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A kite is flown at some angle and elevation. Without wind, the string takes the shape of a catenary curve. But the wind is crucial.

Is there a name for the shape of a kite string -- is it some other well known curve? And is it easy to model based on lift, wind speed, and string parameters? What are the vital parameters in the model?

Ed Pegg
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1 Answers1

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From what I would assume, the two major forces acting on the string are gravity and the wind. There is some percentage of the force of the wind that is giving the kite lift, but assuming the kite's position is fixed, you have a force in one direction that forms the catenary curve, and then another in a perpendicular (to simplify things) direction that is dependent on the angle of the string with relation to the wind vector, assuming a simple wind system with a constant vector.

The wikipedia page for catenary curves goes into the shape of catenary curves under a horizontal force:

http://en.wikipedia.org/wiki/Catenary#Mathematical_description

Jonathan Rich
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  • I mention the catenary curve in my question -- I think it's more complex than that. – Ed Pegg Apr 08 '13 at 22:11
  • I think I might accept this... with just wind or just gravity, a catenary would be formed. So, sum of wind/gravity vectors, and a new catenary forms. If true, if wind force = gravity force, then the curve is equal to the curve between two posts at the same level. – Ed Pegg Apr 09 '13 at 17:05