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Mess with your minds: A wind powered craft going faster than a tail wind speed.
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PlainName:

--- Quote ---What you call that wall of air is the wind (air particles moving in the same direction in average)
--- End quote ---

No! The 'wall of air' is the prop wash flowing backwards. The wind is a separate flow going forwards. The two meet at the 'wall'.
Kleinstein:

--- Quote from: electrodacus on December 24, 2021, 06:28:23 pm ---That equation I posted shows the available wind power the stored energy is a separate equation that makes no sense to talk about until you understand that vehicle has no wind power available once wind speed is exceeded.

--- End quote ---

Wise words :  now I understand why some of the equations given by electrodacus make no sense.

The disagreement is about whether it is possible to get wind energy when already faster than the wind or not. So by definition we do no agree on this and can not use this in our arguments, as it would be a circular argument.
electrodacus:

--- Quote from: Kleinstein on December 24, 2021, 07:02:34 pm ---
Wise words :  now I understand why some of the equations given by electrodacus make no sense.

The disagreement is about whether it is possible to get wind energy when already faster than the wind or not. So by definition we do no agree on this and can not use this in our arguments, as it would be a circular argument.

--- End quote ---

There is a big difference between wind power and stored energy. If vehicle was wind powered it could drive forever above wind speed (not possible) but if it is powered by stored energy then it will start to slow down once the stored energy is used up.

It is very important to understand that this direct down wind blackbird will slow down after stored energy is used up and it will not as you all claim maintain above wind speed indefinitely.
PlainName:

--- Quote ---What you call that wall of air is the wind (air particles moving in the same direction in average) and once your vehicle exceeds that the vehicle will face the opposite as not vehicle is no longer pushed by wind
--- End quote ---

OK, so if we ignore the prop and have an infinitely long vehicle with a sail moving from the front to back, don't you agree that the SAIL could be moved at wind speed and the vehicle would then move faster? Ignore for the moment the power needed to move the sail - we are just interested in if we are together at this point.

If you don't agree, please say exactly why not.
electrodacus:

--- Quote from: dunkemhigh on December 24, 2021, 09:16:18 pm ---
OK, so if we ignore the prop and have an infinitely long vehicle with a sail moving from the front to back, don't you agree that the SAIL could be moved at wind speed and the vehicle would then move faster? Ignore for the moment the power needed to move the sail - we are just interested in if we are together at this point.

If you don't agree, please say exactly why not.

--- End quote ---

Not quite sure I understand your infinitely long vehicle but you seems to say the sail will move directly down wind relative to vehicle and then that movement will be used to power the vehicle.
If that is correct then no the vehicle can not move faster than wind since at the point vehicle speed and wind speed are equal the sail will no longer move relative to vehicle body and no movement means no power.
But also when vehicle is above wind speed the sail will move in the opposite direction relative to vehicle thus will slow the vehicle down.
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