my thoughts. it's an additive force. the propeller first acts like a sail, until the cart matches the speed of the wind. During that time, the propeller has been storing energy in the form of momentum(in the spinning propeller). But wind is still pushing. So wind + stored momentum = faster than wind. Ya?
No, it cannot accelerate from wind-speed, using stored momentum. To extract the stored energy it would have to slow down the propellers rotation. But that would slow down the wheel rotation and thus brake, instead of accelerating.
It uses wind power directly, not stored power, so it stays above wind-speed, as long as there is wind. The rotor is always a propeller. The individual rotor blades are always sails tacking downwind on a broad reach.
Okay this is clearly fake. Ignoring the physics of how the contraption works, how is the contraption steering? The front wheel appears to be a caster and I see no mechanism that would allow it stay on the road. The obvious answer it it is being pull by something just off screen.
Google "The cart that launched a thousand flame wars" for an interview with the builder, and "What I've Learned About Wind Carts" for an article with background info on it.
My theory is it is possible because the wind is not only rotating the blades but also pushing them forward like a sail, the two motions added together create more motion than the velocity of the wind alone.
This is a fascinating article that will bring all naysayers up to speed. While this video doesn't prove anything, someone else has built a full size manned version that set a sanctioned record of 2.8 times the speed of wind.
I see no proof that the wind was consistent for the duration of the run. We have only the commentator's word for the windspeed and s.o.g. (speed over ground) It's hardly a controlled environment, though the concept is interesting. This is a neat idea, but not convincing in it's portrayal of DDFTTW
True, you have only the commertatot's word in this example; but I have no reason to believe he lied.
For those who need more convincing, NALSA (North American Land Sailing Assoc) have just confirmed another cart (manned this time) as travelling directly downwind at 2.8 times the speed of the wind. NALSA were not involved in the attempt other than as independent scrutineers.
We will leave this clip on YouTube for its historical significance, but we will not respond to any further comments.
@nytugmaster The apparent wind indicator should provide plenty of proof that it is going faster than the wind. The white string shows the aparent wind of the moving object. When the object first starts movement the string continues to point forward. Further into travel it become clear that it is going faster than any other wind source acting on it. About the only thing that could make it clearer are windsocks along the route.
@nytugmaster The apparent wind indicator should provide plenty of proof that it is going faster than the wind. The white string shows the aparent wind of the moving object. When the object first starts movement the string continues to point forward. Further into travel it become clear that it is going faster than any other wind source acting on it. About the only thing that could make it clearer are windsocks along the route.
shame you didnt' film in front of the skateboard (so we could see it wasn't being pulled), show us how it stayed on the road or provided any evidence it wasnt travelling down a slight decline
Why was it important to push the care in the beginning? Much of the power was provided by the initial push, so it's not so impressive at all actually.
Very little of the speed came from the initial push. The cart can have problems starting from zero, but once it starts going it really goes. It did accelerate throughout the clip until the very end when he applied the brakes, with a remote control of course.
"Why was it important to push the care in the beginning? Much of the power was provided by the initial push, so it's not so impressive at all actually."
Really this is as simple and as counter-intuitive (at first) as the yo-yo along a table & cotton reel examples.
Basically the cart is being _pushed_ by the wind, and uses the rotation of the wheels to turn a propeller which pushes against the wind even more and allows it to move a little faster than the wind which is pushing it.
Most people seem to assume that they see a windmill (turbine) which powers the wheels.
The propeller blades start spinning when the car is going to a lower energy state from a high one; causing the car to go further. The car goes faster than the speed of the wind because it is being incredibly efficient with the energy of the initial push, as well as the speed of the wind. There's no magic creation of energy here.
i dont know much about this machine in particular, but judging from what i can see, it's not being pushed forward by the wind. when the cart is pushed, it rotates the propeller. there is probably some transmission used to make the prop spin faster. when it's fast enough, it goes into self-sustained motion, much like a turbofan or ramjet.
Nothing. Indeed it would be easy to fake, but many has done this independently, and it is clearly theoretically possible. The physics are well understood, although the conclusion is slightly counter intuitive.
ya i cant believe you guys did not catch this the windmill thing would be turning propelling wind behind it from the natural force nut the only reason that white flag is moving backward is because the windmill is making it.
Science fail. Windmills aren't propellers. They don't generate any wind. Unless you mean the windmill is driving the wheels, and the speed from that is causing a relative headwind that forced the flag back.
Actually the wheels are driving the propeller. It would be quite possible to build a car going slower than the wind, powered by a simple sail (or the general drag of the car), and having a propeller making a local wind pushing a streamer back.
That is not what this is though. If I had done it I would have put the streamer in another place though.
I have to admit I was wrong on a previous comment. This is possible, check out the smaller scale models posted by spork33. It runs off the difference in speed between the wind and the ground. Do not think of the wind blowing directly on the cart and it might help. Since it works off of a difference in wind speed it would no work if there was no wind. There is no perpetual motion or over unity involved.
no it is completely not. There is no moving air on the threadmill. There is a power source: the threadmill. The device stay still compared to it's sourrounding air. It's in all ways different. If you just state that it's equivalent when it's not, then all the following conclusions will be invalid.
Come one, it is not a hard coordinate transformation to do.
There is a power source outside as well: The wind(!). You have air and ground with a fixed relative velocity. They are equivalent. Sporks car is not stationary in relation to the air - it moves forward! That means it feels a headwind.
I am sorry to say this, but you sound like all those guys who claim that this is impossible.
not exactly. So on the threadmill the air, relative to the car is still. The floor is moving, the propeller is rotating.
On the street, relative to the car: the floor is moving, the propeller is rotating and the air is moving... but in what direction is the air moving in relation to the car??? Seems the air is coming from the front, at least behind the propeller the little flag indicates this.
The air is invisible. And so there you are: people are discussing about something impossible to see.
Well obviously if the car is going at the speed of the wind, then the air is still relative to the car. If the car is going slower, then it is coming from behind. If it is going faster then it is coming from ahead.
On the treadmill therfore standing still coresponds to moving at the speed of the wind, moving forewards coresponds to moving faster.
how does this work? if the car stands still, wind blowing from behind turns the blades which turn the wheels and the car advances. Or is it that the wind pushes the car which turns the wheels who drive the blades which then push the car faster than the wind?
This is a big difference, depending of the way it works the blade run clockwise or counter clockwise (windmill or propeller)
If you look closely, on the video the blades turn counter clockwise and so it's a propeller.
Yes. It is a propeller in all the DWFTTW's. The wind tries to turn the propeller one way (as a wind mill), but it gives a forward push which makes it turn the other way.
Because of the gearing the second force is bigger. This way the cart sacrifices force for speed.
Had the gearing ratio been different so that the windmill effect won, then the cart would advance slowly upwind.
Yes. Exactly. The wind pushes the car, causing the wheels to spin, causing the propeller to spin, causing it to push back on the air giving thrust. Now as the car reaches wind speed the push from the wind has diminished, but not reached zero because the propeller is turning. As it goes still faster the thrust will eventually diminish enough to be balanced by the friction and air resistance of the body of the car.
@MrTweetyhack That's right. I worded it the way I did because many people think that the wind "goes away" when the cart is moving at the speed of the wind. Even when the cart is moving at wind speed there is still a difference between the speed of the wind and the speed of the ground that the cart can harvest.
@flinchey I know that, but the ultimate source of power is the difference between the speed of the wind and the speed of the road. If you saw the various treadmill videos you would see why I worded it that way. In that case the wind (the air in the room) is stationary and the road (the treadmill belt) is moving.
