Vortex Cannon construction
HV Enthusiast, Thu Aug 24 2006, 01:29AMWell, its official. I showed the guy in charge of demonstrations for the Family Day event at my company and he wants a Vortex cannon for the kids. So guess who has to build one. Good thing I get to do this on company time!
Anyways, I plan on using a large plastic garbage can and probably purchase an cheap commercial fog machine.
Just a couple of questions:
1. Is there any tricks on properly sizing the exit hole for this cannon, or is it pretty much trial and error or not that important?
2. Also, i'll probably get a rubber sheet from McMaster-Carr. Any ideas on what would be a good rubber compound to use for the end membrane???
Thanks in advance!
Re: Vortex Cannon construction
Superkuh, Thu Aug 24 2006, 04:37AM
I have collected a few documents on higher energy vortex cannons that you may be interested in at:
http://nervousenergy.net/vortex/
[MODERATOR EDIT: Company Proprietary information is not permitted to be posted on the website.]
[Superkuh EDIT: Government Information. Approved for public release, distribution unlimited.]
I found the above removed document on a public database (STINET DTIC), and it seems to be funded with public resources. I appreciate your efforts to maintain the forums integrity, though.
Superkuh, Thu Aug 24 2006, 04:37AM
I have collected a few documents on higher energy vortex cannons that you may be interested in at:
http://nervousenergy.net/vortex/
[MODERATOR EDIT: Company Proprietary information is not permitted to be posted on the website.]
[Superkuh EDIT: Government Information. Approved for public release, distribution unlimited.]
I found the above removed document on a public database (STINET DTIC), and it seems to be funded with public resources. I appreciate your efforts to maintain the forums integrity, though.
STINET DTIC wrote ...
Accession Number:
ADA372518
Full Text (pdf) Availability:
Size: 3 MB
Handle / proxy Url:
Citation Status:
ACTIVE
Title:
Vortex Ring Generator: Mechanical Engineering Design for 100-kpsi Operating Pressures
Fields and Groups :
200400 - FLUID MECHANICS
Corporate Author:
ARMY RESEARCH LAB ADELPHI MD
Personal Author(s):
Lucey, George K., Jr
Report Date:
JAN 2000
Media Count:
52 Pages(s)
Organization Type:
A - ARMY
Report Number(s):
ARL-TR-2096 (ARLTR2096)
XAARL/ADELPHI (XAARLADELPHI)
DescriptiveNote:
Final rept.
Monitor Acronym(s):
XA (XA)
Monitor Series:
ARL/ADELPHI (ARLADELPHI)
Descriptors:
*VORTICES, TECHNOLOGY TRANSFER, SAFETY, MECHANICAL ENGINEERING, MACH NUMBER, STATIC PRESSURE, GAS GENERATING SYSTEMS, EXPLOSIVE GASES, VORTEX GENERATORS, JET STREAMS, SUBSONIC NOZZLES, NONLETHAL WEAPONS.
Identifiers:
EXPLOSIVE GAS GENERATOR, VORTEX RING GENERATORS, CROWD CONTROL, PE62120A
Abstract:
This report documents engineering design guidelines used to construct an explosive gas generator (100 kpsi maximum) and an adjustable area ratio (2844 maximum) nozzle. The equipment enables ring vortices to be generated using jet streams with significantly higher Mach numbers than previously reported in the literature. Studies are planned of the risks, limits, and capabilities of ring vortices for nonlethal crowd control applications. The focus is limited to 40-mm weapons, so this report is written to facilitate technology transfer to investigators interested in other applications and launch platforms.
