Ring of Smoke:

In the lab we were able to create a small version of a vortex ring generator. This was made out of a coffee can and a balloon. By experimenting with the can we were able to observe the quality and the quantity of rings produced. Follow these links to find out more on vortex rings and how to make your own:

What we observed was the smoke channels remained fairly symmetrical without a very large wake or serration area. This plane doesn’t receive a lot of lift based on the way it is built, however because it is so light it is still able to fly.

WELL, when the surface of the ball is roughened or DIMPLED, air flowing around the ball becomes more turbulent by moving the oncoming air from the front of the ball out of the way. The turbulent boundary layer then becomes more "sticky" and causes the air to stick to the ball longer. This reduces the wake which in turn reduces drag on the golf ball allowing it to fly farther. 

Click to see an enlarged version

Check out this web site for more information on the dimples on golf balls:

Interested in 2D fluid dynamics?

This can be created at a reasonable cost for classroom use. Check out these sites for more information: