Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 73 users online :: 4 registered, 0 hidden and 69 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Staged combustion chambers.

Post questions and info about combustion (flammable vapor) powered cannons here. This includes discussion about fuels, ratios, ignition systems, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Staged combustion chambers.

Unread postAuthor: inonickname » Thu Sep 10, 2009 4:49 am

I'm currently looking into how much muzzle velocity I can obtain from a 1x combustion launcher. Fuel will be hydrogen-oxygen or perhaps methane-oxygen. I am considering a new design to keep combustion pressures (and more importantly, temperature) up during the entire transition through the barrel by using staged combustion chambers, inspired by the V-3 cannon.

link

The gun used multiple propelling charges placed along the barrel's length and timed to fire as soon as the projectile passed them by, to provide an additional boost.


My idea is to use multiple smaller combustion chambers which run co-axial to the barrel with multiple high surface area ports. Each of these combustion chambers would be fueled with a stoichometric mixture of oxygen-hydrogen or oxygen-methane. As the projectile passes, the combustion gasses ignite the fresh fuel in each chamber and provides more pressure (throughout the barrel) and higher temperature. Assuming there is no projectile blow-by (and with the ammunition I'm using, there wouldn't be) there would be no issue with timing. Some of the gas from each combustion chamber may be lost but I wouldn't be concerned given the large flammability range of hydrogen.

Any thoughts? Before I'm told this isn't practical, I know. It's research, and an experimental launcher.

Tl;dr: using staged combustion chambers for moar pressure and temperature throughout the length of the barrel.
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: psycix » Thu Sep 10, 2009 5:37 am

Might work, but I dont think there will be a lot of improvement vs one large chamber.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: theBOOM » Thu Sep 10, 2009 7:18 am

Hm I'm not clear on what your trying to do here....
You basically want to make a combustion based spudgun that uses multiple chambers which are connected leading to a barrel?

This is the sentence that has me stomped: "As the projectile passes, the combustion gasses ignite the fresh fuel in each chamber and provides more pressure (throughout the barrel) and higher temperature."

Also what size are you planning to be building this in?
  • 0

User avatar
theBOOM
Major
Major
 
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX
Reputation: 0

Unread postAuthor: inonickname » Thu Sep 10, 2009 7:46 am

As a projectile passes through the barrel, the gasses lose temperature (and thus velocity) and pressure (velocity again). The idea is to use co-axial chambers placed throughout the barrel to be ignited by the gasses from the first combustion chamber and keep pressures and temperatures higher.

In 5.5-6.5mm (q-tip).

I can probably achieve similar performance with a low mix hybrid though.
  • 0

Attachments
stages.PNG
Black chamber is the initial chamber. Red chambers have ports to the barrel and are ignited as the projectile passes.
stages.PNG (5.71 KiB) Viewed 1392 times
PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: jmadden91 » Thu Sep 10, 2009 7:56 am

I don't know if this will be a problem or not, but could the gasses from the coaxial chambers interfere with the motion of the projectile? Perhaps causing it to strike the edge of one of the ports as it travels?
  • 0

User avatar
jmadden91
2nd Lieutenant
2nd Lieutenant
 
Posts: 246
Joined: Thu May 07, 2009 6:03 pm
Location: Queensland, Australia
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Thu Sep 10, 2009 8:08 am

It's been suggested before. I stand by the comments made in the previous thread, but don't let that stop you try and prove me wrong ;)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: jimmy101 » Thu Sep 10, 2009 9:05 am

Like Jack said, doesn't seem likely to work but if you think you can solve the various problems then go for it.

How will you seal the secondary chambers from the barrel to keep the fuel mix from leaking out the barrel? How do they get unsealed when the projectile passes?
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3128
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Sponsored

Sponsor
 


Unread postAuthor: Hubb » Thu Sep 10, 2009 9:14 am

Have you considered a ram accelerator?
http://www.tbfg.org/papers/Ram%20Accelerator%20Technical%20Risks%20ISDC07.pdf

That's basically what you are trying to do. I have been researching these types of launchers for over a year now, but never have had any desire to build one (I was tempted when the competition came out, but didn't).

The biggest problem I foresee with the V3 design or a ram accelerator is the same the JSR explained. It looks good on paper, but is probably a lot harder to put together.

Now, with that said, since I've taken an interest in this type of launcher, I will put faith in you and hope you can get it done. I would really like to see a fully functioning version of it. Oh, and if I can provide any assistance to you (maybe some of my diagrams I've sketched up for the ram accelerator) just let me know.

