[Drag] chute drag...

[Jack Gifford]

Any wild guesses about how much the exposed chute pack on my lakester slows it down? (You can see it in my avatar photo). I'm mostly just curious, as I've got many more important things to do get it operational.

[kiwi belly tank]

There's likely something to be gained. Pack it in a tube & you'll find out.
  Sid.

[Rex Schimmer]

Jack,
As there is a pretty good chance that the air that the chute pack sees is air that has been attached to the tank body so it is probably turbulent but still attached so when it hits the chute pack it still  has good energy. I would take the frontal area of the pack, use a Cd of 1 and then calculate the hp required to push it through the air at your max speed. If you use a tube or cover the chute pack with a proper aero shape you will then be able to use that hp to go faster.

Rex

[robfrey]

Don't forget the exposed end of the tube will have drag (separation). Make sure it's part of your calculation if you are looking for accurate numbers. A good place to start will be 50% of  area of tube as flat plate equivalent.