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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.83
             Issued by the Asian TOP Panel, November 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)

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    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.

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[Contents]


1) Development of Combined Heat and Power System applied Distributed Heat Storage     Units in Multifamily Building (Source: JSME)
2)  Condition Monitoring of Railway Track Using In-Service Vehicle (Source: JSME)
3)  Risk-Based-Approach of Machinery Safety (Source: JSME)
4)  Goldfire Innovator: The Solution to Support all People who are Involved in      Manufacturing Business (Source: JSME)
5)  Development of Micro Gear Reducer (Source: JSME)
6)  Design Method of Magnetorheological Fluid Shock Absorber for Car Suspension     (Source: CMES)
7)  Simplified Scaling Transformation for the Numerical Simulation of MEMS Devices
     with Thin Film Structures (Source: CMES)

8)  Approach for Maintenance Strategy Decision Making with Mixed Data
     (Source: CMES)

9)  Hybrid Welding Process for Sheet Metal and Narrow Gap Fill Pass (Source: KSME)
10)Numerical Study of Pulsatile Blood Flow in Stenotic Artery (Source: KSME)
11)High Power Laser Driven Shock Compression of Metals and Its Innovative
     Applications (Source: KSME)


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1)Development of Combined Heat and Power System applied Distributed Heat    Storage Units in Multifamily Building

    Yoshinori HISAZUMI, Osaka Gas Co.,LTD

In order for economically viable distributed generation systems for local community to spread, it is essential to develop an efficient and low-cost heat supply system. We propose a new heat supply system presented at the ICOPE-07 Hangzhou, China. The key technology for the system is to connect compact heat supply units installed in all the households of the local community, such as a condominium, by a single loop of hot water piping. Phase change material was used for a heat supply unit as heat storage material. However to improve handling ability and to reduce the cost down of the unit, we have developed a new heat supply unit whose heat storage tank is made of plastic. Hot water for space heating is used as heat storage material. Furthermore, we constructed a heat supply system for 7 lived-in households with a 5 kW gas engine and a 42 kW boiler as heat sources. Some experiments for a heat supply unit and a heat supply system and dynamic simulations for heat demand have been conducted, such as heat storage and supply of the heat supply unit, and COP evaluation of a new CO2 heat pump system using low- temperature exhaust from the cogeneration system.


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2) Condition Monitoring of Railway Track Using In-Service Vehicle

    Hitoshi TSUNASHIMA, Nihon University

 The development of a portable condition monitoring system for railway track which is easily set on in-service vehicle is summarized. In this system, irregularities of rail are estimated from vertical and lateral acceleration of car body. A roll angle of car body, which is calculated using a rate gyroscope, is used to distinguish irregularity of line from irregularity of level. Rail corrugation can be detected from cabin noise with spectral peek calculation. GPS system and map matching algorithm localizes the fault on track. A field test was conducted using a commercial line in cooperation with a railway operating company. Track irregularity was detected by vertical and lateral acceleration measured while the vehicle was running, and corrugation was detected by spectral peaks of cabin noise. Track condition was displayed on a route map in real time together with information of the location based on the position information obtained by GPS. The field results show that the condition monitoring of railway track using in-service vehicle is possible with the developed probe system.

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3) Risk-Based-Approach of Machinery Safety

    Takashi KABE, NPO Safety Engineering Laboratory

 The development of science and technology brings on one hand welfare to the society, but on the other hand danger to human being. The products are human-made and designers of machinery have therefore the responsibility to control hazards according to Risk-Based-Approach (RBA) to prevent accidents beforehand. The Japanese domestic legislation and standards have implemented the framework of global approach on safety of machinery in these days. This framework consists out of labor safety law and Japanese industrial standard (JIS), which is adapted to international standards, ISO or IEC on safety of machinery. In case of Japan, the relevant law requires the responsibility of user of machinery only and not yet of the machinery manufacturer. Thus users of machinery are required to pay attention, that purchasing machines are safe and fulfill also requirements of products liability law or contract law. The methodology risk assessment has a major role in this prevention way.

