Infrasound (less than 15Hz) Weapon

[Bander]

<h1>Theoretical Design of a ~7 Hz Whistle</h1>


<img src="http://www.darknebula.org/superkuh/science/infrasound/whistle1.gif" width="457" height="106">

I have done extensive research into the design of human flesh resonance weapons
and I have come to the conclusion that they are possible. To what extent is
still questionable. There are many amateur (<a href="#1">1</a>) documents that
say a ~150 decibel 7 Hz tone can kill, but I have had a hard time finding the
same data in the few military and professional R&D documents (<a href="#2">2</a>)
that are available to the public. Luckily, most sources seem to agree that a
~7 Hz tone matches the resonance frequency of some human flesh and will cause
nausea. (as long as we're on the subject, 3000hz is the resonance frequency
of the ear canal)

So far I have heard of 3 ways to generate this effect and apply it to a biological.
<ol>
Through the use of a modulated fast firing vortex weapon (<a href="#3">3</a>).
<font size="1">(that's a future post in itself)</font></li>
By altering a standard whistle to lower it's frequency.</li>
Really fucking large tubes (not sure how this works) ;-)</li>
[/list=a]

Large tubes are out of the question, so that leaves me with 1 and 2. My work
on the modulated vortex weapon should be complete in a few months, but I am
concerned about the feasibility of shooting 7 high energy vortices a second
(possibly a modified 2 cylinder motorcycle engine). Because of this I did a
little research into the physics behind everyday whistles (<a href="#4">4</a>).
And from the little knowledge I have gathered I think it's possible to make
7 Hz 'tone' using a basic design.

<img src="http://www.darknebula.org/superkuh/science/infrasound/whistle2.gif" width="225" height="201" align="top"> http://www.darknebula.org/superkuh/science/infrasound/whistle3.gif

<font size="1">Simple Diagram Showing the Operation of a Whistle and The
Design of an Efficient Lip to Cut Down Turbulence</font>

So, because of that research I found a bastardized equation for whistle frequency:

f = 17174 / L, where f = frequency or pitch in Hz , L = length in centimeters
and the diameter to length ratio is 1: 2

With a little simple math this leads me to conclude that a 248.714 cm long,
12.435 cm diameter tube would produce a ~7 Hz tone. I do not know how the size
of the fipple (hole that lets air out) effects the design so experimentation
would be required (unless someone here knows).

If this whistle were to be powered by compressed air, or something to that
effect, I think it would be possible to get a sufficient decibel level. Anyway,
I'm sure there are people here far more knowledgeable than myself, is this possible?
If so, is there anything I've let out that could adversely effect the performance
of the device?

<a name="1"></a>1.
<a target=_top target=_top href="http://www.overloadmedia.co.uk/library/deadvib.shtml" >http://www.overloadmedia.co.uk/library/deadvib.shtml</a>
<a href="http://paranormal.about.com/gi/dynamic/offsite.htm?site=http%3A%2F%2Fwww.borderlands.com% 2Farchives%2Farch%2Fgavreaus.htm">http://paranormal.about.com/gi/dynamic/offsite.htm? site=http%3A%2F%2Fwww.borderlands.com%2Farchives%2 Farch%2Fgavreaus.htm</a>
<a target=_top target=_top href="http://groups.yahoo.com/group/Skyopen/message/1495" >http://groups.yahoo.com/group/Skyopen/message/1495</a>
<a target=_top target=_top href="http://hometown.aol.com/ultra21753/" >http://hometown.aol.com/ultra21753/</a>
<a target=_top target=_top href="http://www.ocarina.demon.co.uk/horror.html" >http://www.ocarina.demon.co.uk/horror.html</a>
<a target=_top target=_top href="http://home.intekom.com/salbu/apollo/HumB.html" >http://home.intekom.com/salbu/apollo/HumB.html</a>
<a target=_top target=_top href="http://home.intekom.com/salbu/apollo/Infrasound_JohnCody.html" >http://home.intekom.com/salbu/apollo/Infrasound_JohnCody.html</a>
<a target=_top target=_top href="http://home.intekom.com/salbu/apollo/HumA.html" >http://home.intekom.com/salbu/apollo/HumA.html</a>
<a name="2"></a> 2.
<a target=_top target=_top href="http://accoustics.superkuh.com/infrasound/" >My Directory of Infrasound Related pdfs</a>
<a target=_top target=_top href="http://www.acoustics.org/press/137th/altmann.html" >Acoustics.org on Infrasound Effects</a>
<a name="3"></a> 3. <a target=_top target=_top href="http://accoustics.superkuh.com/vortex/" >My Vortex Project (in design stage)</a>
<a name="4"></a> 4. <a target=_top target=_top href="http://www.geocities.com/SoHo/Museum/4915/02.HTM" >Basic Whistle Design</a>

