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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 10, Issue 4 - Nov 2006
Volume 10, Issue 3 - Aug 2006
Volume 10, Issue 2 - May 2006
Volume 10, Issue 1 - Feb 2006
Selecting the target year
A Study on Droplet Distribution of Bio Diesel Fuels Using Immersion Sampling Method
Kim, M.S. ; Doh, H.C. ; Koh, D.K. ; Ahn, S.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 5~10
The purpose of this study is to measure the droplet distribution and Sauter mean diameter(SMD) of biodiesel fuel, using the immersion sampling method. This method involves using an optical microscope and a CCD camera, to take an image of the droplets. These images are then measured by using a 'Sigma Scan' processing program. The results of the above experiment are summarized as followed ; (1) There can be as much as a 10% error rate when measuring the diameter of these droplets, using the image processing method and the naked eye. (2) The result of droplet size distribution test, TVO(transesterified vegetable oil) big size droplet distribution were increased at ambient pressure
. (3) When ambient pressure increased
above, SMD variation of TVO and UVO(used vegetable oil) 30 are small. (4) On Rosin-Rammler analysis, droplets size distribution of UVO(used vegetable oil) 30 uniform more than TVO 20 on ambient pressure
Investigation of Cooling Performance of the Driving Motor Utilizing Heat Pipe
Lee, Dong-Ryul ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 11~16
This research is to verify the cooling effect of the acting surface on the rotary motor using heat pipe and conventional cooling fan. In order to show the cooling performance of the rotary motor and heat pipe with the fin-typed heat sink, the surface temperature of the motor and condenser was measured in real time. The experiments were also conducted as for not only cooling device installed with heat pipe only, but with heat pipe and conventional cooling fan simultaneously. The present experiment reveals that the cooling combination of the heat pipe and cooling fan is far superior to the conventional cooling device for the driving motor such as the fin-typed heat sink. When the driving voltage of 20V and 14V were supplied to the driving motor, the cooling performance of the rotary motor with heat pipe was 170% and 500%, respectively better than that without heat pipe on steady state condition.
Investigation on the Turbulent Flow Field Characteristics of a Gun-Type Gas Burner with and without a Duct
Kim, J.K. ; Jeong, K.J. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 17~24
The turbulent flow field characteristics of a gun-type gas burner with and without a duct were investigated under the isothermal condition of non-combustion. Vectors and mean velocities were measured by hot-wire anemometer system with an X-type hot-wire probe in this paper. The turbulent flow field with a duct seems to cause a counter-clockwise recirculation flow from downstream to upstream due to the unbalance of static pressure between a main jet flow and a duct wall. Moreover, the recirculation flow seems to expand the main jet flow to the radial and to shorten it to the axial. Therefore, the turbulent flow field with a duct increases a radial momentum but decreases a axial momentum. As a result, an axial mean velocity component with a duct above the downstream range of about X/R=1.5 forms a smaller magnitude than that without a duct in the inner part of a burner, but it shows the opposite trend in the outer part.
Numerical Analysis in Unsteady State on variation of Diameter and Environmental Velocity of Carbon Heating Source
Bae, K.Y. ; Lee, Y.H. ; Lee, S.Y. ; Lee, C.S. ; Kim, B.G. ; Lee, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 25~30
This paper represents the numerical analysis in unsteady state on the variation of diameter and environmental velocity of carbon heating source. In general heating system, the oil and sheath heater is widely used, but these systems have many problems. So, the heating source with carbon ingredient has been researched in many country about manufacture, thermal and electrical properties. In this research, the carbon heating source was studied through numerical analysis on several conditions of unsteady state, heat generation, diameter and environmental velocity. The temperature distributions at steady state are appeared as a non-proportional linear pattern with variations of environmental velocity due to the Nesselt number with convective heat flux is proportioned to 0.805 of Reynolds number. As the radius is increasing, the temperature distributions is appeared the minus tilt because of the environmental condition is cooling by constant temperature. So, the correlation equation between temperature at steady state and environmental velocity was obtained.
