shim, Joonhwan ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 778~783
DOI : 10.5916/jkosme.2013.37.7.778
Measurement of liquid level in storage and processing vessels, tanks, wells, reservoirs and hoppers is commonly needed. The several different ways to measure the liquid level of oil or water tank have been provided such as an electrostatic capacity, a supersonic waves and an optical science etc. In the study, we have constructed the stable and efficient measurement system to measure the level of liquid at real-time and to get accurate measurement of the maximum and minimum level of the tank. For this purpose, we suggest double sensing methods by adopting both capacitive and optical sensing. The experimental results, presented in this paper, illustrate the effectiveness of the proposed method under different sensing methods.
Layout design optimization of pipe system in ship engine room for space efficiency
Lee, Dong-Myung ; Kim, Soo-Young ; Moon, Byung-Young ; Kang, Gyung-Ju ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 784~791
DOI : 10.5916/jkosme.2013.37.7.784
Recent advanced IT made layout design fast and accurate by using algorithms. Layout design should be determined by considering the position of equipment with satisfying various space constraints and its component works with optimum performance. Especially, engine room layout design is performed with mother ship data, theoretical optimal solution, design requirements and several design constraints in initial design stage. Piping design is affected by position of equipment seriously. Piping design depends on experience of designer. And also piping designer should consider correlation of equipment and efficiency of space. In this study, space evaluation method has been used to evaluate efficiency of space. And also this study suggested object function for optimal piping route, Average Reservation Index(ARI), Estimated Piping Productivity(EPP) and with modified space evaluation method. In this study, optimum pipe routing system has been developed to reflect automated piping route with space efficiency and experience of piping designer. Engine room is applied to the design of the piping in order to confirm validity of the developed system.
A study on measurement of particulate matter, nitrogen oxide and carbon oxide from main engine in training ship
Choi, Jung-Sik ; Choi, Jae-Hyuk ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 792~798
DOI : 10.5916/jkosme.2013.37.7.792
In this study, we have carried out measurement for exhaust emissions such as particulate matter (PM), nitrogen oxide and carbon oxide from main engines installed on the training ships, HANBADA and HANNARA, of Korea Maritime University. In particular, we considered the two conditions; at arrivals/departures and at constant speed of about 160 rpm. The result showed that the concentration of PM at the ship arrival was 2.41mg/m3. On the other hand, when the ship is on the navigation condition, the concentration of PM was 1.34 mg/m3. The concentrations of nitrogen oxide and carbon oxide were measured in the range of 1,120~1,600 ppm and 320~1,450 ppm at the arrival and departure at the port. Under constant speed condition, the concentrations of nitrogen oxide and carbon oxide were 913~1,470 ppm and 73~460 ppm, respectively. Generally, the concentrations of exhaust emissions under the arrivals and departures were higher than that of constant speed condition. These results imply that the ship operation skill to prevent a sudden load change of main engine is needed during the arrival or departure. In addition, it means that the difference of exhaust emissions according to navigation conditions has to be considered when the reduction technologies of air pollutants from ships are developed.
Measurement of local wind and solar radiation for a hybrid power generation system design, Busan, Korea
Hwang, Kwang-Il ;
Journal of the Korean Society of Marine Engineering, volume 37, issue 7, 2013, Pages 799~806
DOI : 10.5916/jkosme.2013.37.7.799
As a first step to develop the hybrid power generation system, on this study, the time-variable resources of wind and solar radiation of Yeongdo, Busan, Korea had been measured during June and July 2013. And the quantity of generated wind power and solar photovoltaic had also been measured during the same period. It is found out that the wind mainly flew from southwest at the average speed of 2 m/s during 2 months. And it is clear that, because of the low wind velocity, the wind quality to generate the power seems not enough at this area. Meanwhile solar radiation was measured every daytime (6:00~19:00) and the peak solar radiation occurred around 12:00~14:00. And it is clear that the time-based variations of quantity of generated power were proportional to the variations of these resources, respectively. As a proposal, these 2 natural energies can be combined as resources of a hybrid system, because these 2 patterns are not overlapped so much on time base.