Journal of South China University of Technology (Natural Science Edition) ›› 2019, Vol. 47 ›› Issue (1): 127-134.doi: 10.12141/j.issn.1000-565x.180069

• Power & Electrical Engineering • Previous Articles     Next Articles

Behavioral Characteristics of Bubble Collision with Different Extremely Humid Surfaces
 

 JI Xianbing DAI Chao WANG Ye Xu Jinliang    

  1.  Beijing Key Laboratory of Multiphase Flow and Heat Transfer,North China Electric Power University,Beijing 102206,China
  • Received:2018-02-01 Revised:2018-08-07 Online:2019-01-25 Published:2018-12-01
  • Contact: 纪献兵( 1967) ,男,副教授,主要从事相变传热和动力学研究. E-mail:jxb@ncepu.edu.cn
  • About author:纪献兵( 1967) ,男,副教授,主要从事相变传热和动力学研究.
  • Supported by:
      Supported by the National Natural Science Foundation of China( 51676071,51436004) 

Abstract: Three types of surfaces,namely superhydrophilic,low adhesive superhydrophobic and high adhesive superhydrophobic surfaces,were prepared to improve the functionality of the extremely humid surfaces. The behavioral characteristics of bubble collision with different extremely humid surfaces under different rising heights were studied by using high-speed camera. The bubble diameters are 2. 16,2. 59 and 3. 32 mm,respectively. The results show that surface wettability,bubble rising height ( L) and bubble diameter ( D) have important influences on bubble's behavioral characteristics. The bubble stable state is mainly affected by microstructure and surface tension. When bubbles collide with low adhesive surface,bubbles will initially vibrate or bounce,then spread and form a layer of gas film on the surface at last. When bubbles collide with superhydrophilic and high adhesive surfaces,bubbles will also firstly vibrate or bounce,and finally stay on the surfaces with a ball-lacking shape. As bubble collision velocity is large,the bubble can all rebound on the three types of surfaces. With the increasing L, the initial jump height ( h1) increases first and then decreases on three types of surfaces,and they reach the maximum value at L =13. 6 mm,which are 6. 05,5. 53 and 4. 37 mm,respectively. As to the low adhesive superhydrophobic surface,due to the energy dissipation of bubble increases during the collision process,both h1 and the time of bubble spreading decrease with the increasing D. 

Key words: superhydrophilic surface, high adhesive superhydrophobic surface, low adhesive superhydrophobic surface, wettability, kinetics, bubble, spreading, bounce

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