[ January 04, 2002: Message edited by: Bander ]</p>

[Agent Blak]

The question on my mind is...

"Is the Deployment of this type of Device Practical Outside of the Lab?"

The only way I can see this working is as a leave behind device. Possibley operating off of a 12g CO2 Powerlet or a 9oz Paintball style tank. Unless you can figure out a way that this could be used and not harm the user it severely limits this type of device.

Although maybe you could use it with a CO2 Powerlet(12g) as Sonic Grenade of sorts. There is a thread statred by myself from sometime back under the name of White Noise; there is a lot of info on Frequencey of sound etc. it might be worth a gander.

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[Machiavelli]

A french scientist called Gavreaux worked on this stuff, he planned to mount the sonic generators on robotic platforms.

Anyway, great post Bander. I've been interested in this stuff for a long time, but couldn't find any useful resources on sound generation.

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Give someone a match and he'll feel warm for a few seconds, set him on fire and he'll feel warm for the rest of his life

[Bander]

About the potentially lethality of an infrasound device to the user, yes I did realize this (primarily from my readings about Gavreaux's work).

I really don't see how making a delay system would be that hard. If anything finding a pipe with the specified length and diameter is going to be a bitch.

Heh, also I don't think a sonic grenade would quite work. The pipe's length is around 8ft. I think I remember that thread...I'll check it out again, thanks.

A long time ago a member of the forum, 'feticidalfantasy' or something to that effect suggested powering a 7Hz device with a small aircraft engine as a compressor. Imagine the chaos it would cause if the theory is true. http://theforum.virtualave.net/ubb/smilies/tongue.gif

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Round the firewall, Out the modem, Past the server, Through the router, Down the wire, NOTHING BUT NET.

[PYRO500]

What about a sonic missle? with something like that we eliminate the need for a deployment and power source method. you could set it up to be propelled by LARGE rocket engines and have it pass slose to the ground that way the missle would have air blown into the intake, and be deployable.
any ideas on this?

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[Bander]

While the idea of an infrasonic rocket is interesting, but I don't think it would stay over the target for long enough to have any effect.

Also, I re-read a bit of the 'white noise' thread and did a little research on 33hz tones. The information I found conflicts with the claims of the thread.

http://home.intekom.com/salbu/apollo/apollo2.html
and
http://www.sasked.gov.sk.ca/forum/science/archive/messages/1950.html

But I'd love to further discuss and expierement with that frequency for obvious reasons (it'd probably be easier to make 33Hz whistle than a 7Hz, and more fun). Now I just have to find someone/something that will make a aluminum pipe to my specifications, or a formula that will allow for a different diameter to length ratio.

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Round the firewall, Out the modem, Past the server, Through the router, Down the wire, NOTHING BUT NET.

[This message has been edited by Bander (edited October 13, 2001).]

[BoB-]

Wouldnt something powered by Co2 be so loud that it would damage/destroy hearing? No frequency technology would be needed that way, just decibels.

[Bander]

I don't think so Bob, unless you make a really bad whistle (lots of tubulence, ect). The co2 expanding might make a little noise, but not that much. If I wished to make a device to damage hearing (as opposed to a whole body weapon) I'd just make a really loud 3khz tone. The best part about infrasound is exactly what it's name denotes, you cannot hear it.

