1993/12/01 by Hasan N. Oguz, Hasan N. Oğuz, Andrea Prosperetti +1 · 19 citations
Materials Science · Engineering · #Ultrasound and Cavitation Phenomena #Fluid Dynamics and Mixing #Enhanced Oil Recovery Techniques
paper · doi:10.1017/s0022112093003015
Several aspects of the growth and departure of bubbles from a submerged needle are considered. A simple model shows the existence of two different growth regimes according to whether the gas flow rate into the bubble is smaller or greater than a critical value. These conclusions are refined by means of a boundary-integral potential-flow calculation that gives results in remarkable agreement with experiment. It is shown that bubbles growing in a liquid flowing parallel to the needle may detach with a considerably smaller radius than in a quiescent liquid. The study also demonstrates the critical role played by the gas flow resistance in the needle. A considerable control on the rate and size of bubble production can be achieved by a careful consideration of this parameter. The effect is particularly noticeable in the case of small bubbles, which are the most difficult ones to produce in practice.