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1.
Sang-mok Han Nam-sub Woo Young-kyu Hwang 《Journal of Mechanical Science and Technology》2009,23(2):569-577
An experimental study was conducted to study solid-liquid mixture upward hydraulic transport of solid particles in vertical
and inclined annuli with rotating inner cylinder. Lift forces acting on a fluidized particle play a central role in many important
applications, such as the removal of drill cuttings in horizontal drill holes, sand transport in fractured reservoirs and
sediment transport, etc. Annular fluid velocities varied from 0.4 m/s to 1.2 m/s. Effect of annulus inclination and drill
pipe rotation on the carrying capacity of drilling fluid, particle rising velocity, and pressure drop in the slim hole annulus
have been measured for fully developed flows of water and of aqueous solutions of sodium carboxymethyl cellulose (CMC) and
bentonite, respectively. For higher particle feed concentration, the hydraulic pressure drop of mixture flow increases due
to the friction between the wall and solids or among solids.
This paper was recommended for publication in revised form by Associate Editor Gihun Son
Sang-Mok Han received a B.S. degree in Mechanical Engineering from Sung-kyunkwan University in 2001. He then went on to receive his M.S.
degrees from Sungkyunkwan University in 2003. He is a candidate for Ph.D. from 2006 to the present at the School of Mechanical
Engineering at Sungkyunkwan University in Suwon, Korea. His research interests are in the area of Multi-phase flow and drilling.
Nam-Sub Woo received a B.S. degree in Mechanical Engineering from Sungkyunkwan University in 1997. He then went on to receive his M.S.
and Ph.D. degrees from Sunkyunkwan University in 1999 and 2007, respectively. Dr. Woo is currently a Senior Researcher at
the Fire & Engineering Services Research Center at Korea Institute of Construction and Technology in Goyang, Korea. Dr. Woo’s
research interests are in the area of fluid dynamics and plant engineering.
Young-Kyu Hwang received a B.S. degree in Mechanical Engineering from Sungkyunkwan University in 1977. He then went on to receive his M.S.
from University of Wis-consin at Madison in 1980 and Ph.D. degrees from State Uni-versity of New York at Buffalo in 1984,
respectively. Dr. Hwang has served as a Professor, from 1984 to the present at the School of Mechanical Engineering at Sungkyunkwan
University in Suwon, Korea. His research interests are in the area of drilling hydraulics, molecular gas flow and hydrodynamic
instability. 相似文献
2.
Jung Kwan Lee Sang Bong Lee Hyungpil Moon Dongho Oh J. C. Koo 《Journal of Mechanical Science and Technology》2009,23(4):1050-1053
Even a moderate mass imbalance of a high-precision rotor produces a significant level of vibration when it spins at high revolutionary
speed such as 10,000 rpm or faster. As a result, many attempts have been made for the development of dynamic rotor balancing
methods mostly by the precision mechanical system industry; however, intensive studies about the fundamental principles from
a theoretical point of view should be carried out further. In the present paper, a new dual axes dynamic imbalance correction
method is introduced and tested through simulations. The proposed method is more efficient and effective than its predecessors.
This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008.
Jung Kwan Lee is currently a masteral student in the School of Mechanical Engineering at Sungkyunkwan University Korea. He received his
B.S. degree from Sungkyunkwan University. His primary research interests are rotor design, analysis, and rotor dynamics.
Hyungpil Moon received his Ph.D. degree in mechanical engineering from the University of Michigan in 2005. He was a postdoctoral fellow
at Carnegie Mellon University. He joined the faculty of the School of Mechanical Engineering at Sungkyunkwan University in
2008.
Dongho Oh received his Ph.D. degree from KAIST in 1996. He worked as a Principal En-gineer of Samsung Electronics and SAIT. Dr. Oh
is currently an Associate Professor at the Department of Mechanical Engineering at Chungnam National University.
Ja Choon Koo is an associate professor of the School of Mechanical Engineering at Sungkyunkwan University Korea. He was an engineer at
IBM Corporation, San Jose, California. He received his Ph.D from the University of Texas at Austin. His primary research interests
are analysis, and control of dynamic systems, mechatronics, sensors, and actuators. 相似文献
3.
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
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.
Young Chul Kwon Dae Hoon Kim Jae Heon Lee Jun Young Choi Sang Jae Lee 《Journal of Mechanical Science and Technology》2009,23(3):698-706
This paper presents the heat transfer characteristics of the internal heat exchanger (IHX) for CO2 heat pump system. The influence on the IHX length, the mass flow rate, the shape of IHX, the operating condition, and the
oil concentration was investigated under a cooling condition. Four kinds of IHX with a coaxial type and a micro-channel type,
a mass flow meter, a pump, and a measurement system. With increasing of the IHX length, the capacity, the effectiveness, and
the pressure drop increased. For the mass flow rate, the capacity of micro-channel IHX are higher about 2 times than those
of coaxial IHX. The pressure drop was larger at cold-side than at hot-side. In the transcritical CO2 cycle, system performance is very sensitive to the IHX design. Design parameters are closely related with the capacity and
the pressure drop of CO2 heat pump system. Along the operating condition, the performance of CO2 IHXs is different remarkably. For oil concentration 1, 3, 5%, the capacity decreases and the pressure drop increased, as
compared with oil concentration 0%.
This paper was recommended for publication in revised form by Associate Editor Yong Tae Kang
Prof. Young-Chul Kwon received his B.S. degree in Precision Mechanical Engineering from Pusan National University, Korea, in 1989. He then received
his M.S. and Ph.D. degrees from POSTECH, in 1991 and 1996, respectively. Dr. Kwon is currently a Professor at the Division
of Mechanical Engineering at Sunmoon University in Chungnam, Korea. He serves as a chief of the Institute of Automation and
Energy Technology. Dr. Kwon’s research interests include heat exchanger, CO2 cycle, heat pump, and energy recovery ventilator for HVAC&R.