Experimental Study of Characteristics on Double Heat Exchange Pipe Used Separation Type Air-Conditioner
Kim, J.D. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 31~37
In this study, the ability for the function of double pipe inserted liquid pipe with small diameter in the gas pipe with large diameter for the circulating of liquid of high temperature and high pressure and low temperature and low pressure at the same time is presented. And in this double pipe, liquid pipe of high temperature and pressure is used to connect condenser and expansion valve and gas pipe of low temperature is used to connect evaporator and compressor. Also, when liquid refrigerant of high temperature and gas refrigerant of low temperature is circulated by reversed flow in the double pipe. The contribution of liquid gas heat exchange pipe is studied by comparison of the effect of heat transfer by temperature difference when liquid pipe and gas pipe is installed separately.
Characteristics of Pressure Drops in Square Channels with Twisted Tape Inserts plus Axial Interrupted Ribs
Ahn, S.W. ; Bae, S.T. ; Kang, H.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 38~42
Pressure drops and friction factors in square channels with twisted tape inserts plus axial interrupted ribs are investigated. Tests are performed for Reynolds numbers ranging from 8,900 to 29,000. The rib height-to-channel hydraulic diameter,
, is kept at 0.057 and test section length-to-hydraulic diameter,
is 30. The pressure drops and friction factor values are enhanced with axial interrupted ribs and twisted tape inserts. Square channels with twisted tape inserts plus axial interrupted ribs show the greatest pressure loss penalty in the present work. Friction factor data obtained for the square channel with twisted tape inserts plus axial interrupted ribs are less than those in the past publications for circular tubes with axial interrupted ribs and twisted tape inserts.
Thermal Environment Analysis of a Classroom by CFD Simulation to Determine Optimal Temperature Sensor Position in Ceiling Type Air-Conditioning System
Li, M.H. ; Kim, D.G. ; Kum, J.S. ; Jeong, S.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 43~49
Nowadays, the thermal environments of classrooms are usually adjusted by the ceiling type air-conditioning system with a temperature sensor installed on inlet of an air-conditioner. However, it is not clear that the conventional temperature sensor position is proper to satisfy both thermal comport and energy saving in summer especially. Therefore, this study is aimed at finding out the best position of the temperature sensor on the purpose of the comfort thermal environment and energy saving. The different 5 positions for the temperature sensor are supposed in this paper to analyze thermal environment by CFD. From the analysis through the CFD simulations, the best position of the temperature sensor satisfying for both comfort thermal environment and energy saving is obtained.
Flow Characteristics of Oil Jet for Cooling a Piston
Li, L. ; Lee, J.H. ; Jung, H.Y. ; Kim, J.H. ; Lee, Y.W. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 50~55
An efficient cooling system for a piston of an automotive engine is very important. Therefore a large capacity gasoline engine or diesel engine has adopted the direct injection cooling system to increase its cooling efficiency. In this direct cooling system, an cooling oil is injected to a piston directly using an oil jet and this cooling oil flows through an oil gallery inside the piston. Flow rate and injection accuracy of this cooling oil are very important because these are main factors that have influence on its efficiency. The purpose of this study is to understand the changes of flow characteristics with various curvatures and diameters of an outlet nozzle and to check whether engine oil enters into the oil gallery well or not. From this study, we found that secondary flow was formed in a curved part of jet due to centrifugal force and irregular flow pattern appeared at the jet outlet. This pattern has influence on flow characteristics of engine oil entering the gallery. These simulation results have a good agreement with experiments.
Measurement System Development for Three-Dimensional Flow Velocity Components Using Straight-Type Five-Hole Pressure Probe
Kim, J.K. ; Jeong, K.J. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 56~64
This paper shows the development process of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. The data reduction method using a bi-cubic curve-fitting program in a new calibration map was introduced in this study. This new calibration map can be applied up to the application angle,
of a probe. As a result, for the application angle of
, an error for yaw and pitch angles appeared from
, respectively. Moreover, an error for a vector magnitude and a static pressure compared with a dynamic one showed from -7.83% to 4.87% and from -0.73 to 0.77, respectively. Even though this data reduction method showed unsatisfactory errors in a vector magnitude, it resulted in an easy and simple application method. Especially, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole. However, in order to obtain a better result, it is thought that a more sophisticated interpolation method needs to be introduced.
Investigation of the Optimal Cooling Performance Using Peltier Module and Heat Sink
Lee, Dong-Ryul ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 65~70
This study is to experimentally evaluate the cooling performance of the Bonding type and Injection type of heat sink using three different kinds of industrial Peltier module by digital LabViewTM measurement. Injection type of heat sink could be more efficient for the heat transfer than Bonding type, even with 30% more radiating surface area. In addition, the experimental results revealed that the sufficient power supplied was able to show the better cooling performance of Peltier module. In order to verify the optimal cooling performance of the cooling device, two Peltier module, HMN 6040 and HMN 1550 with Bonding and Injection type of heat sink were used. The cooling performance with injection type of heat sink was 2.11% and 6.24% better than that with bonding type of heat sink under the HMN 6040 and HMN 1550, respectively.