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4) Goldfire Innovator: The Solution to Support all People who are Involved in     Manufacturing Business

    Koumei NAGASHIMA, Cybernet Systems Co., Ltd

 In this article, the functionalities and the advantages of Goldfire Innovator, a novel and unique software developed by Invention Machine Corporation (IMC), and a specific example of a user case is introduced. The concept of Goldfire Innovator is to 'accelerate innovation', and according to IMC乫s theory, it can be accomplished by making the product development process more efficient and by utilizing the results repeatedly. Goldfire Innovator makes it possible to cope with the deficiencies of existing products or designs, review the functional designs, and do risk analysis. In order to deliver the advantages above, Goldfire Innovator implements the problem solving methodologies and knowledge management framework integrated. The frameworks include; TRIZ for inventive problem solving, FMEA for risk analysis, function models and value engineering for studying devices and processes, root cause analysis to identify root causes of failures or accidents, patent analysis, and the semantic analyzing technologies to control worldwide engineering documents. One of the best practices of problem solving procedure with above functions is explained. As a user case, you can find how an oil company successfully reached the new bio-energy material using Goldfire Innovator.

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5) Development of Micro Gear Reducer

    Hideo KATORI, Tecpha Japan Inc.,

The necessity of a minute mechanism and the device can enumerate the field of the medical treatment machine in the beginning. That is, to suppress the damage of the body to the minimum, an endoscope as small as possible, a tool of a celiac [**] operation, and a micro pump, etc. are demanded. Then, the micro gear reducer  (1.5mm in the outside diameter and about 4mm in length) by the planetary gear mechanism that was able to be applied to the field of the medical treatment machine was developed.

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6) Design Method of Magnetorheological Fluid Shock Absorber for Car     Suspension

    Liao Changrong, Zhang Honghui, Yu Miao, Chen Weimin
     Chongqing University

 The Bingham constitutive model, which is previously used in depiction of magnetorheological (MR) fluids rheological behaviors for design devices, exhibits discontinuous characteristics in representation of pre-yield behaviors and post-yield behaviors. A Biviscous constitutive model is presented to depict rheological behaviors of MR fluids and design automotive shock absorber. Quasi-static flow equations of MR fluids in annular channels are set theoretically up based on Navier-Stokes equations and several rational simplifications are made. And both flow boundary conditions and flow compatibilities conditions are established. Meantime, analytical velocity profiles of MR fluids though annular channels are obtained via solution of the quasi-static flow equations using Biviscous constitutive model. The predition methodology of damping force offered by MR fluid shock absorber is formulated and damping performances are predicated in order to determine design parameters. MR fluid shock absorber for Mazda 323 car suspension is designed and fabricated in Chongqing University, China. Measurements from sinusoidal displacement cycle by Shanchuan Shock Absorber Ltd. of China North Industry Corporation reveal that the anyalytical methodology and design theory are reasonable.

Key words: Magnetorheological fluid shock absorber, Biviscous constitutive model, Bingham constitutive model

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7) Simplified Scaling Transformation for the Numerical Simulation of MEMS     Devices with Thin Film Structures

    Wang Wei, Li Zhihong
     Peking University

 Thin film is a widely used structure in the present microelectromechanical systems (MEMS) and plays a vital role in many functional devices. However, the great size difference between the film乫s thickness and its planar dimensions makes it difficult to study the thin film performance numerically. In this work, a scaling transformation was presented to make the different dimensional sizes equivalent, and thereby, to improve the grid quality considerably. Two numerical experiments were studied to validate the present scaling transformation method. The numerical results indicated that the largest grid size difference can be decreased to one to two orders of magnitude by using the present scaling transformation, and the memory required by the numerical simulation, i.e., the total grid number, could be reduced by about two to three orders of magnitude, while the numerical accuracies with and without this scaling transformation were nearly the same.

Key words: Scaling transformations, Numerical simulation, Microelectromechanical systems (MEMS), Thin film

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8) Approach for Maintenance Strategy Decision Making with Mixed Data

    Li Changyou, Xu Minqiang, Guo Song, Wang Rixin, Huang Wenhu
     Harbin institute of Technology

 Studying on the problem of maintenance strategy decision making of equipment can reduce the maintenance cost and improve the availability, reliability, safety of a machine, and product quality. Although it has had a certain extent of development, the problem of maintenance strategy decision making with mixed data has never been resolved. The local concordance index and discordance index is defined based on the stochastic dominance to compare one maintenance strategy with others under stochastic evaluation; the fuzzy evaluations are transformed to the corresponding fuzzy numbers, then, the local concordance index and discordance index are defined based on the distance index between the centroid point of a fuzzy number and original point to resolve the problem of maintenance strategy decision making under fuzzy evaluation. Based on the above processing, the fuzzy and stochastic evaluations are treated the same the deterministic in ELECTRE III in order to solve the problem of maintenance strategy decision making with mixed data. The proposed approach is applied to selecting the most appropriate maintenance strategy for the steam turbine of steam-power plant. The result shows that the approach is sound and effective.

