Magnus Effect Calculator, Thanks NASA!

The National Aeronautics and Space Administration's Glenn Research Center has provided a great Java applet that calculates, among other things, the lift on a rotating cylinder due to the Magnus Effect.

Using it I found the following (all for a cylinder twenty feet long):

• for a large radius of three feet and 20RPM, the lift is given as 825lbs.

Wow. That's regardless of the mass of the tube itself. But that's pretty big, what if you use a smaller radius?

• for radius of one foot, an RPM of 180 gives 827lbs.
• for the same radius and only 60RPM, still 274lbs of lift.
  

That's still really impressive. Four smaller tubes would exceed the lift of the one big one at only three times the rotations per minute. But if you're using octet-truss structures to create your cylinders then bigger is better. You can create hollow tubes out of strut-work and make them as large as you please. Let's go with something still managable, say, ten feet in diameter (which seems to be as large as the calculator app wants to go, it seems.)

• A cylinder five feet in radius, turning only ten times in a minute, engenders according to the NASA Java applet, the staggering amount of 1144lbs.

Over a half a ton per twenty foot length of tube. Wow.