U.S. agency DARPA has published interim results of studies of how to influence the fire with sound. It turns out that the sound can not only put out the fire, but also to control gorenie.DARPA conducting research in this area since 2008, during which work out practical ways of fighting fires with the use of sound. What is not satisfied with the military in modern fire extinguishers? The fact is that even the most modern and efficient chemical extinguishers are virtually useless in close quarters, for example, in a compartment of the submarine or the cockpit of a fighter. They are very little space and foaming brim can reduce the ability of the pilot to control the aircraft or even to subject all the crew in danger of suffocating small, cramped compartment.
From the point of view of physics, technology extinguishing flames with sound very simple. On either side of the fire source should be placed two speakers. The effluent of these sound waves increases its air velocity in the flame. After that, the combustion area, that is the boundary of the air and visible flame becomes very thin, down to extinction.
During the study, experts DARPA also found that the sound of many changes on the surface of the burning liquid. The sound wave is on it, which is why its vapor discharge area is greatly increased. Consequently, the concentration of flammable substances in the vapor decreases sharply, which facilitates quenching fire. Moreover, this effect can be achieved with a moderate sound level.
According to the U.S. military, these data will help experts not only in fighting fires, but also in the use of combustion for scientific purposes. For example, the ability to control the temperature of the combustion engine would significantly improve the efficiency of engines.
Scientists are developing another promising technology suppress the flames. It is based on an electrode, which exposes the flame electromagnetic interference. He can reject the flames so much that they would be in space at different points to a source of fire, so burning stops. The truth while so researchers can extinguish burning only 10 square meters. cm, not more.