And yes, the wheels turn the propeller which forces the cart DDWFTTW.
This is absolutely not possible. Once the contraption begins to move at the same speed as the wind, it will perceive itself to be at rest with the air. Such a situation would be IDENTICAL to the contraption sitting stationary in a calm, wind free room. Obviously nothing would happen in this situation and so nothing would happen in the situation whereby the contraption travels with the same speed as the wind.
But how is sitting in your room the same as moving on the road with a wind? You forgot where the analogy begins.
People, it's not the speed of wind vs speed of vehicle that matters. It's speed of wind vs speed of road. That's what matters.
And in both cases the difference is there. If you insist on sitting still in a room with no wind, there is no source of energy and it's not the right situation to talk about.
I agree with you completely, but you misinterpreted my somewhat sarcastic post. I was replying to gamesguru who incorrectly states that this is not possible and that from the inertial frame of reference of the cart, it is like sitting at rest in a still room. When the cart is moving at the speed of the wind, the apparent wind is 0, but gamesguru fails to consider that at the same time the apparent movement of the ground going by is certainly not 0.
The car thing stops then the guy says "Oh I had the break on again" then she pushes it and it goes off but I never saw her take the break off. The guy must have a control to do so. Still doesnt prove its fake or real cos it could be RC for stearing only but yeah im not entering that debate!
since at the end he also applies the brakes again (remotely) it is entirely possible that he added RC brakes. I would have. I wouldn't want that thing getting away from me.
I believe this video has proven that some things in this world are not "impossible." They may be highly unlikely, but this video is out of pure genius. If the world were more open-minded as this person was, just think of the wonderful things that could lie within our grasp! Kudos and a job well done.
I think "likely" and "unlikely" applies only to random events. Engineering either works or it doesn't. This is not the only type of contraption that can move downwind faster than the wind.
It's totally possible to get a machine like this to move directly into the eye of the wind, or across it. He describes the conditions as 'light and variable' - was the wind really coming directly from behind through the run?
You really just need to use your brain. Imagine the craft is going the same speed as the wind downwind. It is in still air. Where can it get its power to go forward in that air? Answer: From the road going past underneath! The road is driving the wheels round and pushing the craft forwards (using the propeller) through the still air. Its not getting its power from the prop - its getting it from the wheels. A brilliant demonstration!
the faster the car moves forwards the more apparent wind generated and the faster the car can go
u do need an initial start tho but once u have some natural wind and some apparent wind the cart will eventually accelerate to speeds faster than the wind.
the way that the propeller is facing wont move the car forward. the wind would cause that propeller to spin clockwise but it needs to spin counter clockwise in order to make the car move forward.
Doesn't anyone else wonder how it managed to stay straight and on the road for that distance? whenever you just let anything go, be it skateboard, go cart shopping cart, etc it will always veer off to the side after a distance, no matter what because the wheels will hit objects, the road isn't level, etc. Unless it was being towed........
It would be easy to use standard radio control equipment for the steering. But I happen to agree with your comment about being towed. I think that is what the vertical post towards the front is for. If the tow line was monofilament fishing line, it would be virtually impossible to see, especially with the very fuzzy image. This thing is a hoax.
I have concluded that the machine is a hoax. The blades are spinning counter clockwise, which is opposite what would happen if the wind were causing them to rotate. In fact, the vanes are being propelled by an internal force, which is what is causing it to move forward. The other factor is that of "apparent wind". As the speed of the machine approached the true wind speed of 6, the apparent wind would drop to zero, hence no energy input to create rotation of the rotors.
I don't fully get it yet - however imagine the situation where the machine is going exactly at the speed of the wind - if the prop belt was off, prop locked into one position and there was no friction what so ever this would be the balanced situation.
The cart rolling at the speed of the wind - right?
Now put a belt on and gear the prop up so that it creates a push. Powered by the wheels mind you - it has to go faster - it cant decelerate because that would resist the wind.
at last some who can think for himself! - my thoughts exactly - when the apparent wind approaches zero the forward thrust goes to zero, hence you cannot go faster down wind than the wind is blowing.
No, when the _roadspeed_ goes to zero the forward thrust goes to zero. As long as the cart is moving the propellor is turning and providing forward thrust.
Sorry, this is sounding like a perpetual motion machine which is impossible according to the First Law of Thermodynamics. Or like trying to lift yourself up by pulling up on your bootstraps. Why don't you just admit that there is an external power source, such as a battery driven motor, or a thin string being pulled from ahead, attached to the vertical pole towards the front?
Why don't I admit that? - because it wouldn't be true! The laws of thermodynamics are not violated.
This cart works because there is a significant difference between the groundspeed of the cart (which determines the energy input) and the apparent windspeed (which determines how much energy you have to add). That speed difference is crucial, and the amount of difference you need to make it work depends on the efficiency of the transmission.
As a thought experiment, try replacing the mechanical transmission with an electrical generator and motor.
You would have no difficulty with generating power from the wheel. You would have no difficulty with an electrically driven propellor driving the cart downwind at speeds faster than windspeed. The question to be asked is "can you generate more power at the wheel than you need to drive the cart?" And the answer is that you can.
"The question to be asked is "can you generate more power at the wheel than you need to drive the cart?" And the answer is that you can."
You are saying that the ouput energy is greater than the input, which is impossible according to the laws of physics. Any high school science student knows that.
1)Why won't you provide decent photos of your device as I have requested twice?
2)Why do you only offer a treadmill demonstration which proves absolutely nothing?
Nicely done! It is very frustrating when a demonstration of quite simple physics results in accusations of fakery fro those too stupid to work it out for themselves, ignore them, they won't change the world.
Great job! Some people don't understand - the wind is blowing in the same direction that the car is moving (down wind) but the prop is "backwards" (facing up-wind) The point of this project is to propel the vehicle faster than the wind, using only the wind. Steering is remote controlled, that is how it stays on the road. Read the document at the URL posted at the top of this page for more info. Great job.
Obviously it is remote controlled, but that doesn't mean it is also powered. It would certainly be easy to fake, but that doesn't mean it is. There is no reason to fake it since it can actually be done for real. This video proves nothing, but theory does.
What's driving folks crazy is a sense of some underlying free energy or perpetual motion voodoo. There's no magic here; you can extract all the force you want from the wind just by building a larger propeller. The speed of the ambient wind doesn't limit how you apply the force you extracted. That is, you can convert your force into a faster speed.
I have no idea if this video is a fake or real. My point is the underlying principle is valid.
how can the wind be comming from the front of the car ??? If you look at the flag at the begining of the video the wind is blowing from behind the car. and at points in the video the flag blows towards the car to
Quite easily, as long as the thrust from the propellor exceeds the drag from the apparent wind.
(Remember the propellor thrust is a function of GROUND speed, not of apparent airspeed. As long as there's enough real wind to reduce the apparent wind to a low value for an appreciable ground speed, then the drive works.)
I understand the part that the propellor is a function of ground speed (ie the propellor is tied to the rear wheel shaft) if the wind is coming from the front of the cart why would it accelerate in that direction (forwards) - the only reason I can see is that external force is being applied by a nylon line tied to the front of the apparently self steering cart.
OK, but how does it scale up when I want to make it do useful work, such as for unattended package delivery (lets say I'm using onboard solar powered GPS guided AI)... how much payload can be added to this minimalistic design?? Can this machine do useful work or are we seeing the height of the designs abilities?
you know I think he posted this just to mess with our minds. Hes a crazy guy that thinks "hm, how can I lie to thousands of people, and about what....how about sailing fast then the wind!?! yes. muhahahahwahaha!!!"
