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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
Editor in Chief :
Volume & Issues
Volume 31, Issue 12 - Dec 2007
Volume 31, Issue 11 - Nov 2007
Volume 31, Issue 10 - Oct 2007
Volume 31, Issue 9 - Sep 2007
Volume 31, Issue 8 - Aug 2007
Volume 31, Issue 7 - Jul 2007
Volume 31, Issue 6 - Jun 2007
Volume 31, Issue 5 - May 2007
Volume 31, Issue 4 - Apr 2007
Volume 31, Issue 3 - Mar 2007
Volume 31, Issue 2 - Feb 2007
Volume 31, Issue 1 - Jan 2007
Selecting the target year
The Interaction Between Modules Caused by Thermal Choking in a Supersonic Duct
Kim, Jang-Woo ; Koo, Kyung-Wan ; Han, Chang-Suk ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 109~115
DOI : 10.3795/KSME-B.2007.31.2.109
Airframe-integrated Scramjet engines of NASA Langley type consist of a compressor, a combustion chamber and a nozzle. When some disturbances occur in one module of the engine, its influences are propagated to other modules. In this study, it is investigated numerically how shock waves were caused by thermal choking in one module propagate upstream and how they influence adjacent modules. The calculations are carried out in 2-dimensional supersonic viscous flow model using explicit TVD scheme in generalized coordinates. The adverse pressure gradient caused by heat addition brings about separation of the wall boundary layers and formation of the oblique shock wave that proceed to upstream. This moving shock wave formed one module blocks the flow coming into the adjacent modules, which makes the modules unstarted.
Cycle Simulation of an Adsorption Chiller Using Silica Gel-water
Kwon, Oh-Kyung ; Yun, Jae-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 116~124
DOI : 10.3795/KSME-B.2007.31.2.116
An adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objective of this paper is to investigate the performance of silica gel-water adsorption chiller from the cycle simulation and to provide a guideline for design of the adsorption chiller. The effect of cycle time, inlet temperature and water flow rate on the cooling capacity and COP is quantified during the cycle operation. It is found that the performance of adsorption chiller is more sensitive to the change of inlet water temperature rather than the water flow rate. It is concluded that the COP is 0.57 in the standard conditions(hot water
, cooling water
, chilled water inlet temperatures
and cycle time 420sec).
A Practical Design of Pressurized Solid Oxide Fuel Cell/Gas Turbine Hybrid Systems
Oh, Kyong-Sok ; Park, Sung-Ku ; Kim, Tong-Seop ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 125~131
DOI : 10.3795/KSME-B.2007.31.2.125
This paper presents guideline for a practical design of the hybrid system combining a pressurized solid oxide fuel cell and a gas turbine. Design of the hybrid system based on a virtually designed gas turbine was simulated using models for off-design operation of the gas turbine. Two system configurations, with different method for supplying reforming steam, are considered and their design characteristics are compared. A higher design cell temperature provides better system performance. However, there exists a maximum allowable design cell temperature because the operating point of the compressor approaches the surge point with increasing fuel cell temperature. Increased pressure loss at the fuel cell moves the compressor operating point toward the surge point and reduces system performance.
A Study on the Measurement of Flame Visualization, Temperature and Soot for Diffusion Flame in a Diesel Engine Using High-Speed Camera
Han, Yong-Taik ; Lee, Ki-Hyung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 132~140
DOI : 10.3795/KSME-B.2007.31.2.132
The temperature and soot of the visualized diesel engine's turbulent flow of the flame was measured qualitatively. In the combustion chamber, in order to judge the affect that the swirl current has on the current ratio two heads with different ratios were used. Using a high speed camera, the results were analyzed using flame visualization. In order to measure the temperature and soot of the turbulent flames like diesel flames, two color methods were used to acquire temperature and the soot of the flames according to the conditions through analyzing the two wavelengths of the flames. It was possible to measure the highest temperature of the non-swirl head visualized engine, which is approximately 2400K, and that swirl head engine managed up to 2100K. With respect to the visualized diesel engine soot, we got the grasp of the KL factor which bears the qualitative information of the soot. This study is dedicated to suggesting the possibility of measuring not only the temperature but also soot of the diffusion flame of the diesel engine turbulent flames.