Also, powering a whistle type device with co2 might have an adverse effect on the frequency. Sound travels at a different speed in pure co2, and even though this whistle design (as opposed to an open tube) doesn't depend on the speed of sound that much, it still might change the frequency the output. Which is why I feel compressed air is the best 'fuel' for a device like this.

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Round the firewall, Out the modem, Past the server, Through the router, Down the wire, NOTHING BUT NET.

[nbk2000]

Not directly related to infrasound, but related in the way of using sound as a weapon.

I had the idea of using those electronic earmuffs that shooters use that filter out loud noises, and modifying them to filter out certain frequencies.

Those frequencies would be coming from high powered electronc "screamer" grenades, like the jogger alarms, only MUCH louder.

The screamers are tossed into a place you're about to do your business in, and anyone inside is going to be deafened. Unable to hear each other, or you, they'd be easier to deal with.

You, on the other hand, can still hear just fine any noises the targets make. The advantage is yours.

As for infrasound, I class that in the same catagory as EMP, HERF, Rail Guns, and other "Be neat to have if I ever take over the world or make a billion dollars" weapons.

Neat to think of, but not within our reach. Stick to guns and bombs, the old reliables.

Speaking of which, this'd be part of the new rules. "NO talk of homemade EMP, HERF, etc, etc. It's a waste of time and counterproductive."



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[kingspaz]

it may be counter productive but even just the concepts of these weapons is interesting. or maybe how to combat EMP devices if employed against you...

[Jhonbus]

Bander is correct in saying that using CO₂ would adversely affect the operation of the whistle as a weapon. The formula stated for the frequency of a whistle is for air only. This formula would include a different constant for operation in different gases.

Think of breathing helium. Helium has a much lower molecular mass than air, and so the resonance frequency of the larynx is increased, producing a mickey mouse voice. The opposite is true of breathing Argon - it gives you an "arnold schwarzenneger voice" (Beware - to remove argon from the lungs you must bend over and breathe deeply several times or risk asphyxiation.)
(I have also tried this with CO₂, also heavier than air, but not as much as argon. It produces the same "Arnie" voice, but unfortunately has an adverse affect on consciousness, so you can only get a few words out before falling on your arse)

Using CO₂ would reduce the resonance frequency of the whistle cavity.

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You must create.

[This message has been edited by Jhonbus (edited October 20, 2001).]

[PYRO500]

I didn't know you could do that with argon, but I have heard about doing that with sulfur hexa floride, I would not recomend anyone try CO2 as it does not only displace air, but it becomes toxic very rapidly and can kill, I had a 12 OZ CO2 paintball tank burst it's seals due to overfilling and I barely got out of my room when I woke up.

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[nbk2000]

Try breathing SF6 and you'll sound like Schwarzenegger when you talk. COOOL. http://theforum.virtualave.net/ubb/smilies/tongue.gif (I know one of the SFx gases is toxic, just got the wrong one. NBK2000) Still not a good idea though.

Argon is inert, thus no toxic effects besides simple asphixiation from air displacement. CO2 alters blood gas balance since it is absorbed.

Since gas density affects resonance, why not use the densest gases you can? I'm thinking freons. High molecular weights, inert, liquids under pressure that readily vaporize at ambient, and available.

Like a pocket airhorn, only evil. http://theforum.virtualave.net/ubb/smilies/smile.gif

As for being counter-productive, it is. All these things are being developed by the military because the CNN effect has them scared of killing "innocent" civilians. Thus the search for non-lethal weapons.

We, on the other hand, as civilians, aren't bound by any such restrictions as the geneva convention, hague treaty, CBW, or any other "Rules of War". Thus, we can strive for the most lethal, heinous weapons conceivable, limited only by our allowances. HAHAHA! http://theforum.virtualave.net/ubb/smilies/wink.gif

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"I have begun evil, I shall end evil. That is the end that awaits me."

