Extinguishing a flame using sound

The Defence Advanced Research Projects Agency (DARPA) sounds like a cool place to work, mostly because they have an “Instant Fire Suppression Program”.

To provide an example of the group’s research, this video demonstrates the use of audio waves from facing speakers to suppress and eventually extinguish the flames of a fire.

As noted by DARPA:

Two dynamics are at play in this approach. First, the acoustic field increases the air velocity. As the velocity goes up, the flame boundary layer, where combustion occurs, thins, making it easier to disrupt the flame. Second, by disturbing the pool surface, the acoustic field leads to higher fuel vaporization, which widens the flame, but also drops the overall flame temperature. As the same amount of heat is spread over a larger area, combustion is disrupted.

My thoughts about this echo those of Jesse Pinkman: