Analysis and Prediction of Equivalent Diameter of Air Bubbles Rising in Water

The equivalent diameter of rising bubbles in liquids is an important parameter that has been investigated for decades by researchers for different purposes. Bubble diameter plays important role in quantifying oil and gas leaks in subsea leak analysis, since it allows the prediction of the magnitude of leaks in seabed petroleum wells and other structures through images obtained by underwater vehicles at great depths. Most studies available in the literature on the subject focus on investigating air bubbles in water; therefore, they were used as the main guide of the experimental apparatus described in this article. Several tests were conducted with air bubble chain in tap water, whose flow rate ranged from 21.1 mL/min to 234.4 mL/min, whereas the bubble equivalent diameter ranged from 4.1 mm to 8.2 mm. In addition, computational fluid dynamics simulations were carried out for comparison purposes; they were validated as potential tools to help designing an automated subsea gas leakage monitoring system based on image analysis algorithms. The herein proposed model could be both analytically and experimentally validated, based on comparisons to findings reported by other authors. This procedure enabled gathering evidence about the most efficient analytical predictions available in the literature for the herein addressed scenario. The results in the present study are consistent to those recorded in the main related articles.