KOUDA Akihiro Tokyo University of Agriculture and Technology, Faculty of Technology, Associate Professor, 工学部, 助教授 (60015039)
SANO Osamu Tokyo University of Agriculture and Technology, Faculty of Technology, Professor, 工学部, 教授 (80126292)
|Budget Amount *help
¥5,700,000 (Direct Cost : ¥5,700,000)
Fiscal Year 2000 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1999 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1998 : ¥3,200,000 (Direct Cost : ¥3,200,000)
A new method is proposed to measure 3D positions of all solid particles dispersed randomly in a liquid. It is usually difficult to visualize internal constructions of 3D particle dispersion systems, because the inner particles are masked by outer ones. In the new method, both particles and liquid are transparent, and laser dye is dissolved in the liquid. The whole system is illuminated by a laser sheet. Moreover, the liquid refractive index is adjusted to be equal to that of solid particles, so that the cross-sectional image by the laser sheet is visible without distortion.
By a preliminary experiment, the combination of particles of acrylic resin and the mixture of two kinds of silicon oil is was shown to give the best result, and an optimum value of liquid temperature was obtained for equal refractive indexes.
Then, a static particle system, where spherical particles of acrylic resin with a uniform diameter were packed in 3D space randomly, was visualized by a mirror and an automati
c linear stage, which shifts the laser sheet perpendicular to itself, and images of several cross sections of the dispersion system were recorded by Video camera. From these images, centers and radii of the particle cross sections were obtained by image processing software, and the 3D particle centers were calculated by a computer program. The result was reconstructed by the use of a conventional software. The result revealed that 3D positions of 400 particles were obtained with a high accuracy.
This method was applied to a system of the same spherical particles, which was fluidized by applying a flow of the silicon oil from below. However, it was not possible to make a precise measurement with the present experimental apparatus, because the particles changed their positions within the shutter time and the interval of the shift of laser light. The result gave positions of about 80 % of particles (probably, with less accuracy). This shortcoming will be overcome by the use of a stronger laser light, a faster shift of the laser sheet and a Video camera with a higher shutter speed. Less