It is curious to see how, of the people who has posted thus far, all the ones who understand how an aerofoil works seems to think this works, and all the ones trying to make sense of it within other frames of reference seems to think it is fake. Please read up on aerofoils and ice yachting/sailing, then look at this again and remember RELATIVE airflow!
at 2:02 the flag on the three wheel thing shows the apparent wind coming from the front of the cart and the comment 13 miles an hour - then at 2:08 I can distinctly see a wire attached to the front of the cart ... looks fishy to me!
Cory - I agree Iceboats go faster than the ground wind speed they use the fact that when they go at right angles to the wind the "apparent wind" is far greater because the ice boat has almost zero resistance to going forward. the wind at right angle to the sail and the vector of the forward thrust is like sqeezing a greased wedge under your foot. This phenomena is NOT the same as sailing down wind like this fake video shows.
Yes it IS the same. The blades of the propeller moves in an angle to the wind in excactly the same way an iceboats sail does. The only difference is that since the propeller is rotating the car itself is allowed do go downwind directly although its "sails" does not.
sailing down wind faster that the wind is not a theory and in fact has been practiced for many, MANY years. it's call ICEBOATING. iceboats travel 4X the wind speed. so much so while, going down wind you trim the sail in tight as if you are heading upwind. this happens because of the iceboats "apparent wind".
Oh, I had the brake on again. Ooh man I am laughing OUT loud, you can fool some of the people some of the time but not all of the people all of the time.
(comment #3)The gear ratio required to maintain a constant speed would have too much load on the propeller for the car to accelerate; the car would slow down. And if the car is slowing down, it will become pushed by the wind again. So, what exactly happened in that video? The car was traveling downhill.
(comment #2) Doing this increases the rpm of the propeller versus rpm of the wheels. Given enough increase, the propeller spinning should create thrust and propel the car faster. The problem in this is that when you travel faster than the wind, any and all thrust aided by the wind is lost. This means that the car must be propelled by its own energy. And as anyone should know, energy cannot be created, only moved...
A prop neither screws thru air nor pushes air to develop thrust. It is a rotating wing developing lift based upon the air moving over its surface. Imagine being on the prop & think about how air is moving over the blade when the car is faster than the wind.
(comment #1)While the documentation certainly makes you think that using gears you can multiply the ratio from wheels turning to propeller spin, it still doesn't work. Here's why. The theory in the car design is this: A strong steady wind starts the car going. The axle from the wheels turning turns a smaller gear, which is connected to the propeller by a belt.
10 miles per hour up to 13 miles per hour - you Sir are perpetrating a hoax. So I have no recourse but to shout out loud "liar liar your pants are on fire"!
(Sigh... Comments are so geh.) What a wonderful concept, very clearly illustrated for the simplest minds to grasp, and yet the broken and blind are the ones who speak the loudest. Do you see the palm trees? And the steady wind? Coastal = FLAT. I guess everyone's a physicist nowadays. Stupid intarwebs
it has a rubber band going from the propeller to the rear axle which turns the rear tires faster than the prop. with a gear ratio of 1.75 to 1. its all on his website.
The reason there is no steering mechanisim attached to the front steering wheel is because the whole thing is being towed by a thin wire and the front wheel is a swivel castor so that it would follow the towing vechicle. Come on and fess up ayrshquk.
The wheels and the prop are a closed system, dependent upon each other so they both drive the machine, not one or the other but it's the fact that the prop blows AGAINST the wind that creates the phenomenon of being able to go faster than the wind.
The blades are coupled the wheels in a way that the wheels cause the prop to spin the opposite direction of a freewheeling blade, literally blowing back against the wind when the machine rolls forward.
If you look carefuly at the pitch of the propellor you will see that the wheels are connected to the propellor via a rubber band and that external force of some kind is being put on this contraption. I suspect a very thin wire attached to the front towing it.
PLEASE DON'T READ THIS. You will get kissed on the nearest possible Friday by the love of your life. Tomorrow will be the best day of your life. However, if you don't post this comment to at least 3 videos, you will die within 2 days. Copy and paste this, to be saved.
Holy God you all make this way too difficult. The prop is connected by big rubberband to rear axl, moving wheels faster through mechanical advantage, like a 1:2 ratio. Good thing it's windy or this car would not move fast enough to keeps it's momentom. Ask yourself how sail planes stay in the air.
You have the first part right, but it is the wheels that are turning the prop, not the prop. turning the wheels. That is what makes the relative air movement over the prop. keep the prop in a lift condition (pulling) when the car is faster than the wind.
Nice experiment. I have seen a catamaran sail boat with this setup replacing the sail. The mechanical power was transmitted to a gearbox via carbon fiber drive shaft. The gearbox is coupled to a sterndrive unit. Very slick setup, and because you can turn the mast/blade to the wind, the boat can travel in any direction.
Here is why this works. Throw out all notions of wind pushing the blade or the bade creating a wind that pushes the car. The explanation lies in the dyn.s of air mov. over the prop airfoil. Lets look at the forces on the prop.
First these conventions: The car dir. is + y. The wind dir. is + y. Looking at the car frm behind the prop is rot. c'clockwise. From a bird's eye view, look at a sect. of prop blade when the blade is at 12 o'clock, the blade is mov. frm R to L. This dir. is - x.
KingBallerina -- Are you saying the wheels are not involved? If so, then you are talking perpetual motion. Airplanes could be self powering. Second, you missed the obvious: It has a left-handed propeller turning CCW (from behind). If it was just spinning in the breeze, it would spin CW. To spin CCW (at speeds lower than wind speed), something must drive it. And, in cases 1, 2 & 3, the CCW rotation of a left-handed propeller means it MUST be providing forward thrust to the cart.
Read it again with the understanding that the wheels drive the prop. That was already explained by its creator. Rem char. to get < 500 is hard. The blade is CCW from behind "c'clockwise". The blade provides the forward force, but not via torque to wheels. The wheels turn the blade.
Q, from reading your past posts I see we are on the same track. I did not make the explanation clear enough. BTW, use the same air stream analysis over the prop assuming the prop is spun by the wing. You'll find such a system self defeating. The layman's notion of "prop" is the confusion. In this case the prop is a sail being moved by the wheels - not a windmill driving the wheels.
There are four conditions to think about. These are: 1) the car is slower than the wind 2) the car is mov. at the same spd as the wind, 3) the car is mov. >> the wind and 4) the car is mov. even >> the wind.
(Sever abbreviation has been made to fit these in 500 char.)
Air mov. rel. to prop sect. at 12 o'clock has 2 parts. 1 part is in + X frm L to R. This part is due to prop rot. and is always in this rel. dir. tow. rot. bld. The other part is the air mov. in the Y dir.. This part is the wnd spd rel. to car spd. It changes magnitude and dir., + Y or - Y, dep. on the car's spd rel. to the wnd. In case 1, it is + Y, coming frm behind. In case 2, it is 0. There is no Y wnd frm the prop's viewpoint. In case 3 and 4 it is -, coming frm in front.
Case 1: X air mov. is +, L to R. Y air mov. is +, frm behnd to forwd. The total result dir. is frm bot. L to upr R. Rel to the prop sect., which is ang frm upr L to bot. R, this air mov. puts bld airfoil in a high ang of attack. Dyn. lift forces on blade act norm to bld surf. Force is ang frm low L to upr R. Y part of force results in car mov. forw. X part of force is prop drag. It acts in op bld's rot.
Case 1 cont.: Drive train mech frict plus this bld drag act to slo car. Y force is enough to overcome losses. Car seeks a faster speed. At some point it reaches case 2.
