BUBBLE DYNAMICS IN 2D BUBBLE COLUMN: COMPARISON BETWEEN HIGH-SPEED CAMERA IMAGING ANALYSIS AND 4-POINT OPTICAL PROBE

Abstract

Two-dimensional (2D) bubble columns have been used in the literature to study the detailed flow field for evaluation and validation of computational fluid dynamics (CFD) and for developing the needed closures and interfacial forces models for gas-water systems. Hence, this work focuses on investigating the bubble dynamics (i.e., local gas holdup, bubble velocity, bubble chord length, and frequency) in a 2D bubble column. Two advanced measurement techniques were implemented in this work, high-speed video camera imaging and a four-point optical probe. A new method for analysis of video camera imaging was employed. The results of both techniques were compared. The results show good overall agreement between the two methods for the horizontal profile of both bubble size and gas holdup. The findings revealed a strong positive correlation between bubble size and gas holdup. It was found that video image analysis could become an accurate, noninvasive alternative to fiber optical probes, at least in 2D systems, although the technique needs more refinement.

Keywords:

• 2D bubble column
• Bubble dynamics
• Fiber optical probe
• Video imaging

Acknowledgment

The work was performed at the Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gcec.