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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers B
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 34, Issue 12 - Dec 2010
Volume 34, Issue 11 - Nov 2010
Volume 34, Issue 10 - Oct 2010
Volume 34, Issue 9 - Sep 2010
Volume 34, Issue 8 - Aug 2010
Volume 34, Issue 7 - Jul 2010
Volume 34, Issue 6 - Jun 2010
Volume 34, Issue 5 - May 2010
Volume 34, Issue 4 - Apr 2010
Volume 34, Issue 3 - Mar 2010
Volume 34, Issue 2 - Feb 2010
Volume 34, Issue 1 - Jan 2010
Selecting the target year
Numerical Investigation of the Effect of IR Heating on Drying Mechanism in a Tumble Dryer
Choi, Chul-Jin ; Jang, Jung-Hyun ; Kim, Chong-Min ; Kim, Man-Young ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 219~228
DOI : 10.3795/KSME-B.2010.34.3.219
A two-dimensional mathematical model was developed to predict the temperature and moisture-content profiles of a tumble dryer during infrared drying. The model is based on the movements of liquid water and moisture in the object and on the fluid and heat transfer in the drying air. The model was solved by the finite volume analysis for the fluid, temperature, and radiation intensity fields. After deriving the governing equations and developing the two-dimensional tumble dryer models, numerical investigations were carried out to examine the effects of various parameters such as the heater temperature and the heating patterns on the drying mechanism of the tumble dryer. All the results show that the drying time can be reduced by using the IR heater.
Optimization of an Annular Fin with a Pipe of Variable Inner Radius for Fixed Fin Volume
Kang, Hyung-Suk ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 229~235
DOI : 10.3795/KSME-B.2010.34.3.229
Optimum values of fin performance and dimensions for an annular fin with a rectangular profile and a pipe with variable inner radius are determined by using a variable separation method. The range of ambient convection characteristic number that results in optimum heat loss is listed. The optimum heat loss, corresponding optimum fin effectiveness, fin length, and fin height are presented as a function of the inner radius of the pipe, inner fluid convection characteristic number, fin volume, and ambient convection characteristic number. One of the results shows that the optimum heat loss, fin effectiveness and fin length increase linearly with the inner radius of the pipe when both the fin volume and fin-base radius are fixed.
Investigation of Effect of Shape of Pintle on Drag and Thrust Variation
Park, Jong-Ho ; Kang, Min-Ho ; Kim, Joung-Keun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 237~243
DOI : 10.3795/KSME-B.2010.34.3.237
In this study, the effect of the shape of a pintle(obstacle) on thrust-modulation performance and drag in a pintle rocket was investigated by a cold flow test and by computational fluid dynamics. Pintle movement caused a monotonic increase in the chamber pressure. Thrust generated by the pressure distribution on the pintle body was linearly changed to the chamber pressure, and this thrust was greater than that generated by the nozzle-wall pressure distribution. Because the shock pattern in the nozzle changes with the shape of the pintle body and pressure ratio, the thrust generated by the nozzle-wall pressure is not directly affected by chamber pressure. The drag due to the pintle(obstacle) can be minimized for a fully linear pintle shape, regardless of chamber pressure.
Gas Temperature Measurement in Supersonic Flows by N
Shin, Ji-Chul ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 245~250
DOI : 10.3795/KSME-B.2010.34.3.245
The procedure for estimating the gas (rotational) temperature of an air discharge in supersonic flows is presented in detail. Since direct measurement of the temperature in a supersonic flow is difficult, a nonintrusive measurement was performed by optical emission spectroscopy based on the emission spectra of nitrogen molecular ions. A detailed explanation, including the equations for emission line intensity, is presented in order to understand the structure of the emission spectra of nitrogen molecular ions. Using the obtained representation for emission spectrum, a synthetic spectrum of the first negative system of
is obtained, and it is compared with the experimentally measured spectrum. Within a relative error of approximately 6.8% for the overall band spectra, the synthetic and measured spectra agree well. In the case of a 25-mA DC air discharge in a supersonic (Mach 3) flow, the gas temperature profile shows an approximately linear variation and a peak temperature of approximately 350 K.
