Airfoil determination ?

[dadspet]

Looking to get a new set of foam cores for my Combat XE wing but I need to know the airfoil type before I can get them made. I have tracings of the cord and tip but don't have a clue on how to determine which airfoil it is. Can you determine the airfoil from the tracings and if so how.

Also is the some real basic description of airfoils for someone who doesn't really want to get into this subject very heavy?:confused:

[Ollie]

NACA (now NASA) had four digit and five digit system names for describing an airfoil based on its mean camber line and thickness distribution. Most other airfoil names do not describe any characteristics of the airfoil. They are just arbitrary. Chuck Anderson's airfoil plotting program generates the coordinate for the airfoil based just on the NACA name of the airfoil. The software program is available from Dream Catchers Hobbies.

You could compare your tacings to pictures of a couple of thousand airfoil shapes to try to find a match. Profili is a share ware program for plotting airfoils that has a library of thousands of airfoils.

Probably the most efficient way would be track down the designer of the model and ask him. Who is the supplier of the model? Are they still in business? Will they sell you a replacement wing?

What do you do if the designer used his left shoe as a french curve to draw the airfoil? In this case you could use the tracings to make formica templates for foam cutting to the specification of some foam cutter and send the templates to the cutter. Better yet, you could learn to cut foam cores yourself and use your own templates.

If all else fails, you could show some knowledgable person your tracings and they could offer an educated guess of the name of the airfoil.