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1.
Jong Won Choi Mo Se Kim Jeong-Seob Shin Sai-Kee Oh Baik-Young Chung Min Soo Kim 《Journal of Mechanical Science and Technology》2009,23(7):1858-1865
In HVAC system, the oil circulation is inevitable because the compressor requires the oil for lubrication and sealing. A small
portion of the oil circulates with the refrigerant flow through the system components while most of the oil stays or goes
back to the compressor. Because oil retention in refrigeration systems can affect system performance and compressor reliability,
proper oil management is necessary in order to improve the compressor reliability and increase the overall efficiency of the
system. This paper describes a numerical analysis of oil distribution in each component of the commercial air conditioning
system including the suction line, discharge line and heat exchanger. In this study, system modeling was conducted for a compressor,
discharge line, condenser, expansion valve, evaporator and suction line. Oil separation characteristics of the compressor
were taken from the information provided by manufacturer. The working fluid in the system was a mixture of a R-410A refrigerant
and PVE oil. When the oil mass fraction (OMF) was assumed, oil mass distribution in each component was obtained under various
conditions. The total oil hold-up was also investigated, and the suction line contained the largest oil hold-up per unit length
of all components.
This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008.
Min Soo Kim received his B.S., M.S., and Ph.D. degree at Seoul National University, Korea in 1985, 1987, and 1991, respectively. After
Ph.D. degree, Prof. Kim worked at National Institute of Standards and Technology (NIST) in U.S.A. for about three years. He
is currently a professor at the School of Mechanical and Aerospace Engineering of Seoul National University, Korea.
Jong Won Choi received B.S. degree in Mechanical Engineering from Korea University in Seoul, Korea, in 2004, and then received M.S. degrees
from Seoul National University in 2006. He is currently a student in Ph.D. course at the School of Mechanical and Aerospace
Engineering of Seoul National University in Seoul, Korea. His research interests include refrigeration system, micro-fluidic
devices, and PEM fuel cell as an alternative energy for next generation.
Mo Se Kim received B.S. degree in Mechanical and Aerospace Engineering from Seoul National University in Seoul, Korea, in 2007. He
is currently a student in M.S. course at the School of Mechanical and Aerospace Engineering of Seoul National University in
Seoul, Korea. He had studied on the oil migration in the heat pump system, and now he studies on the refrigeration system
using an ejector.
Baik-Young Chung received his B.S., M.S., and Ph.D. degrees in Mechanical Engineering from Inha University, Korea in 1984, 1986, and 2001,
respectively. He is currently a research fellow of HAC Research Center at LG Electronics. He is responsible for the commercial
air conditioner group.
Sai-Kee Oh received B.S. degree in Mechanical Engineering from Seoul National University, Korea in 1989, and then received M.S. and
Ph.D. degrees from KAIST, Korea in 1991 and 1997, respectively. He is currently a principal research engineer of HAC Research
Center at LG Electronics. He is responsible for the residential air conditioner group.
Jeong-Seob Shin received B.S. degree in Machine Design and Production Engineering from Hanyang University, Korea in 1988, M.S. degree in
Mechanical Engineering from KAIST, Korea in 1991, and Ph.D. degree in Mechanical Engineering from POSTECH, Korea in 2004.
He has joined HAC Research Center at LG Electronics since 2006 as a principal research engineer. 相似文献
2.
Seung-chai Jung Byung-Hoon Park Hyun Ko Woong-sup Yoon 《Journal of Mechanical Science and Technology》2009,23(3):823-835
Effects of the bulk inlet velocity on the characteristics of dual-inlet side-dump flows are numerically investigated. Non-reacting
subsonic turbulent flow is solved by a preconditioned Reynolds-averaged Navier-Stokes equation system with low-Reynolds number
k − ɛ turbulence model. The numerical method is properly validated with measured velocity distributions in the head dome and the
combustor. With substantial increase in the bulk inlet velocity, general profiles of essential primary and secondary flows
normalized by the bulk inlet velocity are quantitatively invariant to the changes in the bulk inlet velocity.
This paper was recommended for publication in revised form by Associate Editor Do Hyung Lee
Seung-chai Jung received his B.S. degree in Mechanical Engineering from Yonsei University, Korea, in 2001. He then received his M.S. degree
in Mechanical Engineering from Yonsei University, Korea, in 2005. Mr. Jung is currently a Ph. D. candidate at Yonsei University,
where he is majoring in Mechanical Engineering. Mr. Jung’s research interests include propulsion system and particle-surface
collision dynamics.
Byung-Hoon Park received his B.S. degree in Mechanical Design and Production Engineering from Yonsei University in 2003. He is currently
a Ph.D. candidate in Yonsei University in Seoul, Korea. His research interests include performance design of propulsion systems
and nu-merical analysis of instability in multiphase turbulent reacting flow-fields.
Hyun Ko received his B.S. degree in Aerospace Engineering from Chonbuk National University, Korea, in 1996. He then received his
M.S. degree in Mechanical Design from Chonbuk National University, Korea, in 1998. In 2005, he obtained his Ph.D. degree from
Yonsei University, where he majored in mechanical engineering. Dr. Ko is currently a Principal Research Engineer of the MicroFriend
Co., Ltd. in Seoul, Korea. His research interests include propulsion related systems and computational fluid dynamics.
Woong-sup Yoon received his B.S. degree in Mechanical Engineering from Yonsei University, Korea, in 1985. He then received his M.S. degree
from University of Missouri-Rolla in 1989. In 1992, he obtained his Ph.D. degree from the University of Alabama in Huntsville,
where he majored in mechanical and aerospace engineering. Dr. Yoon is currently a professor at the School of Mechanical Engineering
at Yonsei University in Seoul, Korea. His research interests include propulsion system and particle-related environmental/
thermal engineering. 相似文献
3.