Key words: Maintenance strategy, Mixed data, Multiple attribute decision making, Stochastic dominance, Ranking fuzzy numbers, ELECTRE III, Steam turbine

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9) Hybrid Welding Process for Sheet Metal and Narrow Gap Fill Pass

    Hae Woon Choi, Hyun Myung Shin, Moon Hyuk Im
     Keimyung University

 An application of innovative laser+GMA hybrid welding process is presented for reducing bead humping defects in high speed welding and increasing side wall fusion in narrow groove welding without torch or wire oscillation. In this hybrid process, the laser heat input is applied adjacent to the weld pool at a relatively low power density to produce a wider, flatter weld bead. In bead on plate in sheet metal gauges, the hybrid process was able to produce hump-free welds from 70ipm (~1780/min) to over 150ipm (~3810/min) of the travel speed compared to the un-assisted GMAW process. A square-butt joint in 15mm A572 Gr50 steel welds was investigated. A square butt joint with a gap of 3.2 was filled with 6 passes. Liquid Nitrogen calorimetry and innovative CO? laser reflective optics were also developed to demonstrate the concept of hybrid welding.

Key words: Hybrid Welding, Sheet Metal, Narrow Gap

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10) Numerical Study of Pulsatile Blood Flow in Stenotic Artery

      Taewon Seo, Bahtiyor Buriev
      Andong National University

 In the present computational study, simple stenotic artery models using pulsatile flow condition were investigated. A 1 ? non-reversing sinusoidal velocity for pulsatile flow was imposed at the flow inlet and the corresponding Womersley number based on the vessel radius is 2.75. The simple stenotic geometries have been used that consist of 25%, 50% and 75% semicircular constriction in a cylindrical tube. In this paper, numerical solutions are presented for a first harmonic oscillatory flow using commercial software ADINA 8.4. As stenosis and Reynolds number increase, the maximum wall shear stress(WSS) increases while the minimum WSS decreases. As the stenotic rate increases, the pressure drop at the throat severely decreases to collapse the artery and plaque. It is found that the fluid mechanical disturbances due to the constriction were highly sensitive with rate of stenosis and Reynolds number. When Reynolds number and stenosis increase, the larger recirculation region exists. In this recirculation region the possibility of plaque attachment is increasingly higher. The present results enhance our understanding of the hemodynamics of a stenotic artery.

Key words: Pulsatile Flow, Stenotic Artery, Wall Shear Stress, Recirculation, Reattachment


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11) High Power Laser Driven Shock Compression of Metals and Its
     Innovative Applications

     
Hyun-hee Lee, Min-cheol Gwak, Ji-hee Choi, Jai-ick Yoh
     
Seoul National University

Ablation occurs at irradiance beyond 10? W/c? with nanosecond and short laser pulses focused onto any materials. Phenomenologically, the surface temperature is instantaneously heated past its vaporization temperature. Before the surface layer is able to vaporize, underlying material will reach its vaporization temperature. Temperature and pressure of the underlying material are raised beyond their critical values, causing the surface to explode. The pressure over the irradiated surface from the recoil of vaporized material can be as high as 10? ?. The interaction of high power nanosecond laser with a thin metal in air has been investigated. The nanosecond pulse laser beam in atmosphere generates intensive explosions of the materials. The explosive ejection of materials make the surrounding gas compressed, which form a shock wave that travels at several thousand meters per second. To understand the laser ablation mechanism including the heating and ionization of the metal after lasing, the temporal evolution of shock waves is captured on an ICCD camera through laser flash shadowgraphy. The expansion of shock wave in atmosphere was found to agree with the Sedov乫s self-similar spherical blast wave solution.

Key Words:
Pulse Laser, Laser Ablation, Inverse Bremsstrahlung, Shock Wave, Plasma, Plasma Shield Effect

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Editor : International Affairs Committee
Published by The Japan Society of Mechanical Engineers
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