Case 2: The X air mov. is +, L to R. The Y air mov. is 0 because the car is traveling at the same spd as the wnd. The total resultant dir. is frm L to R. Relative to the prop sect., which is angled frm upr L to bot. R, this air mov. puts the bld airfoil in a shallower angle of attack position than case 1.
Case 2 cont: Dyn. lift forces on the bld act as befo . Y part of this force results in the car mov. forw. The X part of this force is the prop drag. The Y force is large enough to overcome the losses so the car seeks a faster spd and at some point reaches case 3.
Case 3: X air mov. is +, L to R. Y air mov. is - becus car is travelng > wnd spd. Total res. air dir. is frm upr L to low R. Rel prop sect., which is ang frm upr L to bot. R, air mov. puts the bld airfoil in shallowr ang of attack pos.
Case 3 cont: In fact at some point >> the wnd, the angle will be inline with the bld sect.. The dyn. lift forces on the bld act as before. A perfectly flat airfoil would have 0 Y part with the air stream in line with the sect.. A well designed airfoil would still have a Y part. This is where the optimum bld sect. comes to play. The Y force is large enough to overcome the losses so the car seeks a faster spd and tries to approach case 4.
Case 4: X air mov. is +, L to R. Y air mov. is - becaus car is traveling >> the wnd spd. The total resultant dir. is frm upr L to lower R. Because the Y part is much larger than in case 3 this angle relative to the prop sect. is beyond the point where the bld generates lift. In fact as some large value of - Y air mov. the bld will generate dyn. forces in the wrong dir.. The car will not go faster. The car will seek an equilibrium spd point somewhere between case 3 and case 4. Faster than wind.
Mmmmmm. Think a friend and i made a very similar device when we were kids.Bring on the hover boards i say. hear hear. I second that.
Ps. No need to post comment telling me that i am a niaeve twit who doesnt appreciate good science. I do appreciate good science.I just much prefer bold radical
Just look at the cotton telltale.. if it's points back, the vehicle is going faster then the wind. Compare that to the cotton telltale at rest.
cwcordes 4 months ago
my thoughts. it's an additive force. the propeller first acts like a sail, until the cart matches the speed of the wind. During that time, the propeller has been storing energy in the form of momentum(in the spinning propeller). But wind is still pushing. So wind + stored momentum = faster than wind. Ya?
MrTweetyhack 1 year ago
@MrTweetyhack
No, it cannot accelerate from wind-speed, using stored momentum. To extract the stored energy it would have to slow down the propellers rotation. But that would slow down the wheel rotation and thus brake, instead of accelerating.
It uses wind power directly, not stored power, so it stays above wind-speed, as long as there is wind. The rotor is always a propeller. The individual rotor blades are always sails tacking downwind on a broad reach.
piratewoodleg 1 year ago
Okay this is clearly fake. Ignoring the physics of how the contraption works, how is the contraption steering? The front wheel appears to be a caster and I see no mechanism that would allow it stay on the road. The obvious answer it it is being pull by something just off screen.
utlo 1 year ago
@utlo
It is radio controlled.
Google "The cart that launched a thousand flame wars" for an interview with the builder, and "What I've Learned About Wind Carts" for an article with background info on it.
eyytee 1 year ago
This has now been officially proven.
My theory is it is possible because the wind is not only rotating the blades but also pushing them forward like a sail, the two motions added together create more motion than the velocity of the wind alone.
MrHurricaneFloyd 1 year ago
I tried to link to an article in my comment below but it was removed.
Google "wired ddwfttw" to see a great in-depth article on the full size manned version setting the record.
spelcheker 1 year ago
This is a fascinating article that will bring all naysayers up to speed. While this video doesn't prove anything, someone else has built a full size manned version that set a sanctioned record of 2.8 times the speed of wind.
spelcheker 1 year ago
@spelcheker you really think people will believe something 100%? See mythbusters moon hoax...
cyberdemon107 1 year ago
@cyberdemon107 Good point. It saddens me, but good point.
spelcheker 1 year ago
I see no proof that the wind was consistent for the duration of the run. We have only the commentator's word for the windspeed and s.o.g. (speed over ground) It's hardly a controlled environment, though the concept is interesting. This is a neat idea, but not convincing in it's portrayal of DDFTTW
nytugmaster 1 year ago
True, you have only the commertatot's word in this example; but I have no reason to believe he lied.
For those who need more convincing, NALSA (North American Land Sailing Assoc) have just confirmed another cart (manned this time) as travelling directly downwind at 2.8 times the speed of the wind. NALSA were not involved in the attempt other than as independent scrutineers.
We will leave this clip on YouTube for its historical significance, but we will not respond to any further comments.
ayrshquk 1 year ago 9
@ayrshquk People are consistently wrong.
planetofthescums 3 months ago
@nytugmaster The apparent wind indicator should provide plenty of proof that it is going faster than the wind. The white string shows the aparent wind of the moving object. When the object first starts movement the string continues to point forward. Further into travel it become clear that it is going faster than any other wind source acting on it. About the only thing that could make it clearer are windsocks along the route.
WindFreak01 1 year ago
@nytugmaster The apparent wind indicator should provide plenty of proof that it is going faster than the wind. The white string shows the aparent wind of the moving object. When the object first starts movement the string continues to point forward. Further into travel it become clear that it is going faster than any other wind source acting on it. About the only thing that could make it clearer are windsocks along the route.
WindFreak01 1 year ago
@nytugmaster If it were going any slower than the wind, the white flag at the back wouldn't be blowing backwards.
arpoot 1 year ago
it's on a hill - DOWNHILL!!
woayerrrr 1 year ago
shame you didnt' film in front of the skateboard (so we could see it wasn't being pulled), show us how it stayed on the road or provided any evidence it wasnt travelling down a slight decline
bnightm 1 year ago
really cool. how much does it weigh and how much weight could it carry?
It'd be fun to ride one, three propellers at the front perhaps?
dazalc 2 years ago
they are building a big one that will carry a person:
google "fasterthanthewind"
also google images for "bauer cart"
eyytee 2 years ago
Why was it important to push the care in the beginning? Much of the power was provided by the initial push, so it's not so impressive at all actually.
Blndrfist 2 years ago
Very little of the speed came from the initial push. The cart can have problems starting from zero, but once it starts going it really goes. It did accelerate throughout the clip until the very end when he applied the brakes, with a remote control of course.
subductionzone 2 years ago
Completely irrelevant dude
realisticHomeboy 2 years ago
This has been flagged as spam show
"Why was it important to push the care in the beginning? Much of the power was provided by the initial push, so it's not so impressive at all actually."
Look up the terms "y-intercept" and "derivative".
kmarinas86 1 year ago
Comment removed
mukmuk7 2 years ago
to go faster than the wind, people say that you have to use gears
aihlo 2 years ago
and eat healthy
realisticHomeboy 2 years ago
do you need to have a rpm limiter on the propeller?
aihlo 2 years ago
Really this is as simple and as counter-intuitive (at first) as the yo-yo along a table & cotton reel examples.
Basically the cart is being _pushed_ by the wind, and uses the rotation of the wheels to turn a propeller which pushes against the wind even more and allows it to move a little faster than the wind which is pushing it.
Most people seem to assume that they see a windmill (turbine) which powers the wheels.
goatpunch 2 years ago 5
The propeller blades start spinning when the car is going to a lower energy state from a high one; causing the car to go further. The car goes faster than the speed of the wind because it is being incredibly efficient with the energy of the initial push, as well as the speed of the wind. There's no magic creation of energy here.
ral8158 2 years ago
There is no magic creation of energy, but the rest of your post makes no sense.
Sgrunterundt 2 years ago
Nice work, how long is the road???
