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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 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
Study on Performance Characteristics of Spiral Fin-Tube Evaporator Applied to Domestic Refrigerator-Freezers
Lee, Sang Hun ; Yoon, Won Jae ; Kim, Yongchan ; Lee, Mooyeon ; Yun, Seongjung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 205~212
DOI : 10.3795/KSME-B.2013.37.3.205
The objective of this study was to investigate the feasibility of replacing a conventional plate fin-tube evaporator with a spiral fin-tube evaporator by comparing the performance of domestic refrigerator-freezers adopting either the plate fin-tube evaporator or spiral fin-tube evaporator. Experiments were conducted for the domestic refrigerator-freezers using either a 2-column and 15-row plate fin-tube evaporator or three spiral fin-tube evaporators with 11, 13, and 15 tube rows (N). The optimum refrigerant charge decreased with a decrease in the number of tube rows. The power consumptions of the domestic refrigerator-freezers using the spiral fin-tube evaporators with N = 11 and 13 were 2.8% and 1.5% lower than those using the plate fin-tube evaporator, respectively. In addition, the cooling capacity of the spiral fin-tube evaporator with N = 13 was 3%-7% higher than that of the plate fin-tube evaporator under the frosting condition. In a cooling speed test, all of the evaporators showed similar performances.
Study on Flow-Shifted Region Depending on Spool Displacement in Hydraulic Servo Valve with Hybrid Lap
Jeong, Hwang-Hun ; Yun, So-Nam ; Lee, Sung-Soo ; Yang, Joo-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 213~219
DOI : 10.3795/KSME-B.2013.37.3.213
This study examined the static characteristics of a spool valve with a hybrid lap between the spool land and the sleeve. The static equation for the pressure characteristics was derived from flow equations that depend on the spool displacement, and the final model was derived from
because the pressure characteristics test needs to block the control port in the valve. The static equation for the flow characteristics was derived from the pressure characteristics when the control port is open (
). The characteristic equation in the shifted region was assumed from the proportional relationship between the pressure-flow characteristics and the spool displacement.
Effect of Injection Pressure and Injection Timing on Spray and Flame Characteristics of Spray-Guided Direct-Injection Spark-Ignition Engine under Lean Stratified Combustion Operation
Oh, Heechang ; Lee, Minsuk ; Park, Jungseo ; Bae, hoongsik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 221~228
DOI : 10.3795/KSME-B.2013.37.3.221
An experimental study was carried out to investigate the effects of the injection timing on the spray and combustion characteristics in a spray-guided direct-injection spark-ignition (DISI) engine under lean stratified operation. An in-cylinder pressure analysis, exhaust emissions measurement, and visualization of the spray and combustion were employed in this study. The combustion in a stratified DISI engine was found to have both lean premixed and diffusion controlled flame combustion characteristics. The injection timing condition corresponding to the stratified mixture characteristics was verified to be a dominant factor for these flame characteristics. For the early injection timing, a non-luminous blue flame and low combustion efficiency were observed as a result of the lean homogeneous mixture formation. On the other hand, a luminous sooting flame was shown at the late injection timing because of an under-mixed mixture formation. In addition, the smoke emission and incomplete combustion products were increased at the late injection timing as a result of the increased locally rich area. On the other hand, the NOx emissions decreased and IMEP increased as the injection timing retarded. The combustion phasing produced by the injection timing was verified as the reason for this observation.
Effect of Bifurcation Angle on Blood Flow in Flexible Carotid Artery
Lee, Sang Hoon ; Choi, Hyoung Gwon ; Yoo, Jung Yul ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 229~235
DOI : 10.3795/KSME-B.2013.37.3.229
To investigate the effect of the flexible artery wall on the blood flow, three-dimensional numerical simulations were carried out for analyzing the time-dependent incompressible flows of Newtonian fluids constrained by a flexible wall. The Navier-Stokes equations for fluid flow were solved using the P2P1 Galerkin finite element method, and mesh movement was achieved using an arbitrary Lagrangian-Eulerian formulation. The Newmark method was employed for solving the dynamic equilibrium equations for the deformation of a linear elastic solid. To avoid complexity due to the necessity of additional mechanical constraints, we used a combined formulation that includes both the fluid and structure equations of motion to produce a single coupled variational equation. The results showed that the flexibility of the carotid wall significantly affects flow phenomena during the pulse cycle. The flow field was also found to be strongly influenced by the bifurcation angle.
