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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 30, Issue 8 - Nov 2006
Volume 30, Issue 7 - Nov 2006
Volume 30, Issue 6 - Sep 2006
Volume 30, Issue 5 - Jul 2006
Volume 30, Issue 4 - May 2006
Volume 30, Issue 3 - May 2006
Volume 30, Issue 2 - Mar 2006
Volume 30, Issue 1 - Jan 2006
Selecting the target year
Review of Shock Test Standards for Unifying Specification
Kim Young-Ju ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 11~21
An Experimental Study on Transient Heat Transfer Characteristics of Gas Turbine Cooled Vane by Using Liquid Crystal Thermography
Suh Nam-Kyu ; Chang Tae-Hyun ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 22~29
Gas turbine engine among Principal internal combustion engines has been mainly applied as an aero and industrial Power plant. In order to increase its thermal efficiency. it has been raised their pressure ratio of compressor and the turbine inlet temperature. To operate above the limit temperature of turbine material, turbine nozzle vanes should be cooled. For this the cooling air is bled from the compressor section of 9as turbine. Meanwhile, to keep high thermal efficiency of 9as turbine, turbine vanes are to be cooled by using small cooling air Therefore, the complex cooling passages are requested to be designed and evaluated the effectiveness of vane cooling by measuring turbine vane temperature. But it is very difficult or impossible for us to measure local turbine temperatures at actual temperature When local heat transfer coefficients are known these can be calculated, therefore this study has been investigated on obtaining these coefficients of turbine vane at room temperature using TLC.
Weldability of Al 7075 Alloy according to different tools and welding conditions by F.S.W
Jang Seok-Ki ; Jeon Jeong-Il ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 30~41
This paper shows mechanical Properties and behaviors of macrostructures for specimens welded by F.S.W according to welding conditions and tool dimensions with
aluminum 7075-T651 alloy plate. It apparently results in defect-free weld zone in case transition speed was changed to 15mm/min 61mm/min and 124mm/min under conditions of tool rotation speed such as 800rpm. 1250rpm and 1600rpm respectively with tool's Pin diameter 40mm and 60mm. The optimum mechanical property, ultimate stress,
is obtained at the condition of 124mm/min of travel speed with 800rpm of tool rotation speed using full screw type pin. shoulder dia.
and pin length 6mm. The full-screw type and the half-screw type pin shows the similar behaviors of weldability. It is found that the size of nugget is depended on tool transition speed and tool dimension by macrostructures of the cross section of weld zone
A Chancteristic of Thermal Efficiency in Order to High Expansion Realization with a Retard of Intake Valve Closing Time in the Low Speed Diesel Engine
Jang Tae-Ik ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 42~49
In this research. the diesel cycle was thermodynamically interpreted to evaluate the possibility of high efficiency by converting diesel engines to the high expansion diesel cycle, and general cycle features were analyzed after comparing these two cycles. Based on these analyses. an experimental single cylinder a long stroke with high expansion-diesel engine. of which S/B ratio was more than 3, was manufactured. After evaluating the base engine through basic experiments, a diesel engine was converted into the high expansion diesel engine by establish VCR device and VVT system Accordingly, the high expansion diesel cycle can be implemented when the quantity of intake air is compensated by supercharge and the effective compression ratio is maintained at its initial level through the reduction of the clearance volume. In this case, heat efficiency increased by
at the same expansion-compression ratio when the apparent compression ratio was 20 and the fuel cut off ratio was 2. As explained above, when the atkinson cycle was used for diesel cycle, heat efficiency was improved. In order to realize high expansion through retarding the intake value closing time, the engine needs to be equipped with variable valve timing equipment, variable compression ratio equipment and supercharged pressure equipment. Then a high expansion diesel cycle engine is realized.
A Study on the Reaching Time of Setting Temperature with Ventilation Air
Kang Tae-Wook ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 50~57
This study describes to analyze the cooling load characteristics for a room air conditioner as a function of supply ventilation air when an air conditioner is running An experimental apparatus consists of a test room, a room air conditioner, a humidifier, an electrical heater a supply fan and a controller The reaching time to the inside setting temperature of the room air conditioner with is evaluated theoretically and experimentally in a conditioned space cooling loads such as supply ventilation air, lighting, occupancy and infiltration. In the conditions of cooling loads for the supply ventilation air of 9.5 L/s(0.98 ACH). lights. one Person, and infiltration, the reaching time to the inside setting temperature (
dry-bulb) increases up to
more than for no supply ventilation air condition. Theoretical modelling of the reaching time shows good agreement with experimental results.
