Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Transactions of the Korean Society of Mechanical Engineers B
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 35, Issue 12 - Dec 2011
Volume 35, Issue 11 - Nov 2011
Volume 35, Issue 10 - Oct 2011
Volume 35, Issue 9 - Sep 2011
Volume 35, Issue 8 - Aug 2011
Volume 35, Issue 7 - Jul 2011
Volume 35, Issue 6 - Jun 2011
Volume 35, Issue 5 - May 2011
Volume 35, Issue 4 - Apr 2011
Volume 35, Issue 3 - Mar 2011
Volume 35, Issue 2 - Feb 2011
Volume 35, Issue 1 - Jan 2011
Selecting the target year
Thermal Investigation of Joule-Heating-Induced Crystallization of Amorphous Silicon Thin Film
Kim, Dong-Hyun ; Park, Seung-Ho ; Hong, Won-Eui ; Ro, Jae-Sang ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 221~228
DOI : 10.3795/KSME-B.2011.35.3.221
The large-area crystallization of amorphous silicon thin films on glass backplanes is one of the key technologies in the manufacture of flat-panel displays. Joule-heating induced crystallization (JIC) is a recently introduced crystallization technology. It is considered a highly promising technique for fabricating OLEDs, because the film of amorphous silicon on glass can be crystallized in tens of microseconds, minimizing thermal and structural damage to the glass. In this study, we theoretically and experimentally investigated the temperature variation during the phase transformation. The critical temperatures for crystallization were determined for both solid-solid and solid-liquidsolid transitions, by carrying out in-situ temperature measurements and numerical analysis of the JIC.
Experimental Study on Optimization of Absorber Configuration in Compression/Absorption Heat Pump with NH
Kim, Ji-Young ; Kim, Min-Sung ; Baik, Young-Jin ; Park, Seong-Ryong ; Chang, Ki-Chang ; Ra, Ho-Sang ; Kim, Yong-Chan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 229~235
DOI : 10.3795/KSME-B.2011.35.3.229
This research aims todevelopa compression/absorption hybrid heat pump system using an
as working fluid.The heatpump cycle is based on a combination of compression and absorption cycles. The cycle consists of two-stage compressors, absorbers, a desorber, a desuperheater, solution heat exchangers, a solution pump, a rectifier, and a liquid/vapor separator. The compression/absorption hybrid heat pump was designed to produce hot water above
using high-temperature glide during a two-phase heat transfer. Distinct characteristics of the nonlinear temperature profile should be considered to maximize the performance of the absorber. In this study, the performance of the absorber was investigated depending on the capacity, shape, and arrangementof the plate heat exchangers with regard tothe concentration and distribution at the inlet of the absorber.
Effect of Orientation on Pool Boiling Heat Transfer in Annulus with Small Gap
Kang, Myeong-Gie ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 237~244
DOI : 10.3795/KSME-B.2011.35.3.237
An experimental study was carried out to investigate the effect of the inclination angle on the nucleate pool boiling of saturated water at atmospheric pressure. We considered an annulus with a gap of 5 mm and a bottom opening. The inner tube of the annulus was heated, and the outer diameter and the length of the tube were 25.4 mm and 500 mm, respectively. The inclination angle was varied from horizontal to vertical. The results were compared to those for an annulus with a larger gap and a single tube. In the small-gap annulus, the effect of the inclination angle on the heat transfer was not significant. However, an early onset of the critical heat flux was observed at 80 kW/
when the annulus was horizontal. Liquid agitation and bubble coalescence were considered to be the major heat-transfer mechanisms.
Numerical Study of Flow Characteristics in Elementary Paths of Velocity-Control Trim
Kim, Dae-Kwon ; Sohn, Chae-Hoon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 245~253
DOI : 10.3795/KSME-B.2011.35.3.245
We investigate the flow characteristics of elementary-flow paths with
bends; a velocity-control trim consists of such paths. For geometric similarity, the width and length of each path are selected, and the number of bends is 0, 4, or 8. The flow tests are conducted with the same flow-path elements. The numerical results are in good agreement with the experimental data. In elements without bends, the volume flow rate decreases with the length of the flow path, with a constant pressure drop between the inlet and the outlet. However, in flow paths with
bends, it increases and then decreases with the length of the flow path. For a fixed number of
bends, better pressure-drop characteristics are observed as the length of the flow path increases. For a fixed flow-path length, a flow-path element with more bends has a smoother pressure drop along the path.
