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 37, Issue 12 - Dec 2013
Volume 37, Issue 11 - Nov 2013
Volume 37, Issue 10 - Oct 2013
Volume 37, Issue 9 - Sep 2013
Volume 37, Issue 8 - Aug 2013
Volume 37, Issue 7 - Jul 2013
Volume 37, Issue 6 - Jun 2013
Volume 37, Issue 5 - May 2013
Volume 37, Issue 4 - Apr 2013
Volume 37, Issue 3 - Mar 2013
Volume 37, Issue 2 - Feb 2013
Volume 37, Issue 1 - Jan 2013
Selecting the target year
Analysis of Inverse Heat Conduction Problem Using OpenFOAM and VisualDoc
Kim, Sung-Won ; Kim, Sun Kyoung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 539~544
DOI : 10.3795/KSME-B.2013.37.6.539
This study provides a solution method for the inverse heat conduction problem based on a combination of a public domain CAE (computer aided engineering) software and a commercial CAO (computer aided optimization) software. The solver system has been implemented without any in-house coding. The proposed method is simple to implement. Moreover, it can be easily reproduced.
Tactile Transceiver for Fingertip Motion Recognition and Texture Generation
Youn, Sechan ; Cho, Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 545~550
DOI : 10.3795/KSME-B.2013.37.6.545
We present a tactile information transceiver using a friction-tunable slider-pad. While previous tactile information devices were focused on either input or output functions, the present device offers lateral position/vertical direction detection and texture expression. In characterizing the tactile input performance, we measured the capacitance change due to the displacement of the slider-pad. The measured difference for a z-axis click was 0.146 nF/
when the x-y axis navigation showed 0.09 nF/
difference. In characterizing the texture expression, we measured the lateral force due to a normal load. We applied a voltage between parallel electrodes to induce electrostatic attraction in DC and AC voltages. We measured the friction under identical fingertip action conditions, and obtained friction in the range of 32-152 mN and lateral vibration in the force range of 128.1 mN at 60 V, 2 Hz. The proposed device can be applied to integrated tactile interface devices for mobile appliances.
Fault Severity Diagnosis of Ball Bearing by Support Vector Machine
Kim, Yang-Seok ; Lee, Do-Hwan ; Kim, Dae-Woong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 551~558
DOI : 10.3795/KSME-B.2013.37.6.551
A support vector machine (SVM) is a very powerful classification algorithm when a set of training data, each marked as belonging to one of several categories, is given. Therefore, SVM techniques have been used as one of the diagnostic tools in machine learning as well as in pattern recognition. In this paper, we present the results of classifying ball bearing fault types and severities using SVM with an optimized feature set based on the minimum distance rule. A feature set as an input for SVM includes twelve time-domain and nine frequency-domain features that are extracted from the measured vibration signals and their decomposed details and approximations with discrete wavelet transform. The vibration signals were obtained from a test rig to simulate various bearing fault conditions.
Effects of Surface Roughness on Contact Angle of Nanofluid Droplet
Kim, Yeung Chan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 559~566
DOI : 10.3795/KSME-B.2013.37.6.559
The effects of solid surface roughness on the contact angle of a nanofluid droplet were experimentally investigated. The experiments were conducted using the solid surface of a 10 mm cubic copper block and the nanofluid of water mixed with CuO nanoparticles. The experimental results showed that the contact angles of nanofluid droplets were lower than those of water droplets and that the contact angle of the nanofluid droplet increased with the solid surface roughness. Furthermore, it was found that the contact angles of water droplets on the solid surface quenched by both water and the nanofluid were lower than those of water droplets on the pure solid surface. However, significant differences were not observed between the contact angles on the solid surfaces quenched by water and the nanofluid.
Investigation of Skin Friction Reduction Mechanism of Outer-Layer Vertical Blades Using POD Analysis
An, Nam Hyun ; Park, Seong Hyeon ; Chun, Ho Hwan ; Lee, Inwon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 567~575
DOI : 10.3795/KSME-B.2013.37.6.567
A POD analysis based on time-resolved PIV measurements in a circulating water channel has been conducted to identify the skin friction reduction mechanism of outer-layer vertical blades. A recent PIV measurement indicated 2.73% and 7.95% drag reduction in the blade plane and the blade-in-between plane, respectively. In the present study, the influence of vertical blades array upon the characteristics of the turbulent coherent structures was analyzed by the POD method. It is observed that the vortical structures are cut and deformed by the blades array and that their temporal evolution is strongly associated with the skin-friction drag reduction mechanism in the turbulent boundary layer flow.