A Thermal Blood Flow Sensor with Contact Force Compensation
Sim, Jai Kyoung ; Youn, Sechan ; Cho, Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 237~242
DOI : 10.3795/KSME-B.2013.37.3.237
This paper proposes a thermal peripheral blood flowmeter integrated with a force sensor that is capable of contact force compensation. We fabricate this blood flowmeter using a nickel RTD (resistance temperature detector) and piezoresistive force sensor by using microfabrication technology. In an experiment, we obtained a decreasing trend for the blood flow under an increasing contact force with a linear tendency of 31.7%/N. We then performed a compensation process based on this obtained trend. As a result, the maximum variance in the blood flow at 1-3N was 9.8%. Thus we achieved consistent blood flow measurement independent of the contact force. In this work, we verified that the thermal blood flowmeter integrated with a force sensor has the ability to accurately measure the blood flow independent of the contact force.
Study of Thermoelectric Generator with Various Thermal Conditions for Exhaust Gas from Internal Combustion Engine using Numerical Analysis
In, Byung Deok ; Lee, Ki Hyung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 243~248
DOI : 10.3795/KSME-B.2013.37.3.243
Internal combustion engines typically expel 30%-40% of the energy supplied by fuel to the environment through their exhaust system. Therefore, further significant improvements in the thermal efficiency of IC engines are possible by recovering the waste heat from the engine exhaust gas. With this fact in mind, a numerical simulation was carried out to investigate the potential of using thermoelectric generation with an internal combustion engine for waste heat recovery. Physical parameters such as the exhaust temperature and mass flow rate were evaluated in the exhaust system, and the optimum location for inserting a thermoelectric generator (TEG) into the system was determined. The TEG will be located in the exhaust system and will use the energy flow between the warmer exhaust gas and the external environment. The optimum position of the temperature distribution and the TEG performance were predicted through numerical analysis. The experimental results obtained showed that the power output significantly increases with the temperature difference between the cold and hot sides of the TEG.
Performance Improvement of Polymer Deposition System by Nozzle Guide and Its Application to Washer Scaffold Fabrication
Sa, Min-Woo ; Kim, Jong Young ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 249~257
DOI : 10.3795/KSME-B.2013.37.3.249
Rapid prototyping was used to design and develop a three-dimensional (3D) scaffold for tissue engineering application. In this study, the nozzle guide (TB-CP-HN, MUSASHI ENGINEERING, INC., JAPAN) used with the syringe of the polymer deposition system (PDS) was evaluated by measuring the scaffold line width and height. 3D scaffolds were fabricated using a biodegradable polymer called poly-caprolactone (PCL). The PCL polymer can be deposited from the needle of a syringe using a 200-
precision nozzle, at a pressure of 600 kPa and temperature of
. The advantages and improvements in this nozzle guide were addressed through washer scaffold fabrication. Overall, this research indicated that the fabrication of a complex-shaped scaffold using an enhanced polymer deposition system may have potential for tissue engineering.
Cluster Cell Separation Algorithm for Automated Cell Tracking
Cho, Mi Gyung ; Shim, Jaesool ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 259~266
DOI : 10.3795/KSME-B.2013.37.3.259
An automated cell tracking system is used to automatically analyze and track the changes in cell behavior in time-lapse cell images acquired using a microscope with a cell culture. Clustering is the partial overlapping of neighboring cells in the process of cell change. Separating clusters into individual cells is very important for cell tracking. In this study, we proposed an algorithm for separating clusters by using ellipse fitting based on a direct least square method. We extracted the contours of clusters, divided them into line segments, and then produced their fitted ellipses using a direct least square method for each line segment. All of the fitted ellipses could be used to separate their corresponding clusters. In experiments, our algorithm separated clusters with average precisions of 91% for two overlapping cells, 84% for three overlapping cells, and about 73% for four overlapping cells.
Effects of Inlet Water Temperature and Heat Load on Fan Power of Counter-Flow Wet Cooling Tower
Nguyen, Minh Phu ; Lee, Geun Sik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 267~273
DOI : 10.3795/KSME-B.2013.37.3.267
In order to provide effective operating conditions for the fan in a wet cooling tower with film fill, a new program to search for the minimum fan power was developed using a model of the optimal total annual cost of the tower based on Merkel's model. In addition, a type of design map for a cooling tower was also developed. The inlet water temperature and heat load were considered as key parameters. The present program was first validated using several typical examples. The results showed that for a given heat load, a three-dimensional graph of the fan power (z-axis), mass flux of air (x-axis, minimum fan power), and inlet water temperature (y-axis, maximum of minimum fan power) showed a saddle configuration. The minimum fan power increased as the heat load increased. The conventionally known fact that the most effective cooling tower operation coincides with a high inlet water temperature and low air flow rate can be replaced by the statement that there exists an optimum mass flux of air corresponding to a minimum fan power for a given inlet water temperature, regardless of the heat load.