Numerical Evaluation of Debris Transport During LOCA Blow-Down Phase of OPR1000 Nuclear Power Plant
Choi, Kyung-Sik ; Park, Jong-Pil ; Jeong, Ji-Hwan ; Kim, Won-Tae ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 255~262
DOI : 10.3795/KSME-B.2011.35.3.255
In a loss-of-coolantaccident, considerable debris may be generated and transported to the recirculation sump. The accumulation of debris will reduce the netpositivesuctionhead and threaten the safety of thenuclear power plant. Both NEI 04-07 and USNRC SER suggesteda CFD methodology. However, additional investigation is needed to consider the unique characteristics of nuclear power plants. The transport of the generated debris is strongly influenced by the break location and the plant characteristics, including the configuration.In this paper, a CFD methodology for blow-down transport evaluation is proposed and applied to an OPR1000 nuclear power plant. The results show that the percentage of small debris transported to the upper containment is 32%, which is 7% larger than the valuegiven in the NEI 04-07 baseline analysis. This result may be used as a point of reference in future analytical studies.
CFD Analysis of Submersible Slurry Pump with Two Blades
Yun, Jeong-Eui ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 263~268
DOI : 10.3795/KSME-B.2011.35.3.263
We aimed to develop a non-clogging submersible slurry pump with two blades to replace the conventional vortex pump. To do this, we simulated the effect of parameters such as the blade angle
and the blade-length angle
on pump efficiency. We used the commercial codes ANSYS CFX and BladeGen. The results showed that the best blade shape was obtained for
and that the pump efficiency was proportional to
in the simulated range.
Air-Side Performance of Fin-and-Tube Heat Exchanger with Copper Plate or Copper Spiral Fins
Lee, Jin-Wook ; Park, Ji-Hoon ; Lee, Jung-Pyo ; Kim, Nae-Hyun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 269~278
DOI : 10.3795/KSME-B.2011.35.3.269
We investigate the heat-transfer and pressure-drop characteristics of fin-and-tube heat exchangers with a copper plate or copper spiral fins. Twenty-four samples with different fin pitches and tube rows were tested. For both configurations, the effect of the fin pitch on the j factor is negligible, and the f factor increases with the fin pitch. The effect of the tube row depends on the configuration. For plate fin-and-tube heat exchangers, the j factor decreases as the row number increases; the reverse is true for spiral exchangers. We explain this by considering the flow pattern. The j factor for plate fin-and-tube heat exchangers is larger than that for spiral exchangers, and the difference decreases as the row number increases. The f factor of the plate fin-and-tube heat exchanger is also larger. We compare our results with existing predictions of correlations.
Onset of Natural Convection in Transient Hot Wire Device for Measuring Thermal Conductivity of Nanofluids
Lee, Seung-Hyun ; Kim, Hyun-Jin ; Jang, Seok-Pil ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 279~285
DOI : 10.3795/KSME-B.2011.35.3.279
We perform a numerical study to determine the time of onset of natural convection in a transient hot wire (THW) device for measuring the thermal conductivity of nanofluids. The samples used in this simulation are water-based
nanofluids with volume fractions of 1%, 4%, and 10%, and the properties are calculated by theoretical models and experimental correlations. The THW apparatus using coated wire is modeled by the control-volume-based finite difference method, and the start of natural convection is determined by observing the temperature rise of the wire under a gravity field. The onset time is 11.5 s for water and 41.6 s for water-based
nanofluids predicted by Maxwell thermal conductivity model with a 10% volume fraction. We confirm that the onset time of natural convection of nanofluids in the cylinder increases with the nanoparticle volume fraction. We suggest a correlation for predicting the onset time on the basis of the numerical results. Finally, it is shown that the measurement error due to natural convection is negligible if the measurement using the transient hot wire method is completed before the onset of natural convection in the base fluid.
First-Order Perturbation Solutions for Liquid Pool Spreading with Vaporization
Kim, Myung-Bae ; Do, Kyu-Hyung ; Han, Yong-Shik ; Choi, Byung-Il ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 287~291
DOI : 10.3795/KSME-B.2011.35.3.287
We solve the simple physical model for liquid pool spreading with vaporization semi-analytically for the first time, using perturbation techniques. The results are compared with those obtained using numerical methods. We use the evaporation rate per unit area as a perturbation parameter, and first-order solutions are obtained for continuous and instantaneous release. The two solutions are nearly identical with respect to the pool radius. The pool volumes are nearly the same at the early stage of the spread and then start to diverge.