Practical Packaging Technology for Microfluidic Systems
Lee, Hwan-Yong ; Han, Song-I ; Han, Ki-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 251~258
DOI : 10.3795/KSME-B.2010.34.3.251
This paper presents the technology for the design, fabrication, and characterization of a microfluidic system interface (MSI); the purpose of this technology is to enable the integration of complex microfluidic systems. The MSI technology can be applied in a simple manner for realizing complex arrangements of microfluidic interconnects, integrated microvalves for fluid control, and optical windows for on-chip optical processes. A microfluidic system for the preparation of genetic samples was used as the test vehicle to prove the effectiveness of the MSI technology for packaging complex microfluidic systems with multiple functionalities. The miniaturized genetic sample preparation system comprised several functional compartments, including compartments for cell purification, cell separation, cell lysis, solid-phase DNA extraction, polymerase chain reaction, and capillary electrophoresis. Additionally, the functional operation of the solid-phase extraction and PCR thermocycling compartments was demonstrated by using the MSI.
An Experimental Investigation of the Effect of Particle Size on the Combustion Characteristics of Pulverized Sub-Bituminous Coal with Low Calorific Value by Using an LFR System
Jeon, Chung-Hwan ; Kim, Yong-Gyun ; Kim, Jae-Dong ; Kim, Gyu-Bo ; Song, Ju-Hun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 259~267
DOI : 10.3795/KSME-B.2010.34.3.259
In this study, the effect of particle size on the combustion characteristics of pulverized sub-bituminous coal was experimentally investigated. A laminar-flow-entrained reactor was designed and implemented to realize the desired heating ratio and temperature corresponding to the combustion atmosphere of a pulverized-coal-fueled furnace. The flame length and structure of burning particles according to different sizes were investigated. Coal combustion processes were clearly distinguished by direct visual observation of the flame structure. The onset point of volatile ignition is greatly affected by changes in the particle size, and the burning time of the volatiles is least affected by changes in the particle size. The length and instability of char flame also increase with the increase of the particle size. However, the char consumption rate within the residential time remains nearly constant.
Off-design Performance Characteristics of SOFC-GT Hybrid System Operating with Syngas Fuel
Choi, Jung-Il ; Sohn, Jeong-Lak ; Song, Seung-Jin ; Kim, Tong-Seop ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 269~274
DOI : 10.3795/KSME-B.2010.34.3.269
As a preliminary study on a SOFC-GT hybrid system integrated a with coal-gasification system, the influence of the concentrations of
and CO in syngas on the performance characteristics of the hybrid system is investigated. It is expected that the differences in the heating values of fuels with different compositions trigger the off-design operation of the gas turbine and result in different performance characteristics of the overall hybrid system. Syngas compositions are found to affect the SOFC performance. Performance of hybrid system with carbon monoxide is poorer than the case with hydrogen. In the case of part-load performance with syngas, performance degradation at part-load operating conditions with hydrogen is more dominant than the case with carbon monoxide.
Characteristics of NOx Emission in a Swirl Flow in Nonpremixed Turbulent Hydrogen Jet with Coaxial Air
Oh, Jeong-Seog ; Yoon, Young-Bin ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 275~282
DOI : 10.3795/KSME-B.2010.34.3.275
The effect of swirl flow on NOx in a nonpremixed turbulent hydrogen jet with coaxial air was studied. The swirl vane angle was varied from
. The fuel jet air velocity and coaxial air velocity were varied in an attached flame region as
. The objective of the current study was to analyze the characteristics of nitrous oxide emission in a swirl flow and to propose a new parameter for EINOx scaling. The experimental results show that EINOx decreases with the swirl vane angle and increased with flame length. Further, EINOx scaling factors can be determined by considering the effective diameter (
) in a far field concept. The EINOx increased in proportion to the flame residence time (
) and the global strain rate (
Experimental Investigation of NOX Reduction using a Hybrid Fuel Lean Reburning System
Kim, Hak-Young ; Baek, Seung-Wook ; Hwang, Chang-Hwan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 283~290
DOI : 10.3795/KSME-B.2010.34.3.283
The main goal of this study is to examine the use of a hybrid -fuel lean reburning system with air staging for
reduction. The experimental variables include the reburn fuel fraction, sizes of reburn- fuel-injection nozzles, oxygen enrichment ratio, and location of reburn- fuel- injection. The effect of the flow field induced by air- staging combustion on
reduction is considered, and then, the
reduction rate is compared with only fuel lean reburning system. On the basis of the effectiveness of each De-
process, the advantage of using the hybrid reburning system with air staging is determined and discussed.
