El Mirage ...lakebed - in the news here!

GyrOZprey

Aussie in Kansas.
Joined
Aug 8, 2011
Messages
3,075
Location
Whitewater KS
Aircraft
Butterfly Aurora N5560Z / Titanium Explorer N456TE & N488TE/ - trained in MTOsport 446QT/488FB
Total Flight Time
845
Very cool! ...great follow-up!
 

kolibri282

Super Member
Joined
Aug 2, 2009
Messages
2,952
Location
Duesseldorf
I think he is still not describing the Black Bird physics correctly. Each propeller blade is the sail of an Americas Cup AC-75 going downwind with the chain drive from the wheels moving the sails the way a sailing craft would move downwind. The craft moves faster than the wind, because its "sails" (i.e. propeller blades) are accelerated to a VMG greater than the wind speed and the cart is attached to those "sails".

The AC-75 hydrofoil craft move downwind faster than the wind just as an ice-yacht. The innovative idea with this cart is, that the sails do not move linearly but rotate about a pivot point. As pointed out earlier one important point is that you have to get the transmission ratio from the wheels to the propeller right so that the propeller blades move fast enough to generate that relative wind over the blades that moves the whole thing.
 
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Tyger

Super Member
Joined
Nov 25, 2017
Messages
1,161
Location
Germantown, NY
Aircraft
Magni M16
Total Flight Time
420
Iceboats routinely go much faster than the wind that drives them...
 
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