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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 32, Issue 8 - Nov 2008
Volume 32, Issue 7 - Nov 2008
Volume 32, Issue 6 - Sep 2008
Volume 32, Issue 5 - Jul 2008
Volume 32, Issue 4 - May 2008
Volume 32, Issue 3 - May 2008
Volume 32, Issue 2 - Mar 2008
Volume 32, Issue 1 - Jan 2008
Selecting the target year
Essential Techniques and Rules in Cruise Ship
Kang, Ho-Keun ; Kim, Houng-Soo ; Ha, Tae-Bum ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 816~826
DOI : 10.5916/jkosme.2008.32.6.816
Basic Configuration Design and Performance Analysis of a 100kW Wind Turbine Blade using Blade Element Momentum Theory
Kim, Bum-Suk ; Kim, Mann-Eung ; Lee, Young-Ho ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 827~833
DOI : 10.5916/jkosme.2008.32.6.827
In this study, mathematical expressions based upon the conventional BEMT(blade element momentum theory) was applied to basic 100kW wind turbine blade configuration design. Power coefficient and related flow parameters, such as Prandtl's tip loss coefficient, tangential and axial flow induction factors of the wind turbine were analyzed systematically. X-FOIL was used to acquire lift and drag coefficients of the 2-D airfoils and Viterna-Corrigan formula was used o interpolate he aerodynamic characteristics in post-stall region. Also, aerodynamic characteristics, measured in a wind tunnel to calculate he power coefficient was applied. The comparative results such as axial and tangential flow factors, power coefficients were presented in this study. Power coefficient, calculated by in-house code was compared with the GH-Bladed result. The difference of the aerodynamic characteristics caused the difference of the performance characteristics as variation as TSR.
The Influence of the Small Circular Hole Defect on the Fatigue Crack Propagation Behavior in Aluminum Alloys
Kim, G.H. ; Lee, H.Y. ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 834~840
DOI : 10.5916/jkosme.2008.32.6.834
We carried out fatigue testing with materials of aluminum alloyC7075-T6, 2024-T4) by rotary bending fatigue tester. We investigated fatigue limit, fatigue crack initiation, fatigue crack propagation behavior and possibility of fatigue life prediction to the different small circular hole defect. The summarized result are as follows; Fatigue limit of the smooth specimens were related tensile strength and yield strength. In case of more large applied stress and small circular hole crack defect, the fatigue crack was grown rapidly. The fatigue crack propagation behavior proceed at according to inclusion. Fatigue crack propagation ratio appeared instability and retardation phenomenon in the first half of fatigue life but appeared stability and replied in the latter half. On other hand, this experimental data of the materials are appeared fatigue life predictability.
A Study on the Structural Analysis of the Supporting System for LNG Vehicle Fuel Tank
Yun, Sang-Kook ; Kim, Dong-Hyuk ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 841~846
DOI : 10.5916/jkosme.2008.32.6.841
Recently the LNG(liquified natural gas) public buses have been introduced to prevent the air pollution in metropolitan areas. As the LNG temperature in fuel tank is as low as
. the thermal and structural effects of tank components need to be studied for safe introduction in the market. Especially the support system of LNG fuel tank in vehicle, which has connected with inside and outside of tanks, should put attention to reduce the structural stress due to cryogenic temperature and to restrict the heat flux from ambient. There are two supporting systems in the tank, that one is connected between inside and outside tanks by welding, and the other is the inserted support system which is a cylindrical SUS bar inserted in a hole of the supporting plate. In this study the temperature distribution and thermal stress of the inserted support system were evaluated by using the utility program as ANSYS. The results showed that the rate of heat transfer to inner tank through this support system was quite small due to limited contact of support bar with plate. but the thermal stress of support plate was obtained beyond the limited tensile value of SUS304. The cautious design for the support plate part, therefore, should be given to make the safe support system of LNG vehicle fuel tank.
