how do you calculate area and wing loading for eliptical wingspan

[rc capo]

If there is a thread like this I couldn't find it...sorry.

How do you calculate the area and the wing loading for a wingspan that is eliptical? (sp?)

I have a Culver Cadet profile plans blown up to a 30" wingspan...the cord at the center/widest part is 7 11/16"

So now what do I do?

Thanks

rc

[Sparky Paul]

Unless you know the semi-major and semi-minor axes dimensions.. and I expect you won't, a reasonably accurate way is to break the area down into trapezoids, and measure each one.. and add the results..
.
Sparky Paul
http://www.angelfire.com/indie/aerostuff
PJB's Seriously Aeronautical Stuff
http://home.earthlink.net/~pjburke1/aindex.html

[Gary Warner]

If you are luck enough to have CAD skills, you should be able to CAD the plan form, maybe from importing a 3-view drawing of the plane (wing). Most CAD programs will give you the area. Loading is derived from area.

Gary
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[Dick Huang]

rc capo,
If we assume you have an elliptical wing for the Culver Cadet then the area=Pi*a*b=3.14159*15*3.84375=181.13 sq in.=1.258 sq ft. If the all up weight is 10 oz then the wing loading would be=10/1.258=7.95 oz/ft^2.
Dick Huang:)

[steve lewin]

Since wings are rarely true ellipses I always used to just trace the wing onto squared graph paper and count the squares. It's pretty easy to estimate the part complete squares. These days CAD will do it more accurately but it's still a pain setting the plan up unless you already have it in CAD format.

Steve

[J Morgan]

Read an article somewhere, sometime, where a guy said for an elliptical wing such as the Spitfire, take a piece of cardboard and make a rectangular section ( so it's easy to measure ). Then draw the wing planform on the same type of carboard. Cut out and WEIGH the cardboard wing . Then weigh the rectangular piece . Compare the weights and figure the percentage factor ( like the elliptical piece is 175% by weight of your rectangular piece). Then just multiply the area of your known piece by that factor to get the area of the elliptical wing. He claims it works but I never had use for it yet- hate hot wiring elliptical shapes. This is alot easier to do than to explain. It does make sense though as long as you stay with a consistent piece of carboard. Hope this helps.

[Gary Warner]

J,

Good idea. Just another way to skin that kitty.

Gary
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