Objectives For the development of composite drag reduction technology of super-hydrophobic surface and bubbles, the coalescence characteristics of bubbles on wetting surface are studied.
Methods Based on the volume of fluid (VOF) method, a numerical model of bubble coalescence on an underwater wetting surface is established. It is used to analyze the bubble coalescence characteristics on wetting surfaces and reveal the influence of surface wettability, bubble spacing and bubble size on bubble coalescence characteristics.
Results The results show that the increase of surface contact angle on wetting surfaces and the decrease of bubble spacing make it easier for bubbles to coalesce. Increasing the bubble size will slow down the spreading speed of bubbles on the surface, which is also not conducive to accelerating bubble coalescence.
Conclusion This study can provide a reference for the coupling design of super-hydrophobic surface and bubble drag reduction technology.
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