• Title, Summary, Keyword: PIV

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Measurement of Flow Field in a Domestic Hot-Water Pump by PIV (PIV에 의한 가정용 온수펌프의 유동장 계측)

  • Lee, H.;Im, Y. C.;Kim, J. H.;Lee, Y. H.
    • 유체기계공업학회:학술대회논문집
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    • pp.264-271
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    • 1999
  • The present experimental study is aimed to investigate the flow characteristics of the high-speed flow field within hot-water pump by PIV(Particle Image Velocimetry). As multi-point simultaneous velocity acquisition, 2-D PIV system based upon the two-frame gray-level cross correlation method is adopted using PC frame-grabber and simple video system. Gated image intensifier CCD Camera to cope with illumination problem is arranged for accurate PIV measurement of high-speed complex flow. The velocity vector distribution, velocity profile, and kinetic energy are represented quantitatively at the full-scale region for the deeper understanding of the unsteady flow characteristics in a pump.

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Measurement of the Velocity field of Rotor-Stator in a Centrifugal Turbine Pump by Using PIV (PIV를 이용한 터빈펌프의 동${\cdot}$정익 속도장 계측)

  • Im, Yu-Cheong;Seo, Min-Sik;Lee, Young-Ho
    • 유체기계공업학회:학술대회논문집
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    • pp.11-18
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    • 1998
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stator region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Fine optical setup deeply concerned with PIV performance is arranged for accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

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A Study on Flow and Efficiency Characteristics in Guide Vane of Diffuser Pump Using PIV Measurement (PIV 계측을 이용한 디퓨져펌프의 정익에서의 성능과 유동특성에 관한 연구)

  • Kim, J. H.;Choi, M. S.;Kim, J. G.;Lee, Young-Ho
    • 유체기계공업학회:학술대회논문집
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    • pp.29-35
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    • 2000
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to guide vane region within diffuser pump. Various different kinds of rotational velocity were selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. Variable flow pattern are represented quantitatively at the stator region.

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Development of Stereocopic-PIV and its Application to the Measurement of the Near Wake of a Circular Cylinder (Stereocopic-PIV 개발과 원주근접 후류 계측)

  • Doh, D.H.;Kim, D.H.;Cho, G.R.;Lee, W.J.;Pyun, Y.B.
    • Proceedings of the KSME Conference
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    • pp.555-559
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    • 2001
  • A new stereoscopic PIV is developed using two CCD cameras, stereoscopic photogrammetry, and a 3D-PTV principle. The wake of a circular cylinder is measured by the developed stereoscopic PIV technique. The B mode vortical structure of the wake over the Reynolds number 300 is clearly seen by the developed technique. The arrangement of the two cameras is based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors are based on 3D-PTV technique.

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PIV measurements of a microfluidic elements fabricated in a plastic chip (플라스틱 미소유체요소 내부유동의 PIV 측정)

  • Lee, In-Won;Choi, Jay-Ho;Lee, In-Seop
    • Proceedings of the KSME Conference
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    • pp.400-404
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    • 2001
  • A micro-PIV(particle image velocimetry) measurement has been conducted to investigate flow fields in such microfluidic devices as microchannels and micronozzle. The present study employs a state-of-art micro-PIV system which consists of epi-fluorescence microscope, 620nm diameter fluorescent seed particles and an 8-bit megapixel CCD camera. Velocity vector fields with a resolution of $6.7\times6.7{\mu}m$ has been obtained, and the attention has been paid on the effect of varying measurement conditions of particle diameter and particle concentration on the resulting PIV results. In this study, the microfluidic elements were fabricated on plastic chips by means of MEMS processes and a subsequent molding process. Flow fields in a variety of microchannels as well as micronozzle have been investigated.

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Flow Characteristics of Guide Vane of Diffuser Pump by PIV Measurement (PIV계측에 의한 디퓨져펌프 안내깃에서의 유동특성)

  • Kim, J.H.;Choi, J.W.;Kim, M.Y.;Lee, H.;Lee, Young-Ho
    • Proceedings of the KSME Conference
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    • pp.391-396
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    • 2000
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to guide vane region within a diffuser pump. Various different kinds of clearance were selected as experimental conditions. Optimized cross correlation identification to obtain velocity vectors was implemented with direct calculation of correlation coefficients. Fine optical setup important in PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. Various flow patterns are represented quantitatively at the stator passages.

