Downwind faster than the wind. Poll

[snowleopard]

So let's see what people think of the claims

Here is one of the videos of the experiment

What do people think of the demonstration?

 

[Ubergeekian]

So let's see what people think of the claims

Here is one of the videos of the experiment

What do people think of the demonstration?

Since the cart is effectively stationary and the bulk air is effective stationary, this demonstrates moving downwind at exactly windspeed.

 

[snowleopard]

Since the cart is effectively stationary and the bulk air is effective stationary, this demonstrates moving downwind at exactly windspeed.

Sorry, bad choice of video. I've replaced the link with one where it is clearly moving forwards.

 

[[32511]]

Surely it's heading upwind, not downwind?

 

[HoratioHB]

Surely it's heading upwind, not downwind?

At last someone else who can see the b****y obvious. I made this argument on the other thread and was accused of trolling whihch frankly I found slightly insulting. Some people will do anything other than debate simple facts when they don't support their own opinion.

 

[snowleopard]

Surely it's heading upwind, not downwind?

As I said on the other thread, the belt is moving right to left so, relative to the belt, the air is moving left to right and the device, moving left to right also, is going downwind.

 

[HoratioHB]

As I said on the other thread, the belt is moving right to left so, relative to the belt, the air is moving left to right and the device, moving left to right also, is going downwind.

Then for the umpteenth time answer the question:

If you turn the vehicle about so it is going the other way - which you say is thererfore the into wind condition (by the way you also have to to turn the prop through 180degrees), how can it accelerate faster than the belt speed??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

or is your deabating technique just to avoid the questions you don't want to answer.

 

[snowleopard]

Then for the umpteenth time answer the question:

If you turn the vehicle about so it is going the other way - which you say is thererfore the into wind condition (by the way you also have to to turn the prop through 180degrees), how can it accelerate faster than the belt speed??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

or is your deabating technique just to avoid the questions you don't want to answer.

I have answered that in the main thread. As I said there, the downwind vehicle is not just an upwind vehicle turned round but another mechanism that looks superficially similar but operates on a different principle using a different source of power.

And please do me the courtesy of reading the post carefully before dismissing it again with a shower of personal insults.

 

[HoratioHB]

I have answered that in the main thread. As I said there, the downwind vehicle is not just an upwind vehicle turned round but another mechanism that looks superficially similar but operates on a different principle using a different source of power.

And please do me the courtesy of reading the post carefully before dismissing it again with a shower of personal insults.

Sorry you can't have it both ways, and I have read your posts carefully and have not accuse you of trolling which you did to me.
You claim the treadmill video shows the down wind condition and that the mechanism is different. Yet when I point out that if you follow your logic then if you turn the vehicle around it MUST be now the into wind condition (which we know works) but couldn't possibly work you simply refuse to even acknowldege the logic.

And the childish video of a few cogs simply shows how gear ratios work.

 

[Ubergeekian]

Then for the umpteenth time answer the question:

If you turn the vehicle about so it is going the other way - which you say is thererfore the into wind condition (by the way you also have to to turn the prop through 180degrees), how can it accelerate faster than the belt speed??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

or is your deabating technique just to avoid the questions you don't want to answer.

Are you doubting that a properly designed and constructed device can make its way into a headwind?

 

[RAI]

Reading some of spork33's comments in the threads below the Youtube videos is informative. As one would expect, the wheel to prop gear ratio is critical.

I think if the device is simply reversed on the treadmill it will try to do exactly the same thing and move up against the treadmill's motion. That's because it is in wheels-drive-propeller mode. To go up wind it would have to be in propeller-drives-wheels mode and would need a different gear ratio for optimum performance.

 

[fireball]

The video does show the downwind condition. As SnowLeopard has pointed out several times ....

The Treadmill belt is going from Right to Left ... so if you put an object on the belt the apparent* wind would be from Left to Right.
The device also travels from Left to Right against the flow of the treadmill - but with the wind - hence the device is travelling Downwind faster than the Apparent Wind*.

*Apparent wind - in this instance - it is induced wind due to the travelling of the (normally fixed) land surface - and is not to be confused with sailing's apparent wind which is effectively the same, but is usually brought about due to different affects.


Going upwind - dunno ... can't be aresed to think of that one atm

 

[snowleopard]

if you turn the vehicle around it MUST be now the into wind condition (which we know works)

What I am attempting to explain is that the vehicle that works going into the wind and the vehicle that works going downwind are not the same. Neither will work when reversed.

If you take an upwind vehicle and point it the other way it will go upwind in reverse! If you take a DDWFTTW vehicle and turn it the other way it will either sit there and do nothing or roll slowly downwind.

 

[Porthandbuoy]

I've stayed out of this, somewhat vitriolic at times, thread; but having voted here's my tuppence worth.

It's impossible. I don't see how any machine with frictional losses (and they all have) can get through the null period between a true following wind and an apparent headwind.

Is an increase in true headwind, say a gust, going to accelerate or decelerate this wonderful device? Sorry, Newtonian physics win.

 

[Marsupial]

So let's see what people think of the claims

Here is one of the videos of the experiment

What do people think of the demonstration?

Ahh that old chestnut, the power supply is the motor that makes the running machine work, some of this power is captured by the wheels of the device that feeds it via a gearbox to a shaft onto which there is a propellor. The thrust of the prop is arranged so it pushes the device along the running machine in the opposite direction to that which it is travelling. IT looks like the device is clawing its way upwind under its own power, but turn off the running machine and the party is over - no more power input.

Great for year 10 science thanks for the link

 

[RAI]

It's impossible. I don't see how any machine with frictional losses (and they all have) can get through the null period between a true following wind and an apparent headwind.

Is an increase in true headwind, say a gust, going to accelerate or decelerate this wonderful device? Sorry, Newtonian physics win.

I started with that view until I had to come to terms with BMW Oracle's down-wind performance. Once I'd managed to get my 1.5 grey cells to accept that (thanks SL) the idea of a propeller using the same principle became clearer.

 

[fireball]

IT looks like the device is clawing its way upwind under its own power, but turn off the running machine and the party is over - no more power input.

DOWNWIND ... write out 100 times ...
The device is travelling DOWNWIND DUFUS!

 

[RAI]

... but turn off the running machine and the party is over - no more power input.

Great for year 10 science thanks for the link

If the wind stopped, it would not work outside either. But that's the point, the energy, whether from the treadmill or from the wind, is input continuously.

The trick is to use that energy to obtain more speed. In this case more speed than the wind, (or treadmill) but not more energy than the wind.

 

[Porthandbuoy]

I started with that view until I had to come to terms with BMW Oracle's down-wind performance. Once I'd managed to get my 1.5 grey cells to accept that (thanks SL) the idea of a propeller using the same principle became clearer.

I remain unconvinced about this, religion, that topic which is banned, and the fragility of seahorses.

 

[Kelpie]

I remain unconvinced about this

About the ability of BMW Oracle to reach a point dead downwind faster than the wind itself?