Design and Experimental Verification of Uni-Injector Using Gas Methane and Lox as Propellants
Jeon, Jun Su ; Min, Ji Hong ; Jang, Ji Hun ; Ko, Young Sung ; Kim, Sun Jin ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 275~283
DOI : 10.3795/KSME-B.2013.37.3.275
An injector that uses methane gas (
) and liquid oxygen (
) as propellants was designed to verify the combustion characteristics of an engine that uses methane, which is one of the next-generation propellants. A swirl/shear coaxial-type injector was used, and flow analysis was performed using Fluent to determine the main design parameters of the injector. A hydraulic test was performed to understand the atomization and spray pattern characteristics of the injector. Next, a combustion test was performed at the design point to understand the ignition and combustion stability. Additional combustion tests were performed according to the O/F ratio to investigate the combustion characteristics and stabilities using the characteristic exhaust velocity (
) and fluctuation of the chamber pressure. The experimental results showed that the combustion efficiency was greater than 90%, and the pressure fluctuation was lower than 2% under all conditions.
Experimental Study on Local Mass Transfer Characteristics of Flat Plate Using Tripping Wire
Yoo, Seong-Yeon ; Cho, Woong-Sun ; Jo, Woo-Sik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 285~292
DOI : 10.3795/KSME-B.2013.37.3.285
The purpose of this research is to investigate how the boundary layer separation caused by a tripping wire installed in front of the flat plate affects the transition from laminar to turbulent flow, and consequently mass transfer. A naphthalene sublimation technique is used to measure the local mass transfer coefficients on the flat plate, and two boundary conditions for the developed and developing flow are considered to evaluate the effects of the flow boundary. The local mass transfer data for a flat plate with a tripping wire are compared with the data for a flat plate without a tripping wire. The variation trends of the local heat transfer coefficients for the plates with and without the tripping wire are similar to each other in the case of the developing flow, but are quite different for the developed flow. The average Sherwood number for the flat plate with a tripping wire is much higher than that without a tripping wire because of the boundary layer separation.
Visualization Study of Wave Generation in Short-Distance Wave Maker
Jung, Eui-Chul ; Yuan, Zhen-Zhong ; Lim, Hee-Chang ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 293~300
DOI : 10.3795/KSME-B.2013.37.3.293
This study used a water tank and wave maker to generate conditions similar to the real ocean environment. Given that the waves were properly generated in the water tank, a precise analysis indicated the quantitative value of the wave force acting on a body. A high-speed camera and wave-level gauge were used to measure the temporal wave motion and period. A series of artificial water waves were successfully generated using three different wave periods and amplitudes. Each of the waves captured by a high-speed camera was sinusoidal and did not maintain its shape properly without a wave absorber, but it was substantially improved and well shaped when the wave absorber was installed.
Design and Evaluation of Portable Forward Osmosis Desalination Device
Park, Chul-Woo ; Kang, Ho ; Jung, Dongho ; Cha, Jaechul ; Kim, Daejoong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 301~305
DOI : 10.3795/KSME-B.2013.37.3.301
This study aims to design a portable desalination device and discusses the feasibility of the device for overcoming a shortage of safe drinking water. A low-energy, self-supporting, and portable desalination device is designed based on forward osmosis (FO) using an ammonium bicarbonate solution. Experiments with various concentrations of ammonium bicarbonate solution and sodium chloride solution showed that the portable desalination device's performance such as volume and flow rate of desalting water and time required satisfied drinking water standards. The device performance is controlled by varying the concentration and temperature of the solution.
Series-Type Hybrid Electric Bus Fuel Economy Increase with Optimal Component Sizing and Real-Time Control Strategy
Kim, Minjae ; Jung, Daebong ; Kang, Hyungmook ; Min, Kyoungdoug ;
Transactions of the Korean Society of Mechanical Engineers B, volume 37, issue 3, 2013, Pages 307~312
DOI : 10.3795/KSME-B.2013.37.3.307
The interest in reducing the emissions and increasing the fuel economy of ICE vehicles has prompted research on hybrid vehicles, which come in the series, parallel, and power-split types. This study focuses on the series-type hybrid electric vehicle, which has a simple structure. Because each component of a series hybrid vehicle is larger than the corresponding component of the parallel type, the sizing of the vehicle is very important. This is because the performance may be greater or less than what is required. Thus, in this research, the optimal fuel economy was determined and simulated in a real-world system. The optimal sizing was achieved based on the motor, engine/generator, and battery for 13 cycles, where DP was used. The model was developed using ASCET or a Simulink-Amisim Co-simulation platform on the rapid controller prototype, ES-1000.