Mr. Dae-Hoon Kim is currently Doctoral student at the Mechanical Engineering from Hanyang University in Seoul, Korea. His research topics
include experimental and numerical of CO2 heatpump system. He has conducted a study on the Analysis of Refrigerating & Air-Conditioning Equipment Industry and Its
Forecasting Supervising and Testing for Performance of Refrigerator, Freezer and Air-Conditioner.
Prof. Jae-Heon Lee received his B.S. degree in Mechanical Engineering from Seoul National University, Korea, in 1971. He then received his M.S.
and Ph. D. degree from Seoul National University in 1977 and 1980, respectively. Dr. Lee is currently a Professor at the school
of Mechanical Engineering at Hanyang University in Seoul, Korea. Dr. Lee is currently a president at the Korea Institute research
interests include simulation of thermal fluid and Plant engineering and construction.
Dr. Jun-Young Choi received his B.S. degree in Mechanical Engineering from Yonsei University, Republic of Korea, in 1989. He then received his
M.S. and Ph. D. degrees from Yonsei University in 1991 and 1999, respectively. Dr. Choi is currently a chief researcher with
the 18 years experience on the energy performance testing of HVAC/R product. He is now assigned to the Energy Technology Center
at Basic Industry Division at Korea Testing Laboratory. He has been involved in the development of Design and Manufacturing
Technology for Air-Conditioner E.E.R. and Performance Testing Equipment for Cooling and Heating System with Non-CFCs, and
natural refrigerants. He has conducted a study on the Analysis of Refrigerating & Air-Conditioning Equipment Industry and
Its Forecasting Supervising and Testing for Performance of Refrigerator, Freezer and Air-Conditioner.
Dr. Sang Jae Lee received his Ph.D. degree in Mechanical Engineering from Hanyang University, KOREA, in 2008. Dr. Lee is currently a Researcher
at the Korea Institute of Industrial Technology in Cheonan, Korea. Dr. Lee’s research interests CO2 heatpump system, liquid desiccant air conditioning system and Micro heat exchanger. 相似文献
6.
Ahn Ryul Choi Tae Sun Yun Kyung Suk Lee Kyoung Kee Min Heon Hwang Ki Young Lee Eui Chaul Oh Joung H. Mun 《Journal of Mechanical Science and Technology》2009,23(1):64-74
Functional asymmetry is among the multitude of risk factors for low-back pain (LBP), the most common injury under general
industrial and agricultural conditions. However, previous studies showed that normal healthy individuals exhibit some functional
asymmetry, indicating that not all asymmetry causes LBP. Therefore, the threshold value that is able to discriminate between
normal and pathological situations is used as critical information to predict LBP. As a preliminary study to find threshold,
the purpose of this study is to quantify the magnitude of bilateral asymmetries of erector spinae muscle forces of a healthy
group during sagittally symmetric lifting. Ten healthy male subjects with no history of back pathology participated in this
study, which collected motion capture, force data, and electromyography signals from six infrared cameras (MCam2, Vicon),
two force platforms (AMTI), and surface EMG (BME Korea). In order to quantify the magnitude of bilateral asymmetry in the
trunk muscle forces, we used 3D linked segment and EMG-assisted modeling approaches, both of which were verified based on
their recapitulation of previously-proposed models. The results indicated that each muscle force in the lumbar region exhibited
asymmetry during the entire lifting process. In particular, the erector spinae muscle forces exhibited an approximate 24%
difference between bilateral sites (p<0.05). The results of this study provided data from normal individuals by which to identify
pathological situations and predict LBP incidence within general industrial and agricultural conditions.
This paper was recommended for publication in revised form by Associate Editor Young Eun Kim
Ahn Ryul Choi received his B.S. and M.S. degrees in Bio-Mechatronic engineering from Sungkyunkwan University in 2005 and 2007, respectively.
Ahn-Ryul Choi is currently a Researcher at the Bio-Mechatronics center and also a candidate in the biomedical Ph.D. program
at Sungkyunkwan University, Korea. His research interests are in the area of digital human modeling and simulation.
Tae Sun Yun received his B.S. and M.S. degrees in mechanical engineering from Korea Aero-space University in 2005 and 2007, respectively.
Tae-Sun Yun is currently a Researcher at the Bio-Mechatronics center and also a candidate in the biomedical Ph.D. program
at Sungkyunkwan University, Korea. His research interests are in the area of digital human modeling and simulation.
Kyung Suk Lee is a specialist with many years experience of the agricultural health and safety in Republic of Korea. Her personal interests
and most publications are in various hazards including ergonomic risk factors and management system set-up in local and national
system. She has been doing her researches in National Academy of Agricultural Science (NIAST). She has also managed lots of
network system that is composed of scientists, national officer, farmers union for agricultural safety and hearth. She is
currently in the Group who is consultant with “safe farm model intervention” in local areas and national safety and health.
Kyoung Kee Min received his Ph.D degree Sungkyunkwan University in 2008. Dr. Min is currently a researcher at the Bio-Mechatronics Center
in Sungkyunkwan University. Dr. Min’s research interests are in the area of disease classification using artificial neural
network, digital human modeling & control.
Heon Hwang received his Ph.D. degree majoring in Engineering Science from the Louisiana State University, Baton Rouge in 1988. Dr. Hwang
is currently a Professor at the Department of Bio-Mechatronic Engineering, Sung-kyunkwan University in Korea. Dr. Hwang’s
research interests are intelligent motion control based on human motor and brain behavior, tele-operative biorobotic system
and interface, and real time on-line bio-image processing and bio-sensing.
