ENGINEERING NEWS IN BRIEF

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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.55
             Issued by the Asian TOP Panel, July 2006

           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 CMES for the year 2006.

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[Contents]

(1) Flow Force Compensation of High Speed on/off Vvalve (Source: CMES)
(2) Application of HGPECM in Micro-manufacture (Source: CMES)
(3) Thinking Model and Application in Product Form Design (Source: CMES)
(4) Self-alignment Technique of Microparts, Which Does Not Require Precision      Servomechanism (Source: JSME)
(5) Development of Nihon University CubeSat “SEEDS” (Source: JSME)
(6) Effects of Water Absorption and Surface Treatment on Mechanical Properties of Sisal      Textile Reinforced Composites (Source : KSME)
(7) Numerical Simulation of Stratified Taylor-Couette Flow (Source : KSME)
(8) A Paddling Based Locomotive Mechanism for Capsule Endoscopes(Source : KSME)

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(1) Flow Force Compensation of High Speed on/off Valve

     ZHOU Sheng XU Bing YANG Huayong Zhejiang University

A new method is presented to reduce flow force of diverged flow cone valve, the damping ring method. At first, an experiment device is designed that used for measuring flow force without friction influence. Then spool flow force with various design parameters is measured by the experiment device. In the end, the relationship between cone valve design parameter and flow force is presented.

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(2) Application of HGPECM in Micro-manufacture

     WU Gaoyang ZHANG Zhijing
     School of Mechanical and Vehicle Engineering, Beijing Institute of Technology

The application of the high frequency group pulse electrochemical machining (HGPECM) in micro-manufacture is presented. It is introduced that how the group pulse is produced, the influence of the reversed current and pressure wave on the machining quality and the principle to design the cathode in the micro-manufacture. Based on the designed moulds of facet and ultrathin structure part, the experiment of the high frequency group pulse electrochemical machining is carried out. It is indicated that high machining quality can be obtained and HGPECM can be used in the micro-manufacture.

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(3) Thinking Model and Application in Product Form Design

     TAN Hao ZHAO Jianghong Hunan University

Product form design is a problem-solving process in ill-structured domain where designers' knowledge and expertise are employed to finish product form problem-solving. The thinking process and model of product form design are the difficult problems in the area of design studies. Through a form design cognitive experiment based on the method of protocol analysis, a product form design thinking model is proposed. The model is that product form design thinking is a design information process in two ways：bottom-up processing and top-down processing. And based on the model, a product form design thinking model based ICAID system is established and put into practice to finish some design works.

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(4) Self-alignment Technique of Microparts, Which Does Not Require Precision     Servomechanism

       Kaiji SATO, Tokyo Institute of Technology

This article introduces a self-alignment technique for micropart assembly using liquid surface tension in the air. The surfaces of the microparts used in the self-alignment, are divided into two areas, namely, high and low wettability areas and have the same patttern of the high wettability area. A micropart needs to be put on the other micropart for the self-alignment by liquid surface tension. It becomes very difficult to satisfy this need for all the microparts as the number of the microparts increases. An applied vibration force is useful to eliminate this need and to stimulate the self-alignment by liquid surface tension. The self-alignment method of a micropart group at a time using liquid surface tension and vibration force are introduced. Then characteristics of the alignment are explained. This method is also useful for self-standing of the micropart. The behavior of the micropart in the experimental self-standing is shown in the article. The size of the micropart is 2.6mm x 1.0 mm x 0.15mm.

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(5) Development of Nihon University CubeSat “SEEDS”

      Yasuyuki MIYAZAKI, Nihon University

Nihon University students had started the development of pico-satellite “SEEDS” (Space Engineering Education Satellite) in 2001, and completed the development in September, 2004. SEEDS is a CubeSat, which has 1kg weight, and 10cm cube in dimension. SEEDS uses the amateur radio frequency as the same as the other universities’ CubeSats. The students also developed the ground station for the operation of the amateur satellites. Nihon University signed the MOU with California Polytechnic State University Foundation for the arrangement of the launch of SEEDS at November, 2003. SEEDS are going to be launched by the DNEPR rocket provided by ISC Kosmotras of Russia. SEEDS and other CubeSats developed by universities in United States will be ejected at a specific insertion point into space orbit from the DNEPR by the Poly Picosat Orbital Deployer (“P-POD”) provided by California Polytechnic State University (Cal Poly). The launch is the so-called cluster launch, i.e. 8 small satellites as well as 14 CubeSats will be launched simultaneously. We exported SEEDS at September, 2004, and passed the acceptance test. SEEDS is now kept in the clean room at Cal Poly. This paper reports the summary of SEEDS, the ground station, the launch status, and the future plan.

