Shin-ichi SATAKE^*, Tomoaki KUNUGI¹, Kazuho SATO², Tomoyoshi ITO^3,4 and Jun TANIGUCHI

Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
¹Department of Nuclear Engineering, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501, Japan
²Toyota Industries Corp., 2-1 Toyoda cyou, Kariya, Aichi 448-8671, Japan
³Japan Science and Technology Agency (JST)
⁴Department of Electronics and Mechanical Engineering, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522, Japan

(Received June 13, 2005; Accepted August 4, 2005)

A micro digital-holographic particle-tracking velocimetry (micro-DHPTV) method for high time-resolution flow field measurement in a micro-channel is developed. The system consists of an objective lens, a high-speed camera and a single high-frequency double pulsed laser. Particle positions in a three-dimensional field can be reconstructed by a computer-generated hologram. The time evolution of a three-dimensional water flow in a semicircular micro-channel of 100-μm width and 40-μm depth is obtained successfully using this micro-DHPTV system. The three-dimensional measurement volume of the system is 410 × 100 × 40 μm³ and is irradiated by one laser beam with the time resolution of 100 μs and a reputation rate of 1 kHz. Consequently, 130 velocity vectors in the semicircular micro-channel can be obtained instantaneously. A significant aspect of this method is that even though both the laser and camera are located in line and perpendicular to the flow direction, velocity vectors can be obtained by reconstructing the particle positions via the computer hologram and the semicircular cross section shape of the micro-channel can be resolved.

Key words: holography, computational optics, optical, computer hologram, micro-channel, particle tracking velocimetry

^*E-mail address: satake@te.noda.tus.ac.jp