Particle manipulation by ultrasonic progressive waves

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• 作者：Marco A.B. Andrade ; Flá ; vio Buiochi ; Julio C. Adamowski
• 关键词：Acoustic radiation force ; Particle manipulation ; Progressive waves
• 刊名：Physics Procedia
• 出版年：2010
• 出版时间：1 January 2010
• 年：2010
• 卷：3
• 期：1
• 页码：283-288
• 全文大小：510 K

文摘

This paper presents a numerical model to determine the trajectory of sphere particles when submitted to ultrasonic progressive waves. This model assumes that the following forces act on the particle: gravity, buoyancy, viscous forces and acoustic radiation force due to progressive wave. In order not to restrict the model to a small particle size range, the viscous forces that act on the sphere are modeled by an empirical relationship of drag coefficient that is valid for a wide range of Reynolds numbers. The numerical model requires the pressure field radiated by the ultrasonic transducer. The pressure field is obtained experimentally by using a calibrated needle hydrophone. The numerical model validation is done by dropping small glass spheres (on the order of 500 μm diameter) in front of a 1-MHz 30-mm diameter ultrasonic transducer. When the particles cross the transducer face, the radiation force produced by the transducer pushes the particles away. The glass particles trajectory is obtained by a CCD camera. The experimental trajectory shows good agreement with that predicted by the numerical model.