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PIV Measurements of the Pressure Driven Flow Inside a T-Shaped Microchannel (T형 마이크로채널 내부 압력구동 유동의 PIV 계측)

  • Choi Jayho;Lee In-Seop
    • Proceedings of the KSME Conference
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    • pp.423-426
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    • 2002
  • A custom micro-PIV optics assembly has been used to measure the flow field inside a T-shaped microchannel. The micro-PIV system consists of microscope objectives of various magnifications, a dichroic cube, and an 8-bit CCD camera. Fluorescent particles of diameters 620nm have been used with a Nd:YAG laser and color filters. A programmable syringe pump with Teflon tubings were used to inject particle-seeded distilled water into the channel at flow rates of $420,\;40,\;60{\mu}L/hr$. The microchannels are fabricated with PDMS with a silicon mold, then $O_2-ion$ bonded onto a slide glass. Results show differences in flow characteristics and resolution according to fluid injection rates, and magnifications, respectively. The results show PIV results with vector-to-vector distances of $2{\mu}m$ with 32 pixel-square interrogation windows at $50{\%}$ overlap.

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A Study on the Evaluation of Interpolation Methods in PIV (PIV에서의 보간기법의 평가에 관한 연구)

  • 최장운;조대한;최민선;이영호
    • Journal of the Korean Society of Marine Engineering
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    • v.20 no.4
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    • pp.90-100
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    • 1996
  • To maintain high spacial accuracy and rapid CPU time in interpolating data from grid to random position or inversely in PIV, proposed many technuques are compared and discussed mainly in terms of interpolating error and computing time. And artificial PIV atmosphere data is furnished by CFD result. First, for interpolation from grid to random position, multiquadric method gives the highest accuracy with the longest CPU time and Taylor series expansion methods give reasonable accuracy with less calculating load. Secondly, the sub-pixel resolution analysis in estimating the coordinates of the maximum correlation coefficients essential in the grey level correlation PIV reveal that 8-neighbours 2nd-order least square interpolation gives utmost accuracy in terms of the real flow conditions.

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Advanced Flow Visualization Technologies and Blue Ocean Strategy (첨단 유동가시화 기법들과 Blue Ocean 전략)

  • Lee, Sang-Joon
    • 유체기계공업학회:학술대회논문집
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    • pp.145-146
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    • 2006
  • Recently, the next-generation advanced flow visualization techniques such as holographic PIV, dynamic PIV, echo-PIV, micro/nano-PIV, and X-ray PIV have been introduced. These advanced measurement techniques have a big potential as the core technology for analyzing outmost thermo-fluid flows in future. These would be indispensable in solving complicated thermo-fluid flow problems not only in the industrial fields such as automotive, space, electronics, aero- and hydro-dynamics, steel, and information engineering, but also in the research fields of medical science, bio-medical engineering, environmental and energy engineering etc. Especially, NT (Nano Technology) and BT (Bio Technology) strongly demand these advanced measurement techniques, because it is impossible for conventional measurement methods to observe most complicated nano- and bio-fluidic phenomena. In this presentation, the basic principle of these high-tech flow visualization techniques and their practical applications which cannot be resolved by conventional methods, such as blood flows in a micro-tube, in vivo analysis of micro-circulation, and flow around a living body will be introduced as a blue ocean strategy.

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Advanced Flow Visualization Technologies and Blue Ocean Strategy (첨단 유동가시화 기법들과 Blue Ocean 전략)

  • Lee, Sang-Joon
    • Journal of the Korean Society of Visualization
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    • v.4 no.2
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    • pp.3-5
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    • 2006
  • Recently, the next-generation advanced flow visualization techniques such as holographic PIV, aynni.c PIV, echo-PIV, micro/nano-PIV, and X-ray PIV have been introduced. These advanced mea-surement techniques have a big potential as the core technology for analyzing outmost thermo-fluid flows in future. They would be indispensable in solving complicated thermo-fluid flow problems not only in industrial fields such as automotive, space, electronics, aero- and hydro-dynamics. steel, and information engineering, but also in the research fields of medical science, bio-medical engineering, environmental and energy technology etc. Especially, NT (Nano Technology) and BT (Bio Technology) strongly demand these advanced measurement techniques, because it is impossible for conventional measurement methods to observe the nano- and bio-fluidic flow phenomena. In this article, the basic principle of these high-tech flow visualization techniques and their practical applications which cannot be resolved by conventional methods, such as blood flows in a micro-tube, in vivo analysis of micro-circulation, and flow around a living body are introduced as a blue ocean strategy.

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