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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korea Society For Power System Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Power System Engineering
Editor in Chief :
Volume & Issues
Volume 13, Issue 6 - Dec 2009
Volume 13, Issue 5 - Oct 2009
Volume 13, Issue 4 - Aug 2009
Volume 13, Issue 3 - Jun 2009
Volume 13, Issue 2 - Apr 2009
Volume 13, Issue 1 - Feb 2009
Selecting the target year
Performance of A Fresh Water Generator Applied Plate Heat Exchangers and Flow in the Channel
Jin, Z.H. ; Ji, M.K. ; Lee, K.S. ; Chung, H.S. ; Jeong, H.M. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 5~10
Numerical Study of Unsteady Mixed Convection in a Cavity with High Viscous Fluid
Bae, D.S. ; Cai, Long Ji ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 11~17
A numerical study of unsteady mixed convection in a cavity with high viscous fluid is presented. Finite volume method was employed for the discretization and PISO algorithm was used for calculating pressure term. The parameters governing the problem are the Rayleigh number (
), the Reynolds number (0 < Re
1), and the aspect ratio (0.5
2). The fluid used is silicon oil, a high prandtl number fluid, Pr = 909.1. The results show velocity vectors and temperature distributions. It is found that the periodic flows in a cavity are observed at very low Reynolds numbers, and the period of periodic flow decreases with increasing Reynolds and Rayleigh numbers, and increases with increasing aspect ratio. Also, the Reynolds number range of periodic flow increases with increasing Rayleigh numbers and aspect ratio.
A Study on Azimuth Thruster for a Small Vessel
Park, J.P. ; Lee, J.M. ; Jin, S.Y. ; Bae, J.H. ; Jung, Y.G. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 18~24
This paper shows the result of development about the revolution system of azimuth thruster which of power is less than 250kW for small ship. Advanced Azimuth revolution system can revolve propeller and rudder from 360 degree so that this system for vessel maneuvering can be excellent of propulsion effectively. Fluid power control system for azimuth thruster is designed with PID control system by using CEMTool/SIMTool program. And the actuator used for servo valve can control rudder angle, pressure and direction. The first, We had a test for the angle control of revolution system. The result of angle control confirmed that it has the good efficiency from experiment result of time input degree
. The second, We had to a test for the pressure characteristic of hydraulic motor. As a result, We confirmed the maximum pressure 3.5MPa and steady state 0.7MPa nom experiment result of time input degree
. In this paper, it is identified the pressure characteristic of hydraulic motor and angle control for azimuth thruster by AMESim, and it has been confirmed the usefulness of AMEsim modeling was verified by comparison between AMESim simulation results and experiments results.
Thermal Numerical Simulation on Fire Suppression Characteristics through Mobile Mist Spray Nozzles
Bae, K.Y. ; Chung, H.T. ; Kim, H.B. ; Jung, I.S. ; Kim, C. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 25~33
In the present study, the numerical investigation has been carried out to see the effects of water mist sprays on the fire suppression mechanism. The special-purposed program named as FDS was used to simulate the interaction of fire plume and water mists. This program solves the fire-driven flows using LES turbulence model, the mixture fraction combustion model, the finite volume method of radiation transport for a non-scattering gray gas, and conjugate heat transfer between wall and gas flow. The computational domain was composed of a rectangular space dimensioned as
with a mist-injecting nozzle installed 1.0 m high from the fire pool. In this paper, two types of nozzles were chosen to compare the performance of the fire suppression. Numerical results showed that the nozzle, type A, with more orifices having smaller diameters had poorer performance than the other one, type B because the flow injected through side holes deteriorated the primary flow. The fire-extinguishing time of type A was 2.6 times bigger than that of type B.
