Do small air bubbles zigzag or spiral when they rise in clean water? This was the question asked by Mingming Wu, Adjunct Associate Professor and Principal Investigator at the Biofluidics Lab (and colleagues) at Cornell back in 2002.
As anyone who has poured a fizzy drink will have observed, although some small bubbles rise straight up, others take a less direct path – but what are the determining factors?
Experiments at the lab found a direct answer – size (and shape) matters…
“Bubbles with diameter less than about 0.15 cm rise rectilinearly. The larger spherical bubbles follow zigzag paths while the larger ellipsoidal bubbles follow spiral paths.”
Link to the full research paper : Experimental studies on the shape and path of small air bubbles rising in clean water. (The work was funded by the National Science Foundation, the Research Corporation, and the Office of Naval Research). Improbable e-mailed the professor to find out if there have been any practical applications of the discoveries since 2002, but has not as yet received a reply.