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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 28, Issue 8 - Nov 2004
Volume 28, Issue 7 - Nov 2004
Volume 28, Issue 6 - Sep 2004
Volume 28, Issue 5 - Jul 2004
Volume 28, Issue 4 - May 2004
Volume 28, Issue 3 - Mar 2004
Volume 28, Issue 2 - Jan 2004
Volume 28, Issue 1 - Jan 2004
Selecting the target year
LNG Carrier Propulsion by ME Engines and Reliquefaction
Grone, Ole ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 7~28
Study on the Condensation Heat Transfer Characteristics in Small Diameter Tubes
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 29~38
The Condensation heat transfer coefficients of R-22 and R-l34a were measured in smooth horizontal copper tubes with inner diameters of 1.77. 3.36 and 5.35 mm. respectively. The experiments were conducted in a closed loop. which was driven by a magnetic gear pump. They were Performed for the following ranges of variables: mass flux (200 to
) saturation temperature
and quality (0 to 1.0). The main results obtained are as follows Condensation heat transfer coefficients in the small diameter tubes (ID < 7 mm) were observed to be strongly affected by inner diameter change and to differ from those in the large diameter tubes. The heat transfer coefficients in the small diameter tubes were 20 ~ 40 % higher than those in the large diameter tubes as the inner diameter of the tube was reduced. Also. it was very difficult to apply some well-known previous predictions (Cavallini-Zecchin's. Haraguchi's and Dobson's correlation) to small diameter tubes. Based on an analogy between heat and mass transfer the new correlation is Proposed to predict the experimental data more accurately.
Fluid Flow and Heat Transfer in the Fluidized Bed Heat Exchanger
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 39~45
The commercial viability of heat exchanger is mainly dependent on their long-term fouling characteristics because the fouling increases the pressure loss and degrades the thermal Performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow and heat transfer in a fluidized bed heat exchanger with circulating various solid particles. The Present work showed that the flow velocity range for Possible collision between the tube wall and the particles was higher with heavier density solid particles. in audition. the solid particle periodically hitting the tube wall broke the thermal boundary laver. and increased the rate of heat transfer.
Numerical Study on the Thermal Characteristics of the Various Cooling Methods in Electronic Equipment
Son, Young-Seok ; Shin, Jee-Young ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 46~55
Thermal characteristics of the various cooling methods in electronic equipment are studied numerically. A common chip cooling system is modeled as a parallel channel with protruding heat sources. A two-dimensional model has been developed for the numerical analysis of compressible. viscous. laminar flow. and conjugate heat transfer between parallel plates with uniform block heat sources. The finite volume method is used to solve this problem. The assembly consists of two channels formed by two covers and one printed circuit board that is assumed to have three uniform heat source blocks. Various cooling methods are considered to find out the efficient cooling method in a given geometry and heat sources. The velocity and the temperature fields. the local temperature distribution along the surface of blocks. and the maximum temperature in each block are obtained. The results are compared to examine the thermal characteristics of the different cooling methods both quantitatively and qualitatively.
Heat Transfer Characteristics on the Cavity with One Heat Source
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 56~64
A numerical study have been performed on a cavity with one heat source by the open ratio and tilt angle. The goal of this study is to get the information for designing a solar collector absorber. semi-conductor equipment and block heater and so on. The parameters for this study is the various open ratio. and tilt angle of the cavity and Rayleigh numbers The finite volume method with SIMPLE computational algorithm are used and calculated the heat transfer in the cavity. As a result, the heat trans(or was promoted by increase of Rayliegh numbers and open ratios But, the heat transfer was not promted at lower wall of cavity because the flow pattern are very small at lower space in the cavity(Or=0.1) As the Rayleigh number is increased the mean nusselt numbers are increased at inside wall.
