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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 14, Issue 6 - Dec 2010
Volume 14, Issue 5 - Oct 2010
Volume 14, Issue 4 - Aug 2010
Volume 14, Issue 3 - Jun 2010
Volume 14, Issue 2 - Apr 2010
Volume 14, Issue 1 - Feb 2010
Selecting the target year
Basic Study on the Spatial Structure Analysis of the Evaporative Diesel Spray
Yeom, J.K. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 5~12
The purpose of this study is to analyze heterogeneous distribution of branch-like structure at downstream region of inner spray. The previous many studies about diesel spray structure have yet stayed in the analysis of 2-D structure, and there are very few of informations which are concerned with 3-D analysis of the structure. The heterogeneous distribution of droplets in inner spray affects the mixture formation of diesel spray, and also the combustion characteristics of the diesel engines. Therefore, in order to investigate 3-D structure of evaporative spray the laser beam of 2-D plane was used in this study. Liquid fuel was injected from a single-hole nozzle (l/d=5) into a constant-volume vessel under high pressure and temperature in order to visualize the spray phenomena. The incident laser beam was offset on the central axis. From the images analysis taken by offset of laser beam, we examine formation mechanism of heterogeneous distribution by vortex flow at the downstream of the diesel spray. As the experimental results, the branch-like structure formed heterogeneous distribution of the droplets consists of high concentration of vapor phase in the periphery of droplets and spray tip of branch-like structure. Also the 3-D spatial structure of the evaporative diesel spray can be verified by images obtained from 2-D measurement methods.
Combustion Characteristics of HCCI Engine Fueled DME and Natural Gas(Unbalance of Cylinder-to-Cylinder and Effect of EGR)
Jung, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 13~18
HCCI engines fueled DME and natural gas have been studied on single-cylinder engine due to availability of reducing on
and PM simultaneously without deteriorating into high thermal efficiency, and thus it is clarified that higher maximum engine load is achieved as DME equivalence is smaller. In this study, combustion tests were accomplished on multi-cylinder engine for practical use of it. When minimum DME equivalence achieved maximum engine load on single-cylinder engine was applied to 4-cylinders engine, there was in unstable running condition that engine revolution fluctuated greatly and cyclically. It is the reason what misfire occurred intermittently with one the same as minimum DME equivalence on single-cylinder due to increase in energy for ignition at No. 1 cylinder with lower cylinder liner temperature. Maximum engine load was achieved by adopting EGR, though it decreased because of knocking at smaller engine load than single-cylinder due to increase in minimum DME equivalence.
A Basic Study of the Snow Melting System for the Anti-Freezing Road using the Pulsating Heat Pipe
Kim, J.S. ; Ha, S.J. ; Son, K.J. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 19~24
The purpose of this study is to develop a snow melting system using the pulsating heat pipe(PHP). The experimental apparatus is consisted of a PHP, a concrete structure, a constant water thermostatic bath and a flowmeter. The experiment was performed at the outdoor air temperature of
and inlet temperature of hot water of
. PHP is the closed and non-loop type heat exchanger which is charging R-410A as an operating fluid. As experimental results, the temperature profile of vertical and horizontal orientation of concrete structure was measured with operating time. The heat flux of the snow melting was required more than 300
. We confirmed that the snow melting system using the PHP was useful for anti-freezing road.
CFD and Experimental Study of Gas Flow inside the Wounding Steel Pipe Fitted in Reciprocating Hydrogen Compressor
Chung, H.S. ; Rahman, M. Sq. ; Lee, G.H. ; Woo, J.S. ; Kim, B.H. ; Jeong, H.M. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 25~32
Optimum Design of Vehicle Powertrain Mounting System
Kim, J.H. ; Lee, S.J. ; Lee, W.H. ; Kim, J.R. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 33~38
Technology of vehicle industry has been developing and it is required a better vehicle performance than before. Therefore, the consumers are asking not only an economic efficiency, functionality, polished design, ride comfort and silence but also a driving stability. The ride comfort, silence and driving stability are influenced by the size of vehicle and various facilities. But the principal factor is a room noise and vibration sensed by a driver and passenger. Thus, the NVH of vehicle has been raised and used as a principal factor for evaluation of vehicle performance. The primary objective of this study is an optimized design of powertrain mounting system. To optimized design was applied MSC.Nastran optimization modules. Results of dynamic analysis for powertrain mounting system was investigated. By theses results, design variables was applied 12 dynamic spring constant. And the weighting factor according to translational displacement and rotational displacement applied 3 cases. The objective function was applied to minimize displacement of powertrain. And the design variable constraint was imposed dynamic spring constant ratio. The constraint of design variable for objective function was imposed bounce displacement for powertrain.
Mobility Stabilization of a
Robot Vehicle by Suspension Kinematics Reconfiguration
Baek, W.K. ; Lee, J.W. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 39~45
The dynamic stability of a robot vehicle can be enhanced by the Force-Angle Stability Margin concept that considers a variety of dynamic effects. To evaluate the robot vehicle stability, a SPI(stability performance index), which is a function of the suspension arm angles, was used. If the SPI has a minimum value, the robot vehicle has maximum stability. The FASM and SPI concepts were incorporated in the mobility simulation by using ADAMS and MATLAB/Simulink. The simulation results using these concepts showed significant improvements of the vehicle stability on rough terrains.
