IMAGE VELOCIMETRY

Hao Pengfei  He Feng  Wang Jian  Zhang Xiwen

(Department of Engineering Mechanics, Tsinghua University, Beijing 100084)

Guo Min  Xing Wanli  Cheng Jing

(National Engineering Research Center for Beijing Biochip Technology, Beijing 102206)

Abstract: The micro particle image velocimetry (Micro-PIV) is used to investigate the micro acoustic streaming generated by piezoelectric lead-zirconate-titanate(PZT) transducer in the micro water droplet between two parallel glass chips. The ultrasound intensity is in range 1～5 W/cm2 and the frequency is about 1.3 MHz. The volume of micro water drop is about 5 mL. The details of flow structures in the water under various ultrasound intensities are obtained by means of Micro-PIV system. The micro vortices are observed in the flow pattern induced by ultrasonic transducer, and the velocity vectors are normal to the vibration direction of ultrasound transducer. The experimental results show the maximum streaming velocity is proportional to the ultrasound intensity.

Key words: Ultrasound transducer  Micro streaming  Micro particle image velocimetry

CLC No: TB552

国家自然科学基金资助项目(10272066). Received 20040515, received in revised form 20041020