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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 23, Issue 6 - Nov 1999
Volume 23, Issue 5 - Sep 1999
Volume 23, Issue 4 - Jul 1999
Volume 23, Issue 3 - May 1999
Volume 23, Issue 2 - Mar 1999
Volume 23, Issue 1 - Jan 1999
Selecting the target year
Corrosion Status of Marine Structures and Applicable Protection Methods for Those Erosion-Corrosion Environments
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 1~8
A Study on Flow Characteristics of Two-Dimensional Backward-Facing Step by CFD
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 9~18
The present study is aimed to investigate flow characteristics of two-dimensional backward-fac-ing step by numerical approach. A convection conservation difference scheme based upon SOLA algorithm is used for the solution of the two-dimensional incompressible Navier-Stokes equations to simulate the laminar transitional and trubulent flow conditions at which the experimental data can be available for the backlward-facing step. The twenty kinds of reynolds number are used for the calculations. In an effort to demonstrate that the reported solutions are dependent on the mesh refinement computations are performed on seven different meshes of uniformly increasing refinement. also to investigate the result of inflow dependence two kinds of the inflow profile are chosen for the laminar flow. Irregular grid is adopted to minimize the errors on the satis-faction fo the discretized continuity. As criterion of benchmarking the result of numerical simula-tion reattachment lengthis used for the selected Reynolds numbers. The results of the present study prove the fact that the numerical predictions agree well with the experimental data and the flow characteristics are shown at the backward-facing step.
An Experimental Study on the Characteristics of NOx Cox Emissions and the Measuring Technique of NOx inMarine diesel Engines
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 19~24
In this paper the emission characteristic of the ship's diesel engine with CPP(Controllable Pitch Propeller) were investigated under the passage test on the sea. As the results it is confirmed that the NOx.
concentrations increase as the engine speed increases and the torque decreases. but the amount of NOx, COx emissions(g./k Wh) decrease as the torque increase regardless of the engine speed. Also it is compared with the NOx concentra-tions measured by the two method-ECC(Electrochemical Cell)and CLD(Chemiluminescence Detector)for the correct measurement and the ECC indicated higher value than the CLD.
An Experimental Study on the characteristic of Exhaust Emissions and the Engine Performacne with Intake Port Water Injection in Diesel Engine
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 25~32
This study was carried out to reduce NOx emissions from diesel engine and to investigate the variation of engine performance using the water injection. In this study the water was extracted from the exhaust gas and injected directly into the intake port with the inlet charge. The water condensing system operated as a closed system without any supplementary water supply. The experimental parameters such as the revolution the torque and the water injection rate are varied and the result from this experiment found the significant NOx reduction whereas the smoke emission increases as water/air ratio increases as the cases like the EGR. In spite of increasing the quantity of the water injection the engine output was slightly decreased and the specific fuel consumption was increased as was anticipated. Especially the system was founded to be effective on the reduction of the NOx emissions at the high load region relatively.
A Study on the Flow Characteristics of developing transitional Steady Flows in the Entrance Region of a Curved Duct
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 33~39
In this paper an experimenatal investigation of characteristics of developing ransitional steady flows in a square-sectional
curved duct is presented, The experimental study is carried out to measure axial velocity profiles secondary flow velocity profiles and entrance length by using Laser Dopper Velocimeter(LDV) system. The flow development is found to depend upon Dean number and curvature ratio. Of special interest is the secondary flow generated by centrifugal effects in the plane of the cross-section of the duct. The secondary flows becomes strong from
of bended angle on the duct. The entrance length of transitional steady flow is obtained to
of bended angle of the duct in this experimental conditions.
Load Frequency Control of Power System using a Self-tuning Fuzzy PID Controller
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 40~46
A self-tuning FPID(Fuzzy Proportional Intergral Derivative) controller fo load frequency control of 2-area power systemis proposed in this paper. The paramters of the proposed self-tuning FPID controller are self-tuned by the proposed fuzzy inference technique. Therefore in this paper the fuzzy inference technique of PID gains using PSGM(Product Sum Gravity Method) is presented and is applied to the load frequency control of 2-area power system. The computer simulation results show that the proposed controller give better more control characteristics than convention-al PID, FLC under load changes.
Numerical Analysis of the Effect of Injection Pressure Variation on Impaction Spray Characteristics
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 47~53
Small compression-ignition direct injection engines have been developed as a measure to improve a fuel efficiency and reduce harmful exhaust gases. Those small engines generally employ high injection pressure increase on the spray impacting on a wall is discussed in this paper. The gas phase is modelled by the Eulerian continuum conservation equations of mass momentum energy and fuel vapour fraction. The liquid phases is modelled following the discrete droplet model approach in Lagrangian form and the droplet wall interaction is modelled as a func-tion of the velocity normal to impaction lands. The droplet distributions vapor fractions and gas flows are analyzed in various injection pres-sure cases. The penetrations of wall spray and vapor increase and the Sauter mean diameter decreases with increasing injection pressure.
