======================================================================

                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.87
             Issued by the Asian TOP Panel, March 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) New Major Player in Bio-diesel Fuel Production : Microalgae (Source: JSME)
2)  Development of 5-axis Vertical Machining Center (Source: JSME)
3)  Development of a Multiscale Simulation Technique (Source: JSME)
4)  Continuous Monitoring System of Derailment Coefficient with Passenger
     Service Vehicles (Source: JSME)

5)  FWS Application for Rolling Stock Body Shell (Source: JSME)
6)  Development of Crashworthy Structures for European Railway Vehicles
     (Source: CMES)

7)  Hybrid Experimental/Numerical Technique for Determination of the Complex      Dynamic Moduli of Elastic Porous Materials (Source: KSME)
8)  Solid-Liquid Mixture Flow through a Slim Hole Annulus with Rotating Inner
     Cylinder
(Source: KSME)
9)  Influence of Steam Injection through Exhaust Heat Recovery on the Design      Performance of Solid Oxide Fuel Cell ? Gas Turbine Hybrid Systems
     (Source: KSME)

10) An Image Navigation Way for Assistant Laparoscope Surgical Robot to Locate       Puncture (Source: CMES)
11) Unsteady Turbulent Simulation and Pressure Fluctuation Analysis for
      Centrifugal Pumps
(Source: CMES)
12) Optimal Design and Dynamic Simulation of Mountain Bike with Rear Suspension       (Source: CMES)


========================================================================

1) New Major Player in Bio-diesel Fuel Production : Microalgae

  Norihide Kurano, Denso Corporation

 Conventional biofuel production processes are now targets for criticism, because increasing consumption of biofuel has pushed up the prices of corn and soybean, which act as feed stocks for both biofuel and food/feed. Microalgae, microscopic aquatic plants, have become to be known as oil accumulators. Many venture companies have their eye on microalgae as potential suppliers of bio-diesel fuel. It is because 1) microalgae production does not compete with food/feed production, 2) productivity of microalgae is much greater than that of terrestrial plants, 3) microalgae can be grown even on land unsuitable for plant cultivation, and 4) microalgae can efficiently absorb carbon dioxide.
 Professor Watanabe, Tsukuba University, vigorously studies on the hydrocarbon production by a green alga. Additionally, is a recently identified hydrocarbon producer.
 Now the ability of microalgae to produce bio-diesel is known to a wide public, however there is still much work remaining to make R&D of microalgae cost competitive with fossil fuels.
______________________________________________________________________________________________________________________________

2) Development of 5-axis Vertical Machining Center

     Shinji Koike, Makino Milling Machine Co., Ltd.

 This paper describes the new 5-axis vertical machining center gD500.h Accuracy and process time on 5-axis machining interest for customers. But conventional 5-axis machines were not so precision and not so high speed for them. In order to solve these difficulties, gD500h have a unique machine structure and@high performance, especially the rotating axes is one of the main technologies. The concept is that the balance of moving performance between linear axis and rotating axis is important.

______________________________________________________________________________________________________________________________

3) Development of a Multiscale Simulation Technique

     Yasutaka Okura, Hitachi, Ltd.

 In recent years, devices made up of thin films with nanometer order thickness, such as hard disk drives or semiconductor devices, are equipped with mobile devices. This requires the high drop impact reliability of the thin film devices. The thin film device has multi-layer structure and each layer has some candidate materials. Therefore too many combinations must be considered and the selection of materials only by experiment needs a long term. This is why it is important to select material combinations that form strong interfaces by using a simulation in a short time and to shorten the development period.
 From this background, a multiscale simulation technique is developed to evaluate the deformation and stress distribution in devices with the multi-layer thin film structure. In this technique, material constants, such as Youngfs modulus or Poissonfs ratio, of thin films with nanometer order thickness are calculated by using molecular dynamics and then by using the calculated material constants, the deformation and stress distribution of a thin film device is calculated by finite element method.