A Study on the Heat Exchange Characteristics of EGR-Cooler with CNC
Lee, Byung-Ho ; Yi, Chung-Seub ; Kim, Bo-Han ; Jeong, Hyo-Min ; Chung, Han-Shik ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 847~853
DOI : 10.5916/jkosme.2008.32.6.847
Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Circle fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The designs adopted in this study were exhaust pipes with solid and hollow fins around them direct surface force measurement in water using a nano size colloidal probe Technique The direct force measurement between colloidal surfaces has been an essential topic in both theories and applications of surface chemistry. As particle size is decreased from micron size down to true Carbon nano Colloid size (<10nm), surface forces are increasingly important. Nanoparticles at close proximity or high solids loading are expected to show a different behavior than what can be estimated from continuum and mean field theories. This paper use Water and CNC fluid at normal cooling system of EGR. Experimental result showed all good agreement at Re=
Heat Transfer Characteristics of Electronic Components in a Horizontal Channel According to Various Cooling Methods
Son, Young-Seok ; Shin, Jee-Young ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 854~861
DOI : 10.5916/jkosme.2008.32.6.854
Heat transfer characteristics of protruding electronic components in a horizontal channel are studied numerically. The system consists of two horizontal channels formed by two covers and one printed circuit board which has three uniform protruding heat source blocks. A two-dimensional numerical model has been developed to predict the conjugate heat transfer. and the finite volume method is used to solve the problem. Five different cooling methods are considered to examine the heat transfer characteristics of electronic components according to the different cooling methods. The velocity and temperature of cooling medium and the temperature of the heat source blocks are obtained. The results of the five different cooling methods are compared to find out the most efficient cooling method in a given geometry and heat sources.
Heat Conductivity Test and Conduction Mechanism of Nanofluid
Park, Kweon-Ha ; Lee, Jin-A ; Kim, Hye-Min ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 862~868
DOI : 10.5916/jkosme.2008.32.6.862
Many studies have been conducted to increase heat transfer in fluid. One of the various heat transfer enhancement techniques is suspending fine metallic or nonmetallic solid powder in traditional fluid. Nanofluid is defined as a new kind of heat transfer fluid containing a very small quantity of nanometer particles that are uniformly and stably suspended in a liquid. This study investigates the effect of nanofluid containing diamond, CuNi and CuAg nanometer particles, and proposes the heat transport mechanism of nanofluid. The test result shows that the thermal conductivity of nanofluid is much higher than that of traditional fluid, and the increasing rate of the conductivity is dependent on the conductivity of the solid metal.
A Study on the Diffuser Inlet Shape of Thermocompressor for MED Desalination Plant
Jin, Chang-Fu ; Song, Young-Ho ; Kim, Kyung-Keun ; Park, Gi-Tae ; Chung, Han-Shik ; Choi, Du-Youl ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 869~876
DOI : 10.5916/jkosme.2008.32.6.869
A thermocompressor is the equipment which compresses a vapor to a desired discharge pressure. Since it was first used as the evacuation pump for a surface condenser, it has been widely adopted for energy saving systems due to its high working confidence. In the present study, the geometrical analysis of the shape between the jet nozzle and the diffuser inlet, the drag force was calculated by means of the integrated equation of motion and the computational fluid dynamic (CFD) package called FLUENT. The computer simulations were performed to investigate the effects by the various suction flow rates, the distance from jet nozzle outlet to the diffuser inlet and the dimensions of the diffuser inlet section through the iterative calculation. In addition, the results from the CFD analysis on the thermocompressor and the experiments were compared for the verification of the CFD results. In the case of a jet nozzle, the results from the CFD analysis showed a good agreement with the experimental results. Furthermore, in this study, a special attention was paid on the performance of the thermocompressor by varying the diffuser convergence angle of
. With the increase of the diffuser convergence angle. the suction capacity was improved up to the degree of
while it was decreased over the degree of
Modeling of Steam Injection Heater for Fresh Water Generator
Hong, Cheol-Hyun ; Lee, Euk-Soo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 877~885
DOI : 10.5916/jkosme.2008.32.6.877
Steam injection heater is the most widely used method for fresh water generator throughout industry. This method is often chosen because of its simplicity. The steam bubbles condense and give up their heat to the surrounding liquid. Experimental study on steam injection heater has been performed in order to find the effect of major parameter. And conservation equation and Bernoulli obstruction theory are used for numerical simulation model of vapor flow-rate. Qualitative comparisons between simulations and measurements show a good agreement and the simulation models are thereby verified.
PIV measurement of the flow field in rectangular tunnel
Park, Sang-Kyoo ; Yang, Hei-Cheon ; Lee, Yong-Ho ; Chen, Gong ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 886~892
DOI : 10.5916/jkosme.2008.32.6.886
The development of fluid mechanics is briefly reviewed and the importance of fluid flows to heat and mass transfer in nature as well as to science and engineering is outlined. This paper presents the experimental results of air flow in the rectangular tunnel which has four different exhaust outlets, each distance of which from the inlet is 0, 30, 60 and 90mm respectively. This experiment is conducted by using the olive oil as the tracer particles and the kinematic viscosity of the air flow is
/s. The flow is tested at the flow rate of 1.3
/h and the velocity of 0.3 m/s. PIV technology can be used to make a good description of the smoke flow characteristics in the tunnel.