A Study on Dynamic Analysis of Vertical Mixed-Flow Pump for Nuclear Power Plants
Seo, Y.S. ; Lim, W.S. ; Chung, H.T. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 71~77
This study introduces the seismic qualification of safety related equipments for nuclear power plants to verify the possibility of resonance in regard to the operating speed and the structural integrity due to external piping nozzle loads as well as seismic dynamic loads using El-Centro earthquake, which was occurred in the 1940's previously. As a first step, it is necessary to investigate the natural frequency of the vertical mixed flow pump in order to determine whether static or dynamic equipment comparing with seismic cut-off frequency, 33hz. Also the normal mode analysis was carried out with the introduction of seismic redesign straint at the middle of vertical pump to increase the natural frequency. In terms of structural integrity, the application of static analysis with normal, upset and faulted nozzle loads event was presented for the comparison of material allowable stress. Also the dynamic analysis was performed to show the design adequacy through the application to the case of El-Centro earthquake.
The vibration and noise characteristics analysis of Sound Insulation Panel for Transformer
Joeng, Han-E ; Kim, H.J. ; Gu, D.S. ; Choi, B.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 78~82
Recently, The demands for the reduction of noise generated by transformers have been increasing. Almost all of the noise generated by transformers is a result of magnetostricitive vibration in the core. The noise radiates into the atmosphere from the tank through the insulation oil. As the noise of transformer irritates residents, needs for decreasing the noise of transformer have been arised. One method of reduction such a noise is to build a free-standing enclosure of concrete and steel plates around the transformer. However, this method has some disadvantages. Another method of noise reduction is to mount a close-fitting sound insulation panel on the side of a transformer tank. Side plate vibrations of transformer are transmitted to such a sound insulation panel along two paths. In one case, they are transmitted through air by sound pressure and in the other through supporting structures. In the paper, the vibration and noise effect which is transferred from reinforce channel to insulation panel generated by transformer have been identified for the several kinds of insulation panel and damping sheet analytically and experimetally.
In-Plane Flexural Vibration Analysis of Arches Using Three-Noded Hybrid-Mixed Element
Kim, J.G. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 83~89
Curved beams are more efficient in transfer of loads than straight beams because the transfer is effected by bending, shear and membrane action. The finite element method is a versatile method for solving structural mechanics problems and curved beam problems have been solved using this method by many author. In this study, a new three-noded hybrid-mixed curved beam element is proposed to investigate the in-plane flexural vibration behavior of arches depending on the curvature, aspect ratio and boundary conditions, etc. The proposed element including the effect of shear deformation is based on the Hellinger-Reissner variational principle, and employs the quadratic displacement functions and consistent linear stress functions. The stress parameters are then eliminated from the stationary condition of the variational principle so that the standard stiffness equations are obtained. Several numerical examples confirm the accuracy of the proposed finite element and also show the dynamic behavior of arches with various shapes.
A Fatigue Analysis of the Common Stand in a Steel Mill through the Evaluation of Thermal Effects
Park, Y.K. ; Kim, J.G. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 90~98
A Study on Prediction of Young's Modulus of Composite with Aspect Ratio Distribution of Short Fiber
Lee, J.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 99~104
Young's modulus of composite has been predicted by Eshelby's equivalent inclusion method modified with Mori-Tanaka's mean field theory, where short fibers of aspect ratio distribution are assumed to be aligned. Young's modulus of the composite is predicted with the smallest class interval for simulating the actual distribution of fiber aspect ratio, which is compared with that computed using different class intervals. Young's modulus of the composite predicted with mean aspect ratio or the largest class interval is overestimated by the maximum 10%. As the class interval of short fibers for predicting Young's modulus decreases, the predicted results show good agreements with those obtained using the actual distribution of fiber aspect ratio. It can be finally concluded from the study that if and only if the class interval of short fiber normalized by the maximum aspect ratio is smaller than 0.1, the predicted results are consistent with those obtained using the actual distribution of aspect ratio.