Distribution Limitation(s):
01 - APPROVED FOR PUBLIC RELEASE
Source Code:
424778
Document Location:
DTIC
Geopolitical Code:
2405
Citation Created:
02 FEB 2000
Citation Updated:
18 JUN 2003
Accession Number:
ADA372518
Full Text (pdf) Availability:
Size: 3 MB
Handle / proxy Url:
Citation Status:
ACTIVE
Title:
Vortex Ring Generator: Mechanical Engineering Design for 100-kpsi Operating Pressures
Fields and Groups :
200400 - FLUID MECHANICS
Corporate Author:
ARMY RESEARCH LAB ADELPHI MD
Personal Author(s):
Lucey, George K., Jr
Report Date:
JAN 2000
Media Count:
52 Pages(s)
Organization Type:
A - ARMY
Report Number(s):
ARL-TR-2096 (ARLTR2096)
XAARL/ADELPHI (XAARLADELPHI)
DescriptiveNote:
Final rept.
Monitor Acronym(s):
XA (XA)
Monitor Series:
ARL/ADELPHI (ARLADELPHI)
Descriptors:
*VORTICES, TECHNOLOGY TRANSFER, SAFETY, MECHANICAL ENGINEERING, MACH NUMBER, STATIC PRESSURE, GAS GENERATING SYSTEMS, EXPLOSIVE GASES, VORTEX GENERATORS, JET STREAMS, SUBSONIC NOZZLES, NONLETHAL WEAPONS.
Identifiers:
EXPLOSIVE GAS GENERATOR, VORTEX RING GENERATORS, CROWD CONTROL, PE62120A
Abstract:
This report documents engineering design guidelines used to construct an explosive gas generator (100 kpsi maximum) and an adjustable area ratio (2844 maximum) nozzle. The equipment enables ring vortices to be generated using jet streams with significantly higher Mach numbers than previously reported in the literature. Studies are planned of the risks, limits, and capabilities of ring vortices for nonlethal crowd control applications. The focus is limited to 40-mm weapons, so this report is written to facilitate technology transfer to investigators interested in other applications and launch platforms.
Distribution Limitation(s):
01 - APPROVED FOR PUBLIC RELEASE
Source Code:
424778
Document Location:
DTIC
Geopolitical Code:
2405
Citation Created:
02 FEB 2000
Citation Updated:
18 JUN 2003
Re: Vortex Cannon construction
Tesladownunder, Thu Aug 24 2006, 05:50AM
Now a veteran of many hundreds of shots mine has been going fine. You don't need a fancy elastic membrane. I used a rubberised picnic blanket which is strong, flexible and airtight and cheap. If you stick a round doorknob into it and fasten it with a plastic tie you dont even have to put a hole in it. This leaves the inside to attach an elastic strap to. Even that is not essential as you can push it in and out manually rather than relying on recoil.
Just a caution on the garbage can. You need to get the smoke in from the smoke generator. If your whole unit is small you can't put it inside and you will need some form of tubing to connect. They are not designed for this and there will be heat and condensation issues.
The smoke generator has a warning not to operate it more than 15 degrees from the vertical. I have blown one for some reason ? pump failure.
The way mine sits the smoke will be directed in a circular manner around the inside of the vortex generator. This I think tends to keep the smoke in and perhaps closer to the edge rather than the center.
A sturdy frame is good preferably aimable and a gun sight on the top will be my next addition.
I used a 50 % hole. A larger hole means bigger rings but more open to the air and smoke loss and fewer shots before refiring the smoke generator.
Note that wind tends to ruin the effect so a sheltered area in sunlight would be best.
Indoors runs the risk of triggering smoke detectors.
Peter
Tesladownunder, Thu Aug 24 2006, 05:50AM
Now a veteran of many hundreds of shots mine has been going fine. You don't need a fancy elastic membrane. I used a rubberised picnic blanket which is strong, flexible and airtight and cheap. If you stick a round doorknob into it and fasten it with a plastic tie you dont even have to put a hole in it. This leaves the inside to attach an elastic strap to. Even that is not essential as you can push it in and out manually rather than relying on recoil.
Just a caution on the garbage can. You need to get the smoke in from the smoke generator. If your whole unit is small you can't put it inside and you will need some form of tubing to connect. They are not designed for this and there will be heat and condensation issues.
The smoke generator has a warning not to operate it more than 15 degrees from the vertical. I have blown one for some reason ? pump failure.