Jae Hyuk Choi Junhong Kim SangKyu Choi Byoung-Ho Jeon Osamu Fujita Suk Ho Chung 《Journal of Mechanical Science and Technology》2009,23(3):707-716
A numerical study on soot deposition in ethylene diffusion flames has been conducted to elucidate the effect of thermophoresis
on soot particles under a microgravity environment. Time-dependent reactive-flow Navier-Stokes equations coupled with the
modeling of soot formation have been solved. The model was validated by comparing the simulation results with the previous
experimental data for a laminar diffusion flame of ethylene (C2H4) with enriched oxygen (35% O2 + 65% N2) along a solid wall. In particular, the effect of surrounding air velocity as a major calculation parameter has been investigated.
Especially, the soot deposition length defined as the transverse travel distance to the wall in the streamwise direction is
introduced as a parameter to evaluate the soot deposition tendency on the wall. The calculation result exhibits that there
existed an optimal air velocity for the early deposition of soot on the surface, which was in good agreement with the previous
experimental results. The reason has been attributed to the balance between the effects of the thermophoretic force and convective
motion.
This paper was recommended for publication in revised form by Associate Editor Ohchae Kwon
Jae Hyuk Choi received his B.S. and M.S. degrees in Marine System Engineering from Korea Maritime University in 1996 and 2000, respectively.
He then went on to receive a Ph.D. degrees from Hokkaido university in 2005. Dr. Choi is currently a BK21 Assistant Professor
at the School of Mechanical and Aerospace Engineering at Seoul National University in Seoul, Korea. Dr. Choi’s research interests
are in the area of reduction of pollutant emission (Soot and NOx), high temperature combustion, laser diagnostics, alternative
fuel and hydrogen production with high temperature electrolysis steam (HTES).
Junhong Kim received his B.S., M.S., and Ph. D degrees in Mechanical Engineering from Seoul National University in 1998, 2000, and 2004,
respectively. His research interests include lifted flames, edge flames, and numerical simulation.
Sang Kyu Choi received his B.S. degree in Mechanical Engineering from Seoul National University in 2004. He is a Ph. D student in the School
of Mechanical Engineering, Seoul National University. His research interests include edge flames, oxy-fuel combustion, and
numerical simulation.
Byoung ho Jeon received his B.S degrees in Mechanical Engineering from kangwon University in 1998, and M.S., Ph. D. degrees in Mechanical
Engineering from Hokkaido University in 2002, 2008, respectively. Dr Jeon is working at Korea Aerospace Research Institute
from 2007. June. as Gasturbine engine developer. Jeon’s research interests are in the area of reduction of pollutant emission
(Soot and Nox), High temperature combustion, combustion system (Furnace, Combine Generation system, IGCC, CTL), and Fire safety
in building.
Osamu Fujita received his B.S., M.S., and Ph. D. degrees in Mechanical Engineering from Hokkaido University in 1982, 1984, and 1987, respectively.
Prof. Fujita is currently a Professor at the division of Mechanical and space Engineering at Hokkaido University in sapporo,
Japan. Prof. Fujita’s research interests are in the area of reduction of pollutant emission (Soot and Nox), solid combustion,
catalytic combustion, high temperature combustion, alternative fuel and fire safety in space.
Suk Ho Chung received his B.S. degree in Mechanical Engineering in 1976 from Seoul National University, and his M.S. and Ph. D. degree
in Mechanical Engineering in 1980 and 1983, respectively from Northwestern University. He is a professor since 1984 in the
School of Mechanical and Aerospace Engineering, Seoul National University. His research interests cover combustion fundamentals,
pollutant formation, and laser diagnostics. 相似文献
4.
Dongji Xuan Zhenzhe Li Jinwan Kim Youngbae Kim 《Journal of Mechanical Science and Technology》2009,23(3):717-728
The output power efficiency of the fuel cell system mainly depends on the required current, stack temperature, air excess
ratio, hydrogen excess ratio, and inlet air humidity. Therefore, the operating conditions should be optimized to get maximum
output power efficiency. In this paper, a dynamic model for the fuel cell stack was developed, which is comprised of a mass
flow model, a gas diffusion layer model, a membrane hydration, and a stack voltage model. Experiments have been performed
to calibrate the dynamic Polymer Electrolyte Membrane Fuel Cell (PEMFC) stack model. To achieve the maximum output power and
the minimum use of hydrogen in a certain power condition, optimization was carried out using Response Surface Methodology
(RSM) based on the proposed PEMFC stack model. Using the developed method, optimal operating conditions can be effectively
selected in order to obtain minimum hydrogen consumption.
This paper was recommended for publication in revised form by Associate Editor Tong Seop Kim
Dong-Ji Xuan received his B.S. degree in Mechanical Engineering from Harbin Engineering University, China in 2000. He then received his
M.S. degree in Mechanical Engineering from Chonnam National University, South Korea in 2006. Currently, he is a Ph.D. candidate
of the Department of Mechanical Engineering, Chonnam National University, South Korea. His research interests include control
and optimization of PEM fuel cell system, dynamics and control, and mechatronics.
Zhen-Zhe Li received his B.S. degree in Mechanical Engineering from Yanbian University, China in 2002. He then received his M.S. degree
in Aerospace Engineering from Konkuk University, South Korea in 2005 and his Ph.D. degree in Mechanical Engineering from Chonnam
National University, South Korea in 2009. Dr. Li is currently a Researcher of the Department of Mechanical Engineering in
Chonnam National University, South Korea. Dr. Li’s research interests include applied heat transfer, fluid mechanics, and
optimal design of thermal and fluid systems.
Jin-Wan Kim received his B.S. degree in Aerospace Engineering from Chosun University, South Korea in 1990. He then received his M.S.
degree in Aerospace and Mechanical Engineering from Korea Aerospace University, South Korea in 2003 and his Ph.D degree in
Mechanical Engineering from Chonnam National University, South Korea in 2008. He is currently a Post Doctor of the Department
of Mechanical Engineering in Chonnam National University, South Korea. His research interests include control of hydraulic
systems, dynamics and control, and mechatronics.
