Engineering: Can a wind driven vehicle drive faster than the wind?

[mikeofaustin]

Perhaps you may have stumbled up the recent nerd rage of, "Can a wind driven vehicle (passive), go faster than the wind itself that drives it"?. The quickest answer, that I myself immediatly came up with is "Obviuosly not". But, to my suprise, it's is possible. It's a head scracher for sure. It all started with the first proto-type on youtube here->
http://www.youtube.com/watch?v=aJpdWHFqHm0

Then later, they actually build a full sized vehicle to prove it. I was swayed because I finally looked at the way the propellar was spinning. It was pushing 'against' the wind. Not using the wind itself to drive the wheels.

Here is the official website http://www.fasterthanthewind.org/

 

[The Beep Goes On]

It looks like the prop is, as you say, going opposite the direction the tailwind would push it naturally. This means that it is going in the direction the forward motion through the air would push it. So, they get a push, the forward motion creates spin, the tailwind provides the moving cushion to push against which increases speed, further increasing spin, until equilibrium is reached. I think. Pretty cool.

 

[mikeofaustin]

It looks like the prop is, as you say, going opposite the direction the tailwind would push it naturally. This means that it is going in the direction the forward motion through the air would push it. So, they get a push, the forward motion creates spin, the tailwind provides the moving cushion to push against which increases speed, further increasing spin, until equilibrium is reached. I think. Pretty cool.

That's exactly right. I don't think this paradigm of engineering has ever been thought of before (at least in this regard). it's crazy. there were many, many highly important scientist that got into this discussion claiming that it would NEVER work. I was wowed too.

EDIT: Ironically, it got me to thinking about the movie 'Water World'.

 

[The Beep Goes On]

It is amazing that we're still finding paradoxically simple principles...

 

[GopherDaGold]

This reminds me of some CVD reactors I worked with that utilized the Bernouli Principle on delicate silicon wafers. In effect, positive airflow was directed in a way to actually cause a vacuum. The paddle sucked the wafer onto it's surface but there was a microscopic layer of air between them so the paddle never makes contact with the silicon wafer. Fascinating stuff!