Development of 3-dimensional PTV with prismatic light sheet

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 13650213
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Thermal engineering
• Research Institution: Tokyo Gakugei University
• Principal Investigator: MOCHIZUKI Takaaki Tokyo Gakugei University, Dept. Technology Education, Associate Professor, 教育学部, 助教授 (70280360)
• Co-Investigator(Kenkyū-buntansha): KAJI Nobufuji Polytechnic University, Dept. Mechanical Engineering, Professor, 産業機械工学科, 教授
• Project Period (FY): 2001 – 2002
• Keywords: 3-dimensional particle tracking / 3-D PIV / 3-D PTV / Prismatic light sheet / 3-dimensional flow visualization / Color image analysis

Research Abstract

When rigid particles pass through a light sheet whose spectrum varies with its thickness, they reflect rays of varying colors. If we observe the particles using a color video camera whose axis is set normal to the light sheet, their motions can be determined from their loci and colors, as observed on a video monitor. Based on this principle, we have developed a novel scheme to determine the 3-dimensional translational motions of rigid particles in a liquid medium using only one color video camera. The rays reflected from particles are related to their loci through color analysis. In this study, we developed two types of illumination system to make the light sheet noted above, and we studied a calibration scheme by which we could obtain a relation between loci of the particles and rays reflected by the particles. Using the calibration curve obtained using the scheme shown in this study, we estimated the loci of particles with a diameter of about 0.1 mm ; the maximum error was 0.51 mm, and the standard deviation of the calibration curve was 0.21 mm when the hue angle was between 0.9 degree and 110 degree. An effect of concentrations of the particles in the liquid medium on the measuring accuracy for determining loci of the particles, and an effect of size distribution of the particles on the accuracy were also studied experimentally. We also studied the way in which loci and rays of the particles recorded in an image by the color video camera were detected through automatic image analysis by a computer.