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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 25, Issue 6 - Nov 2001
Volume 25, Issue 5 - Sep 2001
Volume 25, Issue 4 - Jul 2001
Volume 25, Issue 3 - May 2001
Volume 25, Issue 2 - Mar 2001
Volume 25, Issue 1 - Jan 2001
Selecting the target year
Characteristics of Tubo Pumps Operating in Air-Water Two-Phase Flow
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 957~962
Program Phase and Air-Conditioning Systems of ship
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 963~973
Controllable Pitch Propeller
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 974~985
NOx Reduction Technologies on Marine Diesel Engines
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 986~1016
A Domestic situation and Response on the Global Prohibition of TBT Compounds on the Ship's Anti-fouling Systems
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1017~1024
Analysis of Geometric Parameters for Fully Developed Laminar Flow Between Cylinders Arranged in Regular Array
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1037~1049
Considerable interest has evolved in the flow of non-Newtonian fluids in channels of noncircular cross section in compact heat exchanges. Analytical solution was developed for prediction of the flow rate and maximum velocity in steady laminar flow of any incompressible, time-independent non-Newtonian fluids in straight closed and open channels of arbitrary, but axially unchanging cross section. The geometric parameters and function of shear describing the behavior of the fluid model were evaluated for fluid flow among a bundle of rods arranged in triangular and square array. Numerical values of dimensionless maximum velocities, mean velocities, pressure-drop-flow parameters and friction factors were evaluated as a function of porosity and pitch-to-radius ratio.
A Study on the Analysis of Galloping for Power transmission line
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1051~1057
In this paper, we deal with three types of modelling method for the analysis of galloping in power transmission line (PTL). The single mass model is obtained under linearization method and it is applied into f-order model. On these models, the nature frequencies of PTL are obtained and it makes an effects on the galloping directly. In simulation, we verify that the maximum magnitude of nature frequency depends on the galloping distance of PTL. Also from the analysis of frequency response, a few of reduction method for galloping are introduced which is effected by distance of PTL, wind velocity and icing types.
Development of Probability Distribution Estimation Program for Fatigue Crack Growth Lives
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1058~1064
In this paper, the development of probability distribution estimation program for fatigue crack growth lives was summarize. The probability distribution estimation program of life was developed to increase the reliability of life estimation. In this study, it is considered that the cause of scatter in fatigue crack growth data is due to material inhomogeneity. The material resistance to fatigue crack growth is modelled as a spatial stochastic process, which varies randomly along the crack path. We developed the GUI program to estimate the probability distribution and reliability using the non-Gaussian stochastic process method. This program can be used for the reliability assessment.
A Study on the Transient Phenomenon Analysis at the instant of Parallel Running for A.C. Generators
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1065~1075
It is common knowledge amongst electrical and marine engineers that short-circuit in electrical system may cause large mechanical torque on generator and prime mover However, it is not so widely known that the faulty synchronizing of generators may cause even higher torques than that of short-circuit. In this study, the transient phenomena related to the parallel running of synchronous generators are analyzed and the exact computer simulation method is proposed. In result, maximum transient torque and current take place in case of
voltage angle difference between Master and Slave and that may develop higher torque than the short-circuit according to a condition of synchronizing. When synchronizing in power system using only two generators higher torque and current occur Master, but using multimachine system those occur to Slave. The short-circuit of marine generator does not happen frequently but faulty synchronizing sometimes takes place, therefore, it is necessary for designers to consider these phenomena.
Experimental Investigations of Flow Characteristics by Wing Type Vortex Generators Set up Behind a Circular Cylinder in a Rectangular Channel
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1076~1085
Experimental investigations of the longitudinal vortices, which are produced by wing type vortex generators set up behind a circular cylinder in a rectangular channel, are presented. When the circular cylinder is set up in the rectangular channel, a horseshoe vortex is formed just upsteam of the circular cylinder. It generates a turbulent wake region behind the circular cylinder. Therefore, the region of the pressure loss behind the circular cylinder in increased and the size of the wake is small. These problems can be achieved by longitudinal vortices which are generated by wing-type vortex generator. In order to control the strength of longitudinal vortices, the angle of attack of the vortex generators is varied from 20 degree to 45, but the spacing between the vortex generators is fixed 6cm. The 3-dimensional mean velocity measurements are made using a five-hole probe. The vorticity field and streamwise velocity contour are obtained from the velocity field. The following results are obtained. Circulation strength is the maximum value when the angle of attack(
, and the vorticity field and streamwise velocity contour in case of
show the trend similar to these in case of
, but do not in case of
A Study on the Permissible Gain Ranges of the P and PI Controllers for the Retarded Processes
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1086~1090
In this paper, a method deciding the permissible gains of the P and PT controllers for a retarded process under stable condition is proposed. For analysis, the controlled process is assumed to be first-order system with time delay. At first, the adjustable parameter sets causing stability limit are obtained based on the frequency domain condition which makes the roots of the characteristic equation locate on the imaginary axis. And the cut-in frequency
to bring the parameter set to P control from PI control is derived is derived in terms of L and
is used to compute the maximum gain with stable condition. The results indicate that the permissible controller gains can be described by a unique if parameters L and
A Basis Study on Optimum Design of Air Turbine for Wind Power Generation
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1091~1097
A numerical investigation was performed to determine the effect of airfoil on the optimum flap height using NACA 00XX and 44XX airfoils. The six flaps which have 0.5% chord height difference were selected . A Navier-Stokes code, FLUENT, was used to calculate the flow field of the airfoil. The code was first tested as a benchmark by modelling flow around a NACA 4412 airfoil. Predictions of local pressure coefficients are found to be in good agreement with the result of the experimental results. For every NACA 00XX and 44XX airfoil, flap heights ranging from 0.0% to 2.5% chord were changed by 0.5% chord interval and their effects were also studied. Representative results from each case are presented graphically and discussed. It is conclued that this initial approach gives an idea for the future development of the wind turbine optimum design.