A Study on the Analysis of a Negative Pressure in the Seawater Line of a Main Centeral Cooler (MCC) for a Large LNG Ship
Jin, Chang-Fu ; SaGong, Woon-Gon ; Kim, Jong-Gyu ; Kim, Chung-Sik ; Song, Young-Ho ; Choi, Soon-Ho ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 893~900
DOI : 10.5916/jkosme.2008.32.6.893
The heat exchangers in the ships have been changed from the conventional shell & tube type to the plate type due to some merits as a compactness, a high thermal efficiency and a light-weight. In recent. it is reported that the vacuum phenomena were occurred in the seawater outlet piping of a main central cooler (MCC) on the ships. From the viewpoints of a common sense, the vacuum pressure in the seawater piping is rare event and difficult to be convinced because the seawater is pumped into the piping by a seawater pump with a high discharge head. However, the occurrence of a vacuum pressure in the seawater line of an MCC is real situation and often gives a severe damage to a rubber gasket of an MCC with a plate type heat transfer area. In this study, we analyzed the vacuum pressure in the seawater line of an MCC by using the simpl Bernoulli's equation and found that the vacuum pressure in the seawater line of an MCC is inevitable untill the installation postion of an MCC is not lowered.
The Variation of the Wake behind a Circular Cylinder Having Arc Grooves
Seo, Seong-Ho ; Hong, Cheol-Hyun ; Boo, Jung-Suk ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 901~907
DOI : 10.5916/jkosme.2008.32.6.901
The measurements of velocity vectors are made in the wake(X/d=8) of a circular cylinder with arc grooves. The experiments are conducted by changing the groove number. groove depth, Reynolds number(Re) and the angle of the first formed groove. We know that the optimum groove angle is 70 degree and the wake velocity profiles are improved at a few conditions. According to vortex shedding frequency distributions. the key solutions to vary the flow field behind the circular cylinder are 70 degree groove angle and more deeper grooves than 0.2mm depth.
Influence of the Number of Runner Vanes on Tubular-type Hydroturbine
Nam, Sang-Hyun ; Kim, You-Taek ; Choi, Young-Do ; Lee, Young-Ho ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 908~914
DOI : 10.5916/jkosme.2008.32.6.908
The world is facing a serious energy problem which destroying the environment. In addition, fossil fuel such as oil and coal that caused global warming and the environmental problems due to acid rain had been gradually exhausted. To solve this problem that has crisis of energy, it is necessary time and effort for research and development of renewable energy in the future. As alternative energy, small hydropower generation which has output of less or equal to 100kW is attracting considerable attention. This is because of its small, simple, renewable, and large amount of energy resources. By using a small hydropower generator of which main concept is based on using the different water pressure levels in pipe lines, energy which was initially wasted by use reducing of a valve at the end of the pipeline, is collected by turbine in the small hydropower generator. In this study, we investigated the influence of the number of runner vanes on the characteristics of tubular-type hydroturbine.
A Study on Flow Rate Properties and Optimal Selection of Nitrogen Membrane Module of Hollow Fiber Type
Kim, Jong-Do ; Lee, Sangu-Su ; Kim, Jeon-Ha ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 915~922
DOI : 10.5916/jkosme.2008.32.6.915
The gas separation technology using membrane is widely used to refine various gases in many industry fields and recently is being applying in
recovery technology. In the gas and chemical tanker. nitrogen generators for inerting, purging and padding are on board and most of them have membrane modules of hollow fiber type with long life and vibration resisting properties. Because a membrane module is a key component accounting for 50% of total manufacturing cost of nitrogen generator, adequate selection for it is an important problem. In this paper, the flow performance coefficient based on dimension and specification data of membrane module was relatively selected to compare nitrogen generating capacity of module and various performance tests about the selected PARKER ST6010 membrane module were conducted. As a result, the useful coefficient and basic data in selecting a membrane module were achieved.
