A Simplified Model for Predicting Changes to Ultrafine Bubble Size Distributions under Flowing Conditions

This study investigates the overall change in ultrafine bubble (UFB) size distributions in water under flowing conditions for Reynolds numbers ranging from ~300 to ~9500. The size distribution was segregated into 5nm bins, within which the change in UFB number concentration over a 120 minutes was found to exhibit 2nd order rate dependency. A proposed correlation is able to predict the change in UFB size distributions in recirculating systems for diameters ranging from 100 to 400 nm. Notably, the loss of UFB and the shift in size distribution did not appear to be sensitive to the length of the recirculation loop within the experimental range of this study.