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Force multiplier

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electrodacus:

--- Quote from: james_s on February 14, 2023, 12:36:55 am ---I wonder how much room there is for further optimization to increase performance. Perhaps a flexible driveshaft to optimize the thrust angle would offset the mechanical losses added by the shaft? Variable pitch prop? The whole vehicle is an interesting concept that at a glance is not intuitive, but obviously it has been proven to work and after seeing it work the description of how it works does make sense.

--- End quote ---

There is not much that it can be optimized. The variable pitch is implemented on the large model (blackbird) but that only adds to number of variables like the wind speed variation is about 2x over the course of that record speed test and since the angle of the propeller blades are not in the available data the rest of the data is fairly useless.

But the treadmill model is a way better one to study and understand since there is no variable pitch and wind speed is zero as it is indoor while the treadmill speed is decently constant so not a problem to do a proper test with at least a quality high frame rate video from the side in order to be able to do measurements based on that video.

What will be observed there if measurement where to be done is that acceleration rate drops. That alone can predict when the vehicle will get to peak speed and start to slow down.
The treadmill is way to short but that can be fixed by increasing the weight of the vehicle so that vehicle will not be able to get to the end of the treadmill before it will start to slow down.
But to come up with all this you need to understand the mechanism through with that vehicle works.
And explaining air that is invisible and the fact that it is a compressible fluid it is way above the heads of people looking at this toy device.
There are people that understand what I say way better than me and can do a better job explaining all this but they have a carer and more valuable things to do that teach other physics.

You need to know the correct equation for power needed to overcome drag  https://scienceworld.wolfram.com/physics/DragPower.html since internet is full of the wrong version of this equation.
And also here is the correct implementation https://www.electromotive.eu/?page_id=12&lang=en again plenti of other online calculators use the incorrect equation. The one in the link is the correct one.
That is just in the remote case you will want to look at this problem.

But the easier way will be to start by responding to my question (the one with 4 options).

fourfathom:

--- Quote from: electrodacus on February 14, 2023, 12:42:51 am ---Lying about what ?

Every time the vehicle body is touched in that video the energy storage is charged (no longer a floating body).

--- End quote ---

If the "spork" was touching the rear of the vehicle, preventing it from going backwards, you might have a point.
But it wasn't, and you don't.

HuronKing:

--- Quote from: electrodacus on February 14, 2023, 12:42:51 am ---
--- Quote from: HuronKing on February 14, 2023, 12:32:45 am ---You're a goddamn liar - and this is why spork/Rick Cavallaro told you to f*ck off.

--- End quote ---

Lying about what ?

Every time the vehicle body is touched in that video the energy storage is charged (no longer a floating body).
As long as the vehicle is restricted with hand or any other object touching the body it is nothing more than a treadmill powered fan.

If you take a video of that vehicle after you release from hand and measure in the video the acceleration rate you will see that acceleration rate drops as the energy storage is used up.
That means vehicle will get to a peak speed (point where stored energy can no longer accelerate the vehicle as pressure differential is converted in to vehicle kinetic energy) and then all friction losses will be powered by that stored kinetic energy meaning kinetic energy drops thus vehicle speed drops.


--- End quote ---

This is absolutely not what happens in this video:


And if this is still not satisfactory - how about a treadmill of infinite length so we don't have to worry about the cart flying off the end? Then we can see if the vehicle slows down and speeds back up. As shown in this video, your prediction is, again, absolutely not what happens:



And here the University of Berlin shows the same setup:


The cool part is these are all experiments you can do. Set it up and let it run for 5 minutes or whatever. Other people have, contrary to your lies, done these experiments and shown that stored kinetic energy has nothing to do with the propulsion of the vehicle beyond the wind speed.
https://dsimanek.vialattea.net/museum/DDWFTTW.htm

I'm not even that interested in this problem and I found these demos and evidence of Cavallaro's research in 2 minutes of Googling. Yet you sit there and claim neither he, nor anyone else, has tested these things to rule out your ad hoc explanation (that no one in the entire world, except you, subscribes to).

