CL 2d to 3d

[nico]

Hi,


How a Cl from a 2d case (section data) is used to get the Lift of a wing. I am a student, and I found that in most text books the 2d Cl is not used at all in the computation of the Lift 3d. Is the section shape not so important?

[tspeer]

Good observation! The profile drag is only a part of the total drag, and for many applications the difference between competing section designs is in the noise level.

As the saying goes, "If you're hunting elephants, you have to go where the elephants are," and there are much bigger targets for improving performance than the section drag. At maximum L/D, the induced drag will be equal to all other sources of drag, so there's a big target. A modest increase in span can be more important than the most advanced section design.

And the windage of a sailboat can be as great a source of drag as the whole hull. (see http://steamradio.com/JSYD/Dogstar50-article.html)

[yipster]

maybe also still of interest aldo it isnt very much... http://syr.stanford.edu/WindTunnel.htm
yipster

[jonathan]

I thought you might also be interested by this article.

http://www.amasci.com/wing/rotbal.html

cheers