Three stages of bubble formation on submerged orifice under constant gas flow rate

9th International Symposium on Cavitation

Yu, Xianxian^1 ; Wang, Yiwei^1 ; Huang, Chenguang^1 ; Du, Tezhuan^1

Key Laboratory for Mechanics in Fluid Solid Coupling Systems, Institute of Mechanics, Chinese Academy of Sciences, No.15 Beisihuanxi Road, Hai dian District, Beijing, China^1

关键词: Compressible large eddy simulations;    Engineering applications;    Numerical results;    Rayleigh-Plesset equation;    Reference values;    Simulation and results;    Spherical bubbles;    Uncertain parameters;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012042/pdf
DOI  :  10.1088/1742-6596/656/1/012042

来源: IOP

【 摘 要 】

Bubble formation is involved in many engineering applications. It is important to understand the dynamics of bubble formation. This work reports experimental and numerical results of bubble formation on submerged orifice under constant gas flow rate. Compressible large eddy simulation combined volume of fluid (VOF) was adopted in simulation and results was validated by experiment. Bubble formation is divided into three stages in this paper, expansion stage, elongation stage and pinch-off stage. In expansion stage, The bubble grows radially due to the incoming gas flux, but the bubble base remains attached to the orifice. But as gas injected, the spherical bubble will go into the elongation stage when the downward resultant force is lager than upward resultant force. And when bubble neck's length is bigger than √2Rothe bubble will go into pinch-off stage. Cylindrical Rayleigh-Plesset equation can be used to describe the pinch-off stage. Uncertain parameter r in it is given reference value in this paper.