Prediction of Cavitation Occurrence in a Cryogenic Butterfly Valve by Flow Velocity
Kim, Seong-Dong ; Kim, Beom-Seok ; Choi, Young-Do ; Lee, Young-Eo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 923~930
DOI : 10.5916/jkosme.2008.32.6.923
The butterfly valve is widely used in the industrial field as an on-off or a flow control valve. When the butterfly valve is used as a flow control valve. cavitation sometimes occurs in the range of high flow rate because of the small valve opening. Therefore. the pressure loss and the cavitation characteristics are investigated by use of a commercial CFD code. The results show that the possibility of cavitation occurrence in the cryogenic butterfly valve is very high in the case of valve opening angle below 10 degree and incident velocity over 6m/s. By increasing the inlet velocity at 10 degree of valve opening angle. the value of loss coefficient increased. However. by increasing the inlet velocity at 50 degree of valve opening angle. the value of loss coefficient decreased.
A Study on Rolling Contact Fatigue of Rail by Damage Mechanics
Kang, Sung-Soo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 931~937
DOI : 10.5916/jkosme.2008.32.6.931
The rail/wheel rolling contact affects the microstructure in the surface layer of rail. Recently. continuum damage mechanics allows us to describe the microprocesses involved during the straining of materials and structures at the macroscale. Elastic and plastic strains. the corresponding hardening effects are generally accepted to be represented by global continuum variables. The purpose of continuum damage mechanics is to introduce the possibility of describing the coupling effects between damage processes and the stress-strain behavior of materials. In this study. the continuum damage mechanics caused by elastic deformation was briefly introduced and applied to the fatigue damage of the rails under the condition of cyclic loading. The material parameter for damage analysis was first determined so that it could reproduce the life span under the compressive loading in the vicinity of fatigue limit. Some numerical studies have been conducted to show the validity of the present computational mechanics analysis.
High Temperature Deformation Behavior of Fe-base High Strength Alloys
Kwon, Woon-Hyun ; Choi, Il-Dong ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 938~946
DOI : 10.5916/jkosme.2008.32.6.938
Fe-base amorphous alloy and two crystalline phases composite were fabricated. The effect of temperature and strain rate on mechanical properties was evaluated utilizing compression test. Mixture of non-crystalline and crystalline phases were found using X-ray diffraction (XRD) and differential thermal analysis (DTA) tests. Based on glass transition temperature and crystallization temperature. compression tests were performed in the temperature ranging from
interval. Relationship between microstructure, including fracture surface morphology, and mechanical behavior was studied. The peak stress of Fe-base amorphous alloy was over 2GPa and expected to have a good wear resistance, but it is expected hard to deform because of low ductility. The peak stress and elongation of two crystalline phases composite was over 1GPa and about 20%, therefore it is possible to deform high strength wear resistant materials such as engine valve.
Scheme of Tension control for the Stringing Trolley Wire
Jung, Seoung-Hwan ; Hong, Soon-Ill ; Hong, Jeng-Pyo ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 948~954
DOI : 10.5916/jkosme.2008.32.6.948
Now, but task for stringing trolley wire is worked manually by a measurement of dip, we need to development the automatic control system for a safety and effective tasks. In this paper, in works of stringing trolley wire by a mobile of robot, a method is proposed tension control for the stringing trolley wire. On the basics of a wire model with hard nonlinear, ac servo motor model for torque generating and stringing wire tension, the tension control scheme is design and implemented with a detected wire tension by a load cell. We experimentally show that the performance of the tension response are satisfactory to regulator tension. The proposed system is simulated and experimented, results is verified the utilities.
Practical Encryption and Decryption System using Iterative Phase Wrapping Method
Seo, Dong-Hoan ; Lee, Sung-Geun ; Kim, Yoon-Sik ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 955~963
DOI : 10.5916/jkosme.2008.32.6.955
In this paper, we propose an improved practical encryption and fault-tolerance decryption method using a non-negative value key and random function obtained with a white noise by using iterative phase wrapping method. A phase wrapping operating key, which is generated by the product of arbitrary random phase images and an original phase image. is zero-padded and Fourier transformed. Fourier operating key is then obtained by taking the real-valued data from this Fourier transformed image. Also the random phase wrapping operating key is made from these arbitrary random phase images and the same iterative phase wrapping method. We obtain a Fourier random operating key through the same method in the encryption process. For practical transmission of encryption and decryption keys via Internet, these keys should be intensity maps with non-negative values. The encryption key and the decryption key to meet this requirement are generated by the addition of the absolute of its minimum value to each of Fourier keys, respectively. The decryption based on 2-f setup with spatial filter is simply performed by the inverse Fourier transform of the multiplication between the encryption key and the decryption key and also can be used as a current spatial light modulator technology by phase encoding of the non-negative values. Computer simulations show the validity of the encryption method and the robust decryption system in the proposed technique.
A Study on Basic Characteristics of a Coplanar-type Transmission Line Employing Periodic Structure on Si RFIC
Joh, Han-Nah ; Park, Young-Bae ; Yun, Young ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 964~973
DOI : 10.5916/jkosme.2008.32.6.964
In this study, a short-wavelength coplanar-type transmission line employing periodic ground structure (PGS) was developed for application to miniaturized on-chip passive component on Si Radio Frequency Integrated Circuit (RFIC). The transmission line employing PGS showed shorter wavelength and lower characteristic impedance than conventional coplanar-type transmission line. The wavelength of the transmission line employing PGS structure was 57 % of the conventional coplanar-type transmission line on Si substrate. Using the theoretical analysis. basic characteristics of the transmission line employing PGS (e.g., bandwidth. loss, impedance, and resonance characteristics) were also investigated in order to evaluate its suitability for application to a development of miniaturized passive on-chip components on silicon RFIC. According to the results. the bandwidth of the transmission line employing PGS was more than 895 GHz as long as T is less than 20
, and the resonance characteristic was observed in 1239 GHz, which indicates that the PPGM structure is a promising candidate for application to a development of miniaturized on-chip passive components on Si RFIC.
RCGA-Based State Feedback Control for Seesaw Systems
Oh, Sea-June ; So, Myung-Ok ; Jung, Byung-Gun ; Ryu, Ki-Tak ; Lee, Yun-Hyung ; Lee, Sang-Tae ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 974~980
DOI : 10.5916/jkosme.2008.32.6.974
Generally. most of the physical systems affected by disturbance or incomplete knowledge are complex and highly nonlinear. To control under these circumstances. many researches are ongoing in modern control theory recently. But the researches need apparatuses. which can verify the controller for being not damaged the real plant. In this paper. therefore. a seesaw system is considered control system to analyze and apply the control theory. A seesaw system consists of a moving cart on the rail and seesaw frame made to demonstrate the effectiveness of the control theory. The system has balancing and positioning problems. and the driving force is applied on the DC motor of cart. but not on the pivot. The purpose of control is to maintain an equilibrium of seesaw frame in spite of an allowable disturbance. Computer simulations are given to illustrate the control performance of the proposed scheme.
Development of Automatic Measuring Device for Cylinder Liner Wear Amount in Large Two Stroke Diesel Engine
Kim, Jang-Kyu ; Lee, Min-Cheol ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 981~988
DOI : 10.5916/jkosme.2008.32.6.981
This paper describes a development of automatic measuring device for cylinder liner wear amount. An operator should regularly measure the wear amount of the cylinder liner to prevent the wear amount of the cylinder liner from exceeding the maximum limit specific to the engine type. In previous methods. an operator entered the inside of the cylinder liner on a ladder and measured the amount of wear using a inside micrometer. Such method is unpleasant in severe environments and full of hazards. In addition, in order to enter the cylinder, the piston head had to be detached. requiring much time and money. In order to solve these problems, a new measuring device that consists of two measuring units and a special install jig is developed. The measuring units are installed through the scavenging air port by the install jig and measures the wear amount during 1 revolution of crankshaft. so detaching of the cylinder head and entering inside the cylinder liner are not required.
A Study of Method for Construction of Wireless Vision Monitoring System for Fish-cage in Open Sea
Oh, Jin-Seok ; Kwak, Jun-Ho ; Jung, Sung-Jae ; Ham, Yeon-Jae ;
Journal of the Korean Society of Marine Engineering, volume 32, issue 6, 2008, Pages 989~996
DOI : 10.5916/jkosme.2008.32.6.989
Recently, a few types of fish-cage in open sea are researched. This fish-cage has to operate monitoring system for keeping an optimum living condition for fish. The most efficient monitoring system is WVMS(Wireless Vision Monitoring System) for fish-cage in open sea. WVMS should be able to transmit video signal and communicate with each controller. So. it needs to be based on WLAN(Wireless LAN) which has characteristic of higher transfer-rate, In this paper, we propose a structure of WVMS using WLAN equipments for maritime environment and prove its effectiveness. We present the propagation loss model of WVMS's communication channel. measured by field test, and discuss its validity compared with the predictive value based on the Friss propagation model and Plane earth reflection model. We present the number of frames that is received from WLAN modem connecting with underwater-camera in field test spots. As a result, we confirmed that proposed WVMS is suitable for maritime environment and it is possible to be applied to fish-cage in open sea on 'seogwipo'.