Go here (http://briefcase.yahoo.com/nbk2k) to download the NBK2000 files and videos.

[This message has been edited by nbk2000 (edited October 21, 2001).]

[PYRO500]

I saw it on the jay leno show, I also found several web pages like these.

http://www.physics.umd.edu/deptinfo/facilities/lecdem/h6-05.htm

and a msds I checked before posting.

http://www.boc.com/gases/pdf/msds/G080.pdf


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"Death may come from above, but terror most certainly comes from below."

[Bander]

Sorry to continue a counterproductive topic but I've found the most exceptional source of physics information that has existed...well, quite simply, EVER. It includes a great section on open, closed, and conical tube resonance!

HyperPhysics (http://230nsc1.phy-astr.gsu.edu/hbase/hframe.html)
and
Sound Resonance Section (http://230nsc1.phy-astr.gsu.edu/hbase/sound/rescon.html)

Also, I agree with you to an extent nbk2000, but I believe non-lethals do have a place in the civilian arsenal. While we are not bound by any restrictions, public opinion could be very important in some cases (also, you could avoid the death penalty if caught). If you are trying to coerce the public to believe in your cause it'd probably be best not to kill anyone, else the media would have more material to vilify you.

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Round the firewall, Out the modem, Past the server, Through the router, Down the wire, NOTHING BUT NET.

[nbk2000]

I'm not saying all less-lethal weapons (more accurate description than non-lethal) are useless, just that the applications must be considered diferently than in the military context.

We would use LLWs because we need the targets alive for a purpose later on. Such as access codes, combinations, or such. NOT because we give a fuck about what CNN is going to say about it.

I'm including LLWs in the NBKv2 since they have applications in robbery, kidnapping, etc.

One must always have lethal weapons on hand though for use if the LLW proves inadequate or if the target responds with lethal force.

Remember the RTPB: "Victory Through Superior Firepower".

Also, even if you don't kill anyone, you can still get life in prison with no parole (the Big Bitch) or so many years from multiple counts that you'll never parole.

Now, faced with the prospect of 40 years of life in prison, doesn't death in 5 sound like a much better alternative? Having been there, I'd say kill me quick.

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"I have begun evil, I shall end evil. That is the end that awaits me."

Go here (http://briefcase.yahoo.com/nbk2k) to download the NBK2000 files and videos.

[Mr Cool]

Not an infrasound weapon, but a sound weapon which appeared in a recent New Scientist mag:
It consists of a polymer tube, 1m long and 4cm in diameter, with piezoelectric discs all the way down it's length, facing the opening at the end. The first disc has an electric pulse applied to it, causing a shock wave to travel down the tube. The wave is then amplified in a laser-like fashion, so that when the wave reaches the next disc, that disc fires so it amplifies the pulse. The device operates at 6 to 10 KHz (I think that's what it said), and can produce 140 dB. Apparently effective range will be c. 100m. It causes intense pain and temporary/permanent hearing loss.
Shouldn't be too hard to improvise really, if you assume that the speed of sound is constant in all weather conditions. If not you'll need sensors to time the firing, but I think this would be uneccesary (I hate trying to spell that word, I'm sure I always get it wrong...) with a tube only 1m long, since the effect over the tube's length would be very small.
Apparently the inventor made a small version which nearly knocked him over or something. Get the magazine if you want more detail, I can't remember the rest.

[Cricket]

I once heard on the Discovery channel (Non Lethal Alternatives) that if you direct two seperate VHF (30,000hz seems right) waves at an animal, it will cause sever discomfort and nausea. Then It showed a computer created demonstration of what it would look like. They had two pipes about 5 meters apart shooting the waves at people so that they would intersect just below his sternum (chest bone). Then that had what was basically a pipe with a fuel (kerosene I think) injector and spark plug in it that supposedly caused the same effects. If anyone has cable, the Discovery Channel shows several shows in the evening of the weekends. This is quiet interesting to me, as is the White Noise. In a recent JC Whitney catalog, I saw a speaker that played as low as 10hz for 50USD. That was very cheap and twice as low as any other speakers I could find. I plan to buy it it within the next 1-2 months and do some testing with it http://theforum.virtualave.net/ubb/smilies/smile.gif.

