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Author Topic: Directorly Downwind Faster than the Wind  (Read 148414 times)

Rapadura

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Re: Directorly Downwind Faster than the Wind
« Reply #45 on: April 01, 2010, 02:04:00 AM »
Wait a minute... If this thing can really generate its own thrust WITHOUT natural wind, then they can make a test inside a large covered football stadium (like Veltins-Arena or Amsterdam Arena) where there's no natural wind. And if this thing can run in circles in a closed loop path, then they can put  hundreds of thousands of piezo generators under a track and use this perpetual motion machine as a perpetual electrical generator.

sparks

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Re: Directorly Downwind Faster than the Wind
« Reply #46 on: April 01, 2010, 06:00:35 AM »
  @Stephan
Can you confirm that this machine runs even without any wind.  The streamers on the vehicle reverse but the bulk air mass he is moving through is still moving relative to the ground.  This allows the propellor to act as both a sail and a propellor.  As a sail it anchors itself in the inertial frame of the air.  As a prop powered by the wheels it moves forward in this bulk.  The result is added to the velocity of the vehicle. 

Pirate88179

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Re: Directorly Downwind Faster than the Wind
« Reply #47 on: April 01, 2010, 09:22:30 AM »
Hey, think about it.  IF this principle works as we think it might in air, why not use the same idea underwater?  If it does not work in zero wind than one could make the water version to work in slight currents of the ocean.

The water version would/should be more efficient since water does not compress and less loss due to viscosity level of water vs air.

Just a thought.

This is a fascinating device.  Seeing the full scale version is really wild.

Bill

ramset

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Re: Directorly Downwind Faster than the Wind
« Reply #48 on: April 01, 2010, 10:50:38 AM »
A sail is a propeller.

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

In sailboat racing, and especially in speed sailing, apparent wind is a vitally important factor, when determining the points of sail a sail-boat can effectively travel in. A vessel travelling at increasing speed relative to the prevailing wind will encounter the wind driving the sail at a decreasing angle and increasing velocity. Eventually, the increased drag and diminished degree of efficiency of a sail at extremely low angles will cause a loss of accelerating force. This constitutes the main limitation to the speed of wind-driven vessels and vehicles.

Windsurfers and certain types of boats are able to sail faster than the true wind. These include fast multihulls and some planing monohulls. Ice-sailors and land-sailors also usually fall into this category, because of their relatively low amount of drag or friction.

These boys are onto somethin

Very hard to get the "brain" around this!
But the proof is in the vids  no BS here.


Chet

Rapadura

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Re: Directorly Downwind Faster than the Wind
« Reply #49 on: April 01, 2010, 01:38:48 PM »
The most impressive thing about this vehicle is that, if it's really generating its own thrust, then it can move in any direction (north, south, east, west) at any time (unless the natural wind in the contrary direction is at very fast speed).

The definitive test will be the guys who built it showing it moving in a place with almost no natural wind, and moving in any direction, regardless of the direction of the weak natural wind.

Of course it will need a initial artifical acceleration, because, if it works the way we imagine, the wheels must be spinning at a given minimum speed in order to make the helice (propeller) spin at a speed enough to push the mass of the vehicle forward (if the vehicle was lighter, with less mass, this minimum speed would be lower).

Cloxxki

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Re: Directorly Downwind Faster than the Wind
« Reply #50 on: April 01, 2010, 05:49:37 PM »
I believe torpedo's have been made, powered in part by a wire back to the launching tube.

It needs some wind, however low the total drag of the vehicle.

The magnification factor (land speed vs. wind speed) is however infinite. It all depends on your media and refinement of rolling resisance (maglev would help) and transmission (what about supercooled ferrofluid?) , slipperiness of the vehicle through the air, and prop efficiency. Then, gear ratio greatly effects performance, and will need to be variable to ever become practical.
With this infinite gain ratio on a perfectly built wind car on a perfect road network and support/traction interface, only absolute windless day would result in being "stuck in traffic". Exploiting all wind energy from all directions and using those to power your superlight and super slippery vehicle, you'll collect a lot of speeding tickets. How many no-wind days are there anyway, in most inhabited nations? We like to live by the coast.

Any idea on how to get more thrust from a special prop (system?). I am think 2 fans in a jet style cylinder enclosure, larger fan front, smaller rear. Wind is accelerated aft by the front fan, pressure reduced. The narrowing enclosure negates that, feeds accelerates and compresses air into a smaller prop, plowing through the air faster than the front one of course. Would this be faster than the single large prop, slower, or does nothing you try really matter?
What about no enclosure, and just 2 props in line, with slightly different gearing?
Or, could a single prop of half the diameter, turning at double speed bring the same thrust?

It seems to be all about frontal surface vs. prop surface. The fun thing is that the huge prop doesn't really have much wind drag, due to it thrusting more than it drags.

