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jjll'z:nJGJj):;k~I~f-.1-~if~JiJT 93Journal ofNational Cheng-Kung University, Vol.32 Sci.Eng. & Med. Section pp. 93-114(1997)
Two - Dimensional Digital Particle Tracking Velocimetry
(DPTV): An Investigation of Auto-Processing
Chen Tu Shen
Center for Measurement Standard Shaw Heiu Jou
National Cheng-Kung University Department of Naval Architecture and Marine Engineering
Huang Ming Jer
National Cheng-Kung University Department of Engineering Science
Abstract
Digital Particle Tracking Velocimetry (DPTV) is a full-field two dimensional, noninvasive, quantitative flow visualization techniques. The technique described here includes the novel use of direct digitization of particle images using a 512
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512 pixel's resolution imaging system.And
this image data can be analyzed directly or stored for further analysis by new image processing and analysis software developed for flow experiments.In this technique, one image of four color-streaks with embedded time-mark which combined tens or hundred of frames in real time are recorded. This image of four color-streaks needs only one frame memory to store in computer memory. The analysis software uses thinning algorithm to process and connectivity to recognize the four color-streaks. So it is better than Digital Particle Image Velocimetry (DPIV) which needs many computer memories to store particle images and complex processing procedure, and also better than Pulsed Laser Velocimetry (PL V) which needs complex recording and reconstruction system.
After developing the software of the auto-processing velocimetry, two cases are used to test its availability in this thesis. The experiment in a vertical channel has been verified. The availability of the velocimetry developed in this paper can be proved.
Keywords: Particle Tracking, Auto-Processing Velocimetry, Two Dimensional Flow Field