Caza128 3 years ago
lolwtf forget it, i'm stupid D:
melodiousMO 3 years ago 2
lol nice comparison. the question is, will the wheel of the threadmill move faster then the water, when you let them make a race? :)
melodiousMO 3 years ago
i dont know much about this machine in particular, but judging from what i can see, it's not being pushed forward by the wind. when the cart is pushed, it rotates the propeller. there is probably some transmission used to make the prop spin faster. when it's fast enough, it goes into self-sustained motion, much like a turbofan or ramjet.
naguto 3 years ago
Fake. It's got some form of on board power for steering and breaking, what's to say it's not driving the wheels also?
Einstiensblackid 3 years ago
Nothing. Indeed it would be easy to fake, but many has done this independently, and it is clearly theoretically possible. The physics are well understood, although the conclusion is slightly counter intuitive.
Magnusjen 3 years ago 3
There is both other videos and extensive explanations of the physics involved.
It does seem counter intuitive, but it is indeed possible. The energy of the wind is contained in the relative motion of wind and ground.
This is not a free energy device, just an amusing and amazing novelty. The wind is slowed by the car because of the propeller.
Sgrunterundt 3 years ago
FAAAAAAAAAAAAAKE! How else would it keep steering itself, or stop, unless it's remote controlled?
Einstiensblackid 3 years ago
you missed the point!
ElPulpoTX 3 years ago
What point is that? That a remote controlled fan powered scooter can go forward? Wow! What a breakthrough!
Einstiensblackid 3 years ago
wow, so they have remote control in your tribe?
cdallacosta 3 years ago
you've just answered your own question there ;-)
moondog999 3 years ago
downhill really? so it's losing energy right
aReEeAyeDeeAyeBohok 3 years ago
ya i cant believe you guys did not catch this the windmill thing would be turning propelling wind behind it from the natural force nut the only reason that white flag is moving backward is because the windmill is making it.
johntyle716 3 years ago
Science fail. Windmills aren't propellers. They don't generate any wind. Unless you mean the windmill is driving the wheels, and the speed from that is causing a relative headwind that forced the flag back.
dhasenan 3 years ago
Actually the wheels are driving the propeller. It would be quite possible to build a car going slower than the wind, powered by a simple sail (or the general drag of the car), and having a propeller making a local wind pushing a streamer back.
That is not what this is though. If I had done it I would have put the streamer in another place though.
Magnusjen 3 years ago
I have to admit I was wrong on a previous comment. This is possible, check out the smaller scale models posted by spork33. It runs off the difference in speed between the wind and the ground. Do not think of the wind blowing directly on the cart and it might help. Since it works off of a difference in wind speed it would no work if there was no wind. There is no perpetual motion or over unity involved.
subductionzone 3 years ago 11
spork33 only posts videos on threadmills. Nothing yet outside. I bet his machine could not even outrun the lowest breeze or fastest hurricane :-)
Gunstick 3 years ago
Why? Outside is completely equivalent to a thread mill.
Sgrunterundt 3 years ago
no it is completely not. There is no moving air on the threadmill. There is a power source: the threadmill. The device stay still compared to it's sourrounding air. It's in all ways different. If you just state that it's equivalent when it's not, then all the following conclusions will be invalid.
assimilateborg 3 years ago
Come one, it is not a hard coordinate transformation to do.
There is a power source outside as well: The wind(!). You have air and ground with a fixed relative velocity. They are equivalent. Sporks car is not stationary in relation to the air - it moves forward! That means it feels a headwind.
I am sorry to say this, but you sound like all those guys who claim that this is impossible.
Sgrunterundt 3 years ago
not exactly. So on the threadmill the air, relative to the car is still. The floor is moving, the propeller is rotating.
On the street, relative to the car: the floor is moving, the propeller is rotating and the air is moving... but in what direction is the air moving in relation to the car??? Seems the air is coming from the front, at least behind the propeller the little flag indicates this.
The air is invisible. And so there you are: people are discussing about something impossible to see.
Gunstick 3 years ago
Well obviously if the car is going at the speed of the wind, then the air is still relative to the car. If the car is going slower, then it is coming from behind. If it is going faster then it is coming from ahead.
On the treadmill therfore standing still coresponds to moving at the speed of the wind, moving forewards coresponds to moving faster.
Sgrunterundt 3 years ago
how does this work? if the car stands still, wind blowing from behind turns the blades which turn the wheels and the car advances. Or is it that the wind pushes the car which turns the wheels who drive the blades which then push the car faster than the wind?
This is a big difference, depending of the way it works the blade run clockwise or counter clockwise (windmill or propeller)
If you look closely, on the video the blades turn counter clockwise and so it's a propeller.
Gunstick 3 years ago
Yes. It is a propeller in all the DWFTTW's. The wind tries to turn the propeller one way (as a wind mill), but it gives a forward push which makes it turn the other way.
Because of the gearing the second force is bigger. This way the cart sacrifices force for speed.
Had the gearing ratio been different so that the windmill effect won, then the cart would advance slowly upwind.
Sgrunterundt 3 years ago
Yes. Exactly. The wind pushes the car, causing the wheels to spin, causing the propeller to spin, causing it to push back on the air giving thrust. Now as the car reaches wind speed the push from the wind has diminished, but not reached zero because the propeller is turning. As it goes still faster the thrust will eventually diminish enough to be balanced by the friction and air resistance of the body of the car.
It is a propeller all the way.
Sgrunterundt 2 years ago 2
@subductionzone the difference between the speed of wind and ground is the speed of the wind. ie speed of wind - 0 = speed of wind.
MrTweetyhack 1 year ago
@MrTweetyhack That's right. I worded it the way I did because many people think that the wind "goes away" when the cart is moving at the speed of the wind. Even when the cart is moving at wind speed there is still a difference between the speed of the wind and the speed of the ground that the cart can harvest.
subductionzone 1 year ago
@subductionzone no, it runs off the wheels spinning the prop (or impeller, can never remember which it is)
flinchey 10 months ago
@flinchey I know that, but the ultimate source of power is the difference between the speed of the wind and the speed of the road. If you saw the various treadmill videos you would see why I worded it that way. In that case the wind (the air in the room) is stationary and the road (the treadmill belt) is moving.
And yes, the wheels turn the propeller which forces the cart DDWFTTW.
subductionzone 10 months ago
I love how much controversy this brings, sounds like it is time for the MYTHBUSTERS to weigh in.
davidglover 3 years ago 2
This is absolutely not possible. Once the contraption begins to move at the same speed as the wind, it will perceive itself to be at rest with the air. Such a situation would be IDENTICAL to the contraption sitting stationary in a calm, wind free room. Obviously nothing would happen in this situation and so nothing would happen in the situation whereby the contraption travels with the same speed as the wind.
gamesguru 3 years ago
No. It would be identical to the contraption sitting on a moving treadmill in a calm, wind free room. See the video response above.
VideoJunkie666 3 years ago
Yeah, every time I sit in a calm wind-free room, the floor rushes by underneath me too.
jamesdl00 3 years ago
But how is sitting in your room the same as moving on the road with a wind? You forgot where the analogy begins.
People, it's not the speed of wind vs speed of vehicle that matters. It's speed of wind vs speed of road. That's what matters.
