Experimental study of non-uniform bubbles in a plume  

作　　者：Xin-wei Ye Hao-jie Zhou Dong-dong Shao Xiao-jing Niu 

机构地区：[1]State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing,100084,China [2]State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,Beijing,100875,China

出　　处：《Journal of Hydrodynamics》2022年第1期116-124,共9页水动力学研究与进展B辑（英文版）

基　　金：supported by the State Key Laboratory of Hydroscience and Engineering,Tsinghua University(Grant No.2022-KY-05).

摘　　要：The bubble plume is an important flow phenomenon, ubiquitous in many fields. The non-uniform bubbles in a plume are often simply considered as uniform and moving with a same slip velocity in an integral model. This study aims to have a better understanding of the behavior of the non-uniform bubbles in a plume. A set of experiments are conducted in a transparent water tank, in which the air plumes are generated through different injectors to vary the spectrum of the bubble size. The shadow images of the bubbles are simultaneously recorded with the illumination of a plane backlight. The algorithm used in the image analysis for tracing the bubbles is a newly developed multi-frame method based on the predictor-corrector method, with a good accuracy in estimating the size and the velocity of the overlapped bubbles based on the bubble shadow images. The bubbles are divided into several groups by their equivalent diameters with an interval of 0.5 mm. The spectrums of the bubble size and the void fraction are measured. It is found that the bubbles of different sizes show different dynamics features, resulting in a difference in the radial distribution. It is shown that the large bubbles gather in the center of the plume, while the medium bubbles spread the widest and even wider than the small bubbles. The difference can be explained by the effects of the transverse lift force and the amplitude of the bubble oscillation.

关 键 词：Bubble plume EXPERIMENT image analysis bubble size transverse lift force 

分 类 号：O368[理学—流体力学]