Scalability of flexible kites

by Pierre Benhaïem in Airborne Windenergy Forum · · 2 Replies · View last reply Respond
Pierre Benhaïem
Pierre Benhaïem

There are studies of scalability of flexible kites, comprising https://www.researchgate.net/profile/Guilhem_Bles/publication/262003372, or http://link.springer.com/chapter/10.1007%2F978-3-642-39965-7_31#page-1 .
    Both studies explain that weight/m² fabrics increase faster than kite area due to stress requirement in the fabric. For example when the kite is 1000 m² the weight/m² fabrics is about 2 to 3 times the weight/m² fabrics for a 100 m² kite. So on can deduce the same when the kite is 10000 m² in regard to a 1000 m² kite

Pierre Benhaïem
Pierre Benhaïem

So the weight penalty is also a concern for flexible kites as they scale up.

Pierre Benhaïem
Pierre Benhaïem

In the end flexible kite would be better thanks to lesser cubic-square law penalty, lesser crash risk with lesser impact, public acceptability.

But there is no existing fabric-film having both mechanical robustness and lifetime enough for AWE use 24 h/24. See some indications on http://www.kempsails.com/yacht-sails/sail-fabric.html.

So searches for an efficient laminated complex or fabric for AWE use (24 h/24, several years) should be made. 

If no, rigid wings is a practical but perhaps not viable enough option. Some searches can be made in order to find arrangements to limit cubic-square law penalty of rigid wings.