Downside I see for this DDWFTTW principle, is that vehicles will need to be long in terms of cockpit, and tall in terms of prop.

If train tracks would prevent a train for tipping over (hold them in place), all kinds of airfoils and props could be placed in front, back, side and on top. If would not need to be heavy for stability, as are regular trains. This also aids quick braking.

gmeast

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Re: Directorly Downwind Faster than the Wind
« Reply #51 on: April 01, 2010, 07:18:23 PM »
Hi all,

I read some (not all) of the comments and watched the videos.  This is a CRAZY FANTASTIC concept, but NOT OverUnity me no thinks. 

In sailing you can:
Sail directly into the wind oldies call this "In Irons" because you ain't goin' nowhere.  But put a little angle into the wind and you are "Close Reached or Close Hauled"  you are sailing into the wind but slowly.  90 degrees to the wind or "beam reach" is really fast and you take full advantage of the boat's keel, and sail geometry. 

With the clever concept shown here,  you are able to go directly into the wind.  Now if you were to pivot the propeller mast so that the propeller was pointing head-on into the wind ALWAYS you would have the most "efficient" Land Yacht ever made.

Clue:
gear drive from the prop (90deg gearbox), drop with a vertical drive shaft to a drive 'ring and pinion' on the rear axle.  Maybe even a wind vane steering the propeller head ... like a wind turbine.

My two cents,

Greg






« Last Edit: April 01, 2010, 09:27:34 PM by gmeast »

el-tigre

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Re: Directorly Downwind Faster than the Wind
« Reply #52 on: April 01, 2010, 08:57:27 PM »
Let the prop spin up while the cart is held in place. Adjust pitch to get maximum kinetic energy storage at high rpms.
Then adjust the prop pitch to the other side, effectively reversing thrust.
/quote]

This principal is often used to jump launch gyrocopters  which I think are a flying version of this device. 
http://en.wikipedia.org/wiki/Autogyro 

It's interesting that a much much smaller engine can be used, compared to a powered helicopter, to sustain flight in these aircraft.  The vehicle weight is balanced by the lift generated by the free rotating blades which are moved by the air flow running through them which in turn is generated by a small engine only necessary to create forward motion.  A very neat trick.

Is not a glider the ultimate embodiment of the device, able to climb and travel faster than the wind so long as a temperature thermal exists.  Or even better, the solar powered flying wing that stores electrical energy all day and uses it to stay aloft at night. http://www.nasa.gov/centers/dryden/news/FactSheets/FS-034-DFRC.html

This is a perpetual motion flying machine so long as the sun shines and there is no mechanical failure.

Rapadura

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Re: Directorly Downwind Faster than the Wind
« Reply #53 on: April 01, 2010, 10:16:22 PM »
Let's clarify some things here.

The inventors claim that in this device is not the propeller that provides torque to the wheels, but the opposite: is the rotation of the wheels that provides torque for the propeller. It's what they try to show in this video:

http://www.youtube.com/watch?v=nudBjrOF3LE

So what is alleged is that the movement of the wheels causes the movement of the propeller and the movement of the propeller creates all the necessary wind to propel the vehicle. There is no need of natural wind. The wind speed in the natural environment can be zero.

This naturally requires that, first, the wheels are put to rotate at a minimum speed, which is transmitted to the propeller. The propeller needs to achive the minimum rotating speed necessary to create the artifical wind that can push the vehicle forward.

Once this minimum speed is achieved, the vehicle becomes (allegedly) a perpetual motion machine, because the rotation of the propeller generates an artifical wind that pushes the vehicle forward. And, the movement forward make the wheels rotate, and the rotation of the wheels make the propeller rotate, etc...

So, with ZERO enviromental wind speed, the only thing that is needed is a initial acceleration, that can be given by any mean, in order to make the wheels (and the propeller) rotate at the minimum speed necessary to generate the artificial wind. After that, the machine becomes a perpetuum mobile, and never will need to receive any more energy from external sources.

So, this thing can be adapted to become a perpetual electricity generator, and this infinite electricity can be used to charge the batteries of our Nissan Leaf or Tesla Roadster.

Cloxxki

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Re: Directorly Downwind Faster than the Wind
« Reply #54 on: April 01, 2010, 11:04:25 PM »
Let's clarify some things here.

The inventors claim that in this device is not the propeller that provides torque to the wheels, but the opposite: is the rotation of the wheels that provides torque for the propeller. It's what they try to show in this video:

http://www.youtube.com/watch?v=nudBjrOF3LE

So what is alleged is that the movement of the wheels causes the movement of the propeller and the movement of the propeller creates all the necessary wind to propel the vehicle. There is no need of natural wind. The wind speed in the natural environment can be zero.

