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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 18, Issue 6 - Dec 2014
Volume 18, Issue 5 - Oct 2014
Volume 18, Issue 4 - Aug 2014
Volume 18, Issue 3 - Jun 2014
Volume 18, Issue 2 - Apr 2014
Volume 18, Issue 1 - Feb 2014
Selecting the target year
VVT(Variable Valve Timing) Control Technology in Internal Combustion Engine Area
Yun, So-Nam ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 7~13
Heat Transfer Enhancement of a Piezoelectric Fan for Cooling of Electronic Devices
Kim, Eun-Pil ; Yoon, Jung-In ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 14~21
DOI : 10.9726/kspse.2014.18.1.014
Piezoelectric fans are thin elastic beams whose vibratory motion is actuated by means of a piezoelectric material bonded to the beam. These fans have found use as a means to enhance convective heat transfer while requiring only small amounts of power. This study presents new types of models with heat sink having air passage and investigates experimentally their heat transfer characteristics. From the comparison results for four models, the heat transfer coefficients of model 1 are approximately 44~66% higher than those of the reference model 0. The model 1 show the best overall performance about heat transfer and cooling capability. As shown in above results, it is necessary to design the heat sink with air pass for cooling of electronic devices, in order to increase the convective heat transfer coefficient of a piezoelectric fan for electronic cooling.
The Performance Assessment of a Straight-Type Five-Hole Pressure Probe Using a Zone Partition and Two-Dimensional Curve-Fitting Functions
Kim, Jang-Kweon ; Oh, Seok-Hyung ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 22~31
DOI : 10.9726/kspse.2014.18.1.022
This paper introduced the new calibration algorithm of a straight-type five-hole pressure probe necessary for calculating three-dimensional flow velocity components. The new velocity data reduction method using both a commercial two-dimensional curve-fitting program and the zone partition method of a calibration map was firstly introduced in this study. This new calibration method can be applied up to the wide flow angle of
despite of using a five-hole pressure probe because this data reduction method showed a comparatively good performance in calculating yaw and pitch angles from the calibration map.
Optimum Design of an Indoor Package Air-Conditioner's Flow Path by Taguchi Method
Kim, Jang-Kweon ; Oh, Seok-Hyung ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 32~37
DOI : 10.9726/kspse.2014.18.1.032
In this study, the optimum design process of an indoor package air-conditioner (PAC) was implemented by Taguchi method. The goal of this study is to obtain the best set condition of each control factor composing of an indoor PAC. The number of revolution of a double inlet sirocco fan installed in an indoor PAC was measured by the orthogonal array of
and analysed by using the-smaller- the-better characteristic among the static characteristic analyses. As a result, the optimum condition of an indoor PAC was found as a set of
when the cost of production, assembling and working conditions were considered. Moreover, the number of revolution of a double-inlet sirocco fan used for an optimum condition was reduced about 8.5% more than that of a standard condition for the target flowrate of
The Measurements of Ball Recovery Rate for the Cleaning Apparatus in Plate Heat Exchanger Using Ceramic Ball
Chae, Hee-Man ; Kwon, Jeong-Tae ; Cha, Dong-An ; Kwon, Oh-Kyung ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 38~44
DOI : 10.9726/kspse.2014.18.1.038
The objectives of this study are to measure the ball recovery rate of cleaning apparatus for plate heat exchanger. Ceramic ball is used for plate heat exchanger cleaning. The main components of cleaning apparatus are comprised of ball collector, ball trap, ejector, pump and plate heat exchanger. The ball recovery rate are obtained with change in recovery time and velocity of water. The results show that the ball recovery rate is slightly increased with increase in the recovery time and the velocity of water over 0.4 m/s in the straight flow. In the case of reverse flow, the ball recovery rate more increased than straight flow. The maximum ball recovery rate of the straight flow and reverse flow reach 83.97% and 86.61%, respectively, when the velocity and cleaning time are 0.5 m/s and 15min.
