SCI和EI收录∣中国化工学会会刊

›› 2008, Vol. 16 ›› Issue (4): 547-551.

• TRANSPORT PHENOMENA & FLUID MECHANICS • Previous Articles     Next Articles

The Collapse Intensity of Cavities and the Concentration of Free Hydroxyl Radical Released in Cavitation Flow

ZHANG Xiaodong, FU Yong, LI Zhiyi, ZHAO Zongchang   

  1. R&D Institute of Fluid and Powder Engineering, Dalian University of Technology, Dalian 116012, China
  • Received:2007-06-27 Revised:2007-12-28 Online:2008-08-28 Published:2008-08-28
  • Supported by:
    the National Natural Science Foundation of China(10472024)

The Collapse Intensity of Cavities and the Concentration of Free Hydroxyl Radical Released in Cavitation Flow

张晓冬, 付勇, 李志义, 赵宗昌   

  1. R&D Institute of Fluid and Powder Engineering, Dalian University of Technology, Dalian 116012, China
  • 通讯作者: ZHANG Xiaodong, E-mail: zhangxd56@163.com
  • 基金资助:
    the National Natural Science Foundation of China(10472024)

Abstract: Enhancing the chemical reaction processes by means of the energy released in the collapse of micro bubbles or cavities in the cavitation flow is a new research area. In the previous work, a new approach of measuring concentration of free hydroxyl radicals induced in cavitation flow by using methylene blue as the indicator was developed and used to study concentration of free radical induced in Venturi cavitation flow under various experimental conditions. In the present research, the radial evolution of a cavity bubble and the corresponding collapse pressure in sonic cavitation field are obtained by solving three different bubble dynamics equations[0]: Rayleigh equation, Rayleigh-Plesset equation and Gilmore equation. By comparing with the experimental data on the radial evolution of a cavity bubble in the literature, it is found that the predicted results by the Gilmore equation, which takes account of the compressibility of fluid in addition to the viscosity and interfacial tension, agree with the experimental ones better than those by other two equations. Moreover, the theoretically predicted collapse pressures are consistent with the concentration of the free hydroxyl radical induced in the experimental venture. Thus, the concentration of the liberated free hydroxyl radical not only influences the reaction rate but also is used as an available parameter for measuring collapse intensity of cavities.

Key words: hydrodynamic cavitation, collapse pressure, numerical simulation, free hydroxyl radical

摘要: Enhancing the chemical reaction processes by means of the energy released in the collapse of micro bubbles or cavities in the cavitation flow is a new research area. In the previous work, a new approach of measuring concentration of free hydroxyl radicals induced in cavitation flow by using methylene blue as the indicator was developed and used to study concentration of free radical induced in Venturi cavitation flow under various experimental conditions. In the present research, the radial evolution of a cavity bubble and the corresponding collapse pressure in sonic cavitation field are obtained by solving three different bubble dynamics equations[0]: Rayleigh equation, Rayleigh-Plesset equation and Gilmore equation. By comparing with the experimental data on the radial evolution of a cavity bubble in the literature, it is found that the predicted results by the Gilmore equation, which takes account of the compressibility of fluid in addition to the viscosity and interfacial tension, agree with the experimental ones better than those by other two equations. Moreover, the theoretically predicted collapse pressures are consistent with the concentration of the free hydroxyl radical induced in the experimental venture. Thus, the concentration of the liberated free hydroxyl radical not only influences the reaction rate but also is used as an available parameter for measuring collapse intensity of cavities.

关键词: hydrodynamic cavitation, collapse pressure, numerical simulation, free hydroxyl radical