ENGINEERING NEWS IN BRIEF

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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.48
             Issued by the Asian TOP Panel, December 2005

           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 KSME for the year 2005.

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[Contents]

(1) Product Customer Satisfaction Predictive Model Based on LS (Source: CMES)
(2) Computer Integrated Intelligent Monitoring and Controlling System for Grinding Process (Source: CMES)
(3) Development of a Noncatalytic Diesel Engine Emission Cleanup System Using Nonthermal Plasma (Source: JSME)
(4) Stress and Microstructure Analyses during Elasto-plastic Deformation or Thermo-mechanically Controlled Process by in situ Neutron Diffraction (Source: JSME)
(5) Development of an Injection Molded Disposable Chaotic Micromixer: Serpentine Laminating Micromixer (Source: KSME)

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(1) Product Customer Satisfaction Predictive Model Based on LS (Source: CMES)

Hua Ertian Shanghai University
Ye Feifan Ningbo University
Mao Mingjie Zhejiang University of Technology
Gao Jianhua Zhejiang Sci-Tech University

Through analyzing significance of product customer satisfaction and its study status, a kind of product customer satisfaction predictive model was built based on least square algorithm. In order to improve predictive precision of the model, the dynamic model revisable mechanism has been set up by refurbishing the data, so that it offers important basis to enterprises determining when they should reform their products.

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(2) Computer Integrated Intelligent Monitoring and Controlling System for Grinding Process (Source: CMES)

Liu Guijie Ocean University of China
Wang Yuanshan Northeastern University

Computer integrated intelligent monitoring and controlling system for grinding process was built based on neural network. This system integrated monitoring, failure diagnosis and feedback control together, and the online failure diagnosis of grinding burning, chatter and grinding wheel dull states can be realized by collecting the feature values of RMS peak, FFT peak, standard deviation and the accumulation of AE signal amplitude increments. The grinding parameters can be adjusted on ? line through feedback control, thus, the good grinding performance, high grinding efficiency and stable grinding quality can be realized. Test results indicate the validity of this system.

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(3) Development of a Noncatalytic Diesel Engine Emission Cleanup System Using Nonthermal Plasma (Source: JSME)

Masaaki OKUBO, Osaka Prefecture University

A new plasma-assisted noncatalytic diesel particulate and NOx simultaneous reduction aftertreatment system for diesel engines is reviewed. In the conventional catalytic aftertreatment systems, there are some problems on high temperature requirement (more than 300℃) to activate catalyst, urea solution service stations required, ammonia slip at lower temperature condition, emission of ammonium nitrate (NH4NO3) aerosol to atmospheric environment, catalyst degradation by sulfur in light fuel, drain of harmful heavy metal from catalyst and global lack of precious-metals catalysts in future. In order to avoid these problems, a new particulate matter incineration technology using a combination of nonthermal plasma and Diesel Particulate Filter(DPF) was proposed. Furthermore, a new aftertreatment technology of NOx included in exhaust gas of combustion system using nonthermal plasma desorption and reduction is proposed. Our new aftertreatment system includes these new two technologies. It is shown that the DPF continuous regeneration is possible for a real diesel engine exhaust at the low temperature of 240℃. The energy efficiencies are 0.9 Wh/m3 and 17 g/kWh for the DPF regeneration, and 22 Wh/m3 and 12 g?NO/kWh for NOx reduction. Great efforts have been made to meet the year 2009 post new long-term national regulation.

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(4) Stress and Microstructure Analyses during Elasto-plastic Deformation or Thermo-mechanically Controlled Process by in situ Neutron Diffraction (Source : JSME)

You TOMOTA, Graduate School of Science and Engineering, IBARAKI UNIVERSITY

In situ neutron diffraction is becoming a powerful tool to analyze the elasto-plastic deformation behavior and/or microstructural evolution during thermo-mechanically controlled process (TMCP) for engineering materials. Bulky information as well as distribution of stress and microstructural parameters can be measured. Two examples are shown; one is changes in diffraction profile during a TMCP simulation for a steel, which reveals the austenite to ferrite transformation kinetics and changes in the related micro-scaled parameters; the other is tensile deformation behavior of three pearlite steels, where strengthened mechanisms for patented, swaged-annealed and heavily drawn specimens are demonstrated. Main results include, (1) the stress partitioning between constituents contributes to the work-hardening, (2) the yield strength is controlled by ferrite strength through lamellar spacing and (3) nano-sized ferrite shows ultra-high strength exhibiting the non-linear elastic behavior. Stronger neutron beam, which will be available in near future, is expected to promote the advantages of this technique drastically.

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(5) Development of an Injection Molded Disposable Chaotic Micromixer: Serpentine Laminating Micromixer (Source : KSME)

The flow in a microchannel is usually characterized as a low Reynolds number (Re) so that good mixing is quite difficult to be achieved. Prof. Tai Hun Kwon of Postech developed a novel chaotic micromixer, named Serpentine Laminating Micromixer (SLM) (Transactions of KSME, B, vol. 29). In the SLM, the higher level of chaotic mixing can be achieved by combining two general chaotic mixing mechanisms: splitting/recombination and chaotic advection. The splitting and recombination (in other term, lamination) mechanism is obtained by the successive arrangement of “F”-shape mixing units in two layers. The chaotic advection is induced by the overall three-dimensional serpentine path of the microchannel. Chaotic mixing performance of the SLM was fully characterized numerically. To compare the mixing performance, a T-type micromixer which has the same width, height and length of the SLM was also tested. The three-dimensional numerical mixing simulations show the superiority of the SLM over the T-type micromixer. From the cross-sectional simulation results of mixing patterns, the chaotic advection effect from the serpentine channel path design acts favorably to realize the ideal lamination of fluid flow as Re increases. Chaotic mixing mechanism proposed is expected to be easily integrated in Micro-Total-Analysis-System, Lab-on-a-Chip and so on.

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Editor : Professor Mansoo Choi of Seoul National University,
           Director of General Affairs, KSME
           ksme@ksme.or.kr