Young-Bae Kim received his B.S. degree in Mechanical Design from Seoul National University, South Korea in 1980. He then received his M.S.
degree in Mechanical Engineering from the Korean Advanced Institute of Science and Technology (KAIST), South Korea in 1982
and his Ph.D. degree in Mechanical Engineering from Texas A&M University, USA in 1990. Dr. Kim is currently a Professor of
the School of Mechanical and Systems Engineering in Chonnam National University, South Korea. Dr. Kim’s research interests
include mechatronics, dynamics and control, and fuel cell hybrid electric vehicle (FCHEV) systems. 相似文献
5.
Jin Hwan Ko Jee Woong Kim Soo Hyung Park Doyoung Byun 《Journal of Mechanical Science and Technology》2009,23(6):1727-1735
Nature-inspired flapping foils have attracted interest for their high thrust efficiency, but the large motions of their boundaries
need to be considered. It is challenging to develop robust, efficient grid deformation algorithms appropriate for the large
motions in three dimensions. In this paper, a volume grid deformation code is developed based on finite macro-element and
transfinite interpolation, which successfully interfaces to a structured multi-block Navier-Stokes code. A suitable condition
that generates the macro-elements with efficiency and improves the robustness of grid regularity is presented as well. As
demonstrated by an airfoil with various motions related to flapping, the numerical results of aerodynamic forces by the developed
method are shown to be in good agreement with those of an experimental data or a previous numerical solution.
This paper was recommended for publication in revised form by Associate Editor Do Hyung Lee
Jin Hwan Ko received his B.S. degree in Mechanical Engineering from KAIST, Korea, in 1995. He then received his M.S. and Ph.D. degrees
from KAIST in 1997 and 2004, respectively. Dr. Ko is currently a research professor at the School of Mechanical and Aerospace
Engineering at Seoul National University in Seoul, Korea. His research interests include fluid-structure interaction analysis,
structural dynamics of a micro-scale resonator, and model order reduction.
Soo Hyung Park received his B.S. degree in Aerospace Engineering from KAIST, Korea, in 1996. He then received his M.S. and Ph.D. degrees
from KAIST in 1999 and 2003, respectively. Prof. Park is currently an assistant professor at the Dept. of Aerospace Information
Engineering at Konkuk University in Seoul, Korea. His research interests include computational fluid dynamics, fluid-structure
interaction analysis, rotorcraft aerodynamics, and turbulence modeling. 相似文献
6.
Hyunwoo Bang Won Gu Lee Junha Park Hoyoung Yun Junggi Min Dong-Chul Han 《Journal of Mechanical Science and Technology》2009,23(5):1500-1507
This paper presents a novel method of optimizing particle-suspended microfluidic channels using genetic algorithms (GAs).
The GAs can be used to generate an optimal microchannel design by varying its geometrical parameters. A heuristic simulation
can be useful for simulating the emergent behaviors of particles resulting from their interaction with a virtual microchannel
environment. At the same time, fitness evaluation enables us to direct evolutions towards an optimized microchannel design.
Specifically, this technique can be used to demonstrate its feasibility by optimizing one commercialized product for clinical
applications such as the microchannel-type imaging flow cytometry of human erythrocytes. The resulting channel design can
also be fabricated and then compared to its counterpart. This result implies that this approach can be potentially beneficial
for developing a complex microchannel design in a controlled manner.
This paper was recommended for publication in revised form by Associate Editor Hong Hee Yoo
Hyunwoo Bang was born in Korea on June 2, 1978. He received the B.S. degree in mechanical and aerospace engineering from Seoul National
University, Seoul, Korea in 2001 and the Ph.D. degree in mechanical and aerospace engineering from Seoul National University
in 2007. He did postdoctoral research at University of California Los Angeles, CA that involved the integration of functional
biological components into engineered devices with Prof. Jacob J. Schmidt from April 2007 to August 2008. His current research
interests include microfluidics based Lab-on-a-chip devices and their design optimization using artificial intelligence.
Dong-Chul Han received the B.S. degree from the Department of Mechanical Engineering, Seoul National University, Seoul, Korea, in 1969,
and the Dipl.-Ing. and Dr.-Ing. degrees from the Department of Mechanical Engineering, University of Karlsruhe, Karlsruhe,
Germany, in 1975 and 1979, respectively. He also received the Habilitation from the Department of Mechanical Engineering,
University of Karlsruhe. He had been a professor in the school of Mechanical and Aerospace Engineering at Seoul National University
from 1982 to 2008. His research interests include active magnetic bearing systems, mechanical lubrication, Bio-MEMS (MicroElectroMechanical
Systems) and nano-fabrication. 相似文献
7.
This investigation is concerned with the topology optimization using displacement-based nonconforming finite elements for
problems involving incompressible materials. Although the topology optimization with mixed displacement-pressure elements
was performed, a displacement-based approach can be an efficient alternative because it interpolates displacement only. After
demonstrating the Poisson locking-free characteristics of the employed nonconforming finite elements by a simple patch test,
the developed method is applied to solve the design problems of mounts involving incompressible solid or fluid. The numerical
performance of the nonconforming elements in topology optimization was examined also with existing incompressible problems.
This paper was recommended for publication in revised form by Associate Editor Tae Hee Lee
Gang-Won Jang received his M.S. degree in 2000, and Ph.D. degree in 2004, both from the School of Mechanical and Aerospace Engineering,
Seoul National University, Seoul, Korea. He is currently an Assistant Professor at the School of Mechanical and Automotive
Engineering, Kunsan National University, Jeonbuk, Korea. His current interest concerns topology optimization of multiphysics
problems and thin-walled beam analysis.
Yoon Young Kim received his B.S. and M.S degrees from Seoul National University, Seoul, Korea, and the Ph.D. degree from Stanford University,
Palo Alto, CA, in 1989. He has been on the faculty of the School of Mechanical and Aerospace Engineering, Seoul National University,
since 1991. He is also the Director of the National Creative Research Initiatives Center for Multiscale Design. His main research
field is the optimal design of multiphysics systems, mechanisms, and transducers. He has served as an editor of several Korean
and international journals, and as an organizing committee member of several international conferences. 相似文献
8.
