气泡碰撞亲疏水曲壁的行为特性研究

STUDY ON THE BEHAVIOR OF BUBBLES COLLIDING WITH HYDROPHILIC AND HYDROPHOBIC CURVED WALLS

气泡碰撞固壁行为和影响因素的研究一直以来都是科学界关注的重点之一,其在矿物浮选、气膜减阻等工业领域中的应用也极具科研价值.论文聚焦曲壁对于气泡撞击行为特性的影响研究.采用高速摄像技术记录气泡碰撞不同曲率半径下亲疏水曲壁的撞击过程,分析了曲壁润湿性、曲率半径对气泡碰撞固体曲壁的影响规律.结果表明,气泡碰撞亲水曲壁时会发生多次弹跳直至离开曲壁;曲率半径越大,弹跳次数越少,且第一次反弹的最远距离越近,再次发生碰壁时的速度越小.而碰撞疏水曲壁时会出现碰撞-滑移-附着的现象,此外针对液膜挤压破裂的现象,建立理论模型推导出液膜诱导时间的预测公式,其主要与液膜厚度、液膜临界破裂厚度和液膜被压缩速度有关,预测误差小于5.0%.

The research on the behavior and influencing factors of bubble collision has always been one of the focuses of scientific circles.Its application in industrial fields such as mineral flotation and gas film drag reduction is also of great scientific research value.This paper focuses on the influence of curved wall on bubble impact behavior.The impact process of bubbles colliding with hydrophilic and hydrophobic curved wall under different radius of curvature was recorded by high-speed camera technology,and the effects of wettability and radius of curvature of curved wall on bubbles colliding with solid curved wall were analyzed.The results show that when the bubble collides with the hydrophilic curved wall,it will bounce many times until it leaves the curved wall;The larger the radius of curvature,the less the number of jumps,and the closer the farthest distance of the first rebound,the smaller the speed of hitting the wall again.In addition,aiming at the phenomenon of liquid film extrusion rupture,a theoretical model is established to deduce the prediction formula of liquid film induction time,which is mainly related to the thickness of liquid film,the critical rupture thickness of liquid film and the compression speed of liquid film,and the prediction error is less than 5.0%.