This naturally requires that, first, the wheels are put to rotate at a minimum speed, which is transmitted to the propeller. The propeller needs to achive the minimum rotating speed necessary to create the artifical wind that can push the vehicle forward.

Once this minimum speed is achieved, the vehicle becomes (allegedly) a perpetual motion machine, because the rotation of the propeller generates an artifical wind that pushes the vehicle forward. And, the movement forward make the wheels rotate, and the rotation of the wheels make the propeller rotate, etc...

So, with ZERO enviromental wind speed, the only thing that is needed is a initial acceleration, that can be given by any mean, in order to make the wheels (and the propeller) rotate at the minimum speed necessary to generate the artificial wind. After that, the machine becomes a perpetuum mobile, and never will need to receive any more energy from external sources.

So, this thing can be adapted to become a perpetual electricity generator, and this infinite electricity can be used to charge the batteries of our Nissan Leaf or Tesla Roadster.
What sources have you been reading to make these statements?
The wind does all the work. Bring the cart to (close) its own speed. The prop on the cart, being powered by the wheel resists this, making it a sail that flaps back at the wind.
It would be easier to hold the prop from turning (had it been disconnected from the wheels) than to hold the wheels, with that tailwind blowing against the back of the whole structure. So the prop doesn't have a whole lot to give, but what it has, is EXTRA.

Simplifying the system, I would say that the unused wind force is being extacted by the positive feedback loop. Once wind force - drag components equals prop thrust, equilibrium speed is reached.
Without a speed difference between wind and road, there is nothing to put into the feedback loop. The prop works so well because it sits on a flying carpet that matches the wind speed. The slightest input is going to druft the carpet forward compared to a standard carpet.

Hard to explain, and hard to understand, but if once chooses to not believe, it gets even harder.
Fact: behind a turbine, the wind still moves. Only the amount it was slowed down, is input. This feedback loop gets the most out of the prop. Perhaps a smart person can pull a trick on wind turbines as well, to produce more power for a given rotor surface. Dead wind gets in the way though.

Rapadura

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Re: Directorly Downwind Faster than the Wind
« Reply #55 on: April 02, 2010, 01:38:30 AM »
Well, I don't know what REALLY makes this vehicle move forward, but I think it's clear that the inventors are claiming that is the movement of the wheels that provide torque to the propeller.

ramset

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Re: Directorly Downwind Faster than the Wind
« Reply #56 on: April 02, 2010, 02:42:33 AM »
Clo
to say there has been a lot of research into prop or sail design would be a stupendous "understatement"!

What the heck is going on here?

Do these fellows share specifics anywhere?
any theory?
Claims ??
expectations?

Chet


Rapadura

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Re: Directorly Downwind Faster than the Wind
« Reply #57 on: April 02, 2010, 03:03:41 AM »
Heeeey! Now I remember! I had this same idea when I was 17 years old!

I know nobody will believe what I will say, and nobody has the obligation to believe, I do not want anyone to believe me, just need to say this, because it's something that just left me shocked.

Over ten years ago, when I was 17, I was on a beach here in Brazil when I thought of an idea that was exactly like this idea that we are analyzing here ... I just thought of a small car where the movement of the wheels would be transmitted to a rear propeller, which would create a wind that could push the car forward.

The day I thought about it, not told anyone my idea. I simply dismissed the idea, thinking that  friction somehow should prevent that from work. I ended up completely forgetting the idea. Just now I remembered that toughts of that day!

Nobody needs to believe me, I'm very happy just to know that someone had the same idea I had that day, and, better, someone had put it into practice!

Just registering this recordation. Please don't pay attention to this post.

gmeast

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Re: Directorly Downwind Faster than the Wind
« Reply #58 on: April 02, 2010, 04:33:51 AM »
Let's clarify some things here.

The inventors claim that in this device is not the propeller that provides torque to the wheels, but the opposite: is the rotation of the wheels that provides torque for the propeller. It's what they try to show in this video:

Yes, well that's fine but in the full scale model on the 'flats' the wind starts out moving the wheels (no doubt about that) and if the wind stops then the car stops (no doubt about that).

The treadmill demo is more complex than it appears.  The ground (belt) moving by in stationary air is not the same as the full scale machine.  On the treadmill the air and the cart start out at the same speed (zero) and remain that way.  I admit it is intriguing and it's hard to nail down what's really happening with the treadmill videos.  So that's why we have forums.

Still it is potentially the most efficient Land Yacht ever contrived.

Greg

gmeast

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Re: Directorly Downwind Faster than the Wind
« Reply #59 on: April 02, 2010, 04:46:14 AM »
You see this thing operating and it brings back many memories of independent inventors coming into my machine shop and asking me to help them build the most famous of all overunity gizmos:

...a generator charging a battery that's running the motor that's turning the generator... 

Everyone here has passed that O.U. Hopeful by their brain cells more than once I'm sure.

But this actually appears to be doing something similar