The way mine sits the smoke will be directed in a circular manner around the inside of the vortex generator. This I think tends to keep the smoke in and perhaps closer to the edge rather than the center.
A sturdy frame is good preferably aimable and a gun sight on the top will be my next addition.
I used a 50 % hole. A larger hole means bigger rings but more open to the air and smoke loss and fewer shots before refiring the smoke generator.
Note that wind tends to ruin the effect so a sheltered area in sunlight would be best.
Indoors runs the risk of triggering smoke detectors.
Peter
Re: Vortex Cannon construction
Bjørn, Thu Aug 24 2006, 05:59AM
I have used holes smaller than 30% with quite a lot of pressure to deliver more punch, so the size of the hole is not critical. I would have made a large hole in the garbage can and some plates with different size holes to study the effect.
Bjørn, Thu Aug 24 2006, 05:59AM
I have used holes smaller than 30% with quite a lot of pressure to deliver more punch, so the size of the hole is not critical. I would have made a large hole in the garbage can and some plates with different size holes to study the effect.
Re: Vortex Cannon construction
HV Enthusiast, Thu Aug 24 2006, 11:52AM
Thanks for the info.
So you are saying that I won't be able to put the smoke machine inside the garbage can?
Thanks
Dan
HV Enthusiast, Thu Aug 24 2006, 11:52AM
Thanks for the info.
So you are saying that I won't be able to put the smoke machine inside the garbage can?
Thanks
Dan
Re: Vortex Cannon construction
Tesladownunder, Fri Aug 25 2006, 01:12AM
I don't think you will fit my type of smoke generator in a garbage can without it filling a lot of the space and possibly affecting the flow of air adversely. My generator measures 32x15x15 cm with the outflow at one end so would need some clearance otherwise you will be blowing hot air onto plastic. You might just need to stick it in from the side or try a short corrugated tubing connection with aircon ducting or swimmng pool hose.
Peter
Tesladownunder, Fri Aug 25 2006, 01:12AM
I don't think you will fit my type of smoke generator in a garbage can without it filling a lot of the space and possibly affecting the flow of air adversely. My generator measures 32x15x15 cm with the outflow at one end so would need some clearance otherwise you will be blowing hot air onto plastic. You might just need to stick it in from the side or try a short corrugated tubing connection with aircon ducting or swimmng pool hose.
Superkuh wrote ...
I have collected a few documents on higher energy vortex cannons that you may be interested in at:
http://nervousenergy.net/vortex/
Blowing over a mannequin is a lot easier than blowing over a real person.I have collected a few documents on higher energy vortex cannons that you may be interested in at:
http://nervousenergy.net/vortex/
Peter
Re: Vortex Cannon construction
Nik, Fri Aug 25 2006, 05:19AM
I ended up setteling on a 50% diameter hole in my cannon and it has been fine. I based my cannon off of these plans . I am using a thick plastic bag as a as a diaphram. There is wood clamping together on oposit sides of the plastic (in the center) with an eye-bolt on each side. One as a handle to draw in air, the other is for the bungee cord.
Nik, Fri Aug 25 2006, 05:19AM
I ended up setteling on a 50% diameter hole in my cannon and it has been fine. I based my cannon off of these plans
. I am using a thick plastic bag as a as a diaphram. There is wood clamping together on oposit sides of the plastic (in the center) with an eye-bolt on each side. One as a handle to draw in air, the other is for the bungee cord.Re: Vortex Cannon construction
HV Enthusiast, Fri Aug 25 2006, 11:09AM
TesladownUnder,
I assume you have the center of your tablecloth diaphram connected to a bungee type cord which is then attached to the front of the barrel??
Thanks
Dan
HV Enthusiast, Fri Aug 25 2006, 11:09AM
TesladownUnder,
I assume you have the center of your tablecloth diaphram connected to a bungee type cord which is then attached to the front of the barrel??
Thanks
Dan
Re: Vortex Cannon construction
Nik, Fri Aug 25 2006, 05:25PM
I cant tell you about TDU's cannon but i can tell you that the bungee isnt a necesary part. Larger cannons need only a brisk push on the diphram to launch a ring.