Analysis of Heat Transfer and Pressure Drop During Gas Cooling Process of Carbon Dioxide in Transcritical Region
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 65~74
The heat transfer coefficient and pressure drop of
(R-744) during gas cooling Process of carbon dioxide in a horizontal tube were investigated experimentally and theoretically. The experiments were conducted without oil in the refrigerant loop. The main components of the refrigerant loop consist of a receiver. a variable-speed pump. a mass flowmeter, an evaporator. and a gas cooler(test section). The main components of the water loop consist of a variable-speed Pump. an constant temperature bath. and a flowmeter. The gas cooler is a counterflow heat exchanger with refrigerant flowing in the inner tube and water flowing in the annulus The test section consists of smooth, horizontal stainless steel tube of 9.53 mm outer diameter and 7.75 mm inner diameter. The length of test section is 6 m. The refrigerant mass fluxes were 200 ~ 300 kg/(
) and the inlet pressure of the gas cooler varied from 7.5 MPa to 8.5 MPa. The main results were summarized as follows : The predicted correlation can evaluated the R-744 exit temperature from the gas cooler within
for most of the experimental data, given only the inlet conditions. The predicted gas cooley capacity using log mean temperature difference showed relatively food agreement with gas cooler capacity within
. The pressure drop predicted by Blasius estimated the pressure drop on the
. The predicted heat transfer coefficients using Gnielinski's correlation evaluated the heat transfer coefficients on the
side well within the range of experimental error. The predicted heat transfer coefficients using Gao and Honda's correlation estimated the heat transfer coefficients on the coolant side well within
. Therefore. The predicted equation's usefulness is demonstrated by analyzing data obtained in experiments.
The pulsating pressure in the intake and exhaust manifold of a single cylinder engine by the various of engine revolutions
Chung, Han-Shik ; Choi, Seuk-Cheun ; Jong, Hyo-Min ; Lee, Chi-Woo ; Kim, Chi-Won ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 75~82
In this research, a computer analysis has been developed for predicting the Pipe pressure of the intake and exhaust manifold in a small single cylinder engine. To get the boundary conditions for a numerical analysis one dimensional and unsteady gas dynamic calculation is performed by using the MOC(Method Of Characteristics). The main numerical parameters are engine revolutions. to calculate the Pulsating flow which the intake and exhaust valves are working. The distributions of the exhaust pipe pressures were influenced strongly to the cylinder pressures and the shapes of exhaust pressure variation were similar to the Inside of cylinder pressure As the engine revolutions are increased. the intake pressure was lower than ambient pressure. The amplitude of exhaust pressure had increased and the phase of cylinder pressure
is delayed and the amplitude of cylinder pressure were increased.
Optimal Design of the Forging Processes of Flare Nut for Automobiles using Finite Element Analysis
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 83~89
Flare nut is an important Part that used to joint a brake tube-end in automobiles. It was made of SWCH 10A by machining. But we studied to make it by metal forming. The main focus of this paper is to investigate an optimal forging processes for flare nut using the DEFORM
-3D. commercially available finite element code and tests. Actually an explicit finite element analysis of the flare nut forging processes has been carried out to predict an optimal shape of the flare nut and its results were reflected in the tests of the forging processes design for flare nut. The simulation results which had obtained from finite element analysis were contributed to the forging processes design for flare nut. An optimal shape of nave nut showed agreements with test results. Furthermore. this paper should contribute to a development of the forging process for a variety of parts.s.
Sensorless Speed Control of Direct Current Motor by Neural Network
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 90~97
DC motor requires a rotor speed sensor for accurate speed control. The speed sensors such as resolvers and encoders are used as speed detectors. but they increase cost and size of the motor and restrict the industrial drive applications. So in these days. many Papers have reported on the sensorless operation or DC motor(3)-(5). This paper Presents a new sensorless strategy using neural networks(6)-(8). Neural network structure has three layers which are input layer. hidden layer and output layer. The optimal neural network structure was tracked down by trial and error and it was found that 4-16-1 neural network has given suitable results for the instantaneous rotor speed. Also. learning method is very important in neural network. Supervised learning methods(8) are typically used to train the neural network for learning the input/output pattern presented. The back-propagation technique adjusts the neural network weights during training. The rotor speed is gained by weights and four inputs to the neural network. The experimental results were found satisfactory in both the independency on machine parameters and the insensitivity to the load condition.
Large Eddy Simulation of turbulent flow around a bluff body inside a sudden expansion cylindrical chamber
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 98~108
This study concerns a large eddy simulation (LES) of turbulent flow around a bluff body inside a sudden expansion cylindrical chamber, a configuration which resembles a premixed gas turbine combustor The simulation code is constructed by using the general coordinate system based on the physical contravariant velocity components. The Smagorinsky model is employed and the calculated Reynolds number is 5,000 based on the bulk velocity and the diameter of the inlet pipe. The combined grid technique and cylindrical grid are tested in the numerical simulation with complex geometry. The predicted turbulent statistics are evaluated by comparing with LDV measurement data. The numerical flow visualizations depict the behavior of turbulent mixing process behind the flame holder.