Flaw Detection of Petrochemical Pipes using Torsional Waves
Park, K.J. ; Kang, W.S. ; Kang, D.J. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 46~51
A torsional guided wave was applied to detect a defect in petrochemical pipes. Phase and group velocity dispersion curves for the longitudinal and torsional modes of the inspected pipe were presented for the theoretical analysis. It was found through mode shape analysis that there was mode conversion when torsional wave is incident at an asymmetric defect. An artificial notch was fabricated in the pipe and the detectability was examined from the distance 2m of the end of the pipe by using magnetostrictive sensors. The relativities between the amplitude of the reflected signal and the size of the defect was examined. It was shown that the T(0,1) mode could be used for the long range inspection for the petrochemical pipes.
Stress Function-Based Interlaminar Stress Analysis of Composite Laminates under Complex Loading Conditions
Kim, H.S. ; Kim, J.Y. ; Kim, J.G. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 52~57
Interlaminar stresses near the free edges of composite laminates have been analyzed considering wall effects. Interface modeling of bonding layer was introduced to explain the wall effect. Using Lekhnitskii stress functions and the principle of complementary virtual work, the interlaminar stresses were obtained, which satisfied the traction free boundary conditions not only at the free edges, but also at the top and bottom surfaces of laminates. The interface modeling provides not singular stresses but concentrated finite interlaminar stresses. The significant amount of reductions of stresses at the free edge are observed compared to the results without interface modeling. The real stress state can be predicted accurately and the results demonstrate the usefulness of the proposed interface modeling for the strength design of composite laminates.
Microstructure Evolution of UFG Steel Weld by Hybrid and Laser Welding
Dong, H.W. ; Lee, M.Y. ; Ahn, Y.S. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 58~63
A laser beam welding and an electric arc welding were combined, and the positive points of each welding method are drawn such as high speed, low thermal load, deep penetration, and high productivity. The fiber laser-MIG conjugated welding. namely the hybrid welding has been studied mainly for the automation industry of a pipeline welding. In this study, the MIG welding was combined with a fiber laser welding to make up the hybrid welding. The weld shapes, microstructures and mechanical properties for weld zones after the hybrid welding or only fiber laser welding were investigated on the 700 MPa grade Ultra Fine Grained(UFG) high strength steel. The amount of acicular ferrite in weld metals and HAZ(heat affected zone) was observed larger after hybrid welding compared with after only laser welding. The Vickers hardness of the top area of the fusion zone after fiber laser welding was higher compared with after hybrid welding.
A Study on Optimum Tooth Profile of Pin-Pinion Gear for Linear Motion
Ham, S.H. ; Nam, W.K. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 64~70
In this study, designing of precise linear transferring device which can be applied to industrial machine and robot industry has been introduced. The direction of power flow and output feature are similar to current Rack-Pinion type. However, unlimited length extensity via rack modulizing, and securing high velocity transportation have been realized by applying Pin-Pinion Gear type at the operation part. The analysis has been calculated to obtain the Pin-Pinion Gear's optimized tooth profile. As a result of research, it is impossible to control precisely even overlap at the teeth of involute and sprocket. Because they have peculiar gearing structure. Therefore, modified cycloid tooth has been proposed to perform high velocity, precise control without backlash.
Optimization of Design of Safety Block by Structural Analysis
Nam, K.W. ; Gwon, H.S. ; Son, C.S. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 71~76
The safety block which prevents drop of laborers at high altitude was analyzed by finite element method. Elastic analysis was done by Ansys ver. 11.0. and tetrahedral meshing was used. As load applied more vertically at the fixed face of saw tooth, the stress concentration became smaller and the load distributed broader. When load worked at saw tooth and the shape was more straight to the direction of load, most stresses except principal stress became smaller. When the area of the load increased, principal stress and equivalent stress could be decreased simultaneously. A principal stress and other various stresses occurred in 3D shape, therefore revised model which has smaller equivalent stress than other models shows excellence on the stability and the credibility.
A Study on Pressure Characteristic in Various Inner Structure of Valves
Hur, J.G. ; Oh, I.H. ; Yang, K.U. ;
Journal of the Korea Society For Power System Engineering, volume 14, issue 3, 2010, Pages 77~82
In general, the control valves are essential components in hydraulic systems. Structural changes within the valves remain a challenge because many parameters of valve tend to interact in terms of static and dynamic performance. Therefore, the valve characteristics is applied directly to the stability of hydraulic system. Inner structure of the valve which is used mainly in the industries is made up poppet type and spool type. This paper made a description of the method for numerical analysis and modeling of the valve with a built-in moving part of four-type. Based on the physical parameters of the valves, a numerical model of objected valve is developed using the bond graph method. It is to verified the results that the moving part of four-type has an effect on pressure and flow characteristics. Also, It is analyzed the results which has an effect on response characteristic by angular of poppet valve face and inertia variation of the valve with a built-in moving part. In the results, it is confirmed that the rising and settling time vary with the shape of moving part in valve.