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Old 10-24-2010
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The propeller is NOT driving the wheels, it is the wheels driving the prop, hence it is changing the apparent wind - due to loss and friction, they can only go "somewhat" faster than the wind, hence they aim for 3 times.

Pls. note that BMW Oracle moved from A to B faster than an object that could have moved directly downwind with the speed of the true wind, hence it did the same as the vehicle discussed here (albeit by tacking instead of using a propeller).


Quote:
Originally Posted by tomaz_423 View Post
I try to have open mind about it.

Few centuries ago people believed the earth is flat and a sailboat can sail any wind angle from DDW to reaching (close to 90%), but not higher.

I understand that the wind force is not linear with wind speed but squared and here apparent wind helps to create some healthy forces.
The sailboat can sail faster then true wind, but I understand not faster then apparent wind.

I have problems understanding this part:

Let us say the vehicle is traveling DDW.
Slower then the wind. It accelerates.
It reaches the speed of the wind.
What apparent wind does it have at that point? 0. Nada. Zero.
So, what the hell is turning the prop at that moment?
If there is no force from the wind it must come from somewhere else or we could make wind turbines to generate electricity in no wind.
I must take a closer look at this. At first glance it seems not possible.
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