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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 39, Issue 12 - Dec 2015
Volume 39, Issue 11 - Nov 2015
Volume 39, Issue 10 - Oct 2015
Volume 39, Issue 9 - Sep 2015
Volume 39, Issue 8 - Aug 2015
Volume 39, Issue 7 - Jul 2015
Volume 39, Issue 6 - Jun 2015
Volume 39, Issue 5 - May 2015
Volume 39, Issue 4 - Apr 2015
Volume 39, Issue 3 - Mar 2015
Volume 39, Issue 2 - Feb 2015
Volume 39, Issue 1 - Jan 2015
Selecting the target year
Numerical Study on the Pulse Heating Type Infinitesimal Liquid Mass Flow Meter
Kim, Taig Young ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 119~124
DOI : 10.3795/KSME-B.2015.39.2.119
Numerical study on the new design of the liquid mass flow meter in infinitesimal flow rate for semiconductor production is performed. The heater and thermistor are wired on the circular tube about 0.3mm inner diameter with designed gap between them. After the time interval from the single pulse heating the thermistor reaches its peak temperature and this time interval is almost inversely proportional to the liquid mass flow rate. The axial conduction in tube wall and convection through the flow is combined. As a result, the peak temperature moving velocity is much smaller than flow mean velocity and there is no linear relationship between them. In this study, the effects of design parameters such as the tube inner/outer diameter, wired heater width, and the gap between heater and thermistor are investigated and the trends of optimization in these parameters are discussed.
Combustion Characteristics of Landfill Gas in Constant Volume Combustion Chamber for Large Displacement Volume Engine (III) - Torch Ignition (1) -
Kim, Inok ; Ohm, Inyong ; Kwon, Soon Tae ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 125~134
DOI : 10.3795/KSME-B.2015.39.2.125
This is the third paper on the combustion characteristics of the landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine. It is the first in this series to discuss the effects of the torch device on combustion. The results show that an optimum orifice ratio exists regardless of the torch volume, and a few adverse effects on the combustion are observed for an excessively small orifice ratio. In addition, the torch ignition decreases the initial burn duration, and the decrease in the heat transfer caused by this decreased duration contributes to an increase in the peak combustion pressure. Finally, the torch mostly plays a positive role in shortening the main burn duration when the combustion condition is worsened by a lower methane fraction. Yet, the torch decreases the initial burn duration rather than the main burn as the methane fraction increases.
Combustion Characteristics of Landfill Gas in Constant Volume Combustion Chamber for Large Displacement Volume Engine (IV) -Torch Ignition (2) -
Ko, Ansu ; Ohm, Inyong ; Kwon, Soon Tae ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 135~146
DOI : 10.3795/KSME-B.2015.39.2.135
This paper is the fourth on the combustion characteristics of the landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine and the second dealing with torch ignition. It discusses the combustion characteristics of torch ignition on the basis of the heat release and visualization. The results show that the jet and/or spout from the torch promote combustion by accelerating the flame front in the main combustion chamber. In addition, a hot gas jet exists when the orifice diameter is 4 mm, whereas the flame passes directly through the orifice if the diameter is 6 mm or greater. In addition, the effect of torch ignition differs according to the combination of the methane fraction, torch volume, and orifice size because various combustion processes occur as a result of the interaction of these parameters. Finally, it was found that the most suitable torch should have an orifice diameter of not less than 6 mm and an area ratio of not more than 0.15 to secure a consistent combustion process in a real engine.
Capacitive Skin Piloerection Sensors for Human Emotional State Cognition
Kim, Jaemin ; Seo, Dae Geon ; Cho, Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 147~152
DOI : 10.3795/KSME-B.2015.39.2.147
We designed, fabricated, and tested the capacitive microsensors for skin piloerection monitoring. The performance of the skin piloerection monitoring sensor was characterized using the artificial bump, representing human skin goosebump; thus, resulting in the sensitivity of
and the nonlinearity of 25.9 % for the artificial goosebump deformation in the range of
. We also verified two successive human skin piloerection having 3.5 s duration on the subject's dorsal forearms, thus resulting in the capacitance change of -6.2 fF and -9.2 fF compared to the initial condition, corresponding to the piloerection intensity of
, respectively. It was demonstrated experimentally that the proposed sensor is capable to measure the human skin piloerection objectively and quantitatively, thereby suggesting the quantitative evaluation method of the qualitative human emotional state for cognitive human-machine interfaces applications.
Numerical and Experimental Analysis of Micro Gas Turbine Heat Transfer Effect
Seo, Junhyuk ; Kwon, Kilsung ; Choi, Ju Chan ; Baek, Jehyun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 153~159
DOI : 10.3795/KSME-B.2015.39.2.153
In this study, a 2-W micro-gas turbine engine was designed using micro-electro-mechanical systems (MEMS) technology, and analytical and experimental investigations of its potential under actual combustion conditions were performed. An ultra-micro-gas turbine contains a turbo-charger, combustor, and generator. A compressor, turbine blade, and generator coil were manufactured using MEMS technology. The shaft was supported by a precision computer numerical control machined air bearing, and a permanent magnet was attached to the end of the shaft for generation. An analysis found that the cooling effect of the air bearing and compressor was sufficient to cover the combustor heat, which was verified in an actual experiment.