And in both cases the difference is there. If you insist on sitting still in a room with no wind, there is no source of energy and it's not the right situation to talk about.
molinarok 3 years ago
I agree with you completely, but you misinterpreted my somewhat sarcastic post. I was replying to gamesguru who incorrectly states that this is not possible and that from the inertial frame of reference of the cart, it is like sitting at rest in a still room. When the cart is moving at the speed of the wind, the apparent wind is 0, but gamesguru fails to consider that at the same time the apparent movement of the ground going by is certainly not 0.
jamesdl00 3 years ago
The car thing stops then the guy says "Oh I had the break on again" then she pushes it and it goes off but I never saw her take the break off. The guy must have a control to do so. Still doesnt prove its fake or real cos it could be RC for stearing only but yeah im not entering that debate!
renrutus 3 years ago
since at the end he also applies the brakes again (remotely) it is entirely possible that he added RC brakes. I would have. I wouldn't want that thing getting away from me.
fusionr12 3 years ago
I believe this video has proven that some things in this world are not "impossible." They may be highly unlikely, but this video is out of pure genius. If the world were more open-minded as this person was, just think of the wonderful things that could lie within our grasp! Kudos and a job well done.
bethcmason 3 years ago
I think "likely" and "unlikely" applies only to random events. Engineering either works or it doesn't. This is not the only type of contraption that can move downwind faster than the wind.
jamesdl00 3 years ago
It's totally possible to get a machine like this to move directly into the eye of the wind, or across it. He describes the conditions as 'light and variable' - was the wind really coming directly from behind through the run?
alistairi2002 4 years ago
You really just need to use your brain. Imagine the craft is going the same speed as the wind downwind. It is in still air. Where can it get its power to go forward in that air? Answer: From the road going past underneath! The road is driving the wheels round and pushing the craft forwards (using the propeller) through the still air. Its not getting its power from the prop - its getting it from the wheels. A brilliant demonstration!
ZKMX7 4 years ago
Obvious hoax, you will notice there is no shot down the road, if they did you would see the vehicle towing this.
subductionzone 4 years ago
it is an autogyro
the faster the car moves forwards the more apparent wind generated and the faster the car can go
u do need an initial start tho but once u have some natural wind and some apparent wind the cart will eventually accelerate to speeds faster than the wind.
optidude 4 years ago
the way that the propeller is facing wont move the car forward. the wind would cause that propeller to spin clockwise but it needs to spin counter clockwise in order to make the car move forward.
xtralargesock 4 years ago
humans rock
woodenjames 4 years ago 6
Doesn't anyone else wonder how it managed to stay straight and on the road for that distance? whenever you just let anything go, be it skateboard, go cart shopping cart, etc it will always veer off to the side after a distance, no matter what because the wheels will hit objects, the road isn't level, etc. Unless it was being towed........
whoknowswhoknew 4 years ago
It would be easy to use standard radio control equipment for the steering. But I happen to agree with your comment about being towed. I think that is what the vertical post towards the front is for. If the tow line was monofilament fishing line, it would be virtually impossible to see, especially with the very fuzzy image. This thing is a hoax.
K1Models 4 years ago
Is the cart on a hill? The video appears slighty tipped, and the hydrant @ :30 is tipped to the left.
That would explain the evident energy addition.
Oh, and look at the most recent Make: magazine.
Phantomagn 4 years ago
I have concluded that the machine is a hoax. The blades are spinning counter clockwise, which is opposite what would happen if the wind were causing them to rotate. In fact, the vanes are being propelled by an internal force, which is what is causing it to move forward. The other factor is that of "apparent wind". As the speed of the machine approached the true wind speed of 6, the apparent wind would drop to zero, hence no energy input to create rotation of the rotors.
K1Models 4 years ago
read the PDF from his link. The propeller doesn't rotate the wheels - vice versa. The thrust comes from the propeller which is powered by the wheels.
Nice conclusion but you should first read how the machine works.
kerosene 4 years ago
Kero, I have read how it works. The fundamental problem you raise is : What powers the wheels?
K1Models 4 years ago
The cart moving over the road
ayrshquk 4 years ago
I don't fully get it yet - however imagine the situation where the machine is going exactly at the speed of the wind - if the prop belt was off, prop locked into one position and there was no friction what so ever this would be the balanced situation.
The cart rolling at the speed of the wind - right?
Now put a belt on and gear the prop up so that it creates a push. Powered by the wheels mind you - it has to go faster - it cant decelerate because that would resist the wind.
kerosene 4 years ago
at last some who can think for himself! - my thoughts exactly - when the apparent wind approaches zero the forward thrust goes to zero, hence you cannot go faster down wind than the wind is blowing.
shortattentionspan1 4 years ago
No, when the _roadspeed_ goes to zero the forward thrust goes to zero. As long as the cart is moving the propellor is turning and providing forward thrust.
ayrshquk 4 years ago
The wheels do NOT push the cart - in fact they brake it some as they are extracting energy to feed to the propellor.
ayrshquk 4 years ago
Ok, let me get this straight:
The wind does not propel the cart, so it must be the initial push by the woman that provides the energy.
Then the wheels on the road cause the rotor to turn.
The rotor spin then provides thrust forward.
This causes the wheels to turn faster, which in turn causes the rotor to spin faster, which causes the rotor to spin faster etc etc etc
K1Models 4 years ago
Sorry, this is sounding like a perpetual motion machine which is impossible according to the First Law of Thermodynamics. Or like trying to lift yourself up by pulling up on your bootstraps. Why don't you just admit that there is an external power source, such as a battery driven motor, or a thin string being pulled from ahead, attached to the vertical pole towards the front?
K1Models 4 years ago
Why don't I admit that? - because it wouldn't be true! The laws of thermodynamics are not violated.
This cart works because there is a significant difference between the groundspeed of the cart (which determines the energy input) and the apparent windspeed (which determines how much energy you have to add). That speed difference is crucial, and the amount of difference you need to make it work depends on the efficiency of the transmission.
ayrshquk 4 years ago
It works best straight downwind; it wouldn't work if you tried to go crosswind for example.
ayrshquk 4 years ago
As a thought experiment, try replacing the mechanical transmission with an electrical generator and motor.
You would have no difficulty with generating power from the wheel. You would have no difficulty with an electrically driven propellor driving the cart downwind at speeds faster than windspeed. The question to be asked is "can you generate more power at the wheel than you need to drive the cart?" And the answer is that you can.
ayrshquk 4 years ago
"The question to be asked is "can you generate more power at the wheel than you need to drive the cart?" And the answer is that you can."
You are saying that the ouput energy is greater than the input, which is impossible according to the laws of physics. Any high school science student knows that.
1)Why won't you provide decent photos of your device as I have requested twice?
2)Why do you only offer a treadmill demonstration which proves absolutely nothing?
K1Models 4 years ago
As a thought experiment why not just tell the truth about this hoax asrshquk?
shortattentionspan1 4 years ago
Sailing directly downwind faster than the wind - NO it is impossible!
shortattentionspan1 4 years ago
Nicely done! It is very frustrating when a demonstration of quite simple physics results in accusations of fakery fro those too stupid to work it out for themselves, ignore them, they won't change the world.
jfpuk2004 4 years ago
Great job! Some people don't understand - the wind is blowing in the same direction that the car is moving (down wind) but the prop is "backwards" (facing up-wind) The point of this project is to propel the vehicle faster than the wind, using only the wind. Steering is remote controlled, that is how it stays on the road. Read the document at the URL posted at the top of this page for more info. Great job.
jsprada 4 years ago
#1 why werent there any cars on the road besides yours #2 howd you get that thing to go so far without hitting or crashing into the side of the road
rishay87 4 years ago
Obviously it is remote controlled, but that doesn't mean it is also powered. It would certainly be easy to fake, but that doesn't mean it is. There is no reason to fake it since it can actually be done for real. This video proves nothing, but theory does.