Evaluation of Turbulent Models on the Mixing Flow Structure of
Impinging Jet by Two Round Jets
Kim, J.K. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 34~39
In this paper, the CFD analysis using various turbulent models has been performed to evaluate which type of turbulent models can predict well the mixing flow structure of
impinging round jet. This CFD analysis has been carried out through the commercial Fluent software. As a result, any of turbulent models cannot predict the experimental results definitely all over the flow range. However, as compared with the experimental results, the turbulent model of realizable(RLZ) k-
only predicts well in the limited range between X/
Multi-flexible Body Dynamic Analysis of a Heavy Trailer Vehicle Passing a Bump
Kim, J.Y. ; Kim, H.S. ; Kim, J.G. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 40~45
This article deals with the transient analysis using multi-flexible body dynamics of a trailer vehicle, which is passing a bump on the flat road. In order to investigate the transient dynamic behavior of the trailer, we developed an equivalent finite element model for the trailer and a vehicle dynamic model for the truck using multi-body dynamics. The driving condition considered here is set as the trailer vehicle passes a bump on the flat road in 7km/h. And we investigate the time histories of vertical load and deflections on connecting points between the trailer and truck during the vehicle passes a bump. Due to the dynamic load resulted from the driving condition, additional stress concentrations are found in the trailer and the suspension connecting points between the trailer and rear axles along with kingpin.
Development of HDD Vibration/Shock Simulation Tool for Design Engineers
Kim, J.G. ; Lee, J.K. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 46~51
Recently, the shock resistance and dynamic characteristics of hard disk drives have become more important due to their highly increased storage density and miniaturization. In this study, we have developed an ANSYS/Mechanical/LS-DYNA based HDD vibration/shock simulation tool for design engineers. This simulation tool using ANSYS APDL can produce a parametric finite element modeling of HDD automatically and has GUI-based applications using the script program language Tcl/Tk. In the present tool, we adopt the reliable methodology of vibration/shock simulation, which is experimentally verified. It is expected that this simulation tool can make the repetitive computational efforts for the shock-proof design of HDD drastically reduced.
Investigation of the Thermo-mechanical Crack Initiation of the Gas Turbine Casing Using Finite Element Analysis
Kang, M.S. ; Yun, W.N. ; Kim, J.S. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 52~58
A gas turbine consists of an upstream compressor and a downstream turbine with a combustion chamber, and also the compressor and the turbine are generally coupled using a single shaft. Many casing bolts are used to assemble two horizontally separated casings, the gas turbine casing and the compressor casing, in both of axial and vertical directions. Because drilled holes for casing bolts in vertical direction are often too close to drilled holes for casing bolts in axial direction, one can observe cracks in the area frequently during operations of a gas turbine. In this study of the root cause analysis for the cracking initiating from the drilled holes of the casings of a gas turbine, the finite element analysis(FEA) was applied to evaluate the thermal and mechanical characteristics of the casings. By applying the field operation data recorded from combined cycle power plants for FEA, thermal and thermo-mechanical characteristics of a gas turbine are analyzed. The crack is initiated at the geometrical weak point, but it is found that the maximum stress is relieved when the same type of cracks is introduced on purpose during FEA. So, it is verified that the local fracture could be delayed by machining the same type of defects near the hole for casing flange bolts of the gas turbine, where the crack is initiated.
Study on Statistical Analysis of Measured Fluid Leakage Data and Estimation of the Leakage Rate for Power Plant Valve
Lee, S.G. ; Kim, D.W. ; Kim, Y.S. ; Park, J.H ; Jeong, H. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 59~66
High temperature and pressure valves in power plant have been used for fluid flowing and leakage occurred owing to valve internal damage such as disc wear, crack and inserting of foreign objects etc. in these valves. Recently, multi-measuring technique applied both ultrasonic and acoustic method have been used for evaluation of valve internal leakage in order to raise measurement reliability. Therefore, we have performed various leakage tests using ultrasonic and acoustic measuring system and acquired leakage data for the various leakage conditions. In this study, we developed the estimation method of regression model through leakage data, and expectation method for valve opening ratio, which is directly proportion to leakage rate, using the established estimation model from the measured data, valve size and fluid pressure so as to enhance data reliability. As a result of this study, it was founded that expectation method of leakage rate by statistical analysis method is appropriate to valve leakage evaluation.
Mechanical Properties of Heat Exchanger Element with Higher Capacity Waste Heat Recovery PDC Clean Ventilation System
Ahn, S.H. ; Nam, K.W. ; Ahn, B.H. ; Kim, D.G. ; Jeong, S.K. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 67~75
Recently, the higher capacity waste heat recovery PDC clean ventilation system has a tendency which is increasing due to the excellent energy reduction in factory, big building, and so on. This system was developed to complement the room environment which is deteriorated. However, the researches and technologies about this system were not well studied. Specially, the characteristic for heat exchanger element used to this system were not well known. Therefore, this study was carried out to evaluate the mechanical properties of the heat exchanger element as the core parts compose of this system. From results, tensile strength and elongation of the plate type heat exchanger element had about 10.11~14.32 kgf/
and 8.0~16.2%, respectively.