Ki Young Lee received a B.S., M.S. and Ph D. degree in Electronic Engineering from Myongji University in 1984, 1986 and 1992, respectively.
Since 2004, he also has interested to study on Bioengineering, and finished the Ph D. course from Sungkyunkwan University.
Dr. Lee is currently a Professor at the Department of Biomedical Engineering at Kwandong University in Kangneung, Korea. His
research interests are the area of Bioelectronics and Bio-signal processing.
Euichaul Oh received a B.S. degree in Pharmacy (1983) and a M.S. degree in Physical Pharmacy (1985) from Seoul Nation University, respectively.
He then acquired his Ph.D. degree in Pharmaceutics from the University of Iowa in 1996. Dr. Oh is currently a Chief Scientific
Officer at the R&D Center of Kuhnil Pharm. In Seoul, Korea. He had worked at the pharmaceutical companies in USA as a Senior
Research Scientist for 10 years. He is currently serving as an Editor Board of the Journal of Korean Pharmaceutical Sciences.
Dr. Oh’s research interests are in the areas of Drug Delivery System, Physical and Industrial Pharmacy and Pharmaceutical
Technology and Engineering.
Joung Hwan Mun received his Ph.D. degree majoring in mechanical engineering from the University of Iowa in 1998. Dr. Mun is currently a
Professor at the Department of Bio-Mechat-ronic engineering at Sungkyun-kwan University in Suwon, Korea. He is currently serving
as a director of the Bio-Mechatronics center with regard to an international IMS project. Dr. Mun’s research interests are
in the area of digital human modeling, sports biomechanics, bio-electronics and digital factory for human oriented production
system. 相似文献
7.
Three types of flow passage structure of a total heat exchanger (perforated type, slit type, and embossed and perforated type)
are studied to enhance the heat exchange performance of a heat recovery ventilation system (total heat exchanger). The perforated
type has four punched rows of 6mm holes in the flow passage channel, and the slit type has six processed rows of 40mm length.
The embossed and perforated type has holes of about 1mm diameter and protrusions of about 0.2mm height on all surfaces. The
heat exchange efficiency of the modified total heat exchanger was compared to that of a general total heat exchanger with
a smooth surface. The Korean Standard (KS) heat recovery ventilator test condition was applied for tests. In the case of cooling
operation based on a typical Reynolds number of 140 (typical air flow rate of 100 m3/hr), the perforated type, slit type, and embossed and perforated type showed temperature efficiency improvement of 1.2%,
2.5%, and 5.0%; latent efficiency improvement of 18.0%, 32.3%, and 24.5%; and enthalpy efficiency improvement of 7.9%, 11.5%,
and 11.2%, respectively. The corresponding improvements of heating operation were 3.0%, 3.4%, and 4.0%; 5.0%, 6.6%, and 18.7%;
3.2%, 4.3%, and 7.7%, respectively. On the other hand, the air pressure drop throughout the modified flow passage of the total
heat exchanger increased by up to 1.7% at the typical Reynolds number of 140, from the air pressure drop of the regular total
heat exchanger.
This paper was recommended for publication in revised form by Associate Editor Dae Hee Lee
Kyungmin Kwak received his B.S., M.S. and Ph.D. degrees in Mechanical Engineering from Yeungnam University, Korea, in 1993, 1995 and 1999,
respectively. Dr. Kwak is currently a Researcher at the Automotive RIC at Kyungil University, Korea. His research interests
include heat transfer, refrigeration and air control.
Cheolho Bai received his B.S. and M.S. degrees in Mechanical Engineering from Seoul Na-tional University, Korea, in 1984 and 1986, respectively.
He then received his Ph.D. from UCLA, USA, in 1992. Dr. Bai is currently a Professor at the School of Mechanical Engineering
at Yeungnam University in Kyungsan, Korea. His research interests include heat transfer, refrigeration and air control. 相似文献
8.
Kyoung-Ho Kang Byong-Jo Yun Dong-Jin Euh Won-Pil Baek 《Journal of Mechanical Science and Technology》2009,23(3):758-767
A new instrument, an averaging bidirectional flow tube (BDFT), is proposed to measure single-phase flow rates. This averaging
BDFT has unique measuring characteristics foremost among which is the capability to measure bidirectional flow and insensitivity
of the fluid attack angle. Single phase calibration tests were conducted to demonstrate the performance of the averaging BDFT.
Likewise, to enhance the applicability of the averaging BDFT on various flow conditions, flow analyses using CFD code were
performed focusing on design optimization of the BDFT. The calibration test results indicated that this averaging BDFT has
a linearity within 0.5 % in the Reynolds (Re) number range of above 10,000 where it is meaningful in terms of application.
The flow analyses results demonstrate a good linearity of the averaging BDFT with various design features. Therefore, averaging
BDFT can be applied for measurement of flow rates within a wide range of flow conditions.
This paper was recommended for publication in revised form by Associate Editor Won-Gu Joo
Kyoung-Ho Kang received his B.S. and M. S. degrees in Nuclear Engineering from SNU (Seoul National University), KOREA in 1993 and 1995,
respectively. He then received his Ph.D. degree in Nuclear and Quantum Engineering from KAIST (Korea Advanced Institute of
Science and Technology) in 2009. Dr. Kang is currently a senior researcher at the Korea Atomic Energy Research Institute in
Daejeon, Korea. Dr. Kang’s research interests include analysis and experiments for the nuclear safety, thermal hydraulics,
and experiments and modeling for the severe accidents.
Byong-Jo Yun received his B.S. degree in Nuclear Engineering from SNU (Seoul National University), KOREA in 1989. He then received his
M.S. and Ph.D. degrees from SNU in 1991 and 1996, respectively. Dr. Yun is currently a principal researcher at the Korea Atomic
Energy Research Institute in Daejeon, Korea. Dr. Yun’s research interests include analysis and experiments for the nuclear
safety, thermal hydraulics, two-phase flow, scaling analysis, and development of instrumentation for two-phase flow.