Taewoong Lim Jaeik Jeong Jaewon Chung Jin Taek Chung 《Journal of Mechanical Science and Technology》2009,23(7):1788-1794
In this work, the evaporation phenomena of 20–45 picoliter water droplet (i.e. 50–65 μm diameter) on heated substrates with
different thermal conductivity are studied experimentally. The effect of thermal conductivity of substrates and inter-distance
between jetted droplets on the evaporation is investigated. In addition, the model to predict evaporation rate of the picoliter
droplet on different substrates at a heated condition is developed using approximations for picoliter droplet.
This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008.
Taewoong Lim received his B.S and M.S. degree in mechanical engineering from Korea University, Seoul, Korea in 2007 and 2009, respectively.
His thesis topic was the evaporation of inkjet printed pico-liter droplet and He has been working at Hyundai Motor Company.
Jaeik Jeong received his B.S. degree in mechanical engineering from Korea University in 2008. He is currently a M.S. candidate in mechanical
engineering at Korea University.
Jaewon Chung received his B.S. and M.S. degrees in mechanical engineering from Yonsei University, Seoul, Korea in 1995 and 1997, respectively
and Ph.D. degree from University of California, Berkley in 2002. He was postdoctoral associate in Engineering System Research
Center at University of California, Berkley in 2002–2004 and had worked in the Center of Micro and Nano Technology at Lawrence
Livermore National Laboratory as a visiting collaborator. He is a currently an associate professor at the Department of Mechanical
Engineering at Korea University in Seoul, Korea. His research interests include direct writing methods including drop on demand
inkjet printing, electrohydrodynamic printing and laser material processing for printing electronics.
Jin Taek Chung received his B.S. and M.S. degrees in mechanical engineering from Korea University, Seoul, Korea in 1983 and 1985, respectively
and Ph. D. degree from University of Minnesota, U.S.A. in 1992. He is a currently a professor at the Department of Mechanical
Engineering at Korea University in Seoul, Korea. His research interests are heat transfer and 3-D flow in gas turbines and
thermal management of electronic devices. 相似文献
9.
WookJe Park Sang H. Lee JungIl Song 《Journal of Mechanical Science and Technology》2009,23(2):302-310
This paper describes the flight test method for studying the primary control surface stuck condition and the combination stuck
of the primary control. An aircraft must show controllability and trimmability under post-failure conditions. An aircraft
is successfully tested under various fault conditions. It is recognized that a control surface fault is detected by monitoring
the value of the coefficients related to the control surface deviation. The control surface stuck position is determined by
comparing the trim value with the reference value. To detect and isolate the fault, an analysis that employs the real-time
parameter estimation method is used. If the flight control system is reconfigured using online estimates of aircraft parameters
from a real-time parameter estimation scheme, the reliability increases without the addition of sensors or additional cost.
This paper was recommended for publication in revised form by Associate Editor Eung-Soo Shin
Wook-Je Park received the B.S. and the Ph.D. degrees, both in Aeronautical Engineering, from Korea Aerospace University in 1994 and 2005,
respectively. He is now a Post-Doc in Mechanical and Aeronautical Engineering, Western Michigan University. His research interests
are in fault detection and isolation, real-time parameter estimation method, flight test, and their application in aircraft
and UAV.
Sang-Hyuk Lee received the Ph. D. degree in Electrical Engineering from Seoul National University in 1998. Dr. Lee has been with the Changwon
National University as a research professor since 2006. His research interests include fuzzy theory, game theory, and nonlinear
control.
Jung-Il Song received his Ph. D. degree in Mechanical Engineering from POSTECH, Korea, in 1997. Dr. Song is currently a Professor at the
School of Mechanical Engineering at Changwon National University in Changwon, Korea. His research interests include manufacturing
process and evaluation of composites, biomedical engineering and rehabilitation engineering. 相似文献
10.
The location and the size of a geometrically defected region in the side wall of a corner, which is generated during the flat
end-milling process, are investigated through experiments and geometrical analysis. A corner with inner and outer surfaces
is assumed to be made up of one arc-surface patch and two flat-surface patches. Based on the previous findings that the change
of material removal per tooth affects the geometry of the end-milled side wall, it is expected that the geometrically defected
regions are located around the corner when the tool is approaching and leaving the arc surface. In this respect, analytic
models are proposed to predict the location and the size of a geometrically defected region, which are then validated via
comparison with the experimental results.
This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim
Kun Sang Lee received his B. S. degree in Mechanical Engineering from Seoul National University, Korea, in 1982. He then received his
Dipl.-Ing. and Dr.-Ing. degrees from Technical University of Berlin, Germany, in 1991 and 1993, respectively. Dr. Lee is currently
a Professor at the School of Mechanical and Automotive Engineering at Kookmin University in Seoul, Korea. He serves as a Staff
of the Korea Engineering Education Research Center. His research interests include precision machining, high energy beam material
processing, and creative design methodology.
Kang Kim received his B. S. and M. S. degrees in Mechanical Design and Production Engineering from Seoul National University, Korea,
in 1982 and 1984, respectively. He then received his Ph.D. degree from Purdue University, USA, in 1992. Dr. Kim is currently
a Professor at the School of Mechanical and Automotive Engineering at Kookmin University in Seoul, Korea. His research interests
include material removal processes, and concurrent engineering. 相似文献
11.
Joon Lyou MinSig Kang HwyKuen Kwak YoungJun Choi 《Journal of Mechanical Science and Technology》2009,23(8):2097-2106
This paper presents a combined dual stage-based mechanical and image-based stabilization scheme for a three-axis image-tracking
sight system. To improve the stabilization and tracking accuracy, a secondary stage actuated by a pair of electro-magnets
is mounted on a conventional elevation gimbal. For the remaining roll axis stabilization, an electronic digital- image stabilization
technique is introduced to estimate and correct roll motions. Experimental results are given to demonstrate the effectiveness
of the proposed stabilization system and the image-stabilization scheme.
