《14 The structures and evolution of Smoker in an ultrasonic field 最终网络版》.pdf

Ultrasonics Sonochemistry 19 (2012) 762–766 Contents lists available at SciVerse ScienceDirect Ultrasonics Sonochemistry journal homepage: www.elsevi /locate/ultsonch The structures and evolution of Smoker in an ultrasonic field Lixin Bai ⇑, Chongfu Ying, Chao Li, Jingjun Deng Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, PR China a r t i c l e i n f o a b s t r a c t Article history: The structures and evolution of Smoker in a 20 kHz ultrasonic field were investigated experimentally Received 9 September 2011 with high-speed photography. The spine-plume structure of Smoker was discovered. A few large bubbles Received in revised form 23 December 2011 align themselves along the central line and form the spine of Smoker. Numerous small bubbles move Accepted 5 January 2012 towards the spine and form the plume structures. The size of large bubbles differs almost by an order Available online 13 January 2012 of magnitude from that of small bubbles. The evolution of cavitation structure from Flare to Smoker was found. When a Flare appears near a Smoker, the Flare may merge into the plume structures of the Keywords: Smoker, or form a double-tipped Smoker. A double-tipped Smoker seldom splits into two Smokers, while Cavitation structure Ultrasonic field two separate Smokers tend to merge as one. The large bubbles (or