Dong-Jin Euh received his B.S. degree in Nuclear Engineering from Seoul University, Korea, in 1993. He then received his M.S. and Ph.D.
degrees from same university in 1995 and 2002, respectively. Dr. Euh is currently a researcher at thermal hydraulic safety
research department of Korea Atomic Energy Research Institute in Daejeon, Korea. Dr. Euh’s research interests include two-phase
thermal hydraulics in the Nuclear Systems and Fundamental Phenomena.
Won-Pil Baek has been working at KAERI as the general project manager (director) for development of nuclear thermalhydraulic experiment
and analysis technology since 2001. He received his B.S. degree in nuclear engineering from Seoul National University and
his M.S. and Ph.D. degrees from KAIST. In 1991–2000, he worked for KAIST as a researcher and research professor. Currently
he also serves as an executive editor of the Nuclear Engineering and Technology, an international journal of the Korean Nuclear Society. His research interests include critical heat flux, integral effect
tests, modeling, nuclear safety, and advanced reactor development. 相似文献
9.
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
10.
Kyoung Chun Yang Seong Hyuk Lee Jong-Min Kim Young Ki Choi Dave F. Farson Young Eui Shin 《Journal of Mechanical Science and Technology》2009,23(2):435-441
The interfacial reaction between Cu pad coated with Au/Ni and solder bump of flip chip package, using Sn97.5wt.%-Ag2.5wt%,
was studied under thermal shock stress. All joints were subjected to thermal shock test with −65°C/+150°C temperature range.
For the Sn-2.5Ag solder, a scallop-like (Cu,Ni)6Sn5 intermetallic compound was formed in the solder matrix after 20 cycles of thermal shock. (Cu,Ni)6Sn5 was detached from the interface as (Ni,Cu)3Sn4 grew underneath the (Cu,Ni)6Sn5 IMC(Intermetallic Compound), whereas the elements of Sn, Ni and Cu were moved by interdiffusion at the interface between
solder alloy and Cu pad. The composition of the IMCs in the solder joints and elemental distribution across the joint interfaces
were quantitatively measured with EPMA (electron probe micro analysis). Finally, it was found that the crack initiation point
and its propagation path could be influenced by the thermal shock conditions, two underfills, and their properties.
This paper was recommended for publication in revised form by Associate Editor Chongdu Cho
Kyoung Chun Yang received his B.E. and M.E. degrees in Mechanical Engineering from Chung-Ang University, Korea, in 2006 and 2008, respectively.
His research interests include reliability in electronic packages, micro joints evaluation, advanced IC packaging/assembly
technologies.
Seong Hyuk Lee received his Ph. D. degree in Mechanical Engineering from Chung-Ang University, Korea, in 1999. Dr. Lee is currently an Associate
Professor at the School of Mechanical Engineering of Chung-Ang University in Seoul, Korea. His research interests are mainly
in the micro/nanoscale energy conversion and transport, the computational physics associated with thin film optics, and thermal
and fluid engineering.
Jong-Min Kim received his B.E. and M.E. degrees in Mechanical Engineering from Chung-Ang University, Korea, in 1997 and 1999, respectively.
He then received his Ph.D. degree in Manufacturing Science from Osaka University, Japan, in 2002. Dr. Kim is currently an
Associate Professor at the School of Mechanical Engineering at Chung-Ang University in Seoul, Korea. He has been mainly engaged
in the fields of the interconnection & packaging technology in microelectronics and the intelligent assembly process in micro/nano
systems.
Young Ki Choi received his B.E. and M.E. degrees in Mechanical Engineering from Seoul National University, Korea, in 1978 and 1980, respectively.
He then received his Ph.D. degree in Manufacturing Science from Univ. of California, Berkeley, U.S.A., in 1986. Dr. Choi is
currently a Professor at the School of Mechanical Engineering at Chung-Ang University in Seoul, Korea. He has been mainly
engaged in the fields of the heat transfer in micro-nano systems and the numerical analysis of the heat transfer system.
Dave F. Farson received B.S. and M.S. degrees in Welding Engineering and Ph.D. degree in Electrical Engineering from The Ohio State University
in 1987. He worked at Westinghouse R&D and Applied Research Laboratory at Penn State University before returning Ohio State
University in 1995, where he is currently an Associate Professor in the Department of Integrated Systems Engineering. He is
a past-president and Fellow of the Laser Institute of America and was co-editor of its Handbook of Laser Materials Processing.
He is also active in the American Welding Society. He does research in laser materials processes and materials joining for
a range of applications including biomedical and electronics device fabrication.
Young Eui Shin received his B.E.degree Mechanical Engineering from Chung-Ang University in Korea, and M.S and Ph.D degrees from Nihon Univ.
and Osaka Univ. in 1985 and 1992 respectively. He worked as principal researcher in the Technical central lab of Daewoo Heavy
industry from 1985 to 1988, and as a chief researcher in Technical Center of Samsung Electronics from 1992 to 1994. At present,
he is a Professor at the School of Mechanical Engineering, Chung-Ang Univ., in Korea. He is also working as President, Korea
Micro Joining Association. He has been mainly engaged in eco friendly materials application for micro system packaging and
reliability evaluation for micro joints. 相似文献
11.