Modeling of Crosstalk Behaviors in Thermal Inkjet Print Heads
Lee, You-Seop ; Sohn Dong-Ki ; Kim Min-Soo ; Kuk Keon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 141~150
DOI : 10.3795/KSME-B.2007.31.2.141
This paper presents a lumped model to predict crosstalk characteristics of thermally driven inkjet print heads. Using the lumped R-C model, heating characteristics of the head are predicted to be in agreement with IR temperature measurements. The inter-channel crosstalk is simulated using the lumped R-L network. The values of viscous flow resistance, R and flow inertance, L of connecting channels are adjusted to accord with the 3-D numerical simulation results of three adjacent jets. The crosstalk behaviors of a back shooter head as well as a top shooter head have been investigated. Predictions of the proposed lumped model on the meniscus oscillations are consistent with numerical simulation results. Comparison of the lumped model with experimental results identifies that abnormal two-drop ejection phenomena are related to the increased meniscus oscillations because of the more severe crosstalk effects at higher printing speeds. The degree of crosstalk has been quantified using cross-correlations between neighboring channels and a critical channel dimension for acceptable crosstalk has been proposed and validated with the numerical simulations. Our model can be used as a design tool for a better design of thermal inkjet print heads to minimize crosstalk effects.
Effect of Differential Pressure on the Performance of Motor Operated Flexible Wedge Gate Valve
Kim, Dae-Woong ; Yoo, Seong-Yeon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 151~158
DOI : 10.3795/KSME-B.2007.31.2.151
The mechanism of power transmission from motor torque to stem thrust and the operation characteristic of each stroke position are analyzed using the diagnostic signal, and effects of differential pressure on the performance of motor operated flexible wedge gate valve are investigated. Test facility consists of 76 mm motor operated valve(flexible wedge type), pump and pipe system. Static and dynamic test are performed separately, and two differential pressure conditions are applied in the dynamic test. To evaluate the performance of valve, test signals for the torque, thrust, current, voltage and stroke length are acquired by using UDS which is diagnosis device for motor operated valve, and each diagnostic signal is analyzed and compared. The characteristic of valve performance factors such as stem factor, rate of loading, valve factor, are evaluated, and these factors are found to be severely influenced by the fluid differential pressure.
Mixing Efficiency Evaluation in Y-channel Micromixer Using LIF Confocal Microscope
Kim, Kyoung-Mok ; Shin, Yong-Su ; Ahn, Yoo-Min ; Lee, Do-Hyung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 159~166
DOI : 10.3795/KSME-B.2007.31.2.159
Mixing between two or more reagents is one of important processes in biochemical microfluidics. In efficient micromixer design, it is essential to analyze flow pattern and evaluate mixing efficiency with good precision. In this work, mixing efficiency for Y-channel micromixer is measured by fluorescence intensity using LIF(Laser Induced Fluorescence) Confocal Microscope. The Y-channel micromixers are fabricated with polydimethylsiloxane(PDMS) and those are bonded to glass plate through Plasma bonding. Nile Blue A is injected into the micromixer as a fluorescence dye for measuring of fluorescence intensity by He/Ne laser. For visualization of the flow pattern, dynamic image capturing is carried out using CAM scope. For the comparison with computer simulation, modified SIMPLE algorithm for incompressible flow equation is solved for the same geometry as in the experiment. Throughout the experiments and computer simulation, accurate mixing efficiency evaluation process for a PDMS Y-channel micromixer is established.
Spray Characteristics of Injector Used for HC-DeNOx Catalyst System
Lee, Dong-Hoon ; Jung, Hae-Young ; Lee, Ki-Hyung ; Lee, Jin-Ha ; Yeo, Kwon-Gu ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 167~172
DOI : 10.3795/KSME-B.2007.31.2.167
A new method that optimizes a control of hydrocarbon (HC) addition to diesel exhaust gas for HC type DeNOx catalyst system has been developed. These catalysts are called the HC-DeHOx catalyst in this paper. The system using HC-DeNOx catalyst requires a resonable quantity of hydrocarbons addition in the inlet gas of the catalyst, because the HC concentration in a diesel engine is so low that the HC is not sufficient for NOx conversion. It is expected that this study offers a robust data developing HC injection system.
The Comparative Analysis of Slipstream Phenomena by High-Speed and Traditional Train
Kim, Dong-Hyeon ; Jang, Yong-Jun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 173~180
DOI : 10.3795/KSME-B.2007.31.2.173
A series of field tests were performed to develop aerodynamic characteristic evaluation method and countermeasure technology in conventional and high-speed railway. The strength of rolling stock-induced wind which affect the people and substructure in platform and nearby track were investigated. The slipstream of passing trains was measured by hot-wire array system. The speed of trains was 110 - 125km/h for conventional ones and 300km/h for high-speed ones. The streamlined shape trains cause about 50% smaller-scale slipstream compared to the non-streamlined ones.