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"You will not be taught the knowledge you seek, you must teach yourself." - Megalomania

[nbk2000]

I've got that discovery Channel show on tape!

I'm including bits of it my PDF.

If you could give anything more specific about that article, I may be able to find it on the net.

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"I have begun evil, I shall end evil. That is the end that awaits me."

Go here (http://briefcase.yahoo.com/nbk2ooo) to download the NBK2000 files and videos.

[Cricket]

Yea, thats why I like watching cop shows and the like, to learn how not to get cought doing anything fun. Lets see, what was that guys name... ah I think it was Lt. Sidney Heal (he was on that show), but I'm not sure. You will see him on many of the non-lethal shows and of California's gunfights and car chases. He is (or was when the show was taped) a Marine reservist and got sent to Desert Storm and helped in the devleopment of many non-lethal weapons. That tape you have is valuable. It talks about a study they did in the late 70's of a massive bubble generator to make running harder. Now a days they have something simular in effect (although the people in the bubbles seem as if they are having a good ol time at a pool party), but it is like the shit Spider Man shoots from his wrists. They just shoot the bag guy and he is essentially stuck. One example of the value of the show would be is if it said what the foam was. If it did (it might), you might find out that it is water soluble. In such a case, if you thought fast, you would try to set off the springlers if you are inside (possibly by shooting the sprinkler heads). And the SWAT probably won't be trained what to in that situation, giving you an extra edge and possibly evading capture or aiding in doing so. So if you know all kinds little odds and ends like that, you will be much more likely to know what they will do and what to do to counter act that. One example is in some LA (I think thats where it was) prison riots, the guards would just start lobbing stingball grenades left and right. The prisoners didn't like that to they started using thier matresses as shields (a good idea). But eventually, they started dropping them from the floors above them. Sorry to get off topic though. And I am not sure what you mean, nbk2000, by more specific. I will try to see if it is on this weekend and tape it. Well I just went to discovery.com and searched for it and I can't find it. Mabye someone else will have more luck. I think it was "On the Inside".

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"You will not be taught the knowledge you seek, you must teach yourself." - Megalomania

[Mr Cool]

I've seen those "glue guns" you're talking about that stick people's legs together so they can't run. They reminded me of the guns the Ghost-busters have...
Anyway, I believe it can be removed with an oil - pour oil over it, and you can pull it off without it sticking to your hand. When it has been takem off an area, cover that area in oil so it won't stick back on.
I don't have any more details on the device I was talking about. I think the company that patented it was called "American Technologies".

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"Nothing makes a man fear much, more than to know little." - Francis Bacon.

[Bander]

Here's a link to the piezo-electric sound weapon mentioned by Mr. Cool.
Pentagon considers ear-blasting anti-hijack gun (http://www.newscientist.com/news/news.jsp?id=ns99991564).

The Ultrasound weapon is a semi-proven concept and I have read about it's use to induce naseau many times before. Amazing1.com (http://www.amazing1.com/ultra.htm) has something analogous to that device in their ultrasound section. The kerosene accoustic weapon most likely was infrasound (human flesh resonance) weapon to achieve the same effect. After all, I don't think it's possible to get a combustion tube like that firing 30,000 times a second.

While I love the idea of accoustical weapons, and I do believe they are possible, one has to look at all sides of the arguement. I suggest anyone interested read this paper by the Acoustical Society of America (http://www.acoustics.org/press/137th/altmann.html).

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Round the firewall, Out the modem, Past the server, Through the router, Down the wire, NOTHING BUT NET.

[This message has been edited by Bander (edited 12-09-2001).]

