======================================================================                   ENGINEERING NEWS IN BRIEF                         E-Mail Newsletter                                No.90              Issued by the Asian TOP Panel, June 2009            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 2009. ====================================================================== [Contents] 1)  Microcombustor with a porous catalyst Layer (Source: JSME) 2)  Development of a Noise Control System Array Type of the Noise Insulation Panels      (Source: JSME) 3)  Fatigue Behavior of Friction Stir Welded Joints and Friction Stir Processed Materials     (Source: JSME) 4)  Biomorphic Mineralization: From Biology to Materials (Source: CMES) 5)  Non-steady Flow Method for Measuring the Micro Flow at Constant Micropressure      (Source: CMES) 6)  Grey Relation between Nonlinear Characteristic and Dynamic Uncertainty of Rolling     Bearing (Source: CMES) 7) Design and Analysis of a Twisting-type Thermal Actuator for Micromirrors     (Source: KSME) 8) Molecular Dynamic Simulation of the Melting and Solidification Processes of Argon     (Source: KSME) 9) Experimental Investigation of Nanoparticle Formation Characteristics from Advanced     Gasoline and Diesel Fueled Light Duty Vehicles under Different Certification Driving     Modes (Source: KSME) ======================================================================== 1) Microcombustor with a porous catalyst Layer Shuhei Takahashi, Gifu University  The microcombustor that have a porous catalyst layer inside a narrow ceramics tube has been developed by Gifu University.  The inner and outer diameters of the combustor are only 0.8mm and 1.2mm, and the thermal output of the combustor is about 5W.  The porous catalyst layer is produced by sintering colloidal paste of Pt powders, and very fine mesh structure is formed with very low cost less than $1.00 per a tube.  The combustion efficiency is 95%, and the hot exhaust gas of 1250K is available at the exit.  The combustor can work in the wide range of equivalence ratio and flow rate, and its life time is more than 500 hours at present.  It can be used for spot heating, an igniter and so on as well as the heat source for thermal-electric generator using thermoelectric elements.  The coupling this combustor with Bi-Te thermoelectric elements records 2% final fuel-electricity conversion ratio which implies the potential for ultra-light mobile batteries. ________________________________________________________________________________________________________________________________ 2) Development of a Noise Control System Array Type of the Noise Insulation     Panels     Katsuya Yamamoto, Railway Technical Research Institute  We have developed a panel-type noise reduction system as a new countermeasure for the noise transmitted through a plate without identification of the characteristics of a target plate or the transmitted noise. In the noise reduction system, noise insulation panels with piezoelectric material are arranged in a plane, and the noise transmitted through the noise insulation panels is reduced by a control circuit. The noise reduction system installs on a target plate with an air layer in order to separate from the vibration of the target plate. Although the control circuit is a simple analog resonance circuit, we verified that the noise transmitted through a target panel suppress with bandwidth. In the case that the noise reduction system was applied to a deck of the Shinkansen, the interior noise was reduced by about 4dB in the target frequency range. _________________________________________________________________________________________________________________________________ 3) Fatigue Behavior of Friction Stir Welded Joints and Friction Stir Processed     Materials      Yoshihiko Uematsu, Gifu University  Fatigue behavior of friction stir welded (FSW) joints, friction stir spot welded (FSSW) ones and friction stir processed (FSP) materials was reviewed from the microstructural point of view. In FSW joints, the microstructure of the weld zone was typically classified into three regions: stir zone (SZ), thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ). In the SZ, fine equiaxed grains were observed resulting from dynamic recrystallization. In FSW joints and FSPed materials, fatigue behavior was strongly affected by the microstructures developed by FSW or FSP. However, the dominating microstructures of fatigue behavior were different between FSW joints and FSPed materials, where onion rings played important role in FSPed materials. Consequently, it is very difficult to estimate fatigue strengths of FSW joints and FSPed materials from their tensile strengths, which were relatively insensitive to the microstructures. In FSSW joints, the microstructure in the nugget was largely different from that developed by FSW. And the macroscopic shape parameters on the cross section of the nugget and stress concentration were dominating factors of the fatigue behavior of FSSW joints. _________________________________________________________________________________________________________________________________ 4) Biomorphic mineralization: From biology to materials Fan Tongxiang, Chow Suk-Kwun, Di Zhang        Shanghai Jiaotong University  Since material properties are structure-dependent, new and interesting properties are expected from unusual or complex structures. Biomorphic mineralization