Cam Profile Design of a Fuel Pump Using Dynamic Analysis
Kim Bong-Ho ; Lee Boo-Youn ; Kim Won-Jin ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 58~64
This work focuses on reducing the noise and vibration levels of an LPi fuel pump, which are generated from the dynamic motions of pump elements and non-uniform flow of fuel. The noise and vibration levels increase as the revolution speed of the cam goes up. The fuel pump consists of five cavity cells, plungers and diaphragms, which are driven by the cam. The optimal design of the cam profile is performed to decrease the accelerations of moving Parts and to obtain a smooth hydraulic force through a dynamic analysis of a cam-plunger mechanism. The cam-Plunger with a cavity is modeled as a 2 degrees of freedom system having non-linear contacts, the cam profile being represented in terms of Fourier series in order to determine the optimal shape of the cam. From the optimized cam Profile, the acceleration of the diaphragm is reduced in
, the hydraulic force becoming smoother in case that the hydraulic force is rapidly dropped.
Pressure Loss and Heat Transfer Characteristics of Heat Exchanger Using Static Mixing Technology
Park Sang-Kyoo ; Yang Hei-Cheon ; Jeon Jun-Chul ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 65~72
Heat transfer augmentation in heat exchangers has received much attention in recent years, mainly due to energy efficiency and environmental considerations. Many active and Passive techniques are currently being employed in heat exchangers, with some inserts providing a cost-effective and efficient means of augmenting heat transfer. The Purpose of this paper is to determine the pressure loss and heat transfer characteristics of a heat exchanger using static mixing technology. Experimental measurements were taken on two set-ups: a single tube heat exchanger and a shell-tube heat exchanger with two static mixing inserts. It was concluded that the static mixing inserts resulted in an increase in the pressure loss and heat transfer characteristics as can be expected.
Effect of the Vibration Modes on the Radiation Sound for Plate
Kim Chang-Nam ; Byun Young-Su ; Kim Jeong-Man ; Kim Ue-Kan ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 73~80
In order to compute the radiated sound from a vibrating structure, the Rayleigh's integral equation has to be derived from the Helmholtz equation using Green's function. Generally, the surface velocity in the Rayleigh's integral equation uses the root mean square(rms) velocity. The calculation value is too large, because it's not considered cancelation. On the other hand. using the complex velocity, the sound pressure is calculated too small, because it considers that sound is perfectly canceled out. Therefore, this thesis proposes a correction factor(CF) which considers vibration modes and the method by which to calculate the radiating sound pressure. The theoretical results are compared with the experimental values, and the proposed method can be verified with confluence.
Development of Marine Emission Control System on NOx and SOx through Seawater Electrolysis
Kim Houng-Soo ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 81~87
In marine air pollution control, SCR (Selective Catalytic Reduction) is reconized as the most effect method to control NOx, but on the other hand. seawater scrubber applying the basic characteristic that is naturally alkaline (pH typically around 8.1) is viewed as an economical SOx removal system at present. Especially, seawater scrubber would not be necessary to follow any of the various land based flue gas desulfurization methods. i.e. wet, dry or alkali scrubbing. However, these methods are not readily adaptable to marine conditions due to the quantifies of consumables required i.e. lime or limestone, the means of operation and the commercial availability. This research is undertaken to develop a new method as the main target of eliminating all exhaust emissions, particularly vessel, because of easy access to seawater and apt to apply a wet scrubber system. First, using the acidic seawater by seawater electrolysis, nitric monoxide(NO) is adequately oxidized to nitric dioxide
by ClOx-in the acidic seawater, the electrolyzed alkaline seawater by electrolysis which contains mainly NaOH together with alkali metal ions
, is used as the absorption medium of NOx, the SOx are absorbed by relatively high solubility compared to other components of exhaust pollutants. The results found that the NOx and SOx removals could be achieved nearly Perfect.
Combustion Characteristics of Heavy Fuel Oil-water Emulsion
Kim Houng-Soo ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 88~92
This study is intended to check the flame temperature to raise in burning grade C heavy fuel oil and emulsion fuel oil in a boiler and to measure the concentration of Dry Shoot(DS) and Soluble Organic Fraction(SOF) after collecting the Particulate Matters (PM). The flames temperature in boiler was measured by burning grade C heavy oil and oil-water emulsion (C heavy oil
of water) Combustion characteristics of two fuels was also compared by trapping particulate matters (PM) in exhaust gas and measuring the generated quantities of DS and SOF in fuel gas.