A Study on the Modeling Analysis for Kaplan Micro-turbines
Kim, O.S. ; Kim, I.S. ; Kim, H.H. ; Shim, J.Y. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 105~110
Among many other alternative energy resources, small scale hydro power has been brought into attention as a reliable source of energy today, which had been relatively neglected since 1960s. Especially, Kaplan micro-turbine can be applied to various kind of small hydro power plants, such as reservoirs for agriculture purpose, sewage treatment plants and water purification plants. However present low head of Kaplan micro-turbines and small scale hydro turbines, have limitations in the minimum required head and flow rate for efficient operation. This research is to develop modeling analysis for the Kaplan micro-turbine, which can improve economical features of small hydro power plants. The contents and scope of this research are the efficiency improvement of Kaplan micro-turbine.
A Study on the Corrosion Properties of Underwater Wet Arc Welds using the SM 41
Kwak, H.H. ; Kim, C.G. ; Kim, M.N. ; Hwang, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 111~118
Underwater wet arc welds were experimentally performed on 11mm thick KR-RA steel plate using six different types of flux coated electrodes of 4.0mm diameter, KSKR, KSKT, USBL, JPUW, UWEA and UWEB. From analysis of bead appearance, detachability of weld slag, spatter occurrence and arc stability, JPUW gives the best result, and UWEB is superior to KSKR and KSKT. By experimental result of hardness distribution on the weld bonds, UWEB weld has the narrowest bond structure which is probable condition to get the best mechanical properties of weld. UWEB and JPUW welds have more even hardness distribution across weld deposit and base metal. Upon polarization test to measure the respondency of corrosion, the electrode of UWEB shows the most excellent degree due to the low open circuit potential difference.
A Study on Gerotor Design with Optimum Tip Clearance for Low Speed High Torque Gerotor Hydraulic Motor
Seo, J.S. ; Chung, H.S. ; Jeong, H.M. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 119~126
Gerotor hydraulic motor is widely used in hydraulic systems due to its low speed, high torque output and compactness in rotational direct driving of a heavy weight. Gerotor is a Planar mechanism consisted of a pair of rotor and circular teeth of stator assembly which forms a closed space, so called a chamber. The motion of rotor relative to the circular tooth is produced by the pressure difference of hydraulic operating fluid between the adjacent chamber. As all active contact points of rotor and circular teeth are subjected to very high sliding friction, a reduction in the performance of the gerotor hydraulic motor can not be avoided. Therefore, the core design parameters of gerotor profile used in hydraulic motors is to minimize a friction force by high contact stresses. The analytical design method of gerotor profile, based on envelope of a family of curves, is proposed. In this study, the influence of the tip clearances on three critical contact points between rotor and circular teeth of stator assembly has been explored by experimental data in this paper. At the same time a improvement method to reduce the friction force is proposed and the tip clearances on three critical points for getting an optimum gerotor profile are also analyzed.
The Estimation of Shape Parameter of Pneumatic Cylinders
Kang, B.S. ; Song, C.S. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 127~132
Pneumatic cylinders that are usually applied in the factory automation line have complicated failure cause because they are composed of various elements. In this study, we performed life test and performance test of double acting pneumatic cylinders according to the international standards and then analyzed the life and the main failure mode of the cylinders in the same load condition. On the basis of these processes, we can estimate shape parameter for the reliability estimation of pneumatic cylinders and their data analysis of life distribution.
A Study on Effective Thermal Conductivity of Particulate Reinforced Composite
Lee, J.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 133~138
Effective thermal conductivity of particulate reinforced composite has been predicted by Eshelby's equivalent inclusion method modified with Mori-Tanaka's mean field theory. The predicted results are compared with the experimental results from the literature. The model composite is polymer matrix filled with ceramic particles such as silica, alumina, and aluminum nitride. The preliminary examination by Eshelby type model shows that the predicted results are in good agreements with the experimental results for the composite with perfect spherical filler. As the shape of filler deviates from the perfect sphere, the predicted error increases. By using the aspect ratio of the filler deduced from the fixed filler volume fraction of 30%, the predicted results coincide well with the experimental results for filler volume fraction of 40% or less. Beyond this fraction, the predicted error increases rapidly. It can be finally concluded from the study that Eshelby type model can be applied to predict the thermal conductivity of the particulate composite with filler volume fraction less than 40%.
