ENGINEERING NEWS IN BRIEF
Issued by the Asian TOP Panel, October 2008
The Chinese Mechanical Engineering Society (CMES)
The Institution of Engineers, Indonesia (PII)
The Japan Society of Mechanical Engineers (JSME)
The Korean Society of Mechanical Engineers (KSME)
According to the agreement made in the 2nd Asian TOP Panel Meeting,
the ENGINEERING NEWS IN BRIEF (E-mail newsletter) has now been edited
by the JSME for the year 2008.
1) Preparation of High Performance Optical Coatings with 乬Nano Particle Coating乭 (Source: JSME)
2) Active Compensation for Magnetic Noise (Source: JSME)
3) Experimental Study on Biodiesel Engine Emissions Using Non-thermal Plasma
4) Elastohydrodynamics Lubrication Analysis of Misaligned Journal Bearing Considering Surface Roughness (Source: CMES)
5) Agreement of Cooperation Signed between SOE and CMES (Source: CMES)
6) High-Accuracy Digital-Analog Actuators Using Load Springs Compensating
Fabrication Errors (Source: KSME)
7) Structural Optimization of the Lower Parts in a Humanoid Considering Dynamic Characteristics (Source: KSME)
8) A study on Thermal Performance of Micro Channel Water Block for Computer CPU Cooling (Source: KSME)
1) Preparation of High Performance Optical Coatings with 乬Nano Particle Coating乭
Tsuyoshi Murata, Nicon Corporation
2) Active Compensation for Magnetic Noise
When measuring weak magnetic fields such
as a biomagnetic measurement, it is
to reject the disturbing background
Hence, a magnetically shielded room
with multiple layers of permalloy is
used to reduce environmental magnetic
noise. Unfortunately, the MSR is expensive
and hardly transportable. However,
applications, it is preferable to measure
in an unshielded environment.
Cai Yixi , Wang Pan , Wang Jun , Wang Jing
Based on the dielectric barrier discharge theory, the non-thermal plasma reactor was designed. The main components of the biodiesel sample were detected using gas chroma-tography-mass spectrometry. The bench test experiment was carried out, and the reduction of diesel engine harmful emissions with NTP operating on both biodiesel and No 0 diesel had been investigated. Scanning electronic microscope and X-ray energy spectrometer were used to detect the surface structure and chemical component of particular samples from the exhausts of diesel engine. Results show that the particular matter is decreased remarkably but NOx emissions change a little by NTP, the biodiesel can improve the performance of combustion and the particular matter from the oxygenated fuel has less component and small diameter. The results of elemental analysis reveals that NTP is unaffected by exhausts impurity such as sulfur, and is one promising technology for diesel engine emissions reduction.
Key words: dielectric barrier discharge; non-thermal
plasma (NTP); biodiesel; bench test
Sun Jun, Wang Zhenhua, Gui Changlin, Liu
Average Reynolds equation was used to analyze bearing lubrication. The surface deformation of bearing was calculated by deformation-matrix method. The results show that the oil viscosity-pressure relationship has large effect on the lubrication characteristics of misaligned bearing, especially under condition of great misalignment angle. The surface roughness affects lubrication characteristics of misaligned bearing when eccentricity ratio and angle of journal misalignment are all large and not considering surface deformation of bearing. The directional parameter of surface has obvious effect on lubrication of misaligned bearing when ratio of least film thickness to surface roughness is small. The surface roughness and directional parameter of surface have little effect on lubrication of misaligned bearing when considering deformation of bearing surface. Although having little effect on lubrication of aligned bearing, the deformation of bearing surface has remarkable effect on lubrication of aligned bearing. The larger the eccentricity ratio, the greater the effect of the deformation of bearing surface has on lubrication of misaligned bearing.
Key words: rough surface; viscosity-pressure relationship;
surface deformation; journal misalignment;
On October 20, the SOE (Society of Operations
Engineers, UK) delegation led by SOE
Mr. Walter Ian Talbot Ling visited
The two sides held friendly talk and
an agreement of reciprocal recognition
professional qualifications for engineers
of both organizations.
Won Han, Won Chul Lee, Young-Ho Cho
We present a high-accuracy digital-to-analog (DA) actuator using a load spring, specially designed to compensate the output displacement errors caused by fabrication errors. The compensated linear DA actuator is capable to change the slope of input-output modulation line in order to compensate fabrication errors. We design, fabricate, and characterize three different prototypes: one uncompensated design and two compensated designs respectively for a specific value and for a given range of fabrication error. The compensated linear DA actuators show the output displacement errors of -0.20亇0.23? and -0.13亇0.18?, respectively, reduced by 64.3% and 76.8% of the output displacement error, 0.56亇0.20?, produced by the conventional uncompensated linear DA actuator. We experimentally verify the fabrication error compensation capability of the present compensated linear DA actuators, thus demonstrating high-accuracy actuation performance immune to fabrication errors.
Key words: Digital-to-Analog Actuator, Fabrication Error Compensation, High-Accuracy Actuation
Eul-Pyo Hong*, Il-Kwon Lee**, Bum-Jae You***, Chang-Hwan Kim***, Gyung-Jin Park*
*: Han Yang University, **: Sam Sung Engineering Co., ***: KIST
A humanoid is a robot with its overall appearance
based on that of the human body. When the
humanoid moves or walks, dynamic forces act
on the body structure. Although the humanoid
keeps the balance by using a precise control,
the dynamic forces generate unexpected deformation
or vibration and cause difficulties on the
control. Generally, the structure of the
humanoid is designed by the designer乫s experience
and intuition. Then the structure can be
excessively heavy or fragile. A humanoid
design scenario for a systematic design is
proposed to reduce the weight of the structure
while sufficient strength is kept. Lower
parts of the humanoid are selected to apply
the proposed design scenario. Multi-body
dynamics is employed to calculate the external
dynamic forces on the parts and structural
optimization is carried out to design the
lower parts. Because structural optimization
using dynamic forces directly is fairly difficult,
linear dynamic response structural optimization
using equivalent static loads is utilized.
Topology and shape optimizations are adopted
for two steps of initial and detailed designs,
respectively. Various commercial software
systems are used for analysis and optimization.
Improved designs are obtained and the design
results are discussed.
Oh-Kyung Kwon, Mi-Jin Choi, Dong-An Cha,
The object of this paper is to study on the thermal performance of a micro channel water block for computer CPU cooling. The effects of liquid flow rate, micro channel width and height on the thermal performances of water block are investigated experimentally. The water block was fabricated Al and machined with a micro milling. The water block consisted of rectangular micro channels 0.5 to 0.9噊 width and 1.5 to 4.5 噊 height. The experiments were conducted using deionized water, over a liquid flow rate ranging from 0.2 to 2.0 噑/min. The base temperature and thermal resistance decrease with increasing of liquid flow rate. The increase of a channel height is more effective on the thermal resistance than the decrease of a channel width. At the flow rate of 0.7 噑/min, input power of 100W, the base temperature and thermal resistance of sample 6 is 33亷 and 0.13 亷/W respectively.
Key Words: Base Temperature, Micro Channel, Pressure
Drop, Thermal Resistance, Water Block
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