Flow Characteristics of Al
Nanofluids with Nanoparticles of Various Shapes
Hwang, Kyo-Sik ; Ha, Hyo-Jun ; Jang, Seok-Pil ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 293~299
DOI : 10.3795/KSME-B.2011.35.3.293
To study the flow characteristics of water-based
nanofluids according to the shape of the nanoparticles, we measure the pressure drop in a fully developed laminar flow regime. Water-based
nanofluids of 0.3 Vol.% with sphere-, rod-, platelet-, and brick-shaped nanoparticles are manufactured by the two-step method. Zeta potential is measured to examine the suspension and dispersion characteristics, and TEM image is considered to confirm the shape characteristics of the nanoparticles. The experimental results show that the pressure drop of
nanofluids depends on the shape of the nanoparticles although the nanofluids has same volume fraction of nanoparticles. This is explained by the surface area per unit mass of the nanoparticles and the size of the nanoparticles suspended in the base fluids.
Performance Analysis for Turbo Blower According to Inlet-Vane Angles
Jang, Choon-Man ; Lim, Soo-Jung ; Yang, Sang-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 301~307
DOI : 10.3795/KSME-B.2011.35.3.301
Turbo blowers are mainly used in refuse collection systems. We discuss blower performance in relation to the angle of the inlet vane installed at the upstream of the blower. The flow characteristics of the components are analyzed by three-dimensional Navier-Stokes analysis and compared to experimental results. A two-stage serially connected turbo blower is introduced to analyze the performance experimentally. Throughout the experimental measurements and the numerical simulation, the distorted inlet velocity generated in the small vane angle reduces the performance of the blower, because of the local leading-edge separation and the resulting non-uniform blade loading. We also perform a detailed flow analysis using the results obtained in the numerical simulation.
Study on Heat-Loss-Induced Self-Excitation in Laminar Lifted Jet Flames
Yoon, Sung-Hwan ; Park, Jeong ; Kwon, Oh-Boong ; Kim, Jeong-Soo ; Bae, Dae-Seok ; Yun, Jin-Han ; Keel, San-In ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 309~319
DOI : 10.3795/KSME-B.2011.35.3.309
We experimentally investigated lifted propane jet flames diluted with nitrogen to obtain flame-stability maps based on heat-loss-induced self-excitation. We found that heat-loss-induced self-excitations are caused by conductive heat loss from premixed flame branches to trailing diffusion flames as well as soot radiation. The conductive-heat-loss-induced self-excitation at frequencies less than 0.1 Hz is explained well by a suggested mechanism, whereas the oscillation of the soot region induces a self-excitation of lift-off height of the order of 0.1 Hz. The suggested mechanism is also verified from additive experiments in a room at constant temperature and humidity. The heat-loss-induced self-excitation is explained by the Strouhal numbers as a function of the relevant parameters.
Effect of Applied DC Electric Fields in Flame Spread over Polyethylene-Coated Electrical Wire
Jin, Young-Kyu ; Kim, Min-Kuk ; Park, Jeong ; Chung, Suk-Ho ; Yun, Jin-Han ; Keel, Sang-In ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 321~330
DOI : 10.3795/KSME-B.2011.35.3.321
We experimentally investigated the effect of applied DC electric fields on the flame spread over polyethylene-coated electrical wire. The flame-spread rates over electrical wire with negative and positive DC electric fields from 0 to
kV were measured and analyzed. We compared the results for DC electric fields with previous results for AC electric fields. We explored whether or not various flame shapes could be obtained with DC electric fields and the main reason for the flame-spread acceleration, particularly at the end of the electrical wire, for AC electric fields. We found that DC electric fields do not significantly affect the flame-spread rates. However, the flame shape is mildly altered by the ionic wind effect even for DC electric fields. The flame-spread rate is relevant to the flame shape and the slanted direction in spite of the mild impact. A possible explanation for the flame spread is given by a thermal-balance mechanism and fuel-vapor jet.
Application Status and Prospects of CNC-Based Technologies in Gas Turbine Industry
Kang, Sin-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 3, 2011, Pages 331~336
DOI : 10.3795/KSME-B.2011.35.3.331
The three-dimensional complex curvature of the airfoil complicates the manufacture and repair of gas-turbine components. As a result of the developments in computer technology since the early 1990s, CNC-based technologies for machine tools and related programs have been increasingly applied in the gas turbine industry. In particular, fiveaxis simultaneous machines with adaptive functions have proven its excellent flexibility and productivity due to the capability in determining the 3D data from the unknown curvature. A well-organized robot system with eight-axis simultaneous control can lead to powerful standardization and high productivity. We summarize and review CNC technologies and their applications in the gas turbine industry, with a discussion of the manufacture and repair of gas turbine parts.