• Title/Summary/Keyword: 입자영상유속계

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입자영상유속계(PIV) 시스템 표준화사업

  • 도덕희
    • 한국가시화정보학회:학술대회논문집
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    • pp.65-69
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    • 2004
  • 한국표준협회의 민간단체표준화 사업의 일환으로 우리 학회회원인 도덕희 교수(연구책임자, 한국해양대)가 "입자영상유속계 시스템의 표준화 사업"을 수행하고 있다. 이 사업은 현재 본 학회가 한국표준협회를 통한 "가시화시스템 기술 포럼"의 개최 추진에 연계가 되는 것이라서 의의가 크다고 볼 수 있다. 따라서, 본 보에서 이를 소개함으로써 차기에 추진되어야 할 가시화시스템 기술 포럼개최를 위한 주변여건을 형성하고자 한다.

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4D-PTV(Dynamic 3D-PTV) Measurement on an Impinged Jet (4차원 입자영상유속계(다이나믹 3차원 입자영상유속계)에 의한 충돌분류측정)

  • Doh, Deog-Hee;Hwang, Tae-Gyu;Cho, Yong-Beom;Pyeon, Yong-Beom;Koji, Okamoto
    • Proceedings of the KSME Conference
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    • pp.1767-1771
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    • 2004
  • A 4D-PTV system was constructed. The measurement system consists of three high-speed high-definition cameras, Nd-Yag laser(10mJ, 2000fps) and a host computer. The GA-3D-PTV algorithm was used to extract three-dimensional velocity vectors in the measurement volume. A horizontal impinged jet flow was measured with the constructed system. The Reynolds number is about 40,000. Spatial temporal evolution of the jet flow was examined in detail and physical properties such as spatial distributions of vorticity and turbulent kinetic energy were obtained with the constructed system.

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원형실린더의 벽면효과에 관한 연구

  • Bae, Bong-Gap;O, U-Jun;Choe, Min-Seon;Jo, Dae-Hwan;Lee, -GyeongU
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.134-135
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    • 2009
  • 선박에서 주로 채택되는 열교환기는 쉘튜브형과 판형열교환기로 분류된다. 이 연구에서는 소형쉘튜브형 열교환기의 설계에서 중요한 요소인 냉각튜브와 벽면과의 간격에 따른 유동특성을 입자영상유속계를 이용하여 계측하였다. 연구 결과 벽면과의 거리변화에 따른 임계간격비는 0.25전후로 추정되었으며 벽면효과에 따른 정량적 데이터를 확보하였다.

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Development of Algorithm for Stereoscopic PIV using Normalized Cross-correlation (정규상호상관도를 이용한 입체 입자영상유속계 알고리즘 개발)

  • Oh, Jung-Keun;Kim, Yoo-Chul;Ryu, Min-Cheol;Koh, Won-Kyou;Suh, Jung-Chun
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.6
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    • pp.579-589
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    • 2007
  • Contrary to the conventional single-point measuring devices such as LDV, pitot-tube, hot-wire, etc., it would be possible to measure instantaneously 3-D flow fields with a stereoscopic PIV system. In this paper, we present an analysis algorithm for a stereoscopic PIV system using the normalized cross-correlation (NCC) and a 3-D calibration based reconstruction method. The evaluation method based on NCC is one of the most accurate correlation-based methods. We validated the developed algorithm through a benchmarking comparison with 3-D artificial SPIV images and calibration target images.

On the Measurement Technique of Void Fraction by Single Camera Two Phase PIV (단일 카메라 입자영상유속계를 이용한 이상유동 기포율 측정방법)

  • Choi, Dong-Whan;Sung, Jae-Yong;Yoo, Jung-Yul
    • Proceedings of the KSME Conference
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    • pp.1558-1563
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    • 2004
  • A measurement technique for the void fraction and the bubble dynamics in gas-liquid two-phase flows has been proposed using a time-resolved two-phase PIV system. For the three-dimensional evaluation of the bubble information, both the images from the front and side views are simultaneously recorded into a high speed CCD camera by reflecting the side image into the front view with the help of a $45^{\circ}$ oriented mirror. Then, a stereo-matching technique is applied to calculate the void fraction, bubble size and shape. To obtain the rising bubble velocities, the 2-frame PTV method was applied. Consequently, the present technique shows good feasibility for the measurements of the volume fractions, mean diameters, aspect ratios and velocities of the bubbles at the three-dimensional point of view.

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Flow Visualization around the Endothelial Cell Model by the PIV System (입자영상유속계를 이용한 혈관내피세포 모형 주위의 유동가시화)

  • Roh, Hyung-Woon;Suh, Sang-Ho;Yoo, Sang-Sin
    • Proceedings of the KSME Conference
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    • pp.381-384
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    • 2000
  • Relationships between biochemical phenomena and hemodynamics on human endothelial cells are very important to study the mechanism of atherosclerotic formation and development. The objective of this study is to investigate the flow phenomena around the endothelial cell model by the PIV experiment. The microscopic images of endothelial cells were acquired by a CCD camera to fabricate the shape of endothelial cell. The cell models were fabricated by using a photoforming process. Two consecutive particle images were captured by the CCD camera for the image processing. Conifer powder as the tracing particles was added to water to visualize the flow field. The cross-correlation method was applied fer the image processing of the flow visualization. Pressure and wall shear stress variations on the surfaces of the endothelial cells were calculated to investigate the effects of hemodynamic forces on the morphological changes.

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High-Resoultion Stereoscopic PTV (고해상 스테레오PTV)

  • Doh D. H.;Lee W. J.;Cho Y. B.;Pyeon Y. B.;Jang S. W.
    • Proceedings of the KSME Conference
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    • pp.511-512
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    • 2002
  • A new stereoscopic PTV was developed using two CCD cameras, stereoscopic photogrammetry based on a 3D-PTV principle. The arrangement of the two cameras was based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors were based on Genetic Algorithm based 3D-PTV technique. The constructed Stereoscopic W technique was tested on the standard images of the impinged jet proposed by VSJ. The results on the turbulent properties of the jet obtained by the constructed system showed a good agreement with the original LES data.

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Measurement of Turbulent Properties of a Circular Cylinder with a New Stereoscopic PIV (스테레오PIV에 의한 원주후류 난류통계량 계측)

  • Doh D. H.;Lee W. J.;Cho Y. B.;Pyeon Y. B.;Ha S. U.
    • Proceedings of the KSME Conference
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    • pp.471-474
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    • 2002
  • A new stereoscopic PIV has been constructed using two CCD cameras, stereoscopic photogrammetry, and 3D-PTV principle. The capability of the developed stereoscopic PIV was verified through a test on the Standard Images which are provided on the website of VSJ. The arrangement of the two cameras was based on angular position For the acquisition of 3D velocity vectors, 2D velocity vectors were obtained using the gray-level cross-correlation method from the two camera images and they were matched stereoscopically. The wake of a circular cylinder was measured and turbulent properties were presented.

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