_____________________________________________________________________________________________________________________________

4) Continuous Monitoring System of Derailment Coefficient with Passenger     Service Vehicles

    Hiroyuki Ohno, National Traffic Safety and Environment Laboratory

 In railway system, the contact characteristic values between rail and wheel have great influences on the railway vehiclefs performances. It is very important to understand those values, but it is very difficult to obtain those values accurately in practice.
 A new measuring method introduced can measure derailment coefficient between wheel and rail without special wheelsets with slip rings or telemeters. In this method the lateral contact force is obtained from the lateral distortion of wheel measured directly by several non-contact gap sensors. The measured values are small, but accurate value of lateral force can be calculated by the compensation of axial movement and inclination of wheelset. Normal contact forces are also measured from the distortion of primary springs without strain gauges. Now we are building a new bogie with this system for practical use, and carried out the practical running test on commercial lines.
 By using non-contact gap sensors and proper compensation we successfully obtained the measurement of contact forces and derailment coefficient without special PQ wheelsets. This new method can realize the continuous monitoring of the derailment coefficient and friction coefficient between wheel and rail from on-board of passenger service vehicles.

_____________________________________________________________________________________________________________________________

5) FWS Application for Rolling Stock Body Shell

     Takenori Wajima, Hitachi, Ltd.

 Recently aluminum extrusion technique has extensively developed and now large size hollow extrusion bar can be manufactured. Especially for rolling stocks, the use of the integral hollow extruded aluminum bar in large size, permits us to reduce the number of construction parts for manufacturing the car body shell.
 For welding hollow extruded aluminum bar, in the past, we used to use MIG welding. Since 1990's, FSW(Friction Stir Welding) technology has been developed and applied to aluminum body shells of rolling stocks.
 FSW exhibits excellent merit in quality control compared to arc welding. MIG arc welding must be controlled under the conditions of mechanical, chemical, electrical, thermal, atmospheric, and a matter of human skill; thus giving rise to a number of difficulties. In contrast in FSW process, we can only focus the mechanical and thermal conditions. These control factors are easy to regulate, and properly be incorporated into automatic control.
 The total number of cars to which FSW has been applied is up to 2000.

______________________________________________________________________________________________________________________________

6) Development of Crashworthy Structures for European Railway Vehicles

     Takeshi Yamaguchi, Takeshi Kawasaki, Toshihiko Mochida,
     Hitachi, Ltd.

 Hitachi, Ltd. received an order for a high-speed train for operation between London and the Channel Tunnel, which crosses the Strait of Dover. The train must satisfy UK and European standards, which are significantly different from those in Japan, especially, crashworthiness. We describe crashworthy structure we developed, which meets UK and European standards.


7) Hybrid Experimental/Numerical Technique for Determination of the     Complex Dynamic Moduli of Elastic Porous Materials

    Amir Hamza, Yeon June Kang
     Institute of Advanced Machinery and Design, School of Mechanical and     Aerospace Engineering, Seoul National University

Abstract : Polyurethane (PU) and other plastic foams are widely used as passive acoustic absorbers. For optimal design, it is often necessary to know the viscoelastic properties of these materials in the frequency range relevant to their application. An experimental/numerical technique has been implemented to determine the Young and shear dynamic moduli and loss factor of poroelastic materials under low-frequency 40-520Hz random excitation. The method consists of measuring the dynamic response of the sample at its surface, and matching the response with the predictions from a finite element model in which the two complex elastic moduli are the adjustable parameters. Results are presented for measurements made in air, under standard pressure and temperature conditions, and compared with predictions based on Okunofs model. The dependence of elastic moduli on the dimension of the sample and its boundary conditions is also studied.
Keyword : Youngfs modulus; Shear modulus; Loss factor; Finite element method (The Journal of Mechanical Science and Technology, vol. 23, no. 2, pp.283-290, 2009)

______________________________________________________________________________________________________________________________

8) Solid-Liquid Mixture Flow through a Slim Hole Annulus with Rotating Inner     Cylinder

    Sang-mok Han, Nam-sub Woo, and Young-kyu Hwang
     School of Mechanical Engineering, Sungkyunkwan University

Abstract : 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.

Keyword : Solid-liquid mixture flow; Slim hole annulus; Particle concentration; Pressure drop (The Journal of Mechanical Science and Technology, vol. 23, no. 2, pp.569-577, 2009)

_____________________________________________________________________________________________________________________________

9) Influence of Steam Injection through Exhaust Heat Recovery on the     Design Performance of Solid Oxide Fuel Cell -Gas Turbine Hybrid     Systems


    Sung Ku Park1, Tong Seop Kim1*, and Jeong L..Sohn2
    1.Department of Mechanical Engineering, Inha University
    2. School of Mechanical and Aerospace Engineering, Seoul National       University

