30 ppl in my MMAE class calculated it last week and we all got .445 which is what my prof said it should be, so I'm pretty sure its .445

a golf ball should be Cv .52

the drag coefficient of the dart with no fins is Cv .2 but I have no idea what the Cv is with fins

and the drag coefficient of a sphere is .445

I am trying to find the drag coefficient of a shaved tennis ball. The drag coefficient of a regular tennis ball is .55 but i cant figure it out for a shaved one.

Anyone please help!!!!!!!!!!! I need to find this out for my MMAE class but have gotten stumped.

Thanks in advance to whoever helps!!

To give you an idea of what I meant, I ran a GGDT on a plan I drew up for a potential future project. Shooting a one pound tennis ball out of a 8 foot 2.5 inch barrel with 5 foot 3 inch chamber at 160 psi with helium gas, I can expect somewhere around 3,212.2 ft lbs of muzzle energy. Thats more ...

OK thanks for the info, I think i will make the chamber out of 3in PVC (instead of 2 1/2in) and cut it about 4-6in shorter then the barrel.

OK one more question, would it be beneficial to have the volume of the chamber larger than the volume of the barrel?

Thanks... I gess that answers my question. And what I meant about the optimal length of the barrel is that eventualy the tennis ball will stop in the barrel if it is to long. But I can't go much over 4 - 5 ft so that wont be a problem.

Thanks for the quick response!!
Stephen

I have a quick question. I am making a tennis ball cannon and would like to find out how long I need to make the barrel to achieve maximum range. The cannon will need to be air powered and have a presure no greater than 150 psi, and will be fired by a solenoid valve. Also, im not sure if this info ...