Young-Do Choi Chang-Goo Kim Young-Ho Lee 《Journal of Mechanical Science and Technology》2009,23(6):1693-1701
The purpose of the present study is to investigate the effect of wave conditions on the performance and internal flow of a
newly developed direct drive turbine (DDT) model for wave energy conversion experimentally. All the experiments using the
test turbine models are conducted in a 2-D wave channel. Monochromatic waves of various conditions of wave height and wave
period are applied to the turbine performance test. The influences of turbine configuration on turbine performance are also
investigated. Test results show that rotational speed, differential pressure, incident flow rate, maximum output power, and
best efficiency of the turbine model vary considerably depending on the wave conditions. Installation of a front guide nozzle
and a rear water reservoir to the test turbine improves the turbine performance. Large passage vortex occurs both at the front
and rear turbine nozzles in turn through a reciprocating flow in the turbine passage.
This paper was recommended for publication in revised form by Associate Editor Jun Sang Park
Young-Do Choi received his B.E. and M.E. degrees in Mechanical Engineering from Korea Maritime University, Korea in 1996 and 1998, respectively.
He received his Ph.D. in Engineering from the Yokohama National University, Japan in 2003. Dr. Choi is currently a research
professor at the School of Mechatronics, Chanwon National University in Changwon, Korea. His research interests include ocean
energy, wind power, small hydro power, fluid machinery, PIV and CFD.
Chang-Goo Kim received his B.E. and M.E. degrees in Mechanical Engineering from Korea Maritime University, Korea in 2007 and 2009, respectively.
Mr. Kim is currently a doctorate student in the Department of Mechanical Engineering, Graduate School, Korea Maritime University.
His research interest includes ocean energy.
Young-Ho Lee received his B.E. and M.E. degrees from Korea Maritime University, Korea. He received his Ph.D. in Engineering from the University
of Tokyo, Japan. Dr. Lee is currently a Professor at the Division of Mechanical and Information Engineering, Korea Maritime
University. His research interests include ocean energy, wind energy, small hydro power, fluid machinery, PIV, and CFD. 相似文献
12.
Baeksuk Chu Daehie Hong Jooyoung Park 《Journal of Mechanical Science and Technology》2009,23(2):311-323
The appropriate operation of a tunnel ventilation system provides drivers passing through the tunnel with comfortable and
safe driving conditions. Tunnel ventilation involves maintaining CO pollutant concentration and VI (visibility index) under
an adequate level with operating highly energy-consuming facilities such as jet-fans. Therefore, it is significant to have
an efficient operating algorithm in aspects of a safe driving environment as well as saving energy. In this research, a reinforcement
learning (RL) method based on the actor-critic architecture and nonparametric policy gradients is applied as the control algorithm.
The two objectives listed above, maintaining an adequate level of pollutants and minimizing power consumption, are included
into a reward formulation that is a performance index to be maximized in the RL methodology. In this paper, a nonparametric
approach is adopted as a promising route to perform a rigorous gradient search in a function space of policies to improve
the efficacy of the actor module. Extensive simulation studies performed with real data collected from an existing tunnel
system confirm that with the suggested algorithm, the control purposes were well accomplished and improved when compared to
a previously developed RL-based control algorithm.
This paper was recommended for publication in revised form by Associate Editor Hong Hee Yoo
Baeksuk Chu received his B.S. degree in 1999, M.S. degree in 2001, and Ph.D. in 2006, respectively in Mechanical Engineering from Korea
University. Dr. Chu is currently a Research Professor at the Division of Mechanical Engineering at Korea University in Seoul,
Korea. Dr. Chu’s research interests are in the area of robotics, control engineering, and reinforcement learning.
Daehie Hong received his B.S. degree in 1985 and M.S. degree in 1987, respectively in Mechanical Engineering from Korea University. He
then went on to receive his Ph.D. degree from UC Davis in 1994. Dr. Hong is currently a Professor at the Division of Mechanical
Engineering at Korea University in Seoul, Korea. He is currently serving as an Editor of the International Journal of Precision
Engineering and Manufacturing. Dr. Hong’s research interests are in the area of mechatronics and field robotics.
Jooyoung Park received his B.S. degree in Electrical Engineering from Seoul National University in 1983, and his Ph.D. degree in Electrical
and Computer Engi-neering from the University of Texas at Austin in 1992. He joined Korea University in 1993, where he is
currently a Professor in the Department of Control and Instrumentation Engineering. Dr. Park’s recent research interests are
in the area of rein-forcement learning and kernel methods. 相似文献
13.
Jintaek Kim Byungjoon Baek Jeekeun Lee 《Journal of Mechanical Science and Technology》2009,23(7):1877-1884
If fire breaks out on an airplane, a large amount of fire extinguishing agents should be discharged within a very short time.
For effective fire extinguishing, increased discharge velocity of the fire extinguishing agents is required. This can be achieved
by using a large-sized vessel in which the fire extinguishing agents are highly pressurized by noncombustible gases. It is
important to understand the flow characteristics of a fire extinguishing system for optimal system design. This study reports
a numerical analysis of the flow characteristics of an airplane fire extinguishing system using halon-1301 as a fire extinguishing
agent. The unsteady flow model was simulated with the general-purpose software package “FLUENT”, to study the flow characteristics
of the fire extinguishing agents in the system. The effects of the rupture surface area and tube diameter on the flow characteristics
were investigated for optimal system design. From the analysis results, it was clarified that the characteristics of the halon
discharge from the end of tube are very sensitive to the rupture surface area and significantly affected by the tube diameter.
This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008.
Byung-Joon Baek received his B.S. degree in Mechanical Engineering from Seoul National University, KOREA, in 1979. He then received his M.S.
and Ph.D. degrees from Seoul National University, KOREA, in 1981 and University of Missouri-Rolla USA, in 1989, respectively.
Dr. Baek is currently a Professor at Division of Mechanical System Engineering at Chonbuk National University in Jeonju, Korea.
Dr. Baek’s research interests include the thermal control of micro-fluidics.