That is why you are lying.

electrodacus:

--- Quote from: fourfathom on February 14, 2023, 01:06:22 am ---If the "spork" was touching the rear of the vehicle, preventing it from going backwards, you might have a point.
But it wasn't, and you don't.

--- End quote ---

It is irrelevant what part of the vehicle body is in contact with ground either through his hand or an object in his hand.
But you will need to understand why that vehicle works to understand why touching the vehicle in the way he did recharges the stored energy.

I do not want to discuss the more complex direct downwind version and prefer to stay with the current discussion that is about the direct upwind version witch is what case (a) is the equivalent to.

Attempting to answer my last question (the one with 4 choices) should lead to understanding what I'm trying to explain and a good start to understand how both upwind and eventually more complex downwind faster than wind works.

electrodacus:

--- Quote from: HuronKing on February 14, 2023, 01:17:34 am ---
This is absolutely not what happens in this video:

And if this is still not satisfactory - how about a treadmill of infinite length? Then we can see if the vehicle slows down and speeds back up. As shown in this video, your prediction is, again, absolutely not what happens:



And here the University of Berlin shows the same setup:


The cool part is these are all experiments you can do. Set it up and let it run for 5 minutes or whatever. Other people have, contrary to your lies, done these experiments and shown that stored kinetic energy has nothing to do with the propulsion of the vehicle beyond the wind speed.

I'm not even that interested in this problem and I found these demos and evidence of Cavallaro's research in 2 minutes of Googling. Yet you sit there and claim neither he, nor anyone else, has tested these things to rule out your ad hoc explanation (that no one in the entire world, except you, subscribes to).

That is why you are lying.

--- End quote ---

What you see in that treadmill video is a treadmill powered fan.
As long as vehicle body is constrained to ground in any way it is nothing else than a treadmill powered fan. The charged energy can not be used so it is charged and remains charged.

The circular setup is not equivalent and has nothing to do with the linear treadmill experiment that is a good equivalent of the faster than wind direct downwind version as long as the body is not constrained in any way as in both of those videos you linked.

It is not just me that understands how this vehicle's work and there are people that have a way deeper understanding than I do since this is not my area of expertise apart of energy and energy storage where I'm by definition an expert.
Thus the claim (indirect) of breaking the energy conservation that got my interest. I did learned quite a bit more while trying to explain how it works and also learned more what is that many people have problems with.
I narrowed down to Newton's 3'rd law and energy conservation.

The explanation Rick and his believers including Derek of how the direct down wind vehicle works is this.
Get energy from the wheel (not understanding that energy comes from vehicle kinetic energy) then use that energy to power the propeller.
This is the entire explanation and sound exactly like you get a generator connect that to a motor with some gear ratio may be and you have a perpetuum mobile in fact even overunity.

The only way wind (moving air particles) can power any vehicle is by colliding elastically with the vehicle body and so transferring kinetic energy.
When vehicle is above wind speed it can no longer be powered directly by wind power as no particles will be able to collide with the back of the vehicle as vehicle moves faster than the air particles in exactly the same direction.
But the part that is ignored is that air is a compressible fluid so air particles still hit the back of the vehicle because when vehicle was below wind speed it used wind energy not only to accelerate the vehicle but most of it it was diverted to propeller that created a pressure differential thus storing energy allowing vehicle to exceed wind speed for a limited amount of time proportional with the amount of stored energy.

I can build a vehicle without a propeller that can exceed wind speed directly downwind using another form of energy storage like say a supercapacitor.
All you need is a small ideally foldable sail spend some time below wind speed to charge the supercapacitor then use that energy to exceed wind speed.
It will be cheaper less dangerous than the 20m^2 swept area propeller and achieve the exact same thing witch is to say fairly useless thus the reason you do not see any commercial applications using this.


But I need to insist that we return to the question with 4 possible answers as that will provide the missing understanding and it will be a good point to start and understand why this wind powered vehicles are not what they appear to be and do not work as advertised.

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