I don't understand how this car works.

@BillRM,

BillRM wrote:

Quote:
It is a machine that mimics the actions and physics of a tacking sail, without actually requiring the vehicle itself to move from side to side. That's it. How hard is that to grasp?

Because such a device is not possible as if you have zero wind in relationship to the craft when you have zero wind in relationship to the craft. The only way to get any added force is to place the craft in a position to enjoy a wind in relationship to the craft and all the hand waving in the air is not going to change that fact.

Why is that so hard for you to understand?

Because it's a false assertion. You haven't provided any evidence for why the wind has to be in relation to the craft and not just the sail.

Cycloptichorn

0 Replies

@BillRM,

BillRM wrote:

Why is that so hard for you to understand?

It's not that its hard to understand, it's that you've got the device wrong.

1: Wrong in theory - as evidenced by support by some of the brightest minds in math and aero and by accurate equations showing such
2: Wrong it practice - as evidence by nearly 2 dozen now of these working devices constructed by over a dozen independent groups and individuals.
3: Wrong in understanding (yours). The device doesn't extract energy from the wind the way that you insist it must.

JB

1 Reply

@ThinAirDesigns,

I think you should give up on BillRM, ThinAir....

Some people don't think we really landed on the moon either.

2 Replies

@ebrown p,

ebrown p wrote:

I think you should give up on BillRM, ThinAir....

Yes ... I think you can see I'm not attempting to walk him through it like I am with DrewDad -- Bill isn't interested in knowledge. His mind is made up, why confuse him with the facts. :-)

JB

0 Replies

@BillRM,

BillRM wrote:

In the case of the old iceboat if you point it directly down wind then it can not go go over the vel. of the wind.

But point it at a 45 degree angle from the wind, and it will reach and maintain velocity where the downwind component is greater than wind speed.

The idea that a wind-powered vehicle cannot have a downwind speed component greater than wind speed is simply false.

http://en.wikipedia.org/wiki/Sailing_faster_than_the_wind

http://sites.google.com/site/yoavraz2/sailingboatspeedvs.windspeed

That's the mistake I made. Once you eliminate that misconception, then a machine to go directly downwind faster than the wind becomes a matter of how to do it.

2 Replies

@DrewDad,

DrewDad wrote:

That's the mistake I made. Once you eliminate that misconception, then a machine to go directly downwind faster than the wind becomes a matter of how to do it.

Perfectly put DD -- it's only an *engineering* problem, not a physics problem.

JB

0 Replies

@DrewDad,

Lord no craft of any kind or in any manner can pick up one mill-watt of added energy from the wind at the times when there is no wind in relationship to the craft.

Under the condition that a craft is going directly downwind once it reach the speed of the wind there is no wind in relationship to the craft, no force from the wind on the craft and the craft therefore can not have a steady state speed over the speed of the wind.

Thinairdevice is waving his hands in the air, as we are not talking about conditions where you are tacking from one side to the other in order to maintain a wind in relationship to the craft for the majority of it running time downwind.

We are talking about the condition and only the condition of a craft/device going directly down wind until it reach the wind speed and also in this case the wind vel. at which point there is zero wind force on it.

No magic and no kind of prop design or connecting the prop to the wheels is going to change that in anyway or in any manner.

And for the hundred and one times speed and vel are not one and the same either.

DrewDad, Thinairdevice is doing his very best to confused you and everyone else but hold onto the condition of a wind power craft going directly downwind.

2 Replies

@BillRM,

Quote:

Thinairdevice is waving his hands in the air, as we are not talking about conditions where you are tacking from one side to the other in order to maintain a wind in relationship to the craft for the majority of it running time downwind.

Christ, you're dumb. The angle of the props means that the sail is always tacking a little, even in a direct tailwind. The device is, from a physics standpoint, constantly tacking.

You don't know the first thing about what you are talking about - you just asset the same **** over and over again and pretend that this makes a good argument.

Cyclotpichorn

0 Replies

@BillRM,

BillRM wrote:

... we are not talking about conditions where you are tacking from one side to the other in order to maintain a wind in relationship to the craft for the majority of it running time downwind.

You can say that hundreds of times, but it still won't make it true.

0 Replies

@BillRM,

Quote:

Because such a device is not possible as if you have zero wind in relationship to the craft when you have zero wind in relationship to the craft

Except the propeller is NOT moving the same speed as the craft Bill. In fact if the propeller is spinning simple physics should tell you that the inner part of the propeller is not moving at the same speed as the tips.

Quote:

The only way to get any added force is to place the craft in a position to enjoy a wind in relationship to the craft and all the hand waving in the air is not going to change that fact.

Hmmm.. So the speed of the sail has no relationship to the speed of the craft in a simple boat?

1 Reply

@parados,

Take two ice boats. Connect them by rope.

The leading boat jibes back and forth, while the trailing boat goes directly down wind....

0 Replies

Take two iceboats on a mirrored series of reaches. Connect them by a long telescoping pole. Place the pilot's seat and the controls in the center of this pole.

Now you have a vehicle whose cockpit, pilot and CG are all traveling DDWFTTW.

JB

0 Replies

Take two iceboats on a mirrored series of reaches. Run a long monofilament from the rear of each waaaaay back (in a deep "V") to a small unpowered ice cart with the pilot on board.

Same as above.

JB

0 Replies

Put two iceboats on mirrored reaches in a frame like this one.

Now again ... a vehicle with the CG going DDWFTTW.

1 Reply

@ThinAirDesigns,

Take an iceboat, attach a big, steerable kite. Now fly the kite in a circle in front of you....

1 Reply

@DrewDad,

DrewDad wrote:

Take an iceboat, attach a big, steerable kite. Now fly the kite in a circle in front of you....

Nope -- if the iceboat skates are pointed DDW you won't get to windspeed, let alone above.

I'll let you stew on that one.

JB

1 Reply

Here's one that is called the "watercartwheel".

Directly downcurrent faster than the current:

http://talkrational.org/attachment.php?attachmentid=821&stc=1&d=1254347176

1 Reply

@ThinAirDesigns,

Dammit!

Just when I thought I had it....

1 Reply

@DrewDad,

DrewDad wrote:

Just when I thought I had it....

LOL -- you'll be fine -- but it does take time.

Think about our vehicle with the chain unhooked from the wheels -- the airfoils (prop) will fly around in a nice circle, but it's never going to get to windspeed. Same thing if we took a kite and flew it around in circles in front.

JB

0 Replies

Of course the WaterCartWheel device is just a play on the yoyo which can be used to demonstrate 'directly downstring faster than the string (and also 'directly upstring faster than the string')

http://www.mediafire.com/imgbnc.php/b6c267ad06aa7d5ac94e27be1466a3b45g.jpg

0 Replies

I don't understand how this car works.

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