• 제목/요약/키워드: Micro-mixing

검색결과 260건 처리시간 0.03초

마이크로 믹서의 형상 최적화 (Shape Optimization of a Micro-Static Mixer)

  • 한석영;김성훈
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.166-171
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    • 2004
  • In this study, shape optimization of micro-static mixer with a cantilever beam was accomplished for mixing the mixing efficiency by using successive response surface approximations. Variables were chosen as the length of cantilever beam and the angle between horizontal and the cantilever beam. Sequential approximate optimization method was used to deal with both highly nonlinear and non-smooth characteristics of flow field in a micro-static mixer. Shape optimization problem of a micro-static mixer can be divided into a series of simple subproblems. Approximation to solve the subproblems was performed by response surface approximation, which does not require the sensitivity analysis. To verify the reliability of approximated objective function and the accuracy of it, ANOVA analysis and variables selection method were implemented, respectively. It was verified that successive response surface approximation worked very well and the mixing efficiency was improved very much comparing with the initial shape of a micro-static mixer.

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능동형 미소혼합기의 근사최적화 (Approximate Optimization of an Active Micro-Mixer)

  • 박재용;김상락;유진식;임민규;김용대;한석영;맹주성
    • 한국공작기계학회논문집
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    • 제17권5호
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    • pp.95-100
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    • 2008
  • An active micro-mixer, which is composed of an oscillating micro-stirrer in the micro-channel to provide effective mixing was optimized. The effects of molecular diffusion and disturbance by the stirrer were considered with regard to two types of mixer models: the simple straight micro-channel and micro-channel with an oscillating stirrer. Two types of mixer models were studied by analyzing mixing behaviors such as their interaction after the stirrer. The mixing was calculated by Lattice Boltzmann methods using the D2Q9 model. In this study, the time-averaged mixing index formula was used to estimate the mixing performance of time-dependent flow. The mixing indices of the two models were compared. From the results, it was found that the mixer with an oscillating stirrer was much more enhanced and stabilized. Therefore, an approximate optimization of an active micro-mixer with an oscillating stirrer was performed using Kriging method with OLHD(Optimal Latin Hypercube Design) in order to determine the optimal design variables. The design parameters were established as the frequency, the length and the angle of the stirrer. The optimal values were obtained as 1.0346, 0.66D and $\pm45^{\circ}$, respectively. It was found that the mixing index of the optimal design increased by 88.72% compared with that of the original design.

마이크로 광 조형기술을 이용한 3차원의 배리어가 포함된 케닉스 마이크로 믹서의 개발 (Development of a Three-Dimensional Barrier Embedded Kenics Micromixer by Means of a Micro-Stereolithography Technology)

  • 이인환;권태헌;조동우;김동성
    • 대한기계학회논문집A
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    • 제29권6호
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    • pp.904-912
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    • 2005
  • The flow in a microchannel is usually characterized as a low Reynolds number (Re) so that good mixing is quite difficult to be achieved. In this regard, we developed a novel chaotic micromixer, named Barrier Embedded Kenics Micromixer (BEKM). In the BEKM, the higher level of chaotic mixing can be achieved by combining two general chaotic mixing mechanisms: (i) splitting/reorientation by helical elements inside the microchannel and (ii) stretching/folding via periodically located barriers on the channel wall. The fully three-dimensional geometry of BEKM was realized by a micro-stereolithography technology, in this study, along with a Kenics micromixer and a circular T-pipe. Mixing performances of three micromixers were experimentally characterized in terms of an average mixing color intensity of phenolphthalein. Experimental results show that BEKM has better mixing performance than other two micromixers. Chaotic mixing mechanism, proposed in this study, could be integrated as a mixing component with Micro-Total-Analysis-System, Lab-on-a-chip and so on.

미소 T 채널의 혼합 특성에 관한 연구 (Study on mixing characteristics of T-type micro channel)

  • 이상현;안철오;서인수;이상환
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2495-2500
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    • 2008
  • We simulated the mixing characteristics in micro T-channel using Lattice Boltzmann Method. We studied the relation a mixing length and pressure-drop due to inlet and outlet ration in Reynolds number 0.5, Peclet number 500 and Schmidt 1000. The ratio of a down-inlet to up-inlet was $0.5{\sim}1.5$ times, up-inlet to outlet was $1{\sim}3$ times and outlet length was 250 times to up-inlet. The mixing length decrease linearly as outlet ratio decreased, and pressure-drip increase non-linearly. Initial stage of micro channel mixture was fast by down-inlet ratio, however, the mixing length is not influence.