is a technique that produces materials with morphologies and structures resembling those of nature living things, through employing bio-structures as templates for mineralization. The products, biomorphic materials, combine natural geometry with synthetic material chemistry. Fundamental information along with recent advances in biomorphic mineralization and biomorphic materials are provided in this review through discussions on the following aspects: biomorphic materials produced through synthesis or assembly using a range of templates including biomolecules, microorganisms, plants and animals; processing methods and mechanisms of biomorphic mineralization; properties and emerging applications of biomorphic materials in multiple areas including electronics, magnetics, photonics, biotech, sensing, and filtration. The potential of various natural structures for biomimicking to produce advanced materials will be also discussed. We conclude by making a prospect on biomorphic mineralization and biomorphic material, which is the product of close conversations between human and nature and the product of close co-operation between scientists from diverse fields. Key Words: Biology Material Mineralization 5) Non-steady Flow Method for Measuring the Micro Flow at Constant     Micropressure      Wei Liejiang, Ji Hong, Li Shaonian, Qiang Yan, Wei Zhongying      Lanzhou University of Technology  In order to measure the micro flow in micro channel precisely and easily, a new measuring method based on the idea of utilizing non-steady flow state to be equivalent to steady flow state used in traditional measurement is proposed. The applicable condition of pressure head for the new measuring method is derived. Based on Lagrange integral principle in fluid dynamics, a mathematic model in form of non-linear differential equation is built and analyzed numerically by using MATLAB software, so the theoretical error of the proposed method is obtained. The numerical results reveal that the difference between measurement result under the non-steady flow state and that under the steady flow state reduces with the decreasing of the ratio of the areas of the micro channel and the tube in upper stream when the pressure loss in the tube is omitted. Then, an apparatus for measuring the micro flow is established according to the proposed method. The measured results form the apparatus agree well with the theoretical calculation results. Both results show that the measuring error is lower than 2.27% when the applicable condition of pressure head is satisfied and the ratio of cross sectional areas of the micro channel and the tube in upper stream is smaller than 3.422%. Key Words: Micro flow  Micropressure  Non-steady flow  Measurement method   Precision _________________________________________________________________________________________________________________________________ 6) Grey Relation between Nonlinear Characteristic and Dynamic Uncertainty of     Rolling Bearing Friction Torque Xia xintao, Wang Zhongyu        Henan University of Science and Technology        Beijing University of Aeronautics and Astronautics  The rolling bearing friction torque which is characterized by its uncertainty and nonlinearity affects heavily the dynamic performance of a system such as missiles, spacecrafts and radars, etc. it is difficult to use the classical statistical theory to evaluate the dynamic evaluation of the rolling bearing friction torque for the lack of prior information about both probability distribution and trends. For this reason, based on the information poor system theory and combined with the correlation dimension in chaos theory, the concepts about the mean of the dynamic fluctuant range (MDFR) and the grey relation are proposed to resolve the problem about evaluating the nonlinear characteristic and the dynamic uncertainty of the rolling bearing friction torque. Friction torque experiments are done for three types of the rolling bearings marked with HKTA, HKTB and HKTC separately; meantime, the correlation dimension and MDFR are calculated to describe the nonlinear characteristic and the dynamic uncertainty of the friction torque, respectively. And the experiments reveal that there is a certain grey relation between the nonlinear characteristic and the dynamic uncertainty of the rolling bearing friction torque, viz. MDFR will become the nonlinear increasing trend with the correlation dimension increasing. Under the condition of fewer characteristic data and the lack of prior information about both probability distribution and trends, the unitive evaluation form the nonlinear characteristic and the dynamic uncertainty of the rolling bearing friction torque is realized with the grey confidence level of 87.7%-96.3%. Key Words: Rolling bearing  friction torque   time series   correlation dimension   mean of dynamic fluctuant range (MDFR)   information poor system theory 7) Design and analysis of a twisting-type thermal actuator for micromirrors      Dong Hyun Kim1, Kyung Su Oh1 and Seungho Park2       1. Department of Mechanical Engineering, Hongik University,       2. Department of Mechanical and System Design Engineering,         HongikUniversity, Abstract : This paper reports the design of a novel twisting-type micromirror actuation system. The actuating mechanism for driving the micromirror combines two paralleled bimorph actuators bending in opposite directions for rotational control of the