Effect of Primer Coating Condition and Gap Clearance in
Laser Welding of Primer-coated Steel for Shipbuilding
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 109~115
The spatter and porosity could be occurred during
CW laser welding of Primer- coated steel for shipbuilding. This study has suggested an alternative idea by examining of weld-defect formation mechanism. The primer-coated plate induced the spatter humping bead and porosity and these are main part of the welding defect. attributed to the powerful vaporizing pressure of primer attached on the base metal The zinc of Primer has a boiling point that is the lower temperature than melting point of steel zinc vapor will build up at the interface between the two sheets and this tends to deteriorate the quality of the weld by ejecting weld material from lap position or leaving porosity. Therefore introducing a small gap clearance in the lap position. the zinc vapor could escape through it and sound weld beads can be acquired. In conclusion, we suggested the occurred and prevented mechanism of weld defects with searching the factor.
Experimental Study on Flow Characteristics of ERF by using PIV Technique
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 116~123
An experimental investigation was performed to study the characteristics of ER (Electro-Rheological) fluid flow in a horizontal rectangular tube with or without D.C volatage. To determine some characteristics of the ER flow. 2D PIV(Particle Image Velocimetry) technique is employed for velocity measurement. This research found the mean velocity distribution with 0 kV/mm. 1.0kV/mm and 1 5kV/mm for Re=0, 0.62, 1.29 and 2.26. When the strength of the electric field increased. the claster of ERF are clearly strong along the test tube and the flow rate decreased.
An Experimental Study on the Wake of a Square Cylinder Using PIV Technique
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 124~135
An experimental study is performed turbulent flow behind a square cylinder by using 2-D PIV technique. The Reynolds number investigated are 10.000. 30.000 and 50,000. The mean velocity vector, time mean axial velocity turbulence intensity. kinetic energy and Reynolds shear stress behind the cylinder are measured, The numerical method used this study is a CFD code, STAR-CD. The numerical results are compared with these of experimental.
A Position Control of Nonlinear Hydraulic System using Variable Design-Parameter Fuzzy PID Controller
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 136~144
In general a hydraulic system which uses a single rod hydraulic as an actuator is modeled as a nonlinear system and reveals uncertain Parameter characteristics such as the density variation of hydraulic oil and is subject to load variations and severe disturbances during operation. A variable design-parameter fuzzy PID controller is adopted to solve these undesirable internal and external problems and its effectiveness is verified through computer simulations for control performance and real time control possibility.
The characteristic analysis of contact-less Power supply by 3D finite element method
Park, Han-Seok ; Cho, Yun-Hyun ; Jung, Hong-Sub ; Woo, Kyung-il ; Kim, Kyung-Ho ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 145~151
This paper proposes the calculation method of magnetic coupling coefficient of contact-less power supply by the 3D finite element method with a variation of the secondary core position. The primary, secondary self and leakage inductances and the capacitances of a resonant circuit are calculated by the finite element analysis results. The magnetic coupling coefficients are obtained also. The power factors are obtained by simulation for the magnetic coupling coefficients and compared.
A Study on the Flow Characteristics according to the Shapes of Rod on Impinging Jet by PIV Measurement
Journal of the Korean Society of Marine Engineering, volume 28, issue 1, 2004, Pages 152~161
The thermal load is a very important problem to be solved in many industrial systems including the electronic equipment. Impinging Jets have been known to provide a large heat transfer rates on surface for many years. The turbulence enhancement of fluid flow is requested for the efficiency elevation of heat transfer. A study on flow fields by rods attached to the wall surface as a promoter of turbulence enhancement has been carried out. The exact analysis on chracteristics of impinging jet field is requested to obtain the optimum design of the impinging jet system. By visualizing the flow field and processing the high digital image by computer PIV can afford exact data on the velocity vector kinetic energy and turbulence intensity in the complex turbulence field. In this study. three kinds of rod shape such as square. triangle. and semicircle are selected as the turbulence promoter. Nozzle diameters are 10mm. 17mm. and 23mm. And the analysis of the flow characteristics due to the above rods is carried out at Re No. 2.000, 3.000. and 4,000 by PIV measurement. It is clarified that the rod setup is very useful to obtain the turbulence enhancement and the turbulence intensity according to the shapes of rod appears large in order of the shapes of rod such as square 〉 triangle 〉semicircle.