For those who want to think a bit ... amazing machine

[esgege]

On the video where we see the machine on the road, there is no input of external energy either, and yet it advances

[Olivier22]

Well, the energy supply is the wind in his ass

There is a speed difference between the wind and the ground (even when it rolls faster than the wind), so when we "connect" the 2 by a mechanism we harvest a power corresponding to the difference in energy of the 2 media. .

[esgege]

OKAY! I got it.

When someone explains to me for a long time, I quickly understand ...

Must say that your explanation deserves to be clear.

[jam]

Well, the energy supply is the wind in his ass

There is a speed difference between the wind and the ground (even when it rolls faster than the wind), so when we "connect" the 2 by a mechanism we harvest a power corresponding to the difference in energy of the 2 media. .

But when it moves faster than the wind, it has no thrust behind! The famous cloth shows this.

What are the two backgrounds?

[Olivier22]

It is not a problem that there is no more push from behind.
Or rather if, there is a thrust from behind (created by the propeller) greater than the resistance of the wheels. Because the resistance of the wheels creates a thrust via the propeller TO WHICH THE wind IS ADDED.

We tend to think that the carriage receives head wind, but keep in mind that the rotating propeller always "sees" pressure coming from behind.

Small balance of forces:

Force pushing the cart (propeller) = true wind (back) + "wind" created by the rotation (back) - wind speed of the cart (face)

Force which brakes the carriage = resistance of the wheels driving the propeller (therefore of the wind perceived by the propeller: wind speed of the carriage - "wind" created by the rotation)

So if we do the overall assessment:
Sum of forces on the carriage = real wind (+ wind rotation - wind rotation) (+ wind speed - wind speed)

So the force of the real wind always applies to the carriage, whatever its speed of movement (wind rotation and wind speed)! That the wind speed is greater than the real wind is not a problem, since it cancels out in the global balance.

Obviously this balance does not take into account the performance, in particular the force which brakes the propeller but does not push the carriage: drag of the blades. That's why it doesn't reach the speed of light

[jam]

We tend to think that the carriage receives head wind, but keep in mind that the rotating propeller always "sees" pressure coming from behind.

Not only do we believe it, but we also see it (the rag)!

[Olivier22]

Yes OK we can see it, but the "wind" that counts is the one seen by the blades of the propeller. And that is indeed a "wind" coming from behind (reaction to rotation).
Finally I speak of wind but obviously it is the difference in pressure that counts. This is the effect of the resulting wind on the propeller blades: back wind, head wind (greater than the back wind we agree), and relative wind created by the rotation (canceling, except for the efficiency , the headwind)
The flag only shows the sum back wind + head wind

[Olivier22]

I just thought of a fairly simple explanation which I think will convince the most lost

Imagine a carriage with a gear such that the propeller advances precisely the value of its pitch each time it turns.
When this cart is driven without wind, the propeller therefore generates neither thrust nor brake. It turns "in a vacuum".
It is therefore like a sail not undergoing the relative wind due to the movement of the carriage!

So in case there is absolute wind, even weak, it gets caught in the propeller and pushes the carriage, even if it goes very fast.

[jam]

So, it would be necessary to add small "streamers" to see the direction of the wind on the propeller, either directly on the blades or directly behind the propeller. Or add smoke.

[bpval]

HEY

So, it would be necessary to add small "streamers" to see the direction of the wind on the propeller, either directly on the blades or directly behind the propeller. Or add smoke.

OU



WOW... COOL

I'm kidding

Go all wind