Sgrunterundt 2 years ago 3
the time has come for the quack who posted this to 'fess up and admit it is fake! - This joke has gone on long enough!
shortattentionspan1 4 years ago
Now apply what you did here to an aircraft that uses the same principles. Prehaps you can get the aircraft to fly indefinitly...
edmondsean 4 years ago
dynamic soaring - it's already been done by birds (the albatross), model aircraft, and full size aircraft!
jamesdl00 3 years ago
Nice propeller. Would variable pitch work to deal with relative motion?
beatnic50 5 years ago
thats sweet but what is it used for?
BigAl2828 5 years ago
What's driving folks crazy is a sense of some underlying free energy or perpetual motion voodoo. There's no magic here; you can extract all the force you want from the wind just by building a larger propeller. The speed of the ambient wind doesn't limit how you apply the force you extracted. That is, you can convert your force into a faster speed.
I have no idea if this video is a fake or real. My point is the underlying principle is valid.
illbay 5 years ago
Well done
jmaros15 5 years ago
how can the wind be comming from the front of the car ??? If you look at the flag at the begining of the video the wind is blowing from behind the car. and at points in the video the flag blows towards the car to
miky6660666 5 years ago
wow, u must b like in a car cuz the camera aint movin a bit
ncarter13 5 years ago
wow,you can ether run realy realy fast,or your on somekind of bike.... :P
buttfudge666 5 years ago
Hi ayrshquk,
Here is a question for you, If the apparent wind comes from the front of the cart how can it keep accelerating into the apparent wind?
Yours sinceerly,
shortattentionspan1.
shortattentionspan1 5 years ago
Quite easily, as long as the thrust from the propellor exceeds the drag from the apparent wind.
(Remember the propellor thrust is a function of GROUND speed, not of apparent airspeed. As long as there's enough real wind to reduce the apparent wind to a low value for an appreciable ground speed, then the drive works.)
ayrshquk 5 years ago
I understand the part that the propellor is a function of ground speed (ie the propellor is tied to the rear wheel shaft) if the wind is coming from the front of the cart why would it accelerate in that direction (forwards) - the only reason I can see is that external force is being applied by a nylon line tied to the front of the apparently self steering cart.
shortattentionspan1 5 years ago
Ever seen an aeroplane take off into wind?
ayrshquk 5 years ago
yes I have flown in a glider towed by a ground based high power truck and also towed up by another aircraft, both ways are a lot of fun!
shortattentionspan1 5 years ago
this must have something to do with the size of the propellor? just a thought.
kenntx 5 years ago
OK, but how does it scale up when I want to make it do useful work, such as for unattended package delivery (lets say I'm using onboard solar powered GPS guided AI)... how much payload can be added to this minimalistic design?? Can this machine do useful work or are we seeing the height of the designs abilities?
mmmmna 5 years ago
you know I think he posted this just to mess with our minds. Hes a crazy guy that thinks "hm, how can I lie to thousands of people, and about what....how about sailing fast then the wind!?! yes. muhahahahwahaha!!!"
please stfu
jrmyrook 5 years ago
It is curious to see how, of the people who has posted thus far, all the ones who understand how an aerofoil works seems to think this works, and all the ones trying to make sense of it within other frames of reference seems to think it is fake. Please read up on aerofoils and ice yachting/sailing, then look at this again and remember RELATIVE airflow!
coRn3 5 years ago
yeah most sailing machines can get 2x faster than wind, thanks to the vacum effect
narutard98 5 years ago
at 2:02 the flag on the three wheel thing shows the apparent wind coming from the front of the cart and the comment 13 miles an hour - then at 2:08 I can distinctly see a wire attached to the front of the cart ... looks fishy to me!
cycloneweaver 5 years ago
Cory - I agree Iceboats go faster than the ground wind speed they use the fact that when they go at right angles to the wind the "apparent wind" is far greater because the ice boat has almost zero resistance to going forward. the wind at right angle to the sail and the vector of the forward thrust is like sqeezing a greased wedge under your foot. This phenomena is NOT the same as sailing down wind like this fake video shows.
shortattentionspan1 5 years ago
Yes it IS the same. The blades of the propeller moves in an angle to the wind in excactly the same way an iceboats sail does. The only difference is that since the propeller is rotating the car itself is allowed do go downwind directly although its "sails" does not.
Sgrunterundt 2 years ago
sailing down wind faster that the wind is not a theory and in fact has been practiced for many, MANY years. it's call ICEBOATING. iceboats travel 4X the wind speed. so much so while, going down wind you trim the sail in tight as if you are heading upwind. this happens because of the iceboats "apparent wind".
coreymon77 5 years ago
Oh, I had the brake on again. Ooh man I am laughing OUT loud, you can fool some of the people some of the time but not all of the people all of the time.
shortattentionspan1 5 years ago
(comment #3)The gear ratio required to maintain a constant speed would have too much load on the propeller for the car to accelerate; the car would slow down. And if the car is slowing down, it will become pushed by the wind again. So, what exactly happened in that video? The car was traveling downhill.
Zakamiro 5 years ago
(comment #2) Doing this increases the rpm of the propeller versus rpm of the wheels. Given enough increase, the propeller spinning should create thrust and propel the car faster. The problem in this is that when you travel faster than the wind, any and all thrust aided by the wind is lost. This means that the car must be propelled by its own energy. And as anyone should know, energy cannot be created, only moved...
Zakamiro 5 years ago
A prop neither screws thru air nor pushes air to develop thrust. It is a rotating wing developing lift based upon the air moving over its surface. Imagine being on the prop & think about how air is moving over the blade when the car is faster than the wind.
KingBallerina 5 years ago
(comment #1)While the documentation certainly makes you think that using gears you can multiply the ratio from wheels turning to propeller spin, it still doesn't work. Here's why. The theory in the car design is this: A strong steady wind starts the car going. The axle from the wheels turning turns a smaller gear, which is connected to the propeller by a belt.
Zakamiro 5 years ago
10 miles per hour up to 13 miles per hour - you Sir are perpetrating a hoax. So I have no recourse but to shout out loud "liar liar your pants are on fire"!
shortattentionspan1 5 years ago
(Sigh... Comments are so geh.) What a wonderful concept, very clearly illustrated for the simplest minds to grasp, and yet the broken and blind are the ones who speak the loudest. Do you see the palm trees? And the steady wind? Coastal = FLAT. I guess everyone's a physicist nowadays. Stupid intarwebs
chickenofthewoods 5 years ago
all this user has to do is post another vid with all angles. simple fix
geoff390 5 years ago
it has a rubber band going from the propeller to the rear axle which turns the rear tires faster than the prop. with a gear ratio of 1.75 to 1. its all on his website.
jazzophis 5 years ago
Thats pretty fucking cool and P.S anyone who thought this was fake is a fucking tard. -DG Aerospace Engineer
dave28277 5 years ago
if you go to his site it shows that the steering is radio controlled. the reason i think it is going faster than the wind is it is riding downhill.
jazzophis 5 years ago
Yeah? Well i think the reason is because someone on a bicycle is dragging the thing.
F00dTube 5 years ago
kinda sketchy cause the thing stops...then just goes again...but yea a vid showing all angles would solve the mystery for sure
dubstyl23 5 years ago
why dont we just ask the creator of the vid to make another but show us all angles
geoff390 5 years ago
u should patent that
minitrob 5 years ago
erm dont think so, you cant patent a hoax you simple twat,
dcblackall 5 years ago
obviusly being towed by something, you only ever see the vehicle, nothing else, i.e. the direction in which it travelling, good attempt,
dcblackall 5 years ago
that is not being towed you retard some people are smart....hint hint not u
minitrob 5 years ago
The reason there is no steering mechanisim attached to the front steering wheel is because the whole thing is being towed by a thin wire and the front wheel is a swivel castor so that it would follow the towing vechicle. Come on and fess up ayrshquk.
shortattentionspan1 5 years ago
The wheels and the prop are a closed system, dependent upon each other so they both drive the machine, not one or the other but it's the fact that the prop blows AGAINST the wind that creates the phenomenon of being able to go faster than the wind.
