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 36, Issue 12 - Dec 2012
Volume 36, Issue 11 - Nov 2012
Volume 36, Issue 10 - Oct 2012
Volume 36, Issue 9 - Sep 2012
Volume 36, Issue 8 - Aug 2012
Volume 36, Issue 7 - Jul 2012
Volume 36, Issue 6 - Jun 2012
Volume 36, Issue 5 - May 2012
Volume 36, Issue 4 - Apr 2012
Volume 36, Issue 3 - Mar 2012
Volume 36, Issue 2 - Feb 2012
Volume 36, Issue 1 - Jan 2012
Selecting the target year
Visualization of Water Distribution in Cathode Side of a Direct Methanol Fuel Cell Using Neutron Radiography
Je, Jun-Ho ; Doh, Sung-Woo ; Kim, Tae-Joo ; Kim, Jong-Rok ; Xie, Xiaofeng ; Kim, Moo-Hwan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 965~970
DOI : 10.3795/KSME-B.2012.36.10.965
In this study, the water distribution in the cathode side of a direct methanol fuel cell (DMFC) is visualized using a neutron imaging technique at the Neutron Radiography Facility (NRF), KAERI. It is difficult to quantify the water content in the cathode side because of
gas. A compared open circuit voltage (OCV) image, relative
, and water distribution can be visualized by the neutron imaging technique. This means that the neutron imaging technique is useful for the optimization of the flow field design and the establishment of water management, and, in turn, for the improvement of the cell performance.
Analysis of Fast Injection Response Characteristics Between Solenoid and Piezo-Driven Injector
Jo, In-Su ; Lee, Jung-Hyup ; Lee, Jin-Wook ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 971~977
DOI : 10.3795/KSME-B.2012.36.10.971
It is well known that the performance of a diesel injector is directly related to the power, emission, and fuel consumption of the diesel combustion engine. In this study, the injection response characteristics of CRDi injectors driven by a solenoid coil and a piezoceramic were investigated by using the AMESim simulation code. Some analytical parameters such as the fuel pressure and hole diameter were considered. From this study, it was shown that the piezo-driven injector had a faster response and had better control capability than the solenoid-driven injector. In addition, it was found that the piezo-driven injector can be utilized more effectively in a multiple injection scheme than a solenoid-driven injector.
Analysis of Mass Transport in PEMFC GDL
Jeong, Hee-Seok ; Kim, Jeong-Ik ; Lee, Seong-Ho ; Lim, Cheol-Ho ; Ahn, Byung-Ki ; Kim, Charn-Jung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 979~988
DOI : 10.3795/KSME-B.2012.36.10.979
The 3D structure of GDL for fuel cells was measured using high-resolution X-ray tomography in order to study material transport in the GDL. A computational algorithm has been developed to remove noise in the 3D image and construct 3D elements representing carbon fibers of GDL, which were used for both structural and fluid analyses. Changes in the pore structure of GDL under various compression levels were calculated, and the corresponding volume meshes were generated to evaluate the anisotropic permeability of gas within GDL as a function of compression. Furthermore, the transfer of liquid water and reactant gases was simulated by using the volume of fluid (VOF) and pore-network model (PNM) techniques. In addition, the simulation results of liquid water transport in GDL were validated by analogous experiments to visualize the diffusion of fluid in porous media. Through this research, a procedure for simulating the material transport in deformed GDL has been developed; this will help in optimizing the clamping force of fuel cell stacks as well as in determining the design parameters of GDL, such as thickness and porosity.
Study on Analysis of Flow Field in Ejector Suction Pipe
Kim, Noh-Hyeong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 989~999
DOI : 10.3795/KSME-B.2012.36.10.989
An ejector is a fluid transportation device that operates based on the principle that a high-pressure fluid is spouted through a driving pipe and the pressure of a low-pressure fluid is increased through exchange of momentum with a low-pressure gas. Steam-steam ejectors have been widely used for suction, mixture, and dehydration. They can be easily used in places where fluid moves and expenses are reasonable. In addition, such ejectors are a semi-permanent fluid device that requires little maintenance. In this study, we present an optimized design by analyzing what cannot be obtained through experiments in order to improve the device performance, analyze general contents of a flow by acquiring exact test data on specific and interpretative areas using more advanced experimental techniques, and identify the flow characteristics of a branch pipe by examining the validity of experiments using computer hydrodynamics simulations.
Study on Cooling Characteristics of Mixed Gases with Hot Gas of Liquid Rocket Engine and Injected Liquid Nitrogen
Jeon, Jun-Su ; Yu, I-Sang ; Kim, Joong-Il ; Kim, Jai-Ho ; Ko, Young-Sung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1001~1009
DOI : 10.3795/KSME-B.2012.36.10.1001
In this study, the cooling characteristics of combustion gas were investigated by injecting liquid nitrogen (
) into a liquid rocket combustion chamber, which uses liquid oxygen (Lox) and kerosene as propellants.