Jee-Keun Lee received his B.S. degree in Precision Mechanical Engineering from Chonbuk National University, KOREA, in 1986. He then received
his M.S. and Ph.D. degrees from Chonbuk National University, KOREA, in 1992 and in 1998, respectively. Dr. Lee is currently
an associate Professor at Division of Mechanical System Engineering at Chonbuk National University in Jeonju, Korea. Dr. Lee’s
research interests include the measurement of a turbulent flow and sprays using the laser diagnostics. 相似文献
14.
Katsuki Masashi Chung Jin-Do Kim Jang-Woo Hwang Seung-Min Kim Seung-Mo Ahn Chul-Ju 《Journal of Mechanical Science and Technology》2009,23(3):614-623
Combustion in high-preheat and low oxygen concentration atmosphere is one of the attractive measures to reduce nitric oxide
emission as well as greenhouse gases from combustion devices, and it is expected to be a key technology for the industrial
applications in heating devices and furnaces. Before proceeding to the practical applications, we need to elucidate combustion
characteristics of non-premixed and premixed flames in high-preheat and low oxygen concentration conditions from scientific
point of view. For the purpose, we have developed a special mixing nozzle to create a homogeneous mixture of fuel and air
by rapid mixing, and applied this rapidmixing nozzle to a Bunsen-type burner to observe combustion characteristics of the
rapid-mixture. As a result, the combustion of rapid-mixture exhibited the same flame structure and combustion characteristics
as the perfectly prepared premixed flame, even though the mixing time of the rapid-mixing nozzle was extremely short as a
few milliseconds. Therefore, the rapid-mixing nozzle in this paper can be used to create preheated premixed flames as far
as the mixing time is shorter than the ignition delay time of the fuel.
This paper was recommended for publication in revised form by Associate Editor Ohchae Kwon
Masashi Katsuki received his B.E. degree in Mechanical Engineering from Osaka University, Japan, in 1965. He received his Dr. Eng. from O.
U. in 1985. Dr. Katsuki is currently a Visiting Professor at the Department of Environmental Engineering at Hoseo University
in Chungnam, Korea. He was a Vice President of the Japan Society of Mechanical Engineers. Dr. Katsuki’s research interests
include combustion, computational thermo-fluid dynamics, and molecular dynamics.
Jin-Do Chung received his B. S., M.S. and Ph.D. degrees in Mechanical Engineering from Chungnam University, Korea in 1983, 1985 and 1990.
He then received another Ph.D. in Environmental Engineering from Kanazawa University, Japan in 1996. After that he worked
as Post-doc researcher for 1,6 year at KIMM and Senior researcher for 6years at KEPCO Research Center. Dr. Chung is currently
a Professor at the Department of Environmental Engineering at Hoseo University in Asan, Korea. Dr. Chung’s research interests
include thermal-fluid and environmental engineering.
Jang-Woo Kim received his B. S. degree in Mechanical Engineering from Chungnam University, Korea, in 1990. He then received his M. S.
and Ph. D. degrees from Kyushu University, Japan in 1994 and 1998, respectively. Dr. Kim is currently a Professor at the School
of Display Engineering at Hoseo University in Asan, Korea. Dr. Kim’s research interests include CFD, aerodynamics, and display
equipment technology.
Seung-Min Hwang received the Ph.D. degree in Mechanical Engineering at Osaka University in 2005. After that he worked as visiting researcher
for 3 years at CRIEPI (central research institute of electric power industry) and Osaka University in Japan. He is currently
a Professor at the Graduate School of Venture at Hoseo University in Korea. His major research is thermal-fluid, energy issue
and environment.
Seung-Mo Kim received his Ph. D. degrees in Mechanical engineering from Osaka University, Japan, in 2004. Dr. Kim is currently a research
Professor at Pusan Clean Coal Center at Pusan National University in Pusan, South Korea. Dr. Kim’s research interests include
coal combustion, oxy-fuel combustion, coal gasification, coal de-watering, power generation plant system and energy issues.
Chul-Ju Ahn received his B.S. degree in Mechanical Engineering from Hanyang University, Korea, in 1998. He then received his M.S. and
Ph.D. degrees from Osaka University, Japan, in 2001 and 2006, respectively. Dr. Ahn is currently a Senior Research Engineer
at Samsung Techwin CO. LTD. in Changwon, Korea. Dr. Ahn’s research interests include gas turbine engine, biomass gasification,
and power system. 相似文献
15.
Hyuck-Keun Oh Sae Byul Kang Young Ki Choi Joon Sik Lee 《Journal of Mechanical Science and Technology》2009,23(6):1544-1552
An optimization of rapid thermal processing (RTP) was conducted to obtain uniform temperature distribution on a wafer surface
by using linear programming and radiative heat transfer modeling. The results show that two heating lamp zones are needed
to maintain uniform wafer temperature and the optimal lamp positions are unique for a given geometry and not affected by wafer
temperatures. The radii of heating lamps, which were obtained by optimization, are 45 mm and 108 mm. The emissivity and temperature
of the chamber wall do not significantly affect the optimal condition. With obtained optimum geometry of the RTP chamber and
lamp positions, the wafer surface temperatures were calculated. The uniformity allowance of the wafer surface is less than
±1°C when the mean temperature of the wafer surface is 1000°C.
This paper was recommended for publication in revised form by Associate Editor Dongsik Kim
Hyuck-Keun Oh received the B.S. and M.S degrees in Mechanical & Aerospace Engineering from Seoul National University in 2000 and 2002,
respectively. He had experienced mechanical and electrical engineering in the Samsung SDI Corporation on various display devices
between 2002 and 2007. He is now pursuing the Ph.D degree in Mechanical & Aerospace engineering at Seoul National University,
Korea. His research interests are heat transfer and thermal management with a focus on power generation and energy efficiency.