This paper was recommended for publication in revised form by Associate Editor Dong Hwan Kim
Joon Lyou received a B.S. degree in Electronics Engineering from Seoul National University in 1978. He then went on to receive M.S.
and Ph.D. degrees from KAIST in 1980 and 1984, respectively. Dr. Lyou is currently a professor of the Department of Electronics
Engineering at Chungnam National University in Daejeon, Korea. His research interests include industrial control and sensor
signal processing, IT based robotics, and navigation systems.
MinSig Kang received a B.S. degree from the Department of Mechanical Engineering of Seoul National University in 1980. He then went on
to receive M.S. and Ph.D. degrees from KAIST in 1983 and 1987, respectively. He worked for the Agency for Defence Development
during 1987–1998. Dr. Kang is currently a professor of the Department of Mechanical and Automotive Engineering at Kyungwon
University in Sungnam, Korea. His research interests include dynamic systems measurement and control, industrial robotics,
and manufacturing systems.
HwyKuen Kwak received a B.S. degree in Electronics Engineering from Chungnam National University in 2005. He is currently working on his
M.S. and Ph.D. course at Chungnam National University in Daejeon, Korea. His research areas are image signal processing, sensors
and digital control systems.
YoungJun Choi received a B.S. and M.S. degree in Mechanical Engineering from Kyungwon University in 2004 and 2006. He is currently a researcher
for the Agency for Defence Development in Daejeon, Korea. His research fields are dynamic systems measurement and control,
satellite systems, navigation systems and smart materials. 相似文献
12.
Friction-induced ignition modeling of energetic materials 总被引:1,自引:0,他引:1
Min-cheol Gwak Tae-yong Jung Jack Jai-ick Yoh 《Journal of Mechanical Science and Technology》2009,23(7):1779-1787
The heat released during the external frictional motion is a factor responsible for initiating energetic materials under all
types of mechanical stimuli including impact, drop, or penetration. We model the friction-induced ignition of cyclotrimethylenetrinitramine
(RDX), cyclotetramethylene-tetranitramine (HMX), and ammonium-perchlorate/ hydroxylterminated-polybutadiene (AP/HTPB) propellant
using the BAM friction apparatus and one-dimensional time to explosion (ODTX) apparatus whose results are used to validate
the friction ignition mechanism and the deflagration kinetics of energetic materials, respectively. A procedure to obtain
the time-to-ignition for each energetic sample due to friction is outlined.
This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008.
Min-cheol Gwak received his B.S. degree in Mechanical Engineering from Korea Aerospace University, Korea, in 2007. Now he is a graduate
student of Mechanical and Aerospace Engineering at Seoul National University in Seoul, Korea. His research interests are ignition
of high energy material and combustion phenomena.
Tae-yong Jung received his B.S. degree in Mechanical and Aerospace Engineering from Seoul National University, Korea, in 2007. Now he is
a graduate student of Mechanical and Aerospace Engineering at Seoul National University in Seoul, Korea. His research interests
are solid propellant combustion and phase transformation.
Professor J. Yoh received his BSME from UC Berkeley in 1992 and MSME from UCLA in 1995. His doctoral degree is in Theoretical & Applied Mechanics
from the University of Illinois at Urbana-Champaign, 2001. His research interest is in high energy system design using high
power lasers and condensed energetic materials. 相似文献
13.
Lean premixed combustion is a well known method in gas turbine combustors that can reduce fuel consumption and decrease flame
temperature. In lean premixed flames, flame instabilities can occur because the combustion takes place near the lean flammable
limit. For the purpose of increasing flame stability, a small amount of hydrogen was added into a fuel, which has ultra low
lean flammable limit. The extinction stretch rate increased and total equivalence ratio at extinction decreased with hydrogen
addition; consequently, ultra lean premixed combustion was possible and flame stability could be achieved at low temperature
conditions. The NOx emission increased with hydrogen addition for the same stretch rate and equivalence ratio, but the extinction stretch rate
and lean flammability limit was enlarged. Consequently, NOx emission decreased with hydrogen addition in the near extinction conditions. Hydrogen addition could improve flame stability
and reduce NOx emission in ultra lean premixed combustion.
This paper was recommended for publication in revised form by Associate Editor Ohchae Kwon
Dr. Eun-Seong Cho received his B.S. and M.S. degrees in Mechanical Engineering from Hanyang University, Korea, in 1996 and 1998, respectively.
He then received his Ph.D. degree from Seoul National University, Korea, in 2005. He was a principal engineer of KD Navien
research center and currently a research associate at Delft University of Technology, The Netherlands. His research interests
include eco-friendly clean combustion technology, new and renewable energy systems.
Prof. Suk Ho Chung received his B.S. degree from Seoul National University, Korea, in 1976 and Ph.D. degree in Mechanical Engineering from Northwestern
University, USA, in 1983. He is a Professor since 1984 in the School of Mechanical and Aerospace Engineering at Seoul National
University in Seoul, Korea. His research interests cover combustion fundamentals, pollutant formation, laser diagnostics,
and plasma-assisted combustion. 相似文献
14.
Loop heat pipes often experience start-up problems especially under low thermal loads. A bypass line was installed between
the evaporator and the liquid reservoir to alleviate the difficulties associated with start-up of a loop heat pipe with flat
evaporator. The evaporator and condenser had dimensions of 40 mm (W) by 50 mm (L). The wall and tube materials were stainless
steel and the working fluid was methanol. Axial grooves were provided in the flat evaporator to serve as vapor passages. The
inner diameters of liquid and vapor transport lines were 2 mm and 4 mm, respectively, and the length of the two lines was
0.5 m each. The thermal load range was up to 130 W for horizontal alignment with the condenser temperature of 10°C. The experimental
results showed that the minimum thermal load for start-up was lowered by 37% when the bypass line was employed.
This paper was recommended for publication in revised form by Associate Editor Dae Hee Lee
Joon Hong Boo received his B.S. degree in Mechanical Engineering from Seoul National University in 1978. He then received his M.S.M.E.
and Ph.D. degrees from Georgia Institute of Technology in 1984 and 1989, respectively. Dr. Boo is currently a Professor in
the School of Aerospace and Mechanical Engineering at Korea Aerospace University, where he joined in 1989. His research interests
include heat transfer, heat pipes, and energy systems. He conducted joint research with Texas A&M University and Waseda University
in 1994 and 2008, respectively, as Visiting Professor. Dr. Boo is an active member of the International Heat Pipe Conference
Committee.
