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 64 users online :: 4 registered, 0 hidden and 60 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

Barrel/Chamber length?

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: jimmy101 » Wed Nov 21, 2007 12:18 pm

Hopefully you can get GGDT working, it'll answer all your questions.

Here is what I get. Had to make a few guesses about the ammo mass (used 100g which is probably too heavy), valve parameters etc. The horizontal axis is the barrel length, the vertical the velocity at that barrel length.

As you can see, the optimal barrel length is about 70". But, chopping the barrel length in half to 35" has very little affect on the muzzle velocity.
  • 0

Attachments
GGDT_thetrooper.jpg
GGDT output for TheTrooper
Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3127
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: DYI » Wed Nov 21, 2007 4:56 pm

The inner diameter of 1.5" pipe is 1.61", not 1.5, and he said the bore would be 0.75", not 1.5".

By these specs, he could use a barrel more than 12' long and still be gaining performance.

As for practicality, use as long a barrel as is practical.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Previous

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'