摘要
通过高速摄影结合图像处理算法,研究气体流量和喷嘴直径对气泡尺寸和纵横比分布的影响。结果表明,在所有喷嘴直径下,气泡当量直径的概率密度呈现双峰分布,其中第一个峰值接近直径为1.5~2 mm的小气泡区域,另一个峰值位于较大的气泡区域。将气体流量从0.1 L/min增加到0.2 L/min会导致大气泡的概率密度更高,表明气泡聚并现象普遍存在。当气体流量增加至1.2L/min时,峰值对应的气泡直径变小,并且气泡破裂占主导地位。对于直径为1~2 mm的气泡,形状受气体流量的影响较小,而3~9 mm的气泡在所有气体流量下气泡纵横比概率密度分布的峰值均位于纵横比E=0.5处。Iguchi和Chihara提出的模型能更好地预测气泡脱离直径随气体流量的增大的变化。
The influence of gas flow rates and nozzle diameters on bubble size and aspect ratio distributions was studied using high-speed photography with an image processing algorithm.Results reveal bimodal probability density distributions(PDD)of bubble diameter under all nozzle diameters,with one peak near 1.5-2 mm and the another in the larger bubble range.Increasing gas flow rates from 0.1 to 0.2 L/min leads to a higher probability density of large bubbles,indicating prevalent bubble coalescence.As the gas flow rate rises to 1.2 L/min,the peak shifts to smaller bubble diameters,and the bubble breakage becomes dominant.For 1-2 mm bubbles,shape is less influenced by gas flow rates,while 3-9 mm bubbles exhibit aspect ratio PDD peaks at an aspect ratio(E)of 0.5 across all gas flow rates.The Iguchi and Chihara model can better predict the variation of bubble departure diameter with increasing gas flow rates.
作者
闫红杰
张河杨
刘柳
Thomas ZIEGENHEIN
周萍
Hong-jie YAN;He-yang ZHANG;Liu LIU;Thomas ZIEGENHEIN;Ping ZHOU(School of Energy Science and Engineering,Central South University,Changsha 410083,China;TIV Consultancy,7th Pl Road 1312,85281 Tempe,Arizona,United States)
基金
National Natural Science Foundation of China(No.51906262)
Natural Science Foundation of Hunan Province,China(No.2020JJ5735)
Youth Excellent Sci-Tech Talents Training Plan under Hunan Provincial Sci-Tech Talents Sponsorship Program,China(No.2023TJ-N10)。
关键词
气泡尺寸分布
气泡直径
气泡纵横比
气体流量
喷嘴直径
鼓泡塔
bubble size distribution
bubble diameter
bubble aspect ratio
gas flow rate
nozzle diameter
bubble column