Development of the Scanning PIV Method with Single Optical Axis
Kim, Hyoung-Bum ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 181~187
DOI : 10.3795/KSME-B.2007.31.2.181
Conventional PIV method uses two optical axis configuration during the image grabbing process. That is, the illumination plane and the recording plane must be parallel. This configuration is very natural to grab the whole field without the image distortion. In the real problem, it is often to meet the situation when this configuration is hard to be fulfilled. In the present study, the new PIV method which uses only single optical axis to grab the particle images is developed. This new PIV method becomes possible by utilizing the scanning method similar to the echo PIV technique. One particle image of the scanning PIV consists of scanned several line images and by repeating this scanning process, two particle images were grabbed and processed to produce the velocity vectors. An optimization study was performed to find parameters which minimize the measurement errors. The effects of particle diameter, beam overlap ratio and particle number density were investigated.
A Study on PM Regeneration Characteristics of Diesel Passenger Vehicle with Passive Regeneration DPF System
Lee, Jin-Wook ; Cho, Gyu-Baek ; Kim, Hong-Suk ; Jeong, Young-Il ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 188~194
DOI : 10.3795/KSME-B.2007.31.2.188
New diesel engines equipped with common-rail injection systems and advanced engine management control allow drastic decreases in the production of particulate matters and nitrogen oxides with a significant advantage in terms of the fuel consumption and
emissions. Nevertheless, the contribution of exhaust gas after treatment in the ultra low emission vehicles conception has become unavoidable today. Recently the passive type DPF(Diesel Particulate Filter Trap) system for diesel passenger vehicle has been manufactured into mass production from a French automotive maker since the year of 2000. This passive DPF system fully relies on the catalytic effects from additives blended into the diesel fuel and additives injected into the DPF system. In this study, the effects of PM regeneration in the commercial diesel passenger vehicle with the passive type DPF system were investigated in chassis dynamometer CVS(constant volume sampler)-75 mode. As shown in this experimental results, the DPF regeneration was observed at temperature as low as
. And the engine-controlled the DPF regeneration founded to be one of the most promising regeneration technologies. Moreover, the durability of this DPF system was evaluated with a season weather in terms of the differential pressure and exhaust gas temperature traces from a road test during the total mileage of 80,000km.
An Experimental Study on the Flow Characteristics in Highly Viscous Liquid by Multi-Nozzle Bubbling
Kim, Hyun-Dong ; Ryu, Seung-Gyu ; Kim, Kyung-Chun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 195~201
DOI : 10.3795/KSME-B.2007.31.2.195
A visualization study of flow characteristics in a mixer using multi-nozzle bubbling was performed. The mixer is filed with liquid glycerin (dynamic viscosity =
) and convective mixing is induced by air bubbles generated from 9 orifices installed on the bottom of the mixer. To visualize the flow field, PIV (Particle Image Velocimetry) system consisting of 532nm Nd:YAG laser,
CCD camera and synchronizer is adopted. The bubbles generated with uniform size and frequency form bubble stream and bubble streams rise vertically without interaction between bubble streams. Mixing efficiency is affected by the height of bubbler and the effective height of bubbler is 20nm from the bottom of the mixer.
An Effect of Pressure Fluctuations of a Combustion Chamber on the Modulation of Equivalence Ratio in the Channel of the Burner
Hong, Jung-Goo ; Oh, Kwang-Chul ; Shin, Hyun-Dong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 31, issue 2, 2007, Pages 202~207
DOI : 10.3795/KSME-B.2007.31.2.202
In order to understand the phenomena of combustion instability, an experimental study was conducted at the moderate pressure and ambient temperature conditions. The flame behavior and the pressure fluctuations were measured in a dump combustor. Various types of combustion modes occurred in accordance with the equivalence ratio and the fuel supplying conditions. The fluctuation of pressure, heat release and equivalence ratio were measured by piezoelectric pressure sensor, high speed Intensified Charge Coupled Device (HICCD) camera and gas chromatography respectively. Two representative modes were self-excited pressure oscillations at the resonance of combustion chamber (200Hz) and instabilities related to the modulated fuel flow rate through the fuel holes (10Hz). It is found that, especially in an unchoked fuel flow condition, the modulation of the fuel flow rate affects the characteristics of flame behavior and pressure fluctuations in a lean premixed flame.