Air Pollution Protection onboard by Seawater and Electrolyte
An Suk-Heon ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 93~101
This research makes a new attempt to apply the activated seawater by electrolysis in the development of two-stage wet scrubber system to control the exhaust gas of large marine diesel engines. First, with using only seawater that is naturally alkaline (pH typically around 8.1). the
are absorbed by relatively high solubility compared to other components of exhaust pollutants, and PM (Particulate Matter) is removed through direct contact with sprayed seawater droplets. Besides, the electrolyzed alkaline seawater by electrolysis, which contains mainly NaOH together with alkali metal ions
, is used as the absorption medium of NOx and
. Especially, to increase NOx absorption rate into the alkaline seawater. nitric oxide (NO) is adequately oxidized to nitrogen dioxide
in the acidic seawater, which means both volume fractions are adjusted to identical proportion. The results found that the strong acidic seawater was a valid oxidizer from NO to
and the strong alkaline seawater was effective in
absorption In the scrubber test, the SOx reduction of nearly
could be achieved and also led to a sufficientPM reduction. Hence, the author believes that applying seawater and its electrolyte would bring the marine air pollution control system to an economical measure. Additionally it is well known that NOx and SOx concentration has a considerable influence on the
emission of green house gas. Although the
concentration exhausted from diesel engines is not as high, the green house gas effect is around 300 times greater than an equivalent volume of
. Therefore, we investigated the
removal efficiency with using the electrolyzed seawater too. Finally this research would also plan to treat the effluent by applying electro-dialysis and electro-flotation technique s in the future.
Pool Combustion of Iso-Propanol Fuel including IPA and PCBs in different Type Vessels
An Suk-Heon ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 102~108
On the refutation demanded for a control of various toxic substances. PCBs(poly chlorinated biphenyl) has a fatal poisonous matter in the ecosystem and the environmental pollution as it Is a kind of stable chemical substance. Especially, the gross Product of PCBs is estimated at about one million tonnage all over the world. However it is kept on storing in untreated state, then has a deterioration by the Prolonged storage and a risk of overflowing. Therefore, this research examined the fundamental characteristics of combustion and emission for the target of using the IPA (iso-propyl alcohol) solution as a part of PCBs control. IPA was filled to three kinds of Vessel, i.e. Vessel I, II, and III, and then was investigated as follows combustion shape, flame temperature. mass burning velocity, and PM(Particulate matter). A radial thermometer and a C-A thermocouple measured the flame temperature, and the optical extinction method by using He-Ne laser and the filter weight method used in the PM measurement. As a result, with an increasing of L/S ratio, the flame length become shorter and the burning velocity is more rapid, but the particulate matters is higher. It is supposed that the air flow rate is high on Vessel. and then the combustion is Promoted in the surface area of the upstream zone. The future works plan to investigate the characteristics with an using of the mixing of IPA and PCBs
Hull Form Development of Sailing Yacht with Sails and Appendages
Ahn Hae-Seong ; Yoo Jae-Hoon ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 109~115
An overview of 30 feet sailing yacht design is presented. with an emphasis on the factors contributing to start-up Popularization . After prescribing the configurations of the purposed yacht. the design of the hull form with a rudder and a keel, are schematically described. Also the determinations of the dimensions of the sail and rig are performed
Performance Predictions for Sailing Yacht by Towing Tests and VPP Calculation
Yoo Jae-Hoon ; Ahn Hae-Seong ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 116~124
A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree. which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity Prediction program (VPP) The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.
Evaluation of Yacht Sails Performance by CFD and Experiments
Yoo Jae-Hoon ; Ahn Hae-Seong ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 125~133
It is important to understand flow characteristics and performances of sails for both sailors and designers who want to have efficient thrust of yacht In this Paper the viscous flows around sail-like rigid wings, which are similar to main and jib sails of a 30 feet sloop, are calculated using a CFD tool. Lift, drag and thrust forces are estimated for various conditions of gap distance between the two sails and the center of effort of the sail system is obtained. Wind tunnel experiments are also carried out to measure aerodynamic forces acting on the sails system and to validate the computation. It is found that the combination of two sails produces the lift force larger than the sum of that produced separately by each sail and the gap distance between the two sails is an important factor to determine total lift and thrust.
Consumption Energy Analysis of Quadruped Walking Robot
Eom Han-Sung ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 134~139
A energy efficiency of quadruped walking robot has been studied mathematical modeling, dynamic analysis or simulation by consumption energy per period. In this paper, We used the quadruped walking robot Titan-VIII in order to carry out this experiment. The total moving length is about 2[m] , the stride length is 0.1, 0.2. 0.3, and walking period is changed by 1.0, 1.5, 2.0, 2.5 3.0[sec] Per each stride length. So consumption energy of 15 cases are measured. As a result of this experiment we obtained the best energy efficiency when stride length was 0.3[m], and Period was 1.5[sec].