[atropine]

i thought that frequency was almost directly proportional too the preasure supplied too the whistle. Correct me if im wrong. Oh another frequency is 16Hz which induces epilepsy, and 18.5Hz which makes eye balls resonate

[Mr Cool]

(Edit: Sorry, the main point of this post has already been covered.)

Uurrrghh, that'd be horrid, having a weapon that makes people's eye balls wobble themselves to bits.

[ January 01, 2002: Message edited by: Mr Cool ]</p>

[nbk2000]

Exploding eyeballs....sounds fun :)

Wouldn't be much of a stretch of the imagination to envision the Feds using something like that though. They've already developed and are field testing a "non-lethal" weapon that uses directed microwave energy to raise your skin temperature to around 50C, analogous to touching a 150 watt lightbulb to your skin.

The pain of this is supposeded to "deter" you from whatever it is that you're doing. They do admit though that continued exposure to the beam (more than 20 seconds) will cause 3rd degree burns.

I can see how the seattle WTO riots would have gone if this was already in existance at the time>>>>>

We were trying to disperse the protestors at the World Trade Organization summit by using our newest humane non-lethal compliance device that gently heats the skin to feel like a sunburn.

But the protestors kept laying down to block the road. We had to aim at their faces because they deliberatly dressed in heavy clothes to nullify our non-lethal weapons effect. They even tried to cover their faces in an effort to furthur resist

REALITY: The protestors faces were deliberatly targeted by pigs who think that anyone who doesn't do a 9 to 5, Ozzy and Harriet lifestyle is untermensch (sub-human).

And when their eyes began to explode from being heated to boiling, the flesh peeling off their skulls, and their brains being poached into goo, by a lethal energy weapon, they instinctly grabbed their faces and feel to the ground in agony and blind.

Oh, and they wore heavy clothes because it's fucking cold in Seattle.

Reality is nothing, Perception is the TRUE Reality. And he with the best spin doctor, wins.

And the glue guns are bogus. Ever notice how in every demo that the "victim" is standing still? That's because the foam doesn't do any good unless it gets into a big enough blob to get both legs stuck together.

Buckshot aimed at the legs is much more effective.

[atropine]

i found something interesting on that the other night. It works basicaly as a resonant tube which combustable air fuel mix is burnt through. The frequency is regulated via a timing device much like that of a cars to ignite the mixture at the desired HZ. Due to the fact that the tube is resonant and the "explosion" produces around 100db+ i think this would be great for trying as a "theoretical" weapon. Sorrey about my spelling i just bin informed that im mildly dyslexic

[Bander]

[quote] ...resonant tube which combustable air fuel mix is burnt through. The frequency is regulated via a timing device much like that of a cars to ignite the mixture at the desired HZ. Due to the fact that the tube is resonant and the "explosion" produces around 100db+ i think this would be great for trying as a "theoretical" weapon. <hr></blockquote>

Yes, it is possible to generate very high decible level sounds in this manner. I think the best, cheapest, simplest way to achieve this effect would be a pulse jet. I'm sure a quick look at the links below will explain the topic far better than I ever could.

<a href="http://www.aardvark.co.nz/pjet/howtheywork.shtml" target="_blank">How Pulse Jets Work</a>

<a href="http://home3.inet.tele.dk/kennethm/" target="_blank">A comprehensive archive of Pulse Jet design documents and theory.</a>

<a href="http://www.u.arizona.edu/~tshipley/Engineering/MusicJet.0a0.html" target="_blank">Pulse Jets As Musical Instruments</a>

Of course all the methods for generating the required frequencies of vibration are horribly crippled by the <a href="http://230nsc1.phy-astr.gsu.edu/hbase/acoustic/invsqs.html#c1" target="_blank">inverse square law</a> (not effective at long distances), and omnidirectional except one: modulated high energy vortices. These vortices could carry chemical, marking, ect agents as well. If any of these theorectical devices could succeed it would be a vortex weapon of some sort. On that note I thought I'd mention my newly updated archive o' <a href="http://accoustics.superkuh.com/" target="_blank">acoustic weapons</a>. Still a work in progress but the documents are there. ;)

[ January 05, 2002: Message edited by: Bander ]</p>

[Mr Cool]

I saw a video of a high-powered vortex "cannon" firing at a sheet of water falling from some sprinklers. I know water isn't the hardest of targets, but you could tell it was powerful. Looked enough to knock a man down, so it'd be good for using like an anti-riot water jet, but not as a lethal weapon.
I think the vortex was made by a fuel/air combustion inside a large drum, which only had a small (a foot or so) opening. Also, the edge of the opening may have been shaped to make the vortex more stable.