Sae Byul Kang received the B.S degree in Mechanical engineering from Korea University in 1996. He then went on to receive his M.S and Ph.D.
degrees from Seoul National University in 1998 and 2003, respectively. Dr. Kang is currently a senior researcher at the Korea
Institute of Energy Research in Daejeon, Korea. Dr. Kang’s research interests are development of industrial boiler and burner
for bio-mass.
Young Ki Choi received the B.S and M.S degrees in Mechanical engineering from Seoul National University in 1978 and 1980, respectively
and the Ph.D. de-gree in mechanical engineering from the University of California at Berkeley in 1986. He is currently a professor
at the School of Mechanical Engineering, Chung Ang University, Korea. His research interests are in the area of micro/nanoscale
energy conversion and transport, computational fluid dynamics, and molecular dynamics simulations.
Joon Sik Lee received the B.S and M.S degrees in Mechanical engineering from Seoul National University in 1976 and 1980, respectively
and the Ph.D. degree in mechanical engineering from the University of California at Berkeley in 1985. He is currently a professor
at the School of Mechanical & Aerospace Engineering, Seoul National University, Korea. He is also the director of Micro Thermal
System Research Center. His research interests are in the area of micro/nanoscale energy conversion and transport, thermal
management for power generation and energy efficiency, and various convective heat transport phenomena such as pool boiling
and nanofluid. 相似文献
16.
Suthep Kaewnai Manuspong Chamaoot Somchai Wongwises 《Journal of Mechanical Science and Technology》2009,23(6):1620-1627
The main objective of this work is to use the computational fluid dynamics (CFD) technique in analyzing and predicting the
performance of a radial flow-type impeller of centrifugal pump. The impeller analyzed is at the following design condition:
flow rate of 528 m3/hr; speed of 1450 rpm; and head of 20 m or specific speed (Ns) of 3033 1/min in US-Units. The first stage involves the mesh generation and refinement on domain of the designed impeller.
The second stage deals with the identification of initial and boundary conditions of the mesh-equipped module. In the final
stage, various results are calculated and analyzed for factors affecting impeller performance. The results indicate that the
total head rise of the impeller at the design point is approximately 19.8 m. The loss coefficient of the impeller is 0.015
when 0.6 < Q/Qdesign < 1.2. Maximum hydraulic efficiency of impeller is 0.98 at Q/Qdesign = 0.7. Based on the comparison of the theoretical head coefficient and static pressure rise coefficient between simulation
results and experimental data, from previous work reported in the literature [Guelich, Kreiselpumpen, Springer, Berlin, 2004],
it is possible to use this method to simulate the performance of a radial-flow type impeller of a centrifugal pump.
This paper was recommended for publication in revised form by Associate Editor Seungbae Lee
Somchai Wongwises is currently a Professor of Mechanical Engineering at King Mongkut’s University of Technology Thonburi, Bangmod, Thailand.
He received his Doktor Ingenieur (Dr.Ing.) in Mechanical Engineering from the University of Hannover, Germany, in 1994. His
research interests include two-phase flow, heat transfer enhancement, and thermal system design. Professor Wongwises is the
head of the Fluid Mechanics, Thermal Engineering and Two-Phase Flow Research Laboratory (FUTURE).
Suthep Kaewnai obtained a B. S. degree in Mechanical Engineering, 1980 from the King Monkut’s University of Technology Thonburi and M. S.
degree in Mechanical Engineering, 1983 from Chulalongkorn University. He is currently an assistant professor at King Mongkut’s
University of Technology Thonburi. Suthep’s research interests are in the area of pumps and small hydroturbine.
Manuspong Chamaoot received a B. S. degree, 1972 and M.S. degree in Mechanical Engineering, 1979 from the King Monkut’s University of Technology
Thonburi. He is currently an assistant professor at King Monkut’s University of Technology Thonburi. His research interests
are in the field of mechanical vibration for rotating equipment and computational fluid dynamics. 相似文献
17.
Dae Hee Lee Myeong Chan Jo Jun Sik Lee Yoon Seok Cha Dae Keun Lee 《Journal of Mechanical Science and Technology》2009,23(2):544-549
Measurements of the temperature distributions of the cooling air flow inside a computer system have been made. An investigation
of the optimum cooling condition for the computer system has also been made. Seventy-one K-type (Chromega-Alumega) thermocouples
were used to measure distributions of the air flow temperature inside the computer system. They were calibrated against the
standard platinum resistance thermometer (PRT) in a constant water circulating bath within an accuracy of ± 0.15 °C. It was
found that the number and position of cooling fans as well as their operating condition, whether air intake or air discharge,
can greatly influence the cooling effectiveness in the computer system. The results show that the flow rate of intake air
should not be higher than that of the discharge air for the most effective cooling. It follows that the optimum cooling has
been achieved inside the computer when the three fans are positioned in the inlet front, outlet back, and outlet top in the
computer, respectively. Under these conditions, not only is the average temperature inside the computer system maintained
at an appropriate level, but the most effective cooling around the central processor (CPU) and graphic card which are responsible
for the largest amount of heat dissipation can be accomplished.
This paper was recommended for publication in revised form by Associate Editor Man-Yeong Ha
Dae Hee Lee received a B.S. degree in Mechanical Engineering from Hanyang University in 1984. He then went on to receive his M.S. and
Ph.D. degrees from University of California at Davis in 1984 and 1987, respectively. Dr. Lee is currently a Professor at the
School of Mechanical Engineering and a Dean of Academic Affairs at Inje University in Korea. Dr. Lee’s research interests
are in the area of Convection Heat Transfer, Liquid Crystal Thermography, Co-generation, and Renewable Energy. 相似文献
18.