Convective Heat Transfer Correlations for the Compact Heat Exchanger with Circular Tubes and Flat Tubes-Plate Fins
Moh, Jeong-Hah ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 291~299
DOI : 10.3795/KSME-B.2010.34.3.291
Aspect-ratio-based numerical analysis is carried out to investigate the air-side convective heat transfer characteristics in compact heat exchangers with circular tubes and flat tubes-plate fins. The RNG
model is adopted for turbulence analysis. The numerical analysis is carried out for aspect ratios ranging from 3.06 to 5.44 and for Reynolds numbers ranging from 1,000 to 10,000. The calculated results indicate a correlation between the friction factor and Colburn j factor in the compact heat exchanger system for the range of aspect ratios under consideration. The results obtained for circular tubes and flat tubes-plate fins in this study can be utilized to realize the optimal design of an air conditioning system.
Evaluation of Thermoelectric Characteristics of Peltier Thermoelectric Module for Increasing Response Velocity in Shape Memory Alloy (SMA) Steering Catheter
Oh, Dong-Joon ; Kim, Cheol-Woong ; Kim, Tae-Young ; Lee, Ho-Sang ; Kim, Jay-Jung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 301~307
DOI : 10.3795/KSME-B.2010.34.3.301
Actuation using a shape memory alloy (SMA) is considered to be an important technology that will play a leading role in market for next-generation medical devices because an SMA actuator can accurately imitate skillful and delicate hand movements. However, SMA actuators have not been successfully used because of problems in control design caused by the nonlinear hysteresis effect of SMA, which leads to inaccuracies in control systems. In order to overcome the effect, the authors invented a SMA actuator, which could actively and rapidly cool down and heat up, by combining a SMA catheter and a TE module using the Peltier effect. In order to evaluate the TE characteristics of our TE module system, the changes in the temperature with 1) incremental increases in a continuous electric current and 2) the appearance of a discontinuous constant or reverse current are discussed in this paper.
Digital Particle Holographic System for Flow-Field Measurements
Yan, Yang ; Kang, Bo-Seon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 309~316
DOI : 10.3795/KSME-B.2010.34.3.309
In this study, a digital particle holographic system and its application to channel-flow measurements were investigated. A double-exposure hologram recording system that is capable of recording digital holograms in a short time interval was developed. A correlation coefficient method was used to determine the focal plane of particles. The Wiener filter was used to remove noises and improve image quality. Two-threshold and image segmentation methods were used for binary image transformation. The cross-correlation method was used for particle pairing. The developed system was employed to study channel flow fields, and the axial velocities of channel flow were measured. The measurement errors are acceptable, and this proves the feasibility of using the digital particle holographic system as a good tool for flow-field measurements.
Mass Transfer Analysis of Metal-Supported and Anode-Supported Solid Oxide Fuel Cells
Park, Joon-Guen ; Kim, Sun-Young ; Bae, Joong-Myeon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 317~324
DOI : 10.3795/KSME-B.2010.34.3.317
Metal-supported solid oxide fuel cells (SOFCs) have been developed to commercialize SOFCs. This new type of SOFC has high mechanical strength, but its mass transfer rate may be low due to the presence of a contact layer. In this study, the mass transfer characteristics of an anode-supported SOFC and a metal-supported SOFC are studied by performing numerical simulation. Governing equations, electrochemical reactions, and ceramic physical-property models are determined simultaneously; molecular diffusion and Knudsen diffusion are considered in mass transport analysis of porous media. The experimental results are compared with simulation data to validate the results of numerical simulation. The average current density of the metal-supported SOFC is 23% lower than that of the anode-supported SOFC. However, because of the presence of the contact layer, the metal-supported SOFC has a more uniform distribution than the anode-supported SOFC.
Calibration System for Three-Cup Anemometers
Chun, Se-Jong ; Lee, Saeng-Hee ; Choi, Yong-Moon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 34, issue 3, 2010, Pages 325~331
DOI : 10.3795/KSME-B.2010.34.3.325
Three-cup anemometers are popular devices for measuring wind speeds in automated weather stations, environmental monitoring systems, and wind turbines. Cup anemometers usually suffer from lack of long-term stability owing to the wear of the bearing systems that support the rotational parts. The bearing systems are susceptible to external pollutants, vibrations, and gusts. Therefore, these anemometers have to be calibrated regularly to maintain the desired characteristics for measuring wind speed. In the present study, a new in-situ calibration system to help reduce cost and save time by calibrating the cup anemometers at the installation site is proposed. A portable in-situ calibrator was fabricated. After the characteristics of this calibrator were verified, it was used to calibrate cup anemometers. Some of the calibration results were compared with the data obtained by wind tunnel testing.