Fighting fires with sound frequencies
washingtonpost.com
Fighting fires with sound frequencies
1–10 of 32 posts
Re: Fighting fires with sound frequencies
#2How does it work?
I mean is it a new discovery that some frequencies create resonance and stop the convection and prevent oxygenation of the flame?
Or is it just using sheer power to "blow" the flame off? but instead of a blower, it just uses very high powered speaker in low frequency?
Re: Fighting fires with sound frequencies
#3How does it work? I mean is it a new discovery that some frequencies create resonance and stop the convection and prevent oxygenation of the flame? Or is it just using sheer power to "blow" the flame off? but instead of a blower, it just uses very high powered speaker in low frequency?
[deleted]
Re: Fighting fires with sound frequencies
#4How does it work? I mean is it a new discovery that some frequencies create resonance and stop the convection and prevent oxygenation of the flame? Or is it just using sheer power to "blow" the flame off? but instead of a blower, it just uses very high powered speaker in low frequency?
It pushes/removes the air, so the fire goes out. As I read, this was something that's been researched but it's not useful for anything but blowing out candles, since in a real fire whatever's burning will just reignite since the burning material is not cooled or anything. Simply, the flame is suppressed momentarily.
Re: Fighting fires with sound frequencies
#5How does it work? I mean is it a new discovery that some frequencies create resonance and stop the convection and prevent oxygenation of the flame? Or is it just using sheer power to "blow" the flame off? but instead of a blower, it just uses very high powered speaker in low frequency?
It pushes/removes the air, so the fire goes out. As I read, this was something that's been researched but it's not useful for anything but blowing out candles, since in a real fire whatever's burning will just reignite since the burning material is not cooled or anything. Simply, the flame is suppressed momentarily.
> Simply, the flame is suppressed momentarily.
As long as you can continue to "suppress it momentarily" long enough for the material to cool below its ignition point, you've solved the problem.
Re: Fighting fires with sound frequencies
#6How does it work? I mean is it a new discovery that some frequencies create resonance and stop the convection and prevent oxygenation of the flame? Or is it just using sheer power to "blow" the flame off? but instead of a blower, it just uses very high powered speaker in low frequency?
Sound is a compression wave, so you have areas of high pressure(peaks) and low pressure (valleys) as it propagates. What they're doing here sounds like making a standing wave that holds a low pressure zone around the fire, depriving it of oxygen.
I'm a bit rusty on my physics, but I suspect what happens is that it measures the sound when it reflects back and adjusts the frequency of the wave to put the reflection in phase with the original wave. The sum of the forward and backward components creates the standing wave.
http://en.wikipedia.org/wiki/Standing_wave
Alternately, maybe the rapid switching between high/low pressure is enough to do it without any standing wave shenanigans. I'd guess not, but it's not my area of expertise.
Re: Fighting fires with sound frequencies
#7I've been thinking about this exact concept since the Mythbusters tested it. I'm glad someone has gone out and prove it has legs/pushed it forward.
While I could see the benefit for the scenarios they listed (aircraft, space shuttles, etc) I actually think the real killer use could be for forest fires.
With forest fires you're constantly running out of water, and the only way to ship it the location it is needed is often multi-hour drives (which consume a lot of fuel).
If this concept worked then instead of moving water from A to B you only now have to worry about an energy source (e.g. diesel). So you could drive up a truck with generator on it and diesel in a fireproof tank, and then spend hours extinguishing fires.
Now, yes, fires can reignite. However that is also true with water, water evaporates extremely quickly from an area that was on fire both because that area is extremely dry, because of the ambient heat, and also because it likely started out hot to begin with.
PS - Fire retardants help keeping fires out, but they're bad for the environment and are also hard to keep supplied in remote areas, and when you're refilling directly from a river.
Re: Fighting fires with sound frequencies
#8This isn't an entirely new concept - explosives have been used for over 100 years to put out oil well fires[1] for example, due to the difficulty of cutting off the fuel source.
[1]: http://en.wikipedia.org/wiki/Oil_well_fire#Extinguishing_the...
Re: Fighting fires with sound frequencies
#9How does it work? I mean is it a new discovery that some frequencies create resonance and stop the convection and prevent oxygenation of the flame? Or is it just using sheer power to "blow" the flame off? but instead of a blower, it just uses very high powered speaker in low frequency?
It pushes/removes the air, so the fire goes out. As I read, this was something that's been researched but it's not useful for anything but blowing out candles, since in a real fire whatever's burning will just reignite since the burning material is not cooled or anything. Simply, the flame is suppressed momentarily.
I was wondering: if it starves the fuel of oxygen, it stops the fuel from burning, even if it's still hot, yes? So if it could scale from frying-pan-level to house-level, at the very least, couldn't it be used to suppress the fire, the smoke production, and the further weakening of the structure, to allow a squad to search and rescue more safely? Then when you turn off the sound, maybe the material has cooled below the reignition point, but even if it hasn't, at that point you can fight the fire traditionally.
Re: Fighting fires with sound frequencies
#10So, just add some sort of cooling beam, better: cooling rays technology, cross beams et voilà!
Oh, wait ...