In the curvature applet, you are able to adjust the amount of curvature in the airfoil, turning
the leading edge upwards or downwards. As you do, notice how the streamlines start to bunch up
as the leading edge gets from the original location. Having the leading edge very curved
like this is a condition which is avoided since it is inefficient at any speed.
An interesting thing to try is to bring the curvature to either a minimum or a maximum. Notice
how the streamlines have to bend sharply as they approach the airfoil. This causes huge amounts
of drag, which is why almost all airfoils have relatively small curvature.
Warning: This applet is computationally intensive. On most modern computers, the time it takes
to update after you click is under one-tenth of a second, but on more outdated computers,
it may take as much as five seconds. Please don't click again, thinking nothing happened,
as the applet is recomputing the streamlines.
When the applet loads, you will see an airfoil with many lines around it - the
streamlines. The airfoil which appears by default is representative of
a modern airfoil. To look at an airfoil representative of that on the
Wright Brothers flier, click the "early" button. If you decide
you'd prefer to go back to a more modern airfoil, click the "modern" button.
To adjust the curvature, you can use the two buttons on the right bottom side of the applet. Click
the button with the curved shape you want to approach, ex. the bottom button to make an airfoil
which is shaped like a bowl.