Abstract : This study analyzed the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. Two different configurations (pressurized system and ambient pressure system) were examined and the effects of injecting steam, generated by recovering heat from the exhaust gas, on system performances were compared. Performance variations according to the design of different turbine inlet temperatures were examined. Two representative gas turbine pressure ratios were used. Without steam injection, the pressurized system generally exhibits higher system efficiency than the ambient pressure system. The steam injection augments gas turbine power, thus increasing the power capacity of the hybrid system. The power boost effect due to the steam injection is generally greater in the relatively higher pressure ratio design in both the pressurized and ambient pressure systems. The effect of the steam injection on system efficiency varies depending on system configurations and design conditions. The pressurized system hardly takes advantage of the steam injection in terms of system efficiency. On the other hand, the steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. In particular, a higher pressure ratio provides a better chance of efficiency increase due to the steam injection.
Keyword : Solid oxide fuel cell; Gas turbine; Hybrid; Pressurized system; Ambient pressure system; Steam injection
(The Journal of Mechanical Science and Technology, vol. 23, no. 2, pp.550-558, 2009)

_____________________________________________________________________________________________________________________________

10) An Image Navigation Way for Assistant Laparoscope Surgical Robot to       Locate Puncture

Zhang Lixun, Dong Jiuzhi, Zou Ge, Zhao Guowen , Yu Lingtao
       Harbin Engineering University
       Panyu Peoplefs Hospital

 On the basis of characteristics of laparoscopic robot with active and passive joints, a method based on geometric model and image to locate the relative position of patientfs puncture to the robot was provided. The method offered the laparoscope posture information for the robot to control laparoscope posture precisely. The location system included two lasers and one micro CCD camera. Experimental results indicate that the method can get the puncture location precisely. The process of puncture location is completed by the robot automatically. It can save surgical time, improve efficiency and avoid the errors caused by the doctors.
Key words: assistant laparoscope surgical robot; puncture location; posture location model; image navigation

______________________________________________________________________________________________________________________________

11) Unsteady Turbulent Simulation and Pressure Fluctuation Analysis for      Centrifugal Pumps

     Yuan Shouqi, Ni Yongyan, Pan Zhongyong , Yuan Jianping
      Jiangsu University

 The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition. The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and the three dimensional unsteady turbulent simulation concerning the rotor-stator interaction is executed by a Navier-Stoke solver embedded with k-e turbulence model and with appropriate moving interface boundary conditions. Detecting points are distributed in the flow passage in different radial and circumferential positions to capture the static pressure fluctuation character for one cycle of the impeller. The time-domain spectrums show that the static pressure curves are periodic and have five peaks and five valleys. With the radius increasing, the pressure fluctuation peak-to-peak values in the impeller are increasing, and reach the maximum value on the interface. In the casing flow passage, those values are about 7% of local static pressure except some ones near the tongue. The values become decreasingly in the diffuser pipe. The frequency spectrum transformed by fast Fourier transform (FFT) show that the dominant frequency is approximate with the blade passing frequency, and the pressure fluctuations in impeller passage have high frequency content while those in casing ones have no such information.
Key words: centrifugal pump; rotor-stator interaction; unsteady turbulent flow; pressure fluctuation

_____________________________________________________________________________________________________________________________

12) Optimal Design and Dynamic Simulation of Mountain Bike with Rear      Suspension

      Bu Yan, Xiang Zhongxia, Huang Tian, Zhang Xu, Wang Xinghua
      Tian Jin University

 This research investigates the dynamic design methodology of mountain bikes with rear suspension. Firstly, a multi-rigid body dynamic model of rider and mountain bike coupled system is constructed. The rider model includes 19 skeletons, 18 joints and 118 main muscles. Secondly, to validate the feasibility of the model, an experiment test is designed to reflect the real cycling status. Finally, aiming at enhancing the performance of the rider vibration comfort, the scale parameters of rear suspension are optimized with computer simulation and uniform design. The mathematical model in the vibration performance and the design variables is constructed with regression analysis. The result shows that when the length of side link is 90 mm, the length of connected rod is 336.115 mm and the included angle between absorber and side link is 60, the mountain bike has better vibration comfort. This study and relevant conclusions are of practical importance to the design of the mountain bikefs rear suspension system.
Key words: mountain bike; model building; dynamic simulation; experiment test; vibrant comfort; optical design

_____________________________________________________________________________________________________________________________

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) 2008, The Japan Society of Mechanical Engineers.