Performance Evaluation of Electrocoagulation and Electrodewatering for the Reduction of Water Content in Wastewater Sludge
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1098~1107
This study is to develop the pretreatment for the excess and digested sludge by elector-coagulation and dewatering. Electrocoagulation is applied to excess and digested sludge before transferring to the pistion type for dewatering. Piston type filter press as a laboratory scale plant was used to estimate the dewaterability. MMD of excess sludge was increased from initial diameter of particles (
) to the 87%(
) after electrocoagulation. Al electrode is more effective than Fe electrode for the dewaterabiltity of excess sludge Electrodewatering after electrocoagulation as pretreatment makes the water content of sludge cake 50~60 wt%.
Effect of Stress Ration on Fatigue Crack Propagation Behavior of Pressure Vessel Steel SA516-Grade70 at Higt Temperature.
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1108~1114
The fatigue crack propagation behavior of the SA516-Grade 70 steel which is used for pressure vessels was experimentally examined under the condition of at room temperature,
with stress ration of R=0.1 and 0.3. The fatigue crack propagation rate , da/dN, related with the stress intensity factor range,
N, was influenced by the stress ration within the stable growth of fatigue crack(Region II) with an increase in
N. The resistance to the fatigue crack growth at high temperature is higher in comparison with that at room temperature, and the resistance attributed to the extent of plasticity-induced by compressive residual stress according to the cyclic loads. Fractographic examinations revels that the differences of the fatigue crack growth characteristics between room and high temperatures are mainly explained by the crack and oxide-induced by high temperature.
A Tracking Algorithm for Shipboard Satellite Antenna Systems
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1115~1121
This paper presents the development of a tracking algorithm for shipborad satellite antenna systems which can enhance the tracking performance. In order to overcome some drawbacks of the conventional step tracking algorithm a new tracking algorithm is proposed. The proposed algorithm searches for the best tracking angles using gradient-based formulae and signal intensities measured according to a search pattern. The effectiveness of the proposed algorithm is demonstrated through simulation using real data.
A Basic Study on the Development of Domestic Underwater Wet Arc Welding Electrode
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1122~1129
Underwater wet arc welding process was experimentally investigated by using the six types of flux coated electrodes of 3.2 mm diameter and the KR-RA steel plate of 11 mm thickness as base metal. Two types of electrodes were domestic covered arc welding electrode(CR13, CR14) and another two types of wet welding electrodes(UWCS, TN20)were imported goods, and the other two type (UWX1, UWX2) were individually designed flux coated electrodes for experimental welding purpose. Main experimental results are summerized as follows: 1. It is ascertained that individually designed flux coated electrode(UWX1) could be used in practice with KR-RA steel plate for underwater wet arc bead welds. 2. Welding arc can be generated easily and considerably kept in stable using TN20 and UWX1 electrodes. 3. The micro Vickers hardness value and the portion of martensite in the HAZ were increased in all the electrodes by rapid cooling rate, but it is relatively maintain stable for UWCS, TN20 and UWX1 electrodes.
A Study on the Stifness of Coil Spring in the Three Dimensional Space
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1130~1139
Springs are widely utilized in machine element. To find out stiffness of coil spring, the space beam theory using the finite element method is adopted in this paper. In three dimensional space, a space frame element is a straight bar of uniform cross section which is capable of resisting axial forces, bending moments about two principal axes in the plane of its cross section and twisting moment about its centroidal axis. The corresponding displacement degrees of freedom are twelve. The displacements of nodal points due to small increment of force are calculated by the finite element method and the calculated nodal displacements are added to coordinates of nodal points. The new stiffness matrix of the system using the new coordinates of nodal points is adopted to calculated the another increments of nodal displacements, that is, the step by step method is used in this paper. The results of the finite element method are fairly well agreed with those of various experiments. Using MATLAB program developed in this paper, spring constants can be predicted by input of few factors.
A Study on the Effect of Molding Pressure on the Interlaminar Fracture Toughness
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1140~1147
This paper describes the effect of various molding pressure for Mode I. Mode II interlaminar fracture toughness of carbon fiber reinforced plastic composites by using double cantilever beam(DCB), end notched flexure(ENF) and end loaded split(ELS) Specimen. The value of
as a function of various molding pressure is almost same at 307, 431, 585 kPa, however it shows highest value under 307kPa molding pressure, The SEM photographs show good fiber distribution and interfacial bonding of composites when the molding pressure is the 307kPa.
A Study on the Development of an Electronic Control System for Optimal Start and Idle Speed Control in Gasoline Engines
Journal of the Korean Society of Marine Engineering, volume 25, issue 5, 2001, Pages 1148~1160
An electronic control system of the automobile engine for optimal start and idle speed control has been developed. This system employs the microcoputer-based electronic control unit and crank angle sensor for precise control on fuel injection, ignition timing, and idle speed more quickly and accurately at the start and idling. Consequently, the number of misfire can be reduced during been affected by air flow rate, idle quality(roughness), spark timing, fuel injection, water temperature, and load, Thus, this electronic control system strivers to reach the optimal idle operating point, defined the lowest idle speed(fuel economy) and idle quality(roughness), under any engine operating conditions.