injectors and an extended chamber for mixing were installed at the end of the ordinary LRE combustion chamber, and a nozzle was installed after the chamber for mixing. First, an ignition test of the liquid rocket engine was conducted to verify the stable combustion process. Next, a hot firing test was performed step-by-step for safety. Finally, the test was performed for 20 s. The results showed that the combustion gas of the LRE could be successfully cooled by using
Continuous Photolithography by Roll-Type Mask and Applications
Kwak, Moon-Kyu ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1011~1017
DOI : 10.3795/KSME-B.2012.36.10.1011
We report the development of an optical micro-nanolithography method by using a roll-type mask. It includes phase-shift lithography and photolithography for realizing various target dimensions. For sub-wavelength resolution, a structure is achieved using the near-field exposure of a photoresist through a cylindrical phase-mask, allowing high-throughput continuous patterning. By using a film-type metal mask, continuous photolithography was achieved, and this method could be used to control the period of resultant patterns in real time by changing the rotating speed of the cylinder mask. As an application, we present the fabrication of a transparent electrode in the form of a metallic mesh by using the developed roll-type photolithography process. As a result, a transparent conductor with good properties was achieved by using a recently built cylindrical phase-shift lithography prototype, which was designed for patterning on 100-mm2 substrates.
Direct-Aluminum-Heating-Induced Crystallization of Amorphous Silicon Thin Film
Park, Ji-Young ; Lee, Dae-Geon ; Moon, Seung-Jae ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1019~1023
DOI : 10.3795/KSME-B.2012.36.10.1019
In this research, a novel direct-aluminum-heating-induced crystallization method was developed for the purpose of application to solar cells. By applying a constant current of 3 A to an aluminum thin film, a 200-nm-thick amorphous silicon (a-Si) thin film with a size of
can be crystallized into a polycrystalline silicon (poly-Si) thin film within a few tens of seconds. The Raman spectrum analysis shows a peak of 520
, which verifies the presence of poly-Si. After removing the aluminum layer, the poly-Si thin film was found to be porous. SIMS analysis showed that the porous poly-Si thin film was heavily p-doped with a doping concentration of
. Thermal imaging shows that the crystallization from a-Si to poly-Si occurred at a temperature of around 820 K.
Thermal Deformation of Glass Backplane during Flash Lamp Crystallization Process of Amorphous Silicon
Kim, Dong-Hyun ; Kim, Byung-Kuk ; Kim, Hyoung-June ; Chung, Ha-Seung ; Park, Seung-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1025~1032
DOI : 10.3795/KSME-B.2012.36.10.1025
The flash lamp annealing (FLA) process has been considered highly promising for manufacturing low-temperature polysilicon on large-scale backplanes. Based on a theoretical estimation, this study clarifies the critical mechanisms of glass backplane deformation during the FLA process. A simulation using a commercial FEM code with viscoelastic models shows that the local region, whose temperature is larger than the glass softening point, undergoes permanent structural shrinkage owing to stress relaxation. For larger backplanes (4th Gen), structural shrinkages and gravitational deflection are critical to deformation in the FLA process, resulting in an "M" shape; in smaller backplanes (0th Gen), the latter is negligible, resulting in a "U" shape.
A Study on the Effect of Coal Properties on the Electrochemical Reactions in the Direct Carbon Fuel Cell System
Ahn, Seong-Yool ; Eom, Seong-Yong ; Rhie, Young-Hoon ; Moon, Cheor-Eon ; Sung, Yon-Mo ; Choi, Gyung-Min ; Kim, Duck-Jool ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1033~1041
DOI : 10.3795/KSME-B.2012.36.10.1033
Performance evaluation of a direct carbon fuel cell (DCFC) was conducted according to coals and a graphite particle. Several fuel properties such as thermal reactivity, textural structure, gas adsorption characteristic, and functional groups on the surface of fuels were investigated and their effects on electrochemistry were discussed. The strong carbon structure inside of fuels led the rapid potential decreasing in high current density region, because it caused small surface area and low pore volume. The functional groups on the surface were related to the low current density region. The maximum current density and power density of fuels were affected by the total carbon content in fuels. The effect of operating conditions such as stirring rate and operating temperature was investigated in this study.
Comparison Between Direct- and Indirect-Cooling Core Catchers
Suh, Jung-Soo ; Lee, Jong-Ho ; Bae, Byung-Hwan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1043~1047
DOI : 10.3795/KSME-B.2012.36.10.1043
The European nuclear design requirements, which should be satisfied by nuclear reactors in Europe, usually recommend a so-called core catcher, which is a molten core ex-vessel cooling facility, to manage a severe accident at a nuclear reactor. Two different types of core catcher concepts are compared to determine their abilities to manage severe accidents and cool core melts. The study reveals that direct cooling is better for cooling capacity and is convenient to construct, while indirect cooing is better for the management of a severe accident.
Fabrication and Characterization of High-Performance Thin-Film Encapsulation for Organic Electronics
Kim, Nam-Su ; Graham, Samuel ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 10, 2012, Pages 1049~1054
DOI : 10.3795/KSME-B.2012.36.10.1049
Continued advancements in organic materials have led to the development of organic devices that are thin, flexible, and lightweight and that can potentially be used as low-cost energy-conversion devices. While these devices have many advantages, the environmentally induced degradation of the active materials and the low-work-function electrodes remain a valid concern. Hence, many vacuum deposition processes have been applied to develop low-permeation barrier coatings. In this work, we present the results pertaining to the developed thin-film encapsulation. Multilayer encapsulation involves the use of
with parylene. The effective water vapor transmission rates were investigated using a Ca-corrosion test. The integration of the developed barrier layers was demonstrated by encapsulating pentacene/
solar cells, and the results are presented.