Development of Accident Analysis Model in Car to Pedestrian Accident
Kang, D.M. ; Ahn, S.M. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 76~81
The fatalities of pedestrian account for about 21.2% of all fatalities at 2007 year in Korea. To reconstruct exactly the accident, it is important to calculate the throw distance of pedestrian in car to pedestrian accident. The frontal shape of SUV vehicle is dissimilar to passenger car and bus, so the trajectory and throw distance of pedestrian by SUV vehicle is not the same of passenger car and bus. The influencing on it can be classified into the factors of vehicle and pedestrian, and road factor. It was analyzed by PC-CRASH for simulation, and SPSS s/w was used for regression analysis. From the simulation results, the maximum impact energy of multi-body of pedestrian was occurred to that of torso body at the same time. And the throw distance increased with the increasing of impact velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and the throw distance of wet road was longer than that of dry road. Finally, the regression analysis model of SUV(Nissan Pathfinder type)vehicle in car to pedestrian accident was as follows;
Analysis and Evaluation Study on Diesel Generator Engine Operation Signature
Park, J.H. ; Choi, K.H. ; Lee, S.G. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 82~88
The purpose of this paper is to provide technical background, techniques and actual diesel engine signature analysis evaluation result. Engine signature analysis(ESA) is a process for monitoring the material condition of diesel engine using external sensors, eliminating the need to periodically disassemble the engine. ESA is also used to balanced the engine. Engine balancing is the process of tuning the engine so that all cylinders carry equal load. ESA is a useful tool to non-intrusively determine the operability and performance and assessment of the material condition of internal component of a diesel engine.
Process Optimization for Thermal-sprayed Ni-based Hard Coating by Design of Experiments
Kim, K.T. ; Kim, Y.S. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 89~94
In this work, the optimal process has been designed by
orthogonal array and analysis of variance(ANOVA) for thermal-sprayed Ni-based hard coating. Ni-based hard coatings were fabricated by flame spray process on steel substrate. Then, the hardness test and observation of microstructure of the coatings were performed. The results of hardness test were analyzed by ANOVA. The ANOVA results demonstrated that the acetylene gas flow had the greatest effect on hardness of the coatings. The oxygen gas flow was found to have a neglecting effect. From these results, the optimal combination of the flame spray parameters could be predicted. The calculated hardness of the coatings by ANOVA was found to lie close to that of confirmation experimental result. Thus, it was considered that design of experiments design using orthogonal array and ANOVA was useful to determine optimal process of thermal-sprayed Ni-based hard coating.
Application of Computed Radiography for Nondestructive Testing of Boiler Tube Weldments
Park, S.K. ; Ahn, Y.S. ; Gil, D.S. ;
Journal of the Korea Society For Power System Engineering, volume 13, issue 5, 2009, Pages 95~102
A steam generator (boiler) in thermal power plants, consisting of more than 30,000 parts and components, can lead to the plant shutdown with damage to even the small part of the components; esp., like weld failures on boiler tubes. Consequently it is greatly demanded to improve the quality of the weld on the boiler tube for the stable operation of the power plants. Because of the feature of the welding, which is done past by melting the work pieces and adding a filler material that cools to become a strong coalescence, there is a great possibility that weld failures take place. As a result, it is regulated to make a non-destructive testing, like radiography test, to detect defects and flaws in the weld. The current film radiography test provides a lower image quality exceeding 2.0% of a basic quality level for a penetrameter, it is very likely to fail to detect micro defect. As a result, the prevention for the boiler tube failure has not been made effectively. In this study, computed radiography technology has been applied as a digital radiography test to the boiler tube weld, and Se-75 radiation source was used to improve the image quality, instead of Ir-192 source. As a result of this study, it is proven to save the time and cost for test and to enhance the quality level of penetrameter penetrating image, which enables to upgrade the quality of radiography test to the boiler tube weld.