Thopter 5 years ago
The blades are coupled the wheels in a way that the wheels cause the prop to spin the opposite direction of a freewheeling blade, literally blowing back against the wind when the machine rolls forward.
Thopter 5 years ago
If you look carefuly at the pitch of the propellor you will see that the wheels are connected to the propellor via a rubber band and that external force of some kind is being put on this contraption. I suspect a very thin wire attached to the front towing it.
cycloneweaver 5 years ago
looks likes the small wheels are causing too much drag
chardgha 5 years ago
It's going down hill!
soarhead88 5 years ago
This has been flagged as spam show
PLEASE DON'T READ THIS. You will get kissed on the nearest possible Friday by the love of your life. Tomorrow will be the best day of your life. However, if you don't post this comment to at least 3 videos, you will die within 2 days. Copy and paste this, to be saved.
NBBfan111 5 years ago
Holy God you all make this way too difficult. The prop is connected by big rubberband to rear axl, moving wheels faster through mechanical advantage, like a 1:2 ratio. Good thing it's windy or this car would not move fast enough to keeps it's momentom. Ask yourself how sail planes stay in the air.
wetodedid 5 years ago
You have the first part right, but it is the wheels that are turning the prop, not the prop. turning the wheels. That is what makes the relative air movement over the prop. keep the prop in a lift condition (pulling) when the car is faster than the wind.
KingBallerina 5 years ago
Nice experiment. I have seen a catamaran sail boat with this setup replacing the sail. The mechanical power was transmitted to a gearbox via carbon fiber drive shaft. The gearbox is coupled to a sterndrive unit. Very slick setup, and because you can turn the mast/blade to the wind, the boat can travel in any direction.
Ataraxia27 5 years ago
The thing is just pulled my a car
l5e5m5 5 years ago
Who cares?
ranchoroncho 5 years ago
Here is why this works. Throw out all notions of wind pushing the blade or the bade creating a wind that pushes the car. The explanation lies in the dyn.s of air mov. over the prop airfoil. Lets look at the forces on the prop.
First these conventions: The car dir. is + y. The wind dir. is + y. Looking at the car frm behind the prop is rot. c'clockwise. From a bird's eye view, look at a sect. of prop blade when the blade is at 12 o'clock, the blade is mov. frm R to L. This dir. is - x.
KingBallerina 5 years ago
KingBallerina -- Are you saying the wheels are not involved? If so, then you are talking perpetual motion. Airplanes could be self powering. Second, you missed the obvious: It has a left-handed propeller turning CCW (from behind). If it was just spinning in the breeze, it would spin CW. To spin CCW (at speeds lower than wind speed), something must drive it. And, in cases 1, 2 & 3, the CCW rotation of a left-handed propeller means it MUST be providing forward thrust to the cart.
Quixotix 5 years ago
Read it again with the understanding that the wheels drive the prop. That was already explained by its creator. Rem char. to get < 500 is hard. The blade is CCW from behind "c'clockwise". The blade provides the forward force, but not via torque to wheels. The wheels turn the blade.
KingBallerina 5 years ago
Q, from reading your past posts I see we are on the same track. I did not make the explanation clear enough. BTW, use the same air stream analysis over the prop assuming the prop is spun by the wing. You'll find such a system self defeating. The layman's notion of "prop" is the confusion. In this case the prop is a sail being moved by the wheels - not a windmill driving the wheels.
KingBallerina 5 years ago
There are four conditions to think about. These are: 1) the car is slower than the wind 2) the car is mov. at the same spd as the wind, 3) the car is mov. >> the wind and 4) the car is mov. even >> the wind.
(Sever abbreviation has been made to fit these in 500 char.)
KingBallerina 5 years ago
Air mov. rel. to prop sect. at 12 o'clock has 2 parts. 1 part is in + X frm L to R. This part is due to prop rot. and is always in this rel. dir. tow. rot. bld. The other part is the air mov. in the Y dir.. This part is the wnd spd rel. to car spd. It changes magnitude and dir., + Y or - Y, dep. on the car's spd rel. to the wnd. In case 1, it is + Y, coming frm behind. In case 2, it is 0. There is no Y wnd frm the prop's viewpoint. In case 3 and 4 it is -, coming frm in front.
KingBallerina 5 years ago
Now look at the air spd parts and resulting forces on the 12 o'clock prop sect. for each of the four cases. It will help to draw them on paper.
KingBallerina 5 years ago
Case 1: X air mov. is +, L to R. Y air mov. is +, frm behnd to forwd. The total result dir. is frm bot. L to upr R. Rel to the prop sect., which is ang frm upr L to bot. R, this air mov. puts bld airfoil in a high ang of attack. Dyn. lift forces on blade act norm to bld surf. Force is ang frm low L to upr R. Y part of force results in car mov. forw. X part of force is prop drag. It acts in op bld's rot.
KingBallerina 5 years ago
Case 1 cont.: Drive train mech frict plus this bld drag act to slo car. Y force is enough to overcome losses. Car seeks a faster speed. At some point it reaches case 2.
Case 2: The X air mov. is +, L to R. The Y air mov. is 0 because the car is traveling at the same spd as the wnd. The total resultant dir. is frm L to R. Relative to the prop sect., which is angled frm upr L to bot. R, this air mov. puts the bld airfoil in a shallower angle of attack position than case 1.
KingBallerina 5 years ago
Case 2 cont: Dyn. lift forces on the bld act as befo . Y part of this force results in the car mov. forw. The X part of this force is the prop drag. The Y force is large enough to overcome the losses so the car seeks a faster spd and at some point reaches case 3.
Case 3: X air mov. is +, L to R. Y air mov. is - becus car is travelng > wnd spd. Total res. air dir. is frm upr L to low R. Rel prop sect., which is ang frm upr L to bot. R, air mov. puts the bld airfoil in shallowr ang of attack pos.
KingBallerina 5 years ago
Case 3 cont: In fact at some point >> the wnd, the angle will be inline with the bld sect.. The dyn. lift forces on the bld act as before. A perfectly flat airfoil would have 0 Y part with the air stream in line with the sect.. A well designed airfoil would still have a Y part. This is where the optimum bld sect. comes to play. The Y force is large enough to overcome the losses so the car seeks a faster spd and tries to approach case 4.
KingBallerina 5 years ago
Case 4: X air mov. is +, L to R. Y air mov. is - becaus car is traveling >> the wnd spd. The total resultant dir. is frm upr L to lower R. Because the Y part is much larger than in case 3 this angle relative to the prop sect. is beyond the point where the bld generates lift. In fact as some large value of - Y air mov. the bld will generate dyn. forces in the wrong dir.. The car will not go faster. The car will seek an equilibrium spd point somewhere between case 3 and case 4. Faster than wind.
KingBallerina 5 years ago
Mmmmmm. Think a friend and i made a very similar device when we were kids.Bring on the hover boards i say. hear hear. I second that.
Ps. No need to post comment telling me that i am a niaeve twit who doesnt appreciate good science. I do appreciate good science.I just much prefer bold radical
mind bending science.Have fun.
zipmanjack 5 years ago
This is great. How do you make one ? Are plans available ?
blange6 5 years ago