Measurement of Three Dimensional Velocity Vectors in a Flow Field Based on a SpatioTemporal Correlation Method
Project/Area Number  03650352 
Research Category 
GrantinAid for Scientific Research (C).

Research Field 
計測・制御工学

Research Institution  Kobe University 
Principal Investigator 
KIMURA Ichiro Kobe University, Faculty of Engineering Associate Professor, 工学部, 助教授 (60031134)

CoInvestigator(Kenkyūbuntansha) 
YAMASAKI Yoshiharu Kobe University, Faculty of Engineering, Research Assistant, 工学部, 教務職員 (90174648)
TADOKORO Satoshi Kobe University, Faculty of Engineering Research Associate, 工学部, 助手 (40171730)
TAKAMORI Toshi Kobe University, Faculty of Engineering Professor, 工学部, 教授 (10031098)

Project Fiscal Year 
1991 – 1992

Project Status 
Completed(Fiscal Year 1992)

Budget Amount *help 
¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1992 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1991 : ¥1,100,000 (Direct Cost : ¥1,100,000)

Keywords  Threedimensional velocity vector / Flow visualization / Image processing / Spatiotemporal correlation / 3次元速度ベクトル / 流れの可視化 / 画像処理 / 時空間相関 / 時空間相関法 / 流れ場 / トレサ注入法 
Research Abstract 
A measurement system of 3D velocity vectors is essential in analyzing a highly complex flow field. In this study, a new measurement method of 3D velocity vectors in a flow field using spatiotemporal correlation method was developed. It is an advanced method for 2D velocity vector measurement using correlation. The method needs two travel particle images observed at a short distance in the flow direction. Each of the two images consists of frame time series. The 2D information on a 3D velocity vector can be obtained using spatial correlation. In addition, the temporal correlation gives information on the third dimension. A 3D velocity vector is consequently obtained by calculating the spatiotemporal correlation between the two images. This system was actually applied to a simple 2D flow and a 3D flow with reverse flow to confirm the appropriateness of this technique and its measurement uncertainty was evaluated. In comparison with a conventional stereoscopic measurement method, in which each tracer is tracked in a 3D space, the following advantages were clarified. 1) The method has wide applications to visualized flow images because the images of tracer particles are observed as a spatial pattern. 2) A spatially highdensity vector distribution is obtained in a flow cross section. 3) In principle, the method does not need any known information on the flow characteristics. The disadvantage, however, is that only a velocity vector distribution on a slit plane is obtained. To solve the problem, an improved optical system including slits will have to be devised to obtain many 3D velocity vectors over the entire 3D flow field.

Report
(4results)
Research Output
(8results)