Effects of Driving Frequency on Propagation Characteristics of Methane-Air Premixed Flame Influenced by Ultrasonic Standing Wave
Bae, Dae Seok ; Seo, Hang Seok ; Kim, Jeong Soo ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 161~168
DOI : 10.3795/KSME-B.2015.39.2.161
An experimental study was conducted to scrutinize the influence of the frequency of an ultrasonic standing wave on the variation in the behavior of a methane-air premixed flame. The evolutionary features of the propagating flame were captured by a high-speed camera, and the macroscopic flame behavior, including the flame structure and local velocities, was investigated in detail using a post-processing analysis of the high-speed images. It was found that a structural variation and propagation-velocity augmentation of the methane-air premixed flame were caused by the intervention of the ultrasonic standing wave, which enhanced the combustion reaction. Conclusive evidence for the dependency of the flame behaviors on the driving frequency of the ultrasonic standing wave and equivalence ratio of the reactants is presented.
Numerical and Experimental Study on Mechanical Properties of Gelatin as Substitute for Brain Tissue
Bahn, Yong ; Choi, Deok-Kee ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 169~176
DOI : 10.3795/KSME-B.2015.39.2.169
The mechanical properties of living tissues have been major subjects of interest in biomechanics. In particular, the characteristics of very soft materials such as the brain have not been fully understood because experiments are often severely limited by ethical guidelines. There are increasing demands for studies on remote medical operations using robots. We conducted compression tests on brain-like specimens made of gelatin to find substitutes with the mechanical properties of brain tissues. Using a finite element analysis, we compared our experimental data with existing data on the brain in order to establish material models for brain tissues. We found that our substitute models for brain tissues effectively simulated their mechanical behaviors.
Experimental Study on Characteristics of Ammonia Conversion Rate of Urea Aqueous Solution in 250℃ Exhaust Pipe
Ku, Kun Woo ; Park, Hong Min ; Hong, Jung Goo ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 177~182
DOI : 10.3795/KSME-B.2015.39.2.177
The NOx emissions from diesel engines and industrial boilers are a major cause of environmental pollution. The selective catalytic reduction of urea is an aftertreatment technology that is widely used for the reduction of NOx emissions. The objective of this study was to investigate the characteristics of the thermal decomposition of a urea aqueous solution using laboratory-scale experimental equipment under conditions similar to those of marine diesel engines. A 40 wt. urea aqueous solution was used in this study. It was found that the total conversion rate varied with the inflow gas conditions and flow rates of the urea aqueous solution. In addition, there were conversion rate differences between NH3 and HNCO. At inflow gas temperature conditions of
conversion rate was found to be higher than that of the HNCO, depending on the residence time.
Secondary Flow Patterns of Liquid Ejector with Computational Analysis
Kwon, Kwisung ; Yun, Jinwon ; Sohn, Inseok ; Seo, Yongkyo ; Yu, Sangseok ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 183~190
DOI : 10.3795/KSME-B.2015.39.2.183
An ejector is a type of non-powered pump that is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for fueling the vehicle because of less failures and simple structure. Since most of ejectors in industry are gas-to-gas and liquid to gas ejector, many research activities have been reported in optimization of gas ejector. On the other hand, the liquid ejector is also applied in many industry but few research has been reported. The liquid ejector occurs cavitation, and it causes damage of parts. Cavitation has bees observed at the nozzle throat at the specified pressure. In this study, a two-dimensional axisymmetric simulation of a liquid-liquid ejector was carried out using five different parameters. The angle of the nozzle plays an important role in the cavitation of a liquid ejector, and the performance characteristics of the flow ratio showed that an angle of
was the most advantageous. The simulation results showed that the performance of the liquid ejector and the cavitation effect have to be considered simultaneously.
Comparison of Message Passing Interface and Hybrid Programming Models to Solve Pressure Equation in Distributed Memory System
Jeon, Byoung Jin ; Choi, Hyoung Gwon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 191~197
DOI : 10.3795/KSME-B.2015.39.2.191
The message passing interface (MPI) and hybrid programming models for the parallel computation of a pressure equation were compared in a distributed memory system. Both models were based on domain decomposition, and two numbers of the sub-domain were selected by considering the efficiency of the hybrid model. The parallel performances for various problem sizes were measured using up to 96 threads. It was found that in addition to the cache-memory size, the overhead of the MPI communication/OpenMP directives affected the parallel performance. For small problems, the parallel performance was low because the percentage of the overhead of the MPI communication/OpenMP directives increased as the number of threads increased, and MPI was better than the hybrid model because it had a smaller communication overhead. For large problems, the parallel performance was high because, in addition to the cache effect, the percentage of the communication overhead was relatively low compared to that for small problems, and the hybrid model was better than MPI because the communication overhead of MPI was more dominant than that of the OpenMP directives in the hybrid model.
A Monitoring System Based on an Artificial Neural Network for Real-Time Diagnosis on Operating Status of Piping System
Jeon, Min Gyu ; Cho, Gyong Rae ; Lee, Kang Ki ; Doh, Deog Hee ;
Transactions of the Korean Society of Mechanical Engineers B, volume 39, issue 2, 2015, Pages 199~206
DOI : 10.3795/KSME-B.2015.39.2.199
In this study, a new diagnosis method which can predict the working states of a pipe or its element in realtime is proposed by using an artificial neural network. The displacement data of an inspection element of a piping system are obtained by the use of PIV (particle image velocimetry), and are used for teaching a neural network. The measurement system consists of a camera, a light source and a host computer in which the artificial neural network is installed. In order to validate the constructed monitoring system, performance test was attempted for two kinds of mobile phone of which vibration modes are known. Three values of acceleration (minimum, maximum, mean) were tested for teaching the neural network. It was verified that mean values were appropriate to be used for monitoring data. The constructed diagnosis system could monitor the operation condition of a gas pipe.