Numerical Simulation on Characteristics of Laminar Diffusion Flame Placed Near Wall in Microgravity Environment
Choi Jae-Hyuk ; Fujita Osamu ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 140~149
Characteristics of a laminar diffusion flame placed near wall in microgravity have been numerically analyzed in a two-dimension. The fuel for the flame is
. The flame is initiated by imposing a high temperature ignition source. The flow field, temperature field, and flame shape in microgravity diffusion flame are detailed. Especially, effects of surrounding air velocity and fuel injection velocity on the microgravity diffusion flame have been discussed accounting for standoff distance. And, the effect of curvature rate has been also studied. The results showed that velocities in a diffusion flame were overshoot because of volumetric expansion and distribution of temperature showed regularity by free-buoyancy This means that the diffusion flame in microgravity is very stable, while the flame in normal gravity is not regular and unstable due to buoyancy. Standoff distance decreases with increase in surrounding air velocity and with decrease in fuel injection velocity. With increasing curvature rate, the position of reaction rate moves away the wall.
A Study on the Unsteady Fluid Forces Acting on a Heaving Foil
Yang Chang-Jo ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 150~156
A Flapping foil Produces an effective angle of attack, resulting in a normal force vector with thrust and lift components, and it can be expected to be a new highly effective propulsion system. A heaving foil model was made and it was operated within a circulating water channel at low Reynolds numbers. The unsteady thrust and lift acting on the heaving foil were measured simultaneously using a 6-axis force sensor based on force and moment detectors. We have been examined various conditions such as heaving frequency and amplitude in NACA 0010 Profile. The results showed that thrust coefficient and efficiency increased with reduced frequency and amplitude. We also Presented the experimental results on the unsteady fluid forces of a heaving foil at various Parameters.
Investigation on optimum protection potential of high-strength Al alloy(5456-H116) for application in ships
Kim Sung-Jong ; Ko Jae-Yong ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 157~168
Recently, interest in using Al alloys in ship construction instead of fiber-reinforced plastic (FRP) has increased because of the advantages of A) alloy ships over FRP ships, including high speed, increased load capacity. and ease of recycling. This paper investigated the mechanical and electrochemical properties of Al alloys in a slow strain rate test under various potential conditions. These results will provide reference data for ship design by determining the optimum protection potential regarding hydrogen embrittlement and stress corrosion cracking. In general, Al and Al alloys do not corrode on formation of a film that has resistance to corrosion in neutral solutions. In seawater, however,
ions lead to the formation and destruction of a Passive film. In a potentiostatic experiment. the current density after 1200 sec in the Potential range of
was low. This low current density indicates the protection potential range. Elongation at an applied potential of 0 V was high in this SSRT. However, corrosion protection under these conditions is impossible because the mechanical properties are worse owing to decreased strength resulting from the active dissolution reaction in parallel parts of the specimen. A film composed of
confers corrosion resistance. However, at potentials below -1.6 V forms non-uniform electrodeposition coating, since there is too little time to form a coating. Therefore, we concluded that the mechanical properties are poor because the effect of hydrogen gas generation exceeds that of electrodeposition. Comparison of the maximum tensile strength, elongation, and time to fracture indicated that the optimum protection potential range was from -1.45 to -0.9 V (SSCE).
The Parameter Compensation Technique of Induction Motor by Neural Network
Kim Jong-Su ; Oh Sae-Gin ; Kim Sung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 169~175
This paper describes how an Artificial Neural Network(ANN) can be employed to improve a speed estimation in a vector controlled induction motor drive. The system uses the ANN to estimate changes in the motor resistance, which enable the sensorless speed control method to work more accurately. Flux Observer is used for speed estimation in this system. Obviously the accuracy of the speed control of motor is dependent upon how well the parameters of the induction machine are known. These parameters vary with the operating conditions of the motor; both stator resistance(Rs) and rotor resistance(Rr) change with temperature, while the stator leakage inductance varies with load. This paper proposes a parameter compensation technique using artificial neural network for accurate speed estimation of induction motor and simulation results confirm the validity of the proposed scheme.
A Study on Fabrication of
Thin Films and Their OPtical Properties
Lee Hong-Chan ;
Journal of the Korean Society of Marine Engineering, volume 30, issue 1, 2006, Pages 176~181
In this study, systematical investigations were carried out on crystal qualifies and optical properties of
(x=0.002-0.04) thin films frown by molecular beam epitaxy (MBE). The crystal qualifies and optical properties have been investigated by X-ray diffraction (XRD) and Photoluminescence (PL) measurements, respectively. From the XRD measurements, the crystallographic characteristics showed mediocre crystal quality with increasing the Te composition. From the PL measurements, emission in the visible spectrum region from blue to green was obtained by varying the Te content of the ZnSe:Te epilayers. The efficient blue and green emission were attributed to the recombination of excitons trapped at isoelectronic isolated a single Te atom and
clusters. respectively. The blue emission become dominant in Te tightly doped
epilayers with increasing temperature. For the Te heavily doping condition
, the dominant green emission could be observed at around 160K.