[Bander]

You may download the vortex impact video mentioned above <a href="http://www.darknebula.org/superkuh/science/vortex/vortex%20launcher%20impact.mpg" target="_blank">here</a>.
http://www.ict.fhg.de/images/photos/wi-1sf_13.gifhttp://www.amasci.com/wing/smrg4.gif

Yep, pretty much just a tube with a vortex forming plate on the end. A better design would be a modified 2 stroke engine hooked up to a pipe. One of the big keys to a successful design is to minimize the standing shock wave, turbulence, and burning. Laval nozzels do this quite well.

http://theblog.hypermart.net/thurstonia/miscimage/vortex_shockwave.gif
Illustration of muzzle blast showing (a) turbulence, burning, shocks and (b) traveling blast shockwave and stationary mach disk.

http://theblog.hypermart.net/thurstonia/miscimage/vortex_destroyed.gif
Half view of vortex ring: (a) Expanding over normal shock and (b) ring being consumed by muzzle blast.

http://theblog.hypermart.net/thurstonia/miscimage/vortex_nozzle.gif
Optimal nozzle design.

*Most knowledge came from <a href="http://www.darknebula.org/superkuh/science/vortex/Military%20Non-lethal%20Vortex%20Research.pdf" target="_blank">this document</a>.

[ January 06, 2002: Message edited by: Bander ]</p>

[nbk2000]

I remember a toy gun back in the early 80's that shot an air vortex up to 20' away that would move a foil strip target.

Kinda goofy actually, but the principle worked.

If someone found one and scaled it up it might be useful for something. As it was, it could have been used to propel a bit of teargas powder or toxin.

BTW, the link to the video above was 404, but the file is still there at this link:

<a href="http://www.darknebula.org/superkuh/science/vortex/vortex%20launcher%20impact.mpg" target="_blank">http://www.darknebula.org/superkuh/science/vortex/vortex%20launcher%20impact.mpg</a>

Looks exactly the same to me, but it works.

You'll notice in the video that there's about a seconds delay between the two impacts. Which, from the perceived distance between the two water screens, would indicate a fairly low speed.

From what I've read, the latest military incarnation of this goes about 100 m/s with enough force to hurt at that distance (100m). A football field in one second. :eek:

[Bander]

The toy in question is the "<a href="http://www.yesterdayland.com/popopedia/shows/toys/ty1114.php" target="_blank">Wham-o-Puff</a>" gun. They were pretty popular back in the day until they were taken off the market. Apparently some kid thought it would be funny to shoot it in his sister's ear, blew out her eardrum. They can still be bought on auction sites such as ebay for a good sum of money.

*Link Fixed*

About the speed of military vortices, SARA's HETV (High Energy Toroidal Vortex) was capable of speeds from .5 to .8 the speed of sound and could carry up to 500 joules of energy within it's rapidly rotating core. Compare this to the 449 joules of a 9mm bullet with a muzzle velocity of 1099 ft/s. Pretty impressive. :D

[ January 07, 2002: Message edited by: Bander ]</p>

[Mr Cool]

Bander - d'ya know roughly what the diameter of the vortex from the military one was?

[Bander]

http://theblog.hypermart.net/thurstonia/miscimage/HETV.jpg

From the above picture of the HETV I'd estimate around 6". But I cannot be sure. So I've just sent an email to one of the creators pretending to be a high school student doing a science project on non-lethal weapons. Hopefully I can get a few more specifics very soon.