Nik, Fri Aug 25 2006, 05:25PM
I cant tell you about TDU's cannon but i can tell you that the bungee isnt a necesary part. Larger cannons need only a brisk push on the diphram to launch a ring.
Re: Vortex Cannon construction
Tesladownunder, Sat Aug 26 2006, 01:04AM
Peter
Tesladownunder, Sat Aug 26 2006, 01:04AM
EastVoltResearc wrote ...
I assume you have the center of your tablecloth diaphram connected to a bungee type cord which is then attached to the front of the barrel??
Yep. I have a short cord which allows a full range of movement. With a doubled up length which my son preferred, the rings were much faster but he got blisters after about an hour I reduced it to one length. It is optional and you can simply push the air out slowly but you can still do this with the elastic cord. I assume you have the center of your tablecloth diaphram connected to a bungee type cord which is then attached to the front of the barrel??
Peter
Re: Vortex Cannon construction
Superkuh, Sat Aug 26 2006, 03:27AM
The empirically derived formula for predicting vortices behavior at these high energy levels should work just as well for optimizing less non-linear (at the formation; vortices are still soliton-like when formed) air compression/pressure sources.
Superkuh, Sat Aug 26 2006, 03:27AM
Tesladownunder wrote ...
Blowing over a mannequin is a lot easier than blowing over a real person.
Yes, though the ~500 joules of energy stored in the rapidly rotating core of the SARA combustion prototype is enough to knock both of the mentioned objects over--especially if the coherent core is carrying an appropriate incapacitating chemical agent (to disable the active balance system of the later object). They are just vehicles for the chemical agents if you are talking about crowd control uses.Blowing over a mannequin is a lot easier than blowing over a real person.
The empirically derived formula for predicting vortices behavior at these high energy levels should work just as well for optimizing less non-linear (at the formation; vortices are still soliton-like when formed) air compression/pressure sources.
Re: Vortex Cannon construction
HV Enthusiast, Wed Sept 06 2006, 01:40PM
I plan on using a very sturdy commerical plastic garbage can (35 gallon i think). Do you think a small smoke machine (like the one you have), placed inside the unit would affect performance at all? Of course, i can just try it, but thought i'd ask based on your experience first.
Thanks again
HV Enthusiast, Wed Sept 06 2006, 01:40PM
I plan on using a very sturdy commerical plastic garbage can (35 gallon i think). Do you think a small smoke machine (like the one you have), placed inside the unit would affect performance at all? Of course, i can just try it, but thought i'd ask based on your experience first.
Thanks again
Re: Vortex Cannon construction
Tesladownunder, Wed Sept 06 2006, 03:00PM
You wont be able to mount the smoke generator transversely and only just longitudinally. I would just use some duct tubing into a hole in the side from the generator. It doesn't have to be really air tight as everything is low pressure.
I would just make it first and blow smoke in with the generator from the front. You will have a good idea of what it is like then and how to join it up. Don't have to be too clever with these things as no rockets involved.
While cycling the other day I picked up water dispenser container. I suppose 20litre but has a 2 inch outlet at one end and nearly fully open at the other. Couldn't pass it by as it was 10k from the nearest town. It might be interestig to try to shape the outlet with a central cone to see what effect it has on efficiency.
Peter
Tesladownunder, Wed Sept 06 2006, 03:00PM
You wont be able to mount the smoke generator transversely and only just longitudinally. I would just use some duct tubing into a hole in the side from the generator. It doesn't have to be really air tight as everything is low pressure.
I would just make it first and blow smoke in with the generator from the front. You will have a good idea of what it is like then and how to join it up. Don't have to be too clever with these things as no rockets involved.
While cycling the other day I picked up water dispenser container. I suppose 20litre but has a 2 inch outlet at one end and nearly fully open at the other. Couldn't pass it by as it was 10k from the nearest town. It might be interestig to try to shape the outlet with a central cone to see what effect it has on efficiency.
