Blocked vortex internal pressures

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
User avatar
farcticox1
Sergeant
Sergeant
Posts: 1078
Joined: Sun Mar 31, 2013 12:37 pm
Has thanked: 68 times
Been thanked: 94 times

Fri Jul 24, 2015 5:24 pm

In a blocked vortex setup is the pressure inside the BB hopper feeding the vortex equal to the supply pressure? or is it a lot less due to the venturi effect?
Just wondering how robust I need to make a vortex hopper. :idea:
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Sat Jul 25, 2015 10:16 am

When you say blocked, are you referring to a vortex block or the possibility of a projectile jamming in the barrel?

In normal operation, the BB hopper will be at a somewhat lower pressure than the supply pressure - due to Bernoulli's principle (this more general concept applies better here than the specific application of the venturi effect) there's a pressure loss due to the flow rate.
Also, the hopper is basically constantly leaking air out of the barrel, so as the hopper pressure rises, this leaking rate increases, and the flow from the supply decreases (as the closer it gets to the supply pressure, the less pressure difference there is and thus less flow), so the hopper pressure will naturally tend towards a point where these two flows are in equilibrium.

The vortex block will make some difference compared to a cloud design, as the improved feeding of BBs will reduce the amount of time the barrel is freely venting air, but the exact numbers will depend on the specific BBMG.

However, if the system jams, the hopper pressure can theoretically reach the full supply pressure. To be safe, you should really build your hopper to this specification.
Does that thing kinda look like a big cat to you?
User avatar
mark.f
Sergeant Major 4
Sergeant Major 4
Eritrea
Posts: 3628
Joined: Sat May 06, 2006 11:18 am
Location: The Big Steezy
Has thanked: 52 times
Been thanked: 53 times
Contact:

Donating Members

Sat Jul 25, 2015 11:48 am

Look who decided to show up. :P
User avatar
farcticox1
Sergeant
Sergeant
Posts: 1078
Joined: Sun Mar 31, 2013 12:37 pm
Has thanked: 68 times
Been thanked: 94 times

Sat Jul 25, 2015 3:07 pm

Yes, I guess a blocked barrel would result in full pressure build up.
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Sun Jul 26, 2015 9:23 am

mark.f wrote:Look who decided to show up. :P
Benedict Cumberbatch?? Where?
Does that thing kinda look like a big cat to you?
User avatar
Fnord
First Sergeant 2
First Sergeant 2
Posts: 2239
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Been thanked: 1 time
Contact:

Wed Aug 05, 2015 8:00 pm

Ragnarok wrote:
mark.f wrote:Look who decided to show up. :P
Benedict Cumberbatch?? Where?
No, it was just Hasselhoff again. Nothing to see here.
Image
Post Reply