Quote:
Originally Posted by DavisDad
Thanks James for the heads-up. Compressed air limits are: - Max supply pressure = 60 psig
- Solenoid Cv = 0.35
- Compressor capacity = 1.05 SCFM (says CFM in the rules ???)
My pressure required at the cannon will be less than 10 PSI = 50 PSIG dP. If I'm doing the air Cv calc right, I get between a bit over 10 SCFM.
I'm also looking at high pressure blower feasibility (~ 8 PSIG). Any thoughts on that legality? |
My math says that filling that volume chamber (8in diameter, 8in length, right cylinder) at 10CFM will result in an exit velocity of less than 0.5ft/s. No doubt this equation is simplistic, but it shows that the idea is two orders of magnitude off of what I consider a good exit velocity (50ft/s is what we're 'shooting' for) and I would abandon the idea as unfeasible, pneumatic component legality aside.
Hope this helps guide your design decision.
Using a fan or blower may work, and I don't *think* it would be illegal (I AM NOT THE GDC), but I don't think that it will efficiently transfer kinetic energy to the ball. I spent most of my junior year of college building and running turbo-machinery experiments, so this is a 'semi-expert' opinion, take it for what its worth. A decent,
maximized, blower efficiency is usually around 80%, and I bet you won't be operating near this over a shot cycle given that the ball is accelerating away and therefore your flow rate is changing rapidly. I don't think the work of sizing motors, blower, housings, and a lunch tube to work optimally will be worth all of the inevitable efficiency sacrifices you'll be making.