Numerical Simulation of Quasi-Static Bubble Formation from a Submerged Orifice by the Axisymmetric VOSET Method
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In order to investigate the dynamics of quasi-static bubble formation from a submerged orifice, this paper developed an axisymmetric VOSET method with continuum surface force (CSF) model which can accurately capture the moving phase interface of gas-liquid flow. Test case shows that numerical results are in good agreement with experimental results from the literature. The effects of gas flow rate, orifice size, surface tension, contact angle, liquid density, and gravitational acceleration on bubble shape, departure time and departure volume are investigated and analyzed. It is found that increase in orifice size, surface tension, and contact angle results in the increase in the capillary force resisting bubble detachment, which leads to larger departure time and departure volume. But there is a critical contact angle, and contact angle has no significance effect on the process of bubble formation and detachment, when it is smaller than the critical value. Buoyancy force promoting bubble detachment increases with the increase of liquid density and gravitational acceleration, which results in smaller departure time and departure volume. Also, the forming process of the neck shape of bubble bottom at the bubble detachment stage is observed, and the results show that the position of the smallest part of the neck approximately equals to the orifice radius Rc.
KeywordsAxisymmetric VOSET method Bubble formation Bubble detachment Static contact angle Numerical simulation
The present study is supported financially by the Fundamental Research Funds for the Central Universities (2018MS105) and the joint fund between the Chinese Academy of Sciences (CAS) and National Natural Science Foundation of China (NSFC) under the grant of U1738105.
- Georgoulas, A., Koukouvinis, P., Gavaises, M., Marengo, M.: Numerical investigation of quasi-static bubble growth and detachment from submerged orifices in isothermal liquid pools: the effect of varying fluid properties and gravity levels. Int. J. Multiphase Flow. 74, 59–78 (2015)MathSciNetCrossRefGoogle Scholar
- Wang, T., Li, H.X., Li, Y.: Numerical investigation on coaxial coalescence of two gas bubbles. J. Xi'an Jiaotong Univ. 47, 1–6 (2013)Google Scholar
- Youngs, D.L.: Time-dependent multi-material flow with large fluid distorion. In: Morton, K.W., Baines, M.J. (eds.) Numerical Methods for Fluid Dynamics. Acadimic Press, New York (1982)Google Scholar