Wind-powered vehicle
At the same time, such vehicles are subject to relatively low forward resistance, compared with traditional sailing craft.
Depending on the alignment of the sail with the apparent wind, lift or drag may be the predominant propulsive component.
Land sailing is best suited for windy flat areas; races often take place on beaches, airfields, and dry lake beds in desert regions.
Limitations to iceboat speed are windage, friction, the camber of the sail shape, strength of construction, and quality of the ice surface.
[11] Kite-powered vehicles include buggies that one can ride in and boards that one can stand on as it slides over snow and ice or rolls on wheels over land.
Kite landboarding involves the use of a mountain board or land board—a skateboard with large pneumatic wheels and foot-straps.
[15] A 1904 version employed a re-purposed rotor from a mass-produced windmill with its gearing connected to driving wheels.
In both cases, power comes from the difference in velocity between the air mass and the ground, as received by the vehicle's rotor or wheels.
[24] It won the first prize at the Racing Aeolus held at Den Helder, Netherlands, in August 2008.
In 2009 and 2010 the Spirit of Amsterdam team won first prize at the Racing Aeolus held in Denmark.
[26] Some wind-powered vehicles are built solely to demonstrate a limited principle, e.g. the ability to go upwind or downwind faster than the prevailing windspeed.
In 1904 George Phillips of Webster, South Dakota demonstrated a propeller driven vehicle that could travel against the wind.
[27] In 1969, Andrew Bauer—a wind tunnel engineer for the Douglas Aircraft Company—built and demonstrated a propeller-driven vehicle that could go directly downwind faster than the windspeed, which was recorded in a video.
[29] In 2006, Jack Goodman published a video of a similar homemade design, describing it as "directly downwind faster than the wind" (DDFTTW).
[31] In 2010, Cavallaro built and piloted a wind-driven vehicle, Blackbird,[32] in cooperation with the San Jose State University aviation department in a project sponsored by Google, to demonstrate the feasibility of going directly downwind faster than the wind.
Blackbird has been analyzed a number of times since then, in research papers[37] and on the 2013 International Physics Olympiad,[38] and a working toy model was reconstructed w/ 3d-printing instructions in 2021.
