Using sound to improve boiling efficiency

Scientists at the Georgia Institute of Technology have used an acoustic field to enhance heat transfer and improve liquid boiling efficiency by 17%. This has been achieved by removing vapour bubbles from the heated surface and suppressing the formation of an insulating vapour film.

American Institute of Physics’ (AIP) journal the Physics of Fluids both report the acoustic field induces capillary waves on the bubble, causing its contact line to contract and detach the bubble from the surface, thereby improving the rate of bubble removal.

Three acoustic experiments were used to examine the mechanisms associated with these interactions:

• an air bubble on the underside of a horizontal surface
• a single vapor bubble on the top side of a horizontal heated surface
• pool boiling from a horizontal heated surface

The researchers isolated and identified the dominant forces involved in these acoustically forced motions by measuring the capillary waves induced on the bubbles, bubble motion, and heat transfer during boiling.

Fascinating stuff.

OK, it’s time for a scientific question; to your knowledge, where can audio influence, change or improve other naturally occuring phenomena?