The effect of bubble release techniques on their behaviour at the initial stages of rise

In this research we focus on the differences caused by the experimental conditions in bubble rise tests at the initial phases of motion in Dowfroth 200, Nasfroth 240 and Dowfroth 250 solutions. Two bubble release techniques were used and the first 50 ms of the rise were recorded with high-speed camera.The results suggest that the method of bubble release strongly influences the behaviour of bubbles. The extent of surface deformation caused by different bubble release techniques effect on form drag and therefore the bubble rise velocity due to the different surface stabilization capabilities of frothers.

Figure optionsDownload as PowerPoint slideHighlights
► Bubble rise velocity observation with 5000 fps frame rate over the first 50 ms.
► Two different bubble generation techniques.
► The method of bubble creation has a major effect on the bubble rise velocity.
► Stagnant cap model does not account for the transient phenomena.
► Models describing bubble behaviour in surfactants solutions lack a major building block.