Eui Guk Jung received his B.S. and M.S. degrees in Aerospace and Mechanical Engineering from Korea Aerospace University, in 2002 and 2004,
respectively. He is currently a Ph.D. candidate in the Graduate School at Korea Aerospace University. His research interests
include applications of heat pipes and loop heat pipes. 相似文献
15.
Taewoo Kim Kwanjung Yee Sejong Oh Hee Jung Kang 《Journal of Mechanical Science and Technology》2009,23(1):269-280
A user-friendly, Windows-based Graphic User Interface (GUI) program that automates the generation of the aerodynamic performance
tables for comprehensive helicopter load analysis codes was developed. With this program, computational grids are automatically
created for the given airfoil surface coordinates, and users can verify the grids immediately. In addition, the program’s
post-processing feature can enable the real-time inspection of the interim results of the computation. The aerodynamic performance
tables can be generated by performing automated aerodynamic analysis of the airfoil in various angles of attack and Mach numbers
by using validated CFD code. The Mixed-Language technique was employed to combine the FORTRAN-based CFD codes to the C++-based
GUI program without needing any transformation between these two languages. The MS Access was used to construct the data base
of the aerodynamic tables. The real-time inputs of the analysis results of the ODBC Access data base make it easy to retrieve
the aerodynamic tables. Of the entire range of the angle of attack (−180° to 180°), the CFD analysis is only performed in
the significant angles depending on the Mach number. The aerodynamic data for the other angles were obtained by using an interpolation
method; therefore, the tables could be generated quickly. Various aerodynamic information such as drag divergence Mach number
and stall angle can be extracted from the computed results stored in the database.
This paper was recommended for publication in revised form by Associate Editor Yang Na
Taewoo Kim received a B.S. degree in Aerospace Engineering from Pusan National University in 2007. He is currently a M.S. candidate
at the graduate school of Aerospace Engineering at Pusan National University in Pusan, Korea. His research interests are in
the area of aerodynamics, optimization design, and helicopter aerodynamics.
Kwanjung Yee received a B.S. degree in Aerospace Engineering from Seoul National University in 1992. He then went on to receive his M.S.
and Ph.D. degrees from Seoul National University in 1992 and 1998, respectively. Dr. Yee is currently an Assistant Professor
at the Department of Aerospace Engineering in Pusan National University, Korea. His major research area covers unsteady aerodynamics,
rotorcraft flight dynamics and multidisciplinary design optimization.
Sejong Oh received his B.S. and M.S. degrees in Aerospace Engineering from Seoul National University in 1979 and 1982 respectively.
He finished his Ph.D. degrees from Stanford University in 1988. Prof. Oh is currently a Professor at Department of Aerospace
at Pusan National University in Busan, Korea. He is currently a Board Member of Korean Society of Aeronautical and Space Sciences.
Prof. Oh’s research interests are in the area of Vortex flow and Rotorcraft aerodynamics.
Hee Jung Kang received a B.S. degree in Aerospace Engineering from KAIST in 1994. He then went on to receive his M.S. and Ph.D. degrees
from KAIST in 1996 and 2001, respectively. Dr. Kang is currently a senior research engineer at Rotor Department in KARI (Korea
Aerospace Research Institute). Dr. Kang’s research interests are in the area of helicopter rotor aerodynamics, CFD (Computational
Fluid Dynamics) and simulation of fluid-structure interaction. 相似文献
16.
Zhen-Zhe Li Kwang-Su Heo Dong-Ji Xuan Seoung-Yun Seol 《Journal of Mechanical Science and Technology》2009,23(3):607-613
Thermoforming is one of the most versatile and economical processes available for polymer products, but cycle time and production
cost must be continuously reduced in order to improve the competitive power of products. In this study, water spray cooling
was simulated to apply to a cooling system instead of compressed air cooling in order to shorten the cycle time and reduce
the cost of compressed air used in the cooling process. At first, cooling time using compressed air was predicted in order
to check the state of mass production. In the following step, the ratio of removed energy by air cooling or water spray cooling
among the total removed energy was found by using 1-D analysis code of the cooling system under the condition of checking
the possibility of conversion from 2-D to 1-D problem. The analysis results using water spray cooling show that cycle time
can be reduced because of high cooling efficiency of water spray, and cost of production caused by using compressed air can
be reduced by decreasing the amount of the used compressed air. The 1-D analysis code can be widely used in the design of
a thermoforming cooling system, and parameters of the thermoforming process can be modified based on the recommended data
suitable for a cooling system of thermoforming.
This paper was recommended for publication in revised form by Associate Editor Dongsik Kim
Zhen-Zhe Li received his B.S. degree in Mechanical Engineering from Yanbian University, China, in 2002. He then received his M.S. degree
in Aerospace Engineering from Konkuk University, South Korea, in 2005. He then received his Ph.D. degree in Mechanical Engineering
from Chonnam National University, South Korea, in 2009. Dr. Li is currently a Researcher of the Department of Mechanical Engineering,
Chonnam National University, South Korea. Dr. Li’s research interests include applied heat transfer, fluid mechanics and optimal
design of thermal and fluid systems.
Kwang-Su Heo received his B.S. degree in Mechanical Engineering from Chonnam National University, South Korea, in 1998. He then received
his M.S. and Ph.D. degrees in Mechanical Engineering from Chonnam National University, South Korea, in 2003 and 2008, respectively.
Dr. Heo is currently a Post-doctorial Researcher of the Department of Mechanical Engineering, KAIST(Korean Advanced Institute
of Science and Technology), South Korea. Dr. Heo’s research interests include applied heat transfer, fluid mechanics and thermal
analysis of superconductor.