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(6) Effects of Water Absorption and Surface Treatment on Mechanical Properties of Sisal      Textile Reinforced Composites

      Hyo Jin Kim, Do Won Seo, Han Ju Pak, Yang Bae Jeon, Jae Kyoo Lim
      Chonbik Natonal University

Woven sisal textile reinforced composites were manufactured to evaluate fracture toughness, and tensile test. All specimens were immersed in water five times. All specimens are immersed in pure water during 9 days at room temperature, and dried in 1 day at 50℃. Two kinds of polymer matrices such as epoxy and vinyl-ester were used. Fractured surface were investigated to study the failure mechanism and fiber/matrix interfacial adhesion. It is shown that it can be enhanced to improve their mechanical performance to reveal the relationship between fracture toughness and water absorption fatigue according to different polymer matrices. Water uptake of the epoxy composites was found to increase with cycle times. Mechanical properties are dramatically affected by the water absorption cycles. Water-absorbed samples observed poor mechanical properties such as lower values of maximum strength and extreme elongation. The KIC values demonstrate a decrease in inclination with increasing cyclic times of wetting and drying for the epoxy and vinyl-ester.

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(7) Numerical Simulation of Stratified Taylor-Couette Flow

     Jong-Yeon Hwang, Kyung-Soo Yang, Dong-Woo Kim
     Inha University

The flow regimes for a Taylor-Couette flow with a stable, axial stratification in density are investigated using numerical simulation. The flow configuration identical to that in the experiment of Boubnov, et al. (1995) is considered in the present research. The main objectives of this investigation are to verify the experimental and numerical results carried out by Boubnov, et al. and Hua et al. (1997), respectively, and to further study the detailed flow fields and flow bifurcations. With increasing buoyancy frequency of the fluid (N), the stratification-dominated flow regime, called the S-regime, is observed. It is also confirmed that the important effect of an axial density stratification is to stabilize the flow field. The present numerical results are in good agreement with Boubnov, et al. and Hua et al.'s observations.

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(8) A Paddling Based Locomotive Mechanism for Capsule Endoscopes

     Sukho Park, Hyunjun Park, Sungjin Park, Byungkyu Kim
     Hahkuk Aviation University

Diagnosis and treatment using the conventional flexible endoscope in gastro-intestinal tract are very common since advanced and instrumented endoscopes allow diagnosis and treatment by introducing the human body through natural orifices. However, the operation of endoscope is very labor intensive work and gives patients some pains. As an alternative, therefore, the capsule endoscope is developed for the diagnosis of digestive organs. Although the capsule endoscope has conveniences for diagnosis, it is passively moved by the peristaltic waves of gastro-intestinal tract and thus has some limitations for doctor to get the image of the organ and to diagnose more thoroughly. As a solution of these problems, various locomotive mechanisms for capsule endoscopes are introduced. In our proposed mechanism, the capsule-type microrobot has synchronized multiple legs that are actuated by a linear actuator and two mobile cylinders inside of the capsule. For the feasibility test of the proposed microrobot, a series of in-vitro experiments using small intestine without incision were carried out. From the experimental results, our proposed microrobot can advance along the 3D curved and sloped path with the velocity of about 3.29~6.26 ㎜/sec and 35.1~66.7% of theoretical velocity. Finally, the proposed locomotive mechanism can be not only applicable to micro capsule endoscopes but also effective to advance inside of gastro-intestinal tract.

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Editor : Tian Ruizhu
           The Dept. of Internationa Affairs
           Chinese Mechanical Engineering Society