Peter
Re: Vortex Cannon construction
HV Enthusiast, Wed Sept 06 2006, 03:37PM
Cool, thanks again!
Dan
HV Enthusiast, Wed Sept 06 2006, 03:37PM
Cool, thanks again!
Dan
Re: Vortex Cannon construction
EEYORE, Fri Sept 08 2006, 03:16PM
Hey guys,
while browsing United Nuclear, I came across something you may fimd interesting...
Matt
EEYORE, Fri Sept 08 2006, 03:16PM
Hey guys,
while browsing United Nuclear, I came across something you may fimd interesting...
Matt
Re: Vortex Cannon construction
Dr. Slack, Sat Sept 09 2006, 07:40AM
I saw this thread start while I was painting the ceiling. Finally the 5 litre paint can's empty, and I've got a few minutes to cut a hole in the bottom. A dead air-bed I've kept for who knows how long yielded a rubber diaphram. I used a 'smoke match' for the smoke generator. These are available from plumber's merchants, gas fitters use them for looking for back-flow down flues. A box of 20 for 50p, they burn for 20 seconds or so, so are fine for a quick look, but would get expensive for an open day demonstration.
With a 60mm hole, I saw 2x diameter rings out to 1.5m in daylight, but I'm sure with a torch in the dark I would see better than that.
A smoke generator I made years ago (don't ask me) consisted of a 1 watt resistor wound with several turns of paper, held in place by wire. A few watts pumped into it was enough to char the paper for a minute or two, without it bursting into flames, and allowing the resistor to be used again. Now these would be cheap enough to use continuously just by replacing the paper, rewinding one while the other was smoking.
Dr. Slack, Sat Sept 09 2006, 07:40AM
I saw this thread start while I was painting the ceiling. Finally the 5 litre paint can's empty, and I've got a few minutes to cut a hole in the bottom. A dead air-bed I've kept for who knows how long yielded a rubber diaphram. I used a 'smoke match' for the smoke generator. These are available from plumber's merchants, gas fitters use them for looking for back-flow down flues. A box of 20 for 50p, they burn for 20 seconds or so, so are fine for a quick look, but would get expensive for an open day demonstration.
With a 60mm hole, I saw 2x diameter rings out to 1.5m in daylight, but I'm sure with a torch in the dark I would see better than that.
A smoke generator I made years ago (don't ask me) consisted of a 1 watt resistor wound with several turns of paper, held in place by wire. A few watts pumped into it was enough to char the paper for a minute or two, without it bursting into flames, and allowing the resistor to be used again. Now these would be cheap enough to use continuously just by replacing the paper, rewinding one while the other was smoking.
Re: Vortex Cannon construction
ragnar, Sat Sept 09 2006, 11:32AM
I've used rolled up newspapers to make smoke. The idea being to ignite it at the bottom, on the inside, then extinguish the flame so that it smoulders. By controlling the width of the opening at the base, and the looseness between layers, you can vary the length, density and pooey-yellowness of the smoke. ^^
An A3-sized sheet of newspaper would smoke horribly for at least two minutes =-D
ragnar, Sat Sept 09 2006, 11:32AM
I've used rolled up newspapers to make smoke. The idea being to ignite it at the bottom, on the inside, then extinguish the flame so that it smoulders. By controlling the width of the opening at the base, and the looseness between layers, you can vary the length, density and pooey-yellowness of the smoke. ^^
An A3-sized sheet of newspaper would smoke horribly for at least two minutes =-D
Re: Vortex Cannon construction
HV Enthusiast, Sat Sept 09 2006, 01:53PM
Thanks again for the help. Vortex cannon is complete and i'm ready to do my cousin's 4 year old birthday party this afternoon. Should be the hit of the party!!! I'll post some photos tonite.
Dan
HV Enthusiast, Sat Sept 09 2006, 01:53PM
Thanks again for the help. Vortex cannon is complete and i'm ready to do my cousin's 4 year old birthday party this afternoon. Should be the hit of the party!!! I'll post some photos tonite.
Dan
Print this page