Dong-Ji Xuan received his B.S. degree in Mechanical Engineering from Harbin Engineering University, China, in 2000. He then received his
M.S. degree in Mechanical Engineering from Chonnam National University, South Korea, in 2006. He is currently a Ph.D. candidate
of the Department of Mechanical Engineering, Chonnam National University, South Korea. His research interests include control
& optimization of PEM fuel cell system, dynamics & control, mechatronics.
Seoung-Yun Seol received his B.S. degree in Mechanical Design from Seoul National University, South Korea, in 1983. He then received his
M.S. degree in Mechanical Engineering from KAIST(Korean Advanced Institute of Science and Technology), South Korea, in 1985.
He then received his Ph.D. degree in Mechanical Engineering from Texas Tech University, USA, in 1993. Dr. Seol is currently
a Professor of the School of Mechanical and Systems Engineering, Chonnam National University, South Korea. Dr. Seol’s research
interests include applied heat transfer, fluid mechanics and thermal analysis of superconductor. 相似文献
17.
Yong-Mo Kong Su-Hyun Choi Jin-Dae Song Bo-Suk Yang ByeongKeun Choi 《Journal of Mechanical Science and Technology》2009,23(8):2085-2096
This paper presents a hybrid optimization algorithm which combines an external call type optimization method and a general
stochastic iterative algorithm for the nonlinear integer programming with genetic algorithm (GA). GA can rapidly search the
approximate global optimum under a complicated design environment such as a ship structure. Meanwhile it can handle optimization
problems involving discrete design variables. In addition, there are many parameters that have to be set for GA which greatly
affect the accuracy and calculation time of the optimum solution. However, the setting process is difficult for users, and
there are no rules to decide these parameters. Therefore, to overcome these difficulties, the optimization of these parameters
has been also conducted by using GA itself. It is proven using the trial function that the parameters are optimal. Finally,
the verification of validity and usefulness of nonlinear integer programming is performed by applying this method to the compass
deck of a ship where the vibration problem is frequently occurs.
This paper was recommended for publication in revised form by Associate Editor Eung-Soo Shin
YoungMo Kong received his B.S. degree, M.S. and Ph.D. degrees in Mechanical Engineering from Pukyong National University, Korea, in 1990,
1992 and 2006, respectively. Dr. Kong is currently a Principal Research Engineer at the Vibration & Noise R&D Team at Daewoo
Shipbuilding & Marine Engineering Co.LTD, Korea. His research interests include vibration and noise analysis, optimum design
of rotating machinery and structure.
SuHyun Choi received his B.S. degree and M.S. degrees in Naval Architecture from Seoul National University, Korea, in 1982 and 1984,
respectively and Ph.D. in Mechanical Engineering from The University of Michigan, Ann Arbor in the USA in 1992. Dr. Choi is
currently a Vice President at the Commercial Ship Business Management at Daewoo Shipbuilding & Marine Engineering Co.LTD,
Korea. His research interests include vibration and noise analysis, optimum design of rotating machinery and structure.
Jin Dae Song received his B.S. degree and M.S. degree in Mechanical Engineering from Pukyong National University, Korea, in 2000 and 2002,
respectively. Mr. Song is currently a candidate for the Ph.D degree in Mechanical Engineering from Pukyong National University.
His research interests include vibration analysis and optimum design of rotating machinery.
Bo-Suk Yang is a professor at the Pukyong National University in Korea. He received his Ph.D. degree in Mechanical Engineering from Kobe
University, Japan in 1985. His main research fields cover machine dynamics and vibration engineering, intelligent optimum
design, and condition monitoring and diagnostics in rotating machinery. He has published well over 190 research papers on
vibration analysis, intelligent optimum design and diagnosis of rotating machinery. He is listed in Who’s Who in the World,
Who’s Who in Science and Engineering, among others.
ByeongKeun Choi is an Associate Professor at the Department of Precision Mechanical Engineering at Gyeongsang National University in Korea.
He received his Ph.D. degrees in Mechanical Engineering from Pukyong National University, Korea, in 1999. Dr. Choi worked
at Arizona State University as an Academic Professional from 1999 to 2002. His research interests include vibration analysis
and optimum design of rotating machinery, machine diagnosis and prognosis and acoustic emission. He is listed in Who’s Who
in the World, among others. 相似文献
18.
Insu Paek Luc Mongeau James E. Braun Shin You Kang 《Journal of Mechanical Science and Technology》2009,23(5):1476-1484
Investigations on the relations between the phase angle of the acoustic impedance at the driver piston and the system performance
of a standing wave thermoacoustic cooler were performed. The system performance measured at a fixed acoustic power showed
that the coefficient of performance of the standing wave thermoacoustic cooler increases as the phase angle increases when
the stack temperature span is relatively low. The results were consistent with the simulation results obtained from DELTAE,
a computer code based on linear thermoacoustic theory. Analysis on the temperature profiles along the stack showed that the
cooling efficiency (COP) of the system could be decreased or increased as the phase angle of the acoustic impedance at the
driver piston changes depending on the stack temperature spans.
This paper was recommended for publication in revised form by Associate Editor Yeon June Kang
Insu Paek received the B.S. degree in Mechatronics Engineering from Kangwon National University, Chuncheon, Korea, in 1997, the M.S.
degree in Mechanical Engineering from the University of Texas at Austin, USA, in 2000, and the Ph. D. degree in Mechanical
Engineering from Purdue University, West Lafayette, USA, in 2005. He worked as a postdoctoral researcher in Purdue University
and McGill University in 2006 and 2007. He is currently a faculty member in the Department of Mechatronics Engineering, Kangwon
National University, Chuncheon, Korea. His research interests include thermoacoustic cooling and power generation, solar heat
driven absorption cooling., and wind power.
Luc Mongeau received the B.S. and M.S. degrees in mechanical engineering from the University of Montreal, QC, Canada, in 1984 and 1986,
respectively, and the Ph. D. degree in Acoustics from Pennsylvania State University, University Park, USA, in 1990. He is
currently a professor in the Department of Mechanical Engineering at McGill University, Montreal, QC, Canada. He has published
over 50 archival journal publications on various topics related to acoustics and noise control. His research activities are
in the flow and turbomachinery noise areas, as well as in the areas of voice production, and thermoacoustic refrigeration.