Turbulent Heat Transfer in Rough Concentric Annuli With Heating Condition of Constant Wal Heat Flux
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 54~61
The fully developed turbulent momentum and heat transfer induced by the roughness elements on the outer wall surfaces in concentric annuli are analytically studied on the basis of a modified turbu-lence model. The resulting momentum and heat transfer are discussed in terms of various parame-ters such as the radius ratio the roughness density Reynolds number and Prandtl number accord-ing to the heating condition. The study shows that certain artificial roughness elements may be used to enhance heat transfer rates with advantage from the overall efficiency point of view.
A Study on Strength Characteristic for marine Propeller
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 62~68
The strength data on AlBC3 and HBsC1 which are used for materials of marine propeller blade are insufficient as used of material limited and even rules of KR(Korean Register of Shipping) describe only a point of view that the chemical composition and men values of mechanical proper-ties have to be certain level. In this study distribution characteristics as well as mean values of mechanical properties are investigated through the tensile test and the characteristics of fatigue strength are investigated through the fatigue test.
Pressure Control of Hydraulic Cylinder using high Speed On-Off Solenoid Valve
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 69~78
In this study a new pattern of pressure control of hydraulic cylinder using high speed On-Off solenoid valve in the electro-hydraulic system has been suggested. The control valve is 3-way high speed On-Off solenoid valve which is operated by PWM(Pulse Width Modulation)control signal. The high speed On-Off solenoid valve has a tendency to induce severe pressure fluctuation in the hydraulic actuator so it has not been used for the purpose of closed loop control with direct pres-sure feedback. In this study closed loop control with direct pressure feedback is enabled by using a digital filter which has linear minimum mean square filter algorithm. Through some experiments it is confirmed that stable pressure control can be realized by the proposed control technique.
Operating Condition Diagnosis of the Lubricated Machine Moving Surface by Image Analysis
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 79~87
The most part of the faculty drop a trouble and damage of machine equipment even if whatever cause they break out take place at local and trifling place and the factor dominating their trouble is due to wear debris occurred in the lubricated machine moving surface. This study has been car-ried out to identify morphology of wear debris on the lubricated machine moving system by means of computer image analysis. Namely the wear debris contained in lubricating oil extracted from movable machine equipment will be filtered through membrane filter(void diameter 0.45
) and will be analyzed with its data information such as 50% volume diameter aspect roundness and reflectivity. Morphological characteristic of wear debris is easily distinguished by four shape parameters it is necessary to divide small class of every 100 wear debris in total wear particles in order to distinguish morphological characteristic of wear debris more easily by computer image analysis. We are sure that operation condition diagnosis of the lubricated machine moving surfaces is possible by computer image analysis.
Numerical Analysis on the Triple Flame Structure with Different Kinds of Fuel
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 88~95
This study investigates the effects of different kind fuels on the flame structure by using the numerical simulation in triple flame made by a co-flowing fuels-air stream based on the elementary chemical reaction mechanism. Methane and Hydrogen were used as fuel for this study. In order to interpret the result of the study on numerical simulation Skeletal chemistry is employe as the elementary chemical reaction mechanism for methane Gutheil's as an offset ele-mentary chemical reaction mechanism for hydrogen. The result of this study is as follows. In com-parison between the apparent burning velocity change of triple flame and the one-dimensional pre-mixed flame hydrogen fuel flame is higher than methane fuel flame. The flame thrusts out for-ward in the down stream of the boundary between air-fuel mixture and air stream and a part of the flow is bent and forks out in this protruding flame so that a triple flame is originated.
Sensorless Speed Control of Induction Motor Using Observation Technique
Journal of the Korean Society of Marine Engineering, volume 23, issue 1, 1999, Pages 96~102
Sensorless speed estimation in induction motor systems is one of the most control engineers. Based on the estimated speed the vector control has been applied to the high precision torque control however most speed estimation methods use adaptive scheme so that it takes long time to estimate the speed. Thus the adaptive estimation scheme is not effective to the induction motor which requires short sampling time. In this paper a new linearized equation of induction motor system is proposed and a sensorless speed estimation algorithm based on observation techniques is developed. First the nonlinear induction motor equation is linearized at an equilibrium point. Second a proportional integral(PI) observer is applied to estimate the speed state in the induction motor system. Finally simulation results will assure the effectiveness of the new linearized equation and the sensorless estimation algorithm by using PI observer in the nonlinear induction motor system.