Landyachts
Landyacht testbed build by Landyacht Design Interchange Association (LYDIA). (Apologies for the large size of this file!) This was a proof-of-concept vehicle used to try out new ideas in landyacht design and to investigate technical issues associated with the twin wing landyacht concept. The yacht was sailed with both direct mechanical control of the wing and with the wing free to pivot, controlled only by an aerodynamic surface on a tail boom.
The aerodynamic control was found to be effective for an aft tail but was not workable when configurred as a canard. The partial span flap was effective in providing aerodynamic twist for high winds, but caused excessive drag due to the abrupt change in span loading which increased induced drag and caused stalling of the wing immediately above the flap.
Wind tunnel test data and performance prediction of the landyacht built by LYDIA. The tests were performed by Matt Brown, Daphne Marschalk and Ricardo Camerena at San Diego State University under the direction of Dr. Joseph Katz. Model components were supplied by LYDIA. The surprising discovery from this test was the high drag created by the wheels - 30% to 40% of the total aerodynamic drag was created by the rear wheels alone. Also investigated was the effect of sealing the gap between wing and body which significantly improved the performance.
HTML version of a landyacht performance model. Not executable, but shows all the derivation and sample results.
Predicted performance for a notional landyacht powered by a rigid wing. The results are realistic, however reliable data for an actual design are not available to completely prove out the method.
A parametric study of the effects of wing planform on the efficiency and heeling moment of an isolated wing as would be used as the sail rig for a landyacht. The study is only concerned with lift and induced drag - airfoil parasite drag is not included. Interference with the ground is accounted for, but interference effects of the body are not included.
The origin and rationale for a landyacht which is powered by two rigid wings mounted in an "A" frame arrangement. Results include renderings of the concept and initial feasibility studies. Compared with a conventional landyacht, light air performance is degraded, but higher speeds in high winds are indicated. The twin wing concept has completely different load paths, which may result in a lighter structure.
A parametric study of the effects of wing planform on the efficiency and heeling moment of two isolated wings as would be used as the sail rig for a landyacht. This is a companion study to the single wing parametric study above, and the effects of the twin wing configuration are compared with the corresponding single wing configuration.