Unexpected Behaviour Of Microbubbles
Immediately At The Aerator Exit
Author(s)
V. Tesař
Abstract
Microbubbles (of diameter less than 1 mm) are desirable for many engineering
applications. Until quite recently, generating them efficiently was a problem. A
solution was found in excitation of gas supply by inexpensive and reliable nomoving-
part fluidic oscillators. Strangely, generated microbubbles are larger
than expected. The author studied their formation using a high-speed camera
with a long distance macro-lens. The images revealed the cause being a
conjunction of bubbles, mostly taking place within the very proximity of the
aerator exit. Small bubbles move slowly and do not vacate fast enough from the
position in which they were generated. They thus get into contact with the next
generated bubble. Another cause of slow departure is the increased drag caused
by shape oscillation driven by energy released in the conjunction. The
conjunctions may also occur due to lateral bubble motion if the Reynolds
number exceeds the vortex shedding threshold.
Keywords: bubbles, microbubbles, bubble conjunctions.
Keywords
Keywords: bubbles, microbubbles, bubble conjunctions.
Related Book
Other papers in this volume
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