micromirror. Each actuator is structured by gold and silicon dioxide or nickel and silicon nitride thin films with embedded polysilicon line heaters. With a size of only 15?m in width, 1.3?m in thickness, and 100?m in length, two bimorph actuators can result in a vertical displacement of 25?m at 10 volts dc with the span of 120?m, and thus the micromirror can rotate by angles over 20°, which is a significant improvement, compared to conventional tilting-type micromirrors.Keyword : Micromirror; MEMS; Bimorph thermal actuator; Twisting-mode ________________________________________________________________________________________________________________________________ 7) Technology on Large Scale Numerical Control Machine Tool Condition     Monitoring Based on Built-in Sensors       Zhou Yuqing, Mei Xuesong, Jiang Gedong, Sun Nuogang, Tao Tao        Xi’an Jiaotong University  A kind of large scale numerical control (NC) machine tool condition monitoring system based on AC servo motor encoder, linear or rotary scale and motor current (torque) is proposed. To obtain the state information, the test principles of motor torque, machine tool position and lubrication characteristic are profoundly investigated, and some different sampling methods for open NCs and commercial NCs are suggested. Furthermore, some constant speed tests and lubrication characteristic tests are carried out respectively. The analysis shows that it is feasible and reliable to use the motor current, position, instantaneous velocity, instantaneous acceleration for monitoring the mechanical parts state and evaluating the servo control characteristics, which lays the foundation for large scale numerical control machine tool on-line condition monitoring and fault diagnosis. Key words: NC machine tool; built-in sensors; condition monitoring; fault diagnosis _________________________________________________________________________________________________________________________________ 8) Molecular dynamic simulation of the melting and solidification processes of     Argon       Jae Dong Chung1       Department of Mechanical Engineering, Sejong University Abstract : Molecular Dynamic (MD) simulations have been conducted to look at the melting and solidification of the Lennard- Jones argon (100) interface with small amounts (up to 6.0K) of undercooling and superheating. By combining the fully equilibrated bulk phases of liquid and solid in one simulation box and counting the number of solid?like particles, the interface velocities, i.e. the growth rate or melting rate, were obtained as a function of temperature. The melting temperature, where no growth or melting of crystal particle is expected, is * m T =0.668 which is close to that of the Gibbs free energy calculation. A linear dependence of growth or melting rate on temperature was found except for high superheating, ?T > 6K. The high superheating is believed as the main source of slope discontinuity in the rate, not the misuse of initial regime as discussed in the earlier works. Keyword : Phase transition; Freezing rate; Molecular dynamic simulations; Melting temperature ________________________________________________________________________________________________________________________________ 9) Experimental Investigation of Nanoparticle Formation Characteristics from    Advanced Gasoline and Diesel Fueled Light Duty Vehicles under Different    Certification Driving Modes Hyungmin Lee1, Juwon Kim1, Cha-Lee Myung1 and Simsoo Park1 1.School of Mechanical Engineering, Korea University Abstract : This paper mainly focused on the comparison of nanoparticle size distribution and number concentration level characteristics with gasoline and diesel fueled light duty vehicles. In the engine research, particle size distribution and number concentrations were analyzed by a DMS500 with engine parameters. Time-resolved particle number concentration levels from test vehicles were measured by a golden particle measurement system (GPMS) as recommended by a Particle Measurement Programme (PMP) on certification modes such as New European Driving Cycle (NEDC), Federal Test Procedure (FTP)-75, and Highway Fuel Economy Test (HWFET). In addition, particle emission characteristics from vehicles were analyzed by DMS500 during transient and high-speed driving conditions. From the results, we found that the formation of particles was highly dependent on vehicle speed and load conditions for each mode. The diesel vehicle equipped with a particulate filter showed substantial reduction of the total particle number whose number concentration was equivalent to that of the gasoline vehicle. The nucleation mode particles from gasoline fuel were mainly emitted; however, the accumulation mode particles from the diesel fuel were generally analyzed. Keyword : Nanoparticle; GPMS; Particulate matter; Particulate filter; Nucleation mode; Accumulation mode _____________________________________________________________________________________________________________________________ Editor : International Affairs Committee Published by The Japan Society of Mechanical Engineers Shinanomachi-Rengakan Bldg, Shinanomachi 35, Shinjuku-ku, Tokyo 160-0016, Japan FAX : 81-3-5360-3508 All Rights Reserved, Copyright C 2008 The Japan Society of Mechanical Engineers URL:http//www.jsme.or.jp [English Version]

 

Please feedback us! wwwadmin@jsme.or.jp All Rights Reserved, Copyright (C) 2009, The Japan Society of Mechanical Engineers.