Good luck.
  • 0

User avatar
Hubb
Major General
Major General
 
Posts: 2390
Joined: Mon May 28, 2007 8:39 am
Location: South Georgia
Reputation: 2

Unread postAuthor: Technician1002 » Thu Sep 10, 2009 12:57 pm

Hubb wrote:Have you considered a ram accelerator?
http://www.tbfg.org/papers/Ram%20Accelerator%20Technical%20Risks%20ISDC07.pdf

Good luck.


:shock: Wow. Nice read. Noticed that one is for a 2,000 kilo projectile just under a meter in diameter. I noticed the sonic boom is projected to be above the threshold of pain out about 10 KM. Ouch.

Makes me think of the WWII supergun the V3.
  • 0

User avatar
Technician1002
Chief of Staff
Chief of Staff
 
Posts: 5190
Joined: Sat Apr 04, 2009 11:10 am
Reputation: 14

Unread postAuthor: ramses » Thu Sep 10, 2009 5:54 pm

I am inspired by that paper, and I may research it further. If you entered that in the contest, you would have had my vote.
  • 0

POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
ramses
Major General
Major General
 
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm
Reputation: 3

Unread postAuthor: theBOOM » Thu Sep 10, 2009 5:58 pm

Wow seems like a very interesting design... the only 2 complications I can think that will arouse from this are.
1. It's goanna be hard to time how long it takes for the fuel to ignite and also how long the projectile takes to cross the 2nd chamber / or the 3rd. mainly because if the 2nd or 3rd chamber ignite before the projectile has passed it would act as a "stopper" ..
2. It would be hard to figure out how much time apart you should set up your ignition system to.
  • 0

User avatar
theBOOM
Major
Major
 
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX
Reputation: 0

Unread postAuthor: inonickname » Fri Sep 11, 2009 4:28 am

1. It's goanna be hard to time how long it takes for the fuel to ignite and also how long the projectile takes to cross the 2nd chamber / or the 3rd. mainly because if the 2nd or 3rd chamber ignite before the projectile has passed it would act as a "stopper" ..
2. It would be hard to figure out how much time apart you should set up your ignition system to.


Not really a problem as the chambers are ignited by the heated gasses behind the projectile. Just that care must be taken that the flame front can't outrun the projectile. (hydrogen flame fronts average around 250 m/s).

How will you seal the secondary chambers from the barrel to keep the fuel mix from leaking out the barrel? How do they get unsealed when the projectile passes?


Small lightweight "burst film" could be used.

Perhaps causing it to strike the edge of one of the ports as it travels?


Silencers in spudguns are regularly constructed in a similar manner with little issue.


Unfortunately it's riddled with problems. A low mix hybrid will offer more reliability, power with less service. I still have the 1km/s plans, but have been unable to find suitable materials..yet. It may yet be down scaled again to a smaller bore.
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: jagerbond » Fri Sep 11, 2009 4:52 am

Thought about building something like this with our original twin O-ring designed UHMW rounds... So the pilot could be a simple spray and pray. worse case scenario the sudden increase in pressure could extinguished the combustion and it would a pneumatic with a combustion operated pilot...
  • 0

Attachments
Hybrid Pilot-Model.jpg
crude, but you get the idea.
Mike
Sureshot Inc. / http://www.ultimatespudgun.com
Image
User avatar
jagerbond
1st Lieutenant
1st Lieutenant
 
Posts: 286
Joined: Tue Jul 29, 2008 5:33 am
Location: Hawaii
Reputation: 0

Unread postAuthor: jmadden91 » Fri Sep 11, 2009 5:15 am

inonickname wrote:
Perhaps causing it to strike the edge of one of the ports as it travels?


Silencers in spudguns are regularly constructed in a similar manner with little issue.


In a silencer the forces are moving away from the projectile, into the silencer's chamber. Whereas in your design the force is coming in from coaxial chambers which could potentially knock the projectile off center?

**Note I have no experience in the matter and am talking out of my arse here haha
  • 0

User avatar
jmadden91
2nd Lieutenant
2nd Lieutenant
 
Posts: 246
Joined: Thu May 07, 2009 6:03 pm
Location: Queensland, Australia
Reputation: 0

Unread postAuthor: inonickname » Fri Sep 11, 2009 5:57 am

The idea is that the projectile has already passed before the gas can pass in front/disturb it's motion.

Anyone have ideas on the most reliable/powerful gas injection in terms of spudguns? I have NC and BP but would rather keep it "spudgun legal". This is to drive a piston.. I'm looking at high pressure hydrogen, 20x oxy-hydrogen hybrid or something else..not sure.
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Next

Return to Combustion Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'