I've seen an airfoil/windtunnel online simulation somewhere
on the NASA site, but can't find the link right now.
A similar, even better online simulation called JavaFoil
can be found on Martin Hepperles site www.mh-aerotools.de.
Hepperles site is good reading anyway, lots of interesting
aero stuff, resource to dig in. However, I don't think any software can be close as
convincing as an even crude homemade education windtunnel.
regardsAndre