Cooling and Heating Load Analysis According to Building Type of Apartment House
Yoon, Sung-Meen ; Lee, Kyung-Hee ; Ahn, Young-Chull ; Kim, Yong-Tae ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 45~50
DOI : 10.9726/kspse.2014.18.1.045
This study focuses on the analysis of the cooling and heating load in accordance with apartment houses arrangement type using Ecotect Analysis. Korea have to reduce energy consumption part of building except in industry and transport because the rate of dependence on imports amounts to 94%, Apartment houses built in various forms in order to reduce energy are modelled in each window area ratio, shape, orientation, and climate through simulation. Through this study, we can analyze the cooling and heating load by form, window area ratio, orientation, and climate change and know the optimal elements by the form. In particular, although there have been done research on the window area ratio and the arrangement form, the research of the regional climate characteristics and the direction are hardly carried out. To supplement those problem, adding to seven direction and climatic element of southern region is characteristic(L Type, Y Type, - Type) of this study. The form of apartment houses built 10 years ago is modelled for simulation.
Performance Characteristics of New LNG Liquefaction Cycles with Temperature Differences in the Heat Exchangers
Yoon, Jung-In ; Son, Chang-Hyo ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 51~56
DOI : 10.9726/kspse.2014.18.1.051
In this paper, the performance of the
cascade liquefaction cycle with respect to temperature differences in the LNG heat exchangers is analyzed theoretically using HYSYS software and then compared the COP(coefficient of performance) of the cascade liquefaction cycles using
. In comparison of COP of three cycles, the cascade liquefaction cycles using
showed the highest COP. And the liquefaction cycle using
presented the second and third highest COP, respectively. In case of COP, the
cascade liquefaction cycle yields better COP. But, in terms of the environment and maintain, it is confirmed that the cascade liquefaction cycle using
provides favorable characteristics.
Performance Comparison of Two-stage Compression Refrigeration System Using R404A
Yoon, Jung-In ; Choi, Kwang-Hwan ; Son, Chang-Hyo ; Jo, Hwan ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 57~62
DOI : 10.9726/kspse.2014.18.1.057
This paper present the performance characteristics of R404A two-stage compression refrigeration system. The operating parameters considered in this study include evaporating and condensing temperature, subcooling and superheating degree, compressor efficiency. The main results were summarized as follows: The COP of two-stage compression refrigeration system using R404A has an effect on the variation of evaporation temperature, condensation temperature, subcooling degree and compressor efficiency, but not an effect on the superheating degree. R404A two-stage compression refrigeration system is unstable because COP of this system is significantly changed when evaporating temperature and compressor efficiency decreased. In particular, when compressor efficiency decreased, COP is significantly decreased. This is inefficient for long-term use.
The Numerical Analysis of Fluid Flow in the Tube Cleaning System
Jung, Kyung-Chul ; Lee, Chi-Woo ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 63~68
DOI : 10.9726/kspse.2014.18.1.063
The numerical analysis of fluid flow in the tube cleaning system is examined. The working flow used in this study is seawater, and the temperature change is not considered as the temperature change of seawater in the tube cleaning system is negligible. Also, the analysis is performed under the assumption of steady state. The screens of complicated morphologies are simplified for the analysis, and only one fourth of the tube cleaning system is modeled as the system has a symmetrical shape. The velocity inlet boundary condition is employed for the seawater inlet, whereas the outflow boundary condition is employed for two seawater outlets. In applying the outflow boundary condition for the system with more than two outlets, the flow rate can be arbitrarily assigned. In the analysis, the finite-volume method based numerical analysis tool, the pressure based solver, the standard k-
model are utilized, and the under relaxation factor is modified appropriately. From the analysis, the distribution of velocity vectors, pressure and path lines are obtained, and the physical characteristics of fluid flow in the tube cleaning system is well-examined.
A Study on the Dynamic Characteristics of Nitrogen Mixed Gas for Thermostatic Expansion Valve Sensing Blub
Kim, Si-Young ; Koo, Su-Jin ; Ju, Chang-Sik ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 69~75
DOI : 10.9726/kspse.2014.18.1.069
The pressure and temperature characteristics of mixed refrigerant gases in bulb for thermostatic expansion valve were studied using R22 refrigerant and
gases. The characteristics of mixed refrigerant gases were investigated according to pressure variation and the variation of composition ratio of R22 refrigerant and
gases in the temperature range of -
. The Maximum operating pressure(MOP) of mixed refrigerant gases were showed a tendency to decrease with decreasing the mixing ratio of
gas. The characteristics in the case of the mixing ratio of 90:1 for R22 refrigerant and
gases were the same result as Reference refrigerant. In addition, the characteristics of the mixed refrigerant gases in the mixing ratio of 90:1 for R22 refrigerant and
gases were showed almost linear in the measurement range of pressure-temperature, and the physical properties also were showed similar results with Reference refrigerant. It was able to confirm that a MOP on the thermostatic expansion valve for sensing bulb can be maintained by adjusting the mixing ratio of R22 refrigerant and
Failure Criterion of Straight Pipe with Outer Local Wall Thinning under Internal Pressure
Kim, Soo-Young ; Nam, Ki-Woo ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 76~83
DOI : 10.9726/kspse.2014.18.1.076
This study was carried out an experimental and finite element analysis on the fracture behavior of straight pipes with local wall thinning under internal pressure. Local wall thinning was machined on the pipes in order to simulate erosion/corrosion metal loss. The configurations of the eroded area has an eroded ratio of d/t=0.80~0.92 and an eroded length of l=25, 50 and 102 mm. Three-dimensional elastic-plastic analyses were also carried out using the finite element method, which is able to accurately simulate failure behaviors. In regards to the relation ship between pressure and eroded ratio, the criterion that can be used safely under operating pressure and design pressure were obtained from this calculation. The results of this calculation were in relatively good agreement with that of the experiment.
A Study on the Optimal Crimping Diameter of Aircraft Fuel Hoses in Manufacturing Process
Jeon, Jun-Young ; Kim, Byung-Tak ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 84~90
DOI : 10.9726/kspse.2014.18.1.084
The high pressure hoses are widely used for the vehicles, aircraft, and overall industries. The hose assembly is generally composed of a nipple, a socket and a hose with reinforcement layers to increase the tensile strength. To produce the hose assembly, crimping or swaging process is usually used to clamp its components to ensure the prevention of fluid leakage. Crimping is a cold-working technique to form a strong bond between the workpiece and a non-metallic component. The crimping stroke is a primary parameter to be determined in the metalworking process, and it plays an important role in hose performance. This study aims at investigating the optimal crimping stroke according to the size of aircraft high pressure hose by using MSC/MARC. It is supposed that the results can be useful to get the information about the crimping stroke in manufacturing process, even with the different size of a hose.
Effect of Crack Orientation on Spatial Randomness of Fatigue Crack Growth Rate in FSWed 7075-T651 Aluminum Alloy Joints
Jeong, Yeui-Han ; Kim, Seon-Jin ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 91~98
DOI : 10.9726/kspse.2014.18.1.091
In this investigation, the effect of crack orientation on spatial randomness of fatigue crack growth rate (FCGR) in friction stir welded (FSWed) 7075-T651 aluminum alloy joints has been statistically analyzed by Weibull distribution. The fatigue crack growth tests are conducted under three different constant stress intensity factor range (SIFR) control at room temperature with R = 0.1 and frequency 10Hz on compact tension (CT) specimen machined at base metal (BM) and weld metal (WM). The experimental fatigue crack growth rate data were obtained for two types of specimens having LT and TL orientations. LT specimens both base metal and weld metal showed higher fatigue crack growth rate as compared to TL specimens. In the lower SIFR region, FCGR were found to be almost 3 times higher in higher SIFR region. The shape parameter of Weibull both LT and TL orientation for FCGR was increased with increasing SIFR, the scale parameter was also increased with increasing SIFR. The smallest value of the shape parameter was shown in weld metal specimens having LT orientation at lower SIFR region.