Micro machining of an STS 304 bar by magnetic abrasive finishing 总被引:1,自引:0,他引:1
Ik-Tae Im Sang Don Mun Seong Mo Oh 《Journal of Mechanical Science and Technology》2009,23(7):1982-1988
A magnetic abrasive finishing process is a method of non-traditional precision machining in which the finishing process is
completed using magnetic force and magnetic abrasives. In this research, a STS 304 cylindrical workpiece was finished using
a magnetic abrasive finishing process at 30,000 rpm, and the roughness, roundness, and changes in the micro-diameter were
investigated. The study showed that it is possible to control the micro-diameter and weight of the STS 304 cylindrical workpiece
by using a near linear approach. Surface roughness as fine as 0.06 μm (Ry) and roundness as fine as 0.12 μm (LZS) were achievable
by using a diamond paste with 1 μm particles. Vibrational motion applied to the workpiece improved the surface roughness.
The improvement of the surface roughness was achieved because the vibrational motion effectively removes unevenness in the
rotational direction and the direction orthogonal to it.
This paper was presented at the 9th Asian International Conference on Fluid Machinery (AICFM9), Jeju, Korea, October 16–19, 2007.recommended for publication
in revised form by Associate Editor Dae-Eun Kim
Ik-Tae Im received the B.S., M.S. and Ph.D. degrees in Mechanical Engineering from Hanyang University, Seoul, Korea, in 1993, 1995
and 1999, respectively. He has been a visiting scientist at the Department of Materials Engineering, the University of Tokyo,
Japan, where he studied on the film growth during the MOCVD process. His research interests include the numerical modeling
on the transport phenomena in various materials processing. He is a professor at the Division of Mechanical Design Engineering
at Chonbuk National University in Jeonju, Korea.
Sang Don Mun received the B.S. degree and M.S. in Precision Mechanical Engineering from Chonbuk National University, Korea, in 1991 and
1993, respectively. He then received the Ph.D. in Precision Mechanical Engineering at the same university in 1997. Dr. Mun
is currently a Professor at the Division of Mechanical Design Engineering at Chonbuk National University in Jeonju, Korea.
His research interests include magnetic abrasive finishing, tool wear, and micro machining.
Seong Mo Oh received his B.S. degree in Mechanical Engineering from Wonkwang University, Korea, in 1992. He then received his M.S. and
Ph.D. degrees from Wonkwang in 1994 and 2000 respectively. Dr. Oh is currently a Lecturer at the Division of Mechanical and
Automotive Engineering at Wonkwang University in Jeonbuk, Korea. Dr. Oh’s research interests include tribology, functional
surfaces, and micromachining. 相似文献
19.
Heuy-Dong Kim Min-Sung Kang Yumiko Otobe Toshiaki Setoguchi 《Journal of Mechanical Science and Technology》2009,23(3):856-867
Under-expanded jets which are discharged from an orifice or a nozzle have long been subject of researches for aeronautical
and mechanical applications. Provided that the jet pressure ratio and nozzle configuration are known, the major features of
the steady jet are now well known. However, the jet pressure ratio is often varied even during the process in many practical
applications. Many questions remain unanswered with regard to how the supersonic jet responds to the transient process of
the pressure ratio and whether the steady jet data for a specific pressure ratio can still bear the same during the transient
process of pressure ratio. In the present study, the hysteric phenomenon of under-expanded jets has been investigated with
the help of computational fluid dynamics methods. The under-expanded jets of both dry and moist air have been employed to
investigate the transient processes of the pressure ratio. The effects of nonequilibrium condensation occurring in the under-expanded
moist air jets are explored on the hysteresis phenomenon. It is known that under-expanded air jet produced during the startup
transient of jet behaves differently from the shutdown transient process, leading to the hysteric phenomenon of under-expanded
jet. It is also known that the moist air jet reduces the hysteric phenomenon, compared with the dry air jet, and that non-equilibrium
condensation which occurs in the underexpanded moist air jet is responsible for these findings.
This paper was recommended for publication in revised form by Associate Editor Do Hyung Lee
Heuy-Dong Kim received his B.S. and M.S. degrees in Mechanical Engineering from Kyungpook National University, Korea, in 1986 and 1988,
respectively. He then received his Ph.D. degree from Kyushu University, Japan, in 1991. Dr. Kim is currently a Professor at
the School of Mechanical Engineering, Andong National University, Korea. His research interests include High-Speed Trains,
Ramiet and Scramiet, Shock Tube and Technology, Shock Wave Dynamics, Explosions & Blast Waves, Flow Measurement, Aerodynamic
Noises and Supersonic Wind Tunnels.
Min-Sung Kang received his B.S. and M.S degrees in Mechanical Engineering from Andong National University, Korea, in 2007 and 2009, respectively.
Mr. Kang is currently a researcher at the School of Mechanical Engineering at Andong National University, Korea. His research
interests include cavity and supersonic nozzle flows.
Yumiko Otobe received her B.S. degree in Faculty of Engineering from Yamaguchi University, Japan, in 1978. She then received her Eng.
D. degree from Saga University, Japan, in 2007. Dr. Otobe is currently a Research Associate at the Department of Control &
Information Systems Engineering, Kitakyushu National College of Technology, Japan. Dr. Otobe’s research interests include
sonic and supersonic jets of various gases as well as nonequilibrium condensation phenomena.
Toshiaki Setoguchi received his B.S. degree in Mechanical Engineering from Tokyo University of Agriculture and Technology, Japan, in 1976. He
then received his M.S. and Ph.D. degrees from Kyushu University, Japan, in 1978 and 1981, respectively. Dr. Setoguchi is currently
a Professor at the Department of Mechanical Engineering, Saga University, Japan. His research interests include Nonequilibrium
Condensation, Ramiet and Scramiet, Shock Tube and Technology, Shock Wave Dynamics, Explosions & Blast Waves, Aerodynamic Noises
and Turbomachinery. 相似文献
20.
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