<a href="http://www.sara.com/" target="_blank">Scientific Applications & Research Associates, (SARA) Inc.</a> is the commercial entity (military contractor) that makes it.

The military is also working on adapting their series of grenade launchers to cut deployment costs. In their words:

[quote]
A canidate platform for military police and law enforcement communities is the GL-6 repeating revolver 40mm grenade launcher. The concept is to provide a two piece kit that retrofits to the gun and provides quick converstion between lethal and non-lethal modes of operation. The kit consists of a set of blank cartridges and a disposable rod which slides into the barrel and afixes to the muzzle.
<hr></blockquote>

The rod serves as the vasal nozzle and injects chemical agents applied to it's surface into the vortex. Auto grenade launchers are being considered as well to take advantage of resonance effects.

[ January 09, 2002: Message edited by: Bander ]</p>

[Mr Cool]

Excellent, a picture says a thousand words. Yeah, looks c. 6". I thought it might have been some huge great 3' diameter one.
I've started work on a little model, which may or may not have potential to be scaled up to something decent. Very simple - a 1.5' long bit of 4.5" diameter pipe, with the nozzle on one end (I'm making it similar to the one in the picture Bander posted) that will have an opening of around 1-2". The other end will have a balloon attached inside it, that when inflated will force the air out of the nozzle. The balloon will be inflated by pumping up an air chamber to X psi (I'll have to do some testing to find the best pressure), and then discharging this through a ball valve or sprinkler valve or something into the balloon, to rapidly inflate it. I was going to have an air/propane mixture, but I thought this way would make it simpler to get consistent results, and using the balloon rather than dumping the air straight in will reduce the turbulence inside the big bit of pipe, which has got to be a good thing I suppose. The balloon then deflates by itself through a small opening in the pipe which carries the air from the compresssion chamber to the balloon. I'll try to draw you a diagram to help explain if that isn't clear.

Might work, might not. What do you think?

[Bander]

It sounds like it would work for low power testing, as long as you keep the inflation time sufficiently short. That's one of the keys to forming a good vortex.

Also, vasal nozzles are mostly used to expand gases to atmospheric pressure and eliminate standing shock, problems your device won't have. A simple hole in a typical vortex forming plate configuration will probably give you near the same performance with much less hassle. Plus if you start with a small hole you can test progressively bigger holes easily to find the best ratio. I'd skip the laval nozzle for now. Otherwise it's sounds great.

I'm sure we all know many ways to generate smoke to make the vortices visible, but combining the vapors of hydrochloric acid and ammonia worked the best for me. Just soak two paper towels with the respective liquids and set them in the device. Nice and simple. Toxic fumes make the vortices infinetly more fun as well. :D

[mrloud]

I once used a vortice generating device to blow smoke rings a distance of seven or eight metres. It was as simple as an old bass drum with a 50cm diameter circular hole cut out of one side. A quick squirt from a smoke machine to fill up the drum and I would beat the other side (without the hole) of the drum with a beater. A 1m diameter smoke ring would launch itself out of the drum and shoot accross the stage at about 3 or 4 m/sec.

This leads me to think that a great quantity of air is not required to generate an air vortex. Just a short sharp pulse at one end of a tube. I think a ball valve will release the air far too slowly to be much use. There is a different type of valve available though. I cant remember what they are called but they are almost digital. They are either open or closed and at the touch of a button they open, instantly releasing the pressure behind them. I suspect paintball guns use this type of thing.

[Mr Cool]

Yeah, I realised that about those nozzles today. I remembered the diagram wrong, and thought the vortex was produced inside the nozzle and was helped to stay stable by the walls.

Better idea for getting gas into it - an exhaust valve like on good pneuamtic spud guns, the ones with the piston that flies back and uncovers the rear end of the barrel so the air can rush in. They open almost instantly.

Yeah, I've now decided to have a smaller volume chamber, and a smaller amount of gas going into it, since a c. 6" diameter vortex dosn't need much air, and any excess air would probably only disrupt it rather than helping.