Static Analysis of Trapezoidal Corrugated Plates under Uniformly Distributed Load
Kim, Young-Wann ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 99~105
DOI : 10.9726/kspse.2014.18.1.099
In this paper, the static characteristics of the trapezoidal corrugated plate under uniformly distributed pressure are investigated by the analytical method. Because the corrugated plate is very flexible in the corrugation direction and stiff in the transverse direction, the corrugated plate is treated as the orthotropic plate. This equivalent orthotropic plate must include both the extensional and flexural effect to obtain the precise solution. The effective extensional and flexural stiffness of the trapezoidal corrugated plate are derived to consider these effects in the analysis. To demonstrate the validity of the proposed approach, the comparison is made with the previously published results. Some numerical results are presented to check the effect of the geometric properties.
Effect of Post Heat Treatment on Wear Characteristics of Thermally Sprayed Co-based Self-flux Alloy Coating
Lee, Jae-Hong ; Kim, Yeong-Sik ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 106~111
DOI : 10.9726/kspse.2014.18.1.106
This article describes effect of post heat treatment on wear characteristics of thermally sprayed Co-based self-flux alloy coating. Co-based self-flux alloy coatings were deposited on steel substrates using a flame spray process. Post heat treatments were carried out at 800, 900, 1000 and
for 30min in a vacuum chamber. For analysis of effect of post heat treatment on mechanical properties, wear test and hardness test were performed for post heat-treated coating specimen. Microstructures of heat treated coating layer and wear track were examined using SEM and EDS. Wear loss and hardness became lower with increasing post heat treatment temperature.
Synchronized Control of Active Harmonic Gear System
Kim, Sang-Jin ; Moon, Deok-Hong ; Kim, Young-Bok ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 112~119
DOI : 10.9726/kspse.2014.18.1.112
In this paper, the authors consider a gimbal system in which a camera is installed to reconnoiter the objects or targets. The issue for this considered system is to obtain information with good quality always. To achieve given objective, it is necessary to control the gimbal system with accurate rotation angle and speed. In this paper, the authors design a robust control system based on
control framework. The controller is designed using a plant model obtained by experiment and simulation. And the experiment result with good control performance is presented.
Stabilizing Controller Design for Time-Delay Pure Singularly Perturbed Systems via Lambert W Function
Kim, Beom-Soo ; Ahn, Soo-Whan ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 120~127
DOI : 10.9726/kspse.2014.18.1.120
In this study, Design methods of stabilizing controller for time-delay pure singularly perturbed systems are proposed. Based on the Chang transformation and Lambert W function, we decompose the time-delayed pure singularly perturbed systems into completely decoupled subsystems and derive sufficient stability conditions for
time-delayed pure singularly perturbed systems. An illustrated example is presented to demonstrate the validity and applicability of the proposed methods.
Elasto-hydrodynamic Lubrication Analysis for Biomimetic Riblet Surface like Shark Skin
Kim, Tae-Wan ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 128~134
DOI : 10.9726/kspse.2014.18.1.128
For the characteristic assessment of biomimetic shark skin structure pattern for engineering applications, we conducted the elastic hydrodynamic lubrication analysis for the shark skin surface pattern. The shark skin surfaces with roughness are generated numerically in the similar size with real shark skin scales. For the spherical contact on the generated shark skin surface with two different flow directions which are transversal and longitudinal, 3-dimensional elasto-hydrodynamic lubraction analysis are carried out. The result of the longitudinal flow which are similar with the flow of shark skin shows more beneficial effects with lower pressure and less sensitive effect with surface roughness.
Rejection Degree by Fuzzy Significance Probability
Choi, Gyu-Tag ; Park, Il-Soo ; Nam, Hyun-Woo ; Moon, Jong-Choon ;
Journal of the Korea Society For Power System Engineering, volume 18, issue 1, 2014, Pages 135~139
DOI : 10.9726/kspse.2014.18.1.135
We propose some properties for fuzzy hypothesis test by fuzzy significance probability. First, we define fuzzy number data and fuzzy significance probability for repeatedly observed data with alternated error term. By the agreement index, we compare fuzzy significance probability with significance level and drawing conclusions the degree of acceptance and rejection by agreement index.