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마이크로 채널에서의 열혼합 특성 (Thermal Mixing in a Microchannel)

  • 박경배;안준;김병조;이준식
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.585-588
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    • 2008
  • Thermal mixing phenomena in a Y-type microchannel were investigated using a micro-PIV. Two inlet reservoirs of the microchannel were controlled individually so that the characteristics of thermal mixing in the channel with temperature difference were compared with those without the difference. The velocity field in the mixing process was measured using the micro-PIV system that includes an ICCD (Intensified CCD) camera. The mixing area and uniformity were also analyzed. It is observed that the flow fluctuation in spanwise direction is induced by temperature difference, which enhances mixing process in microchannels.

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마이크로 혼합기 내의 유동 계측 및 혼합 특성 해석 (Analysis of Mining Performance and Flow Measurement Inside a Micro Mixer)

  • 성재용;이인원;김병균;윤의식;이인섭
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2002년도 추계학술대회 논문집
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    • pp.45-48
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    • 2002
  • To investigate the flow related to the mixing, micro PIV measurements were performed in the middle plane of the channel. A passive micro mixer analyzed in this work has been designed in the shape of a three-dimensional microchannel and fabricated with PDMS molding process by KAIST. The mixing performance was evaluated for different flow rates using phenolphthalein and sodium hydroxide solutions. Results show that mixing is enhanced by the increase of flow rate, which yields stronger secondary flows with helical streamlines.

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Filler Nano/Micro 혼합비가 Epoxy 수지의 유전특성에 미치는 영향

  • 정인범;최현민;신종열;이종용;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.249-249
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    • 2009
  • we have studied that a effect depending on dielectric properties of epoxy resin mixing filler nano/micro. When compare with nano/micro composite and virgin, the nano/micro composite is better than virgin. A specimen mixing nano/micro is changed as temperate, however the width of change is low.

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혼합 효율 향상을 위한 마이크로 동적 믹서의 형상최적화 (Shape Optimization of an Active Micro-Mixer for Improving Mixing Efficiency)

  • 박재용;김상락;이원구;유진식;김용대;맹주성;한석영
    • 한국공작기계학회논문집
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    • 제16권6호
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    • pp.146-152
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    • 2007
  • An active micro-mixer, which was composed of an oscillating micro-stirrer in the microchannel to provide rapid, effective mixing at high flow, rates was analyzed. The effects of molecular diffusion and disturbance by the stirrer were considered with regard to two types of mixer models: the simple straight microchannel and microchannel with an oscillating stirrer. Two types of mixer models were studied by analyzing mixing behaviors such as their interaction after the stirrer. The mixing was calculated by Lattice Boltzmann methods using the D2Q9 model. In this study, the time-averaged mixing index formula was used to estimate the mixing performance of time-dependent flow. The mixing indices of the two models compared. From the results, it was found that the mixer with an oscillating stirrer was much more enhanced and stabilized. Therefore, an optimum design for a dynamic micro-mixer with an oscillating stirrer was performed using Taguchi method in order to obtain a robust solution. The design parameters were established as the frequency, the length and the angle of the stirrer and the optimal values were determined to be 2, 0.8D and ${\pm}75^{\circ}$, respectively. It was found that the mixing index of the optimal design increased 80.72% compared with that of the original design.

마이크로 PIM용 Fe 마이크로-나노 복합분말 피드스톡 제조시 혼합거동과 미세구조 변화 (Mixing Behavior and Microstructural Development During Fabrication of Fe Micro-nano-powder Feedstock for Micro-PIM)

  • 유우경;이재성;고세현;이원식
    • 대한금속재료학회지
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    • 제48권7호
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    • pp.630-638
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    • 2010
  • The present investigation has been performed on the mixing behavior and microstructural development during fabrication of Fe micro-nano powder feedstock for a micro-powder injection molding process. The mixing experiment using a screw type blender system was conducted to measure the variations of torque and temperature during mixing of Fe powder-binder feedstock with progressive powder loading for various nano-powder compositions up to 25%. It was found that the torque and the temperature required in the mixing of feedstock increased proportionally with increasing cumulative powder loading. Such an increment was larger in the feedstock containing higher content of nano-powder at the same powder loading condition. However, the maximum value was obtained at the nano-powder composition of not 25% but 10%. It was owing to the 'roller bearing effect' of agglomerate type nano-powder acting as lubricant during mixing, consequently leading to the rearrangement of micro-nano powder in the feedstock. It is concluded that the improvement of packing density by rearrangement of nano-powders into interstices of micro-powders is responsible for the maximum powder loading of about 71 vol.% in the nano-powder composition of 25%.