november 2nd, 2005
The Laddermill is an innovative concept for generating energy from wind using large kite-like wings on a tether. The wings are able to fly in both the regime of airplanes and kites. We therefore call these structures “kiteplanes”. By providing a recurring motion with a large lift during ascending and a lower lift during descending, energy can be generated. The Laddermill is currently under development at the Faculty of Aerospace Engineering at the Delft University of Technology. This paper presents the design and testing of a 3 meter span scaled model of a laddermill kiteplane. First, an introduction to the laddermill will be given. Then the sail wing will be outlined. Both aerodynamic and structural aspects will be addressed. The next section deals with the stability of the kiteplane. The eigenvalues are determined which govern the motions of the kiteplane. After the theory, the paper will go into the building of the kiteplane and the flight testing. The conclusion will go into the relevance of this wing concept to the laddermill and the eventual generation of sustainable energy.