A Study on the Development of Automatic Ship Berthing System
Kim, Y.B. ; Choi, Y.W. ; Chae, G.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 139~146
In this paper vector code correlation(VCC) method and an algorithm to promote the image processing performance in building an effective measurement system using cameras are described for automatically berthing and controlling the ship equipped with side thrusters. In order to realize automatic ship berthing, it is indispensable that the berthing assistant system on the ship should continuously trace a target in the berth to measure the distance to the target and the ship attitude, such that we can make the ship move to the specified location. The considered system is made up of 4 apparatuses compounded from a CCD camera, a camera direction controller, a popular PC with a built in image processing board and a signal conversion unit connected to parallel port of the PC. The object of this paper is to reduce the image processing time so that the berthing system is able to ensure the safety schedule against risks during approaching to the berth. It could be achieved by composing the vector code image to utilize the gradient of an approximated plane found with the brightness of pixels forming a certain region in an image and verifying the effectiveness on a commonly used PC. From experimental results, it is clear that the proposed method can be applied to the measurement system for automatic ship berthing and has the image processing time of fourfold as compared with the typical template matching method.
The Parameter Optimization of Current Amplifier with GA
Yang, J.H. ; Jeong, H.H. ; Kim, Y.W. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 147~152
The current type amplifier is the device that is used for an actuator as the motor's torque controller. However, it is too difficult to select the parameter value that has the desired output because the current type amplifier's transfer function is too complex. This study concern about the design of the current type amplifier with the desired output. From the modeled transfer function of the current type amplifier, the optimal parameter values of the transfer function can be selected in order to have the desired output using the Real Coded Genetic Algorithm(RCGA). The real circuit is made with the selected parameter value. The step response of the real circuit is in good agreement with the desired step response.
Estimation of Blood Flow in a Double Output Centrifugal Blood Pump
Sin, D.C. ; Andy, Tan ; Choi, B.K. ; Kim, W.C. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 153~158
Speed Control for Low Speed Diesel Engine by Hybrid F-NFC
Choi, G.H. ; Yang, J.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 159~164
In recent, the marine engine of a large size is being realized a lower speed, longer stroke and a small number of cylinders for the energy saving. Consequently the variation of rotational torque became larger than former days because of the longer delay-time in fuel oil injection process and an increased output per cylinder. It was necessary that algorithms have enough robustness to suppress the variation of the delay-time and the parameter perturbation. This paper shows the structure of hybrid F-NFC against the delay-time and the perturbation of engine parameter as modeling uncertainties, and the design of the robust speed controller by hybrid F-NFC for the engine. And, The Parameter values of linear equation are determined by RC-GA for F-NFS. The hybrid F-NFC is combined the F-NFC and PID controller for filling up each.
A Study on Gas Pressure Fluctuation Characteristics inside Pipe Line Passing Through a Snubber at Hydrogen Compressor
Shim, K.J. ; Yi, C.S. ; Akbar, Wanda Ali ; Chung, H.S. ; Jeong, H.M. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 165~171
An experiment to observe reduction of pressure fluctuation in the compressing system utilizing snubber has done. The experiment measured pressure at inlet and outlet of snubber. It used an air compressor as a model of hydrogen one. Snubber with buffer and snubber without buffer were used to get comprehensive comparison between both of that snubber. An analysis by using Fast Fourier Transform (FFT) method was conducted to verify working pressure frequency. With this method pure signal of static pressure was filtered from noisy signal. The experiment was run for several speeds of piston movement. It was controlled by adjustable frequency regulator that controled rotation of actuator motor. This was connected to the piston-reciprocating compressor with V-belt. From result obtained, the fluctuation was increasing proportionally when frequency of driver motor was increased.
Shortest Path Planning and Robust Control of Two-wheeled Mobile Robot
Kim, H.K. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 172~180
Speed reducer be indicated a power using of elastic strain
Noh, S.Y. ; Nam, W.K. ; Kang, H.K. ; Kim, N.I. ; Kim, Y.T. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 10, issue 4, 2006, Pages 181~186
In this paper, a noncontact type torque meter using silicone rubber to measure the exact torque value and reduce a vibration and a noise, was developed. When planetary gear speed reducer runs, torque, RPM etc.. of motor change according to load or speed change. So, it needs a device to detect load's change or to diagnose the state of thewhole drive department by monitoring these result values. The noncontact type torque meter using silicone rubber that we're trying to develop this time is low-cost and can measure RPM and torque value simply. Also, it caculate a power using this value and indicate them on screen.