气泡破裂点位置及液膜卷曲速度实验研究

Experimental Research of Punctured Position and Film Rolling Speed for Bursting Bubble

利用高速摄像技术构造可视化装置拍摄纯水中气泡在自由液面处破裂产生膜液滴的整个过程，包括气泡浮动、液膜排液、破裂点形成、液膜卷曲、瑞利不稳定射流形成膜液滴等阶段。气泡破裂点产生相对位置及液膜卷曲速度对于气泡破裂产生膜液滴过程非常重要，通过图像后处理得到两者实验数据。结果表明：对于实验中气泡曲率半径在2～18 m m范围内的137个数据，其破裂点产生位置主要位于气泡底部，气泡顶部同中间有破裂点产生，但发生频率远低于气泡底部。对曲率半径在7～28 m m范围内的气泡数据进行拟合，得到液膜卷曲速度同气泡曲率半径的关系式。

The visualization experiment was built up to record the bubbles bursting at a free water surface with a high speed video camera for the whole process .The whole process could be divided into following successive stages ：A floating bubble , the drainage of the liquid film ,the puncture of the bubble cap ,the film rolling-up and the liquid ring formed with the hole expanding ,fine film drops emission under the effect of destabilization of a Rayleigh type .The punctured position and the film rolling speed of the bursting bubble ,which were both important parameters for the dynamics of the film drop formation ,were obtained by the subsequent image processing .The results of 137 bubbles with 2-18 mm curvature radius range ,shows that the puncture mainly happens at the foot of the bubble ,w hile a few bubbles indeed begin bursting at the top or in the middle of the bubble cap .The expression correlating the bubble curvature radius with the film rolling speed is obtained by fitting the data with the bubble radius ranging from 7mmto28mm.