Software wind-tunnel?

[evermax]

I have a fluid dynamics program I use for visual effects work, and was thinking of adapting it to help in testing designs.
It will handle anything from light gas to flubber like jelly simulations.
It is far from realtime, but will bake simulations overnight.

Does anyone know of any existing aerodynamic wind tunnel software.
I imagine if there is any it will be $$$.

Thanks Evermax

[vintage1]

All I know from a few visits to a Formula one Car company, is that the software they use is very expensive, and not able to fully model all te car enough to be a replacement for a wind tinnel.

Nor are the wind tunnels accurate - scale factors and the fact that the air is particularly rushing past a road in a tunnel that travels with the car, screws that up.

And the road isn't bumpy either :D

They use the simulations to design parts, slap them in the wind tunnel to check, and then road test finally to be sure.

And the software is in the hundreds of thousands of dollars region.

[BMatthews]

http://www.grc.nasa.gov/WWW/K-12/airplane/foil2.html

Works in real time but is limited to a generic airfoil shape but with mods possible to thickness and camber. It starts off at full size but you can change the wing area and flying speed to model values with ease.

I find it very useful for determining lift coefficients so that I can figure out just where in the lift drag curves my wing will be operating at various flight modes.

It does have lots of limitations but it's great for getting a feel of what our models are doing. Just do not put a lot of stock into the stall mode. At our reynolds numbers the basic 10 degree stall is nonsense. "We" stall much sooner than that.

[uav51]

Search the internet for xfoil if you are looking to research airfoils. I think there is a yahoo group dedicated to it, and it is free. The results, like any simulation or wind tunnel need to be taken with a grain of salt, but it is very good for comparison sake. The interface is tricky to learn, but there's lots of info out there for using it. Just remember the results are not to be trusted outright as cl,cd,cm, etc can be quite optimistic or otherwise compared to real life. The results depend much on how well you can set it up, and interpret the results, and can be quite similar to actual wind tunnel tests. It can generate polars as well. Of course you have to adjust things again for aspect ratio, etc. There are more advanced programs out there for going beyond your basic airfoil, but the one's I've come acrossed are rediculously expensive - talking thousands to many many thousands here. Xfoil can be very useful if you know how to use it along with good old equations, but real life testing is the only way to know 100% how an aircraft will really behave. Also just remembered that at the low Reynold's numbers most models will be flying at, the results will be even more unreliable. Haven't kept up on newer versions of Xfoil, so maybe they have improved the low Reynold's number problems somewhat.

[evermax]

Cool Thank You ALL,

Ill post some test with my dynamics app when I get somthing worth while,
Thanks for the head start!

The Nasa applet is a pretty cool learning tool.
Going to check out Xfoil.

Evermax