Yoshio ZAMA, Masaaki KAWAHASHI¹ and Hiroyuki HIRAHARA¹

Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
¹Department of Mechanical Engineering, Saitama University, 255 Sihimo-okubo, Sakura-ku, Saitama 338-8570, Japan

(Received March 9, 2004; Accepted September 15, 2004)

The combination of the optical diagnostics and image processing technique has produced various methods of practical measurement in engineering. The measurement of size and velocity of droplets in fuel spray is one typical example. In general, the spray is a complicated and three-dimensional two-phase flow; therefore multi-dimensional field measurement of the spray field is indispensable. In the present paper, a technique of simultaneous measurement of droplet size and three-components of velocity is proposed and applied to spray issuing from the swirl nozzle as a practical application. The focused image of glare points is captured by a stereoscopic arrangement, and droplet size and the three-components of velocity are evaluated from the doublet image. Fundamental optical arrangements to capture the image of the glare points with a stereo view are established, and the feasibility and the accuracy of the technique are confirmed.

Key words: spray, droplet size, stereoscopic PIV, optical technique, glare points