James E. Braun received the B.S. degree in Mechanical Engineering from the University of Massachusetts, USA, in 1976, and the M.S. and Ph.
D. degrees in Mechanical Engineering from the University of Wisconsin, Madison, USA, in 1980 and 1988, respectively. He is
currently a professor in the Department of Mechanical Engineering, Purdue University, West Lafayette, USA. Professor Braun’s
research combines the use of computer modeling, optimization, and experiments to study and improve the performance of thermal
systems. He has published over 140 papers. Professor Braun is currently an associate editor for the international journal
of HVAC&R Research.
Shin You Kang received the B.S. and M.S. degrees in the Department of Mechanical Design from Seoul National University, Seoul, Korea, in
1982, and 1986, respectively. He then received the Ph.D. in Mechanical Engineering at the same university in 1992. Professor
Kang is currently a professor in the Department of Mechatronics Engineering, Kangwon National University, Chuncheon, Korea.
His research interests include mechanical structure design, crash analysis, optimal design, computational structure analysis
and evaluation. 相似文献
19.
Jeonghoon Yoo Myung Wook Hyun Jun Ho Choi Sungchul Kang Seung-Jong Kim 《Journal of Mechanical Science and Technology》2009,23(8):2236-2243
The response surface method combined with the design of experiment-based design optimization of a variable stiffness joint
(VSJ) is presented in this article. A VSJ used in a manipulator of a robot arm to support 1 kg payload at the end is designed
by considering the minimization of the total weight as the objective function. Owing to the requirement of large rotational
stiffness of the VSJ, over 10 N · m, ring-type permanent magnets are adopted. First, a model composed of two permanent magnets was initially manufactured and
tested for comparison with the analysis results. Then, a three-ring-type permanent magnet-based model is suggested and optimized
to increase the torque of VSJ. The finite element method is used as a magnetic field analysis method to substitute for the
expensive experimental process. Optimization results decrease the weight from 0.899 kg to 0.538 kg, still satisfying the requirement
for the rotational stiffness.
This paper was recommended for publication in revised form by Associate Editor Tae Hee Lee
Jeonghoon Yoo received his B.S. and M.S. degrees in Mechanical Design and Production Engineering from Seoul National University, in 1989
and 1991, respectively. He then received his Ph.D. degrees from the University of Michigan, Ann Arbor, in 1999. Dr. Yoo is
currently a Professor at the School of Mechanical Engineering at Yonsei University in Seoul, Korea. Dr. Yoo’s research interests
include analysis and design of electromagnetic field systems.
Myung Wook Hyun received his B.S. and M.S. degrees in Mechanical Engineering from Yonsei University, Korea, in 1995 and 1997, respectively.
While studying for his M.S. degree, Mr. Hyun also studied variable stiffness unit design. He is now working at Samsung Electronics,
Co. Ltd..
Jun Ho Choi received his B.S. and M.S. degrees in Mechanical Design from Hanyang University, Korea and his Ph.D. degree from the University
of Michigan, Ann Arbor. He is currently a senior research scientist in the Korea Institute of Science and Technology. His
research interests include nonlinear control, manipulator control, and safe-joint design.
Sungchul Kang received his B.S., M.S., and Ph.D. degrees in Mechanical Design and Production Engineering from Seoul National University,
Korea, in 1989, 1991, and 1998 respectively. Dr. Kang is currently a Principal Research Scientist in the Center for Cognitive
Robotics Research, Korea Institute of Science and Technology, in Seoul, Korea. Dr. Kang’s research interests include mobility
and manipulation of field and service robots and haptics.
Seung-Jong Kim received his B.S. degree in Mechanical Engineering from Seoul University, Korea, in 1989, and his M.S. and Ph.D. degrees
from KAIST in 1991 and 1998, respectively. Dr. Kim is currently a Principal Research Scientist at the Korea Institute of Science
and Technology in Seoul, Korea. Dr. Kim’s research interests include the design, control, and dynamic analysis of mechatronic
systems. 相似文献
20.
Defect diagnostics of SUAV gas turbine engine using hybrid SVM-artificial neural network method 总被引:1,自引:0,他引:1
Sang-Myeong Lee Tae-Seong Roh Dong-Whan Choi 《Journal of Mechanical Science and Technology》2009,23(2):559-568
A hybrid method of an artificial neural network (ANN) combined with a support vector machine (SVM) has been developed for
the defect diagnostic system applied to the SUAV gas turbine engine. This method has been suggested to overcome the demerits
of the general ANN with the local minima problem and low classification accuracy in case of many nonlinear data. This hybrid
approach takes advantage of the reduction of learning data and converging time without any loss of estimation accuracy because
the SVM classifies the defect location and reduces the learning data range. The results of test data have shown that the hybrid
method is more reliable and suitable algorithm than the general ANN for the defect diagnosis of the gas turbine engine.
This paper was recommended for publication in revised form by Associate Editor Tong Seop Kim
Tae-Seong Roh received his B.S. and M.S. degrees in Aeronautical Engineering from Seoul National University in 1984 and 1986. He then went
on to receive his Ph.D. degree from Pennsylvania State University in 1995. Dr. Roh is currently a Professor at the department
of Aerospace Engineering at Inha University in Incheon, Korea. His research interests are in the area of combustion instabilities,
rocket and jet propulsion, interior ballistics, and gas turbine engine defect diagnostics.
Dong-Whan Choi received his B.S. degree in Aeronautical Engineering from Seoul National University in 1974. He then went on to receive his
M.S. and Ph.D. degrees from University of Washington in 1978 and 1983. Dr. Choi served three years as a President of the Korea
Aerospace Research Institute from 1999. He is currently a professor at the department of Aerospace Engineering at Inha University
in Incheon, Korea. His research interests are in the area of turbulence, jet propulsion, and gas turbine defect diagnostics. 相似文献