Experimental Study on Fabrication of AZO Transparent Electrode for Organic Solar Cell Using Selective Low-Temperature Atomic Layer Deposition
Kim, Ki-Cheol ; Song, Gen-Soo ; Kim, Hyung-Tae ; Yoo, Kyung-Hoon ; Kang, Jeong-Jin ; Hwang, Jun-Young ; Lee, Sang-Ho ; Kang, Kyung-Tae ; Kang, Heui-Seok ; Cho, Young-June ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 577~582
DOI : 10.3795/KSME-B.2013.37.6.577
AZO (aluminum-doped zinc oxide) is one of the best candidate materials to replace ITO (indium tin oxide) for TCOs (transparent conductive oxides) used in flat panel displays, organic light-emitting diodes (OLEDs), and organic solar cells (OSCs). In the present study, to apply an AZO thin film to the transparent electrode of an organic solar cell, a low-temperature selective atomic layer deposition (ALD) process was adopted to deposit an AZO thin film on a flexible poly-ethylene-naphthalate (PEN) substrate. The reactive gases for the ALD process were di-ethyl-zinc (DEZ) and tri-methyl-aluminum (TMA) as precursors and H2O as an oxidant. The structural, electrical, and optical characteristics of the AZO thin film were evaluated. From the measured results of the electrical and optical characteristics of the AZO thin films deposited on the PEN substrates by ALD, it was shown that the AZO thin film appeared to be comparable to a commercially used ITO thin film, which confirmed the feasibility of AZO as a TCO for flexible organic solar cells in the near future.
Experimental Investigation of Variable Emittance Material Based on (La, Sr)MnO
Han, Sunwoo ; Choi, Bongsu ; Song, Tae-Ho ; Kim, Sun Jin ; Lee, Bong Jae ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 583~590
DOI : 10.3795/KSME-B.2013.37.6.583
Variable emittance radiators can be used in a thermal management system in space because their total emittance changes depending on the temperature of the system. When the temperature of the system decreased, the emittance also decreased so as to minimize the heat loss to the environment. In contrast, when the temperature of the system increased, the emittance also increased such that radiation cooling could occur. Thermochromic materials, whose emittance is a function of the temperature, are often used in variable emittance radiators because no additional parts are needed. In this study, we fabricated a variable-emittance coating by using a sol-gel method based on LSMO (
) and experimentally characterized the emittance change with respect to temperature. Furthermore, we also examined the stability of LSMO film in space environments by exposing it to extremely low pressure and temperature.
Numerical Study of Non-Newtonian Flow Characteristics in Sudden Contraction-Expansion Channel
Kim, Hyung Min ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 591~597
DOI : 10.3795/KSME-B.2013.37.6.591
Because most existing non-Newtonian models are not suitable for application to the lattice Boltzmann method, theoretical and numerical studies in this regard remain challenging. In this study, the hydrokinetic (HK) model was modified and applied to a 3D sudden contraction-expansion channel flow, and the characteristics of the HK model flow were evaluated to generate non-trivial predictions in three-dimensional strong shear flows. The HK model is very efficient for application to the lattice Boltzmann method because it utilizes the shear rate and relaxation time. However, the simulation would be unstable in a high shear flow field because the local relaxation time sharply decreases with an increase in the shear rate in a strong shear flow field. In the HK model, it may become necessary to truncate the relaxation time and non-dimensional parameter to obtain stable numerical results.
Effect of Fluid Viscosity on Centrifugal Pump Performance
Kim, Noh-Hyeong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 599~605
DOI : 10.3795/KSME-B.2013.37.6.599
The characteristics of centrifugal pump performance according to fluid viscosity change were studied experimentally. A small volute pump with low specific speed was tested by changing the viscosity of an aqueous solution of sugar and glycerin, which is considered a Newtonian fluid. After finishing the test, the total head, shaft horsepower, and pump efficiency were compared with those of a water pump. The results are summarized as follows: (1) when the fluid viscosity is increased, the shut-off head shows very little change but the total head decreases gradually as the flow increases, and this makes the H-Q curve leaning rapidly, and (2) when the fluid viscosity is increased, the shaft horsepower shows very little change at the shutoff condition; however, the shaft horsepower increases more rapidly with an increase in the flow and viscosity.
Study of Combustion Characteristics with Variations of Combustion Parameter in Ultra-Lean LPG Direct Injection Engine
Park, Yun Seo ; Park, Cheol Woong ; Oh, Seung Mook ; Kim, Tae Young ; Choi, Young ; Lee, Yong Gyu ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 607~614
DOI : 10.3795/KSME-B.2013.37.6.607
Nowadays, automotive manufacturers have developed various technologies to improve fuel economy and reduce harmful emissions. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of fuel and ignition. This study aims to investigate the development of a spray-guided-type lean-burn LPG direct injection engine through the redesign of the combustion system. This engine uses a central-injection-type cylinder head in which the injector is installed adjacent to the spark plug. Fuel consumption and combustion stability were estimated depending on the ignition timing and injection timing at various air-fuel ratios. The optimal injection timing and ignition timing were based on the best fuel consumption and combustion stability.
Thermopower Wave in Core-Shell Structures of Carbon Nanotube Chemical Fuels
Choi, Wonjoon ; Strano, Michael S. ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 6, 2013, Pages 615~620
DOI : 10.3795/KSME-B.2013.37.6.615
There is considerable interest in developing energy sources capable of larger power densities. In our previous works, we proved that by coupling an exothermic chemical reaction with 1D nanostructures, a self-propagating reactive wave can be driven along its length with a concomitant electrical pulse of high specific power, which we identified as a thermopower wave. Herein, we discuss details about many different aspects of a thermopower wave. Different alignment degree in vertically aligned CNT films is evaluated in the reactive wave speed and correlated with its thermal reaction that affects the change in the magnitude of energy generation. The effects of the temperature-dependent properties of chemical fuels and CNTs are evaluated. Furthermore, we explore the convection and radiation portions in this thermal wave as well as the synchronization between the thermal reaction transfer and the oscillation of the electrical signal.