Sorry Mr. Schumacher, but your ten year record just got obliterated (okay, "beat soundly") by a Briton. On the dry, dusty plains of Ivanpah Lake in Nevada, Sir Richard Jenkins managed to perfectly harness winds of 30MPH in his futuristic Ecotricity Greenbird in order to hit a ridiculously quick 126.1MPH. In all honestly, we can't even fathom how you hit that speed with just 30MPH of wind, but clearly we're not up to speed when it comes to physics and engineering. At any rate, the milestone is pretty important for Ecotricity, which is trying to make
wind power the go-to alternative energy source within the next score. Now, if only we could figure out a cheap and easy way to generate wind on demand, we'd really be onto something.
[Via
BBC]
posted Mar 27th 2009 11:11PM
How does that even work... when you go faster than the wind how does the wind propel you?
Never doubt a record set by a man brave enough to drive a bright green neon car shaped like a penis.
it's possible to sail faster than the the wind speed because of apparent wind speed
when your craft is sailing in 15 knots of wind, you'll find that trimming and
sailing up wind you can realize maybe 22 knots of wind in your face because you're moving into the wind.
sailing that rig that fast is amazing. I'm only familar with sailing boats, but having seen ice boats...
they're sort of like this... sort of.
I put this below, but everyone seems to have the same question.
The solution is tacking the vehicle. lets say the wind blows due north at 30 mph, and we know this car is going 126 mph. In an ideal world, this means that the final vector must be 126 mph (obviously) at a heading of 76.2 degrees ENE. Where does the 76.2 come from? The cosine of the record setting angle must equal the ratio of the wind divided by his speed. Hence; cos-1(30/126)=76.2. Considering losses due to friction, his tack must have been greater than 76.2 degrees off of the winds direction. More than likely, his approach started directly aligned with the wind. As he approached the winds 30 mph, he would have slowly turned his vehicle while keeping the sail perpendicular to the wind. Assuming a steady wind and gradual steering, his speed would have peaked at 126 mph. He would then make slight adjustments until he was at his percieved maximum velocity. (this heading, as stated above, would be >76.2 degrees, and less than 90 degrees for obvious reasons.)
Is everyone on the same page now?
"Now, if only we could figure out a cheap and easy way to generate wind on demand..."
...pull my finger...
It's so easy I'm surprised anyone had to ask.
Start making chicken. When done cooking, get in the car, say:
"Alright. Time's up, lets do this! RIIIIIIIIIIIIIICHHHAAAAAAAARD JEEEEEEEEEEEEEEEEEEEEEEENKIIIIIIIIIIIIIIINS!!!!!"
Jacque Cousteau has a sailboat (Alcyone) built featuring 2 "wings" for sails.
http://www.boatdesign.net/gallery/data/500/alcyone.jpg
This car uses the same tech.
Basically, you have a wing, set on a rotating platform. It faces the wind and creates lift as the wind passes around it, this lift is translated into forward motion for the car.
Not a single person here has provided the correct explanation for the propulsion of this vehicle.
It really is very simple. Think of an aircraft wing, with a horizontal airflow. The wing provides lift vertically (at 90 degrees to the airflow) . Ok, so now put this wing upright (vertical) on a vehicle, such that the wing is 'sideways' to the car's direction of intended forward motion. A wind blowing across the wing will provide 'lift' the same way it provides lift to an aircraft, but instead of the force being 'up', the force is now 'forward', so the vehicle is propelled with a thrust component which is acting at 90 degrees to the direction of the wind. The fact that the wind is only 30MPH is irrelevant, as is all the cosine equations nonsense. The wind is coming from the side, so relative airspeed is also irrelevant and the forward thrust from the wing will remain constant, accelerating the vehicle until the drag component from it's forward motion equals the thrust component of the wing.
http://www.greenbird.co.uk/about-the-greenbird/how-it-works
@switchbitch Looks right to me. It's nothing more than an airfoil creating "lift" (as it were). But still very cool.
Your penis needs immediate medical attention if its shaped like that.
Thats a awfully big green ball.
Are you guys dense? It's so obvious.
The 30 mph wind is not pushing the car directly from the back, but at an angle, so that even though the car is traveling at 120mph, the component of its vector in the direction of the wind is less than 30mph.
That is so obvious, you're right!!!
What's a vector?
oh yeah... the vector. how could I have been so blind.
so obvious
It's like a sailboat, even though the wind is pushing against the sail at 20 mph, the boat goes much faster.
A vector is a quantity of magnitude and direction. An example is a person jogging 5 mph north. 5mph is magnitude, north is direction
Master of the Not-so-"Obvious": Condescension is his Domain
i think i got it.
okay, the "car" is moving in one direction lets say north.
the wind is moving east to west. -->\
you set your sail facing the wind at a 45 degree angle (like this: --wind-->\ sail
the wind pushes against you (always) at 30 mph, the 45 degree sail -->\
turns the wind from a horizontal into a vertical movement.
so, you can get 120 mph on a 30 mph wind.
well, at least thats how i understand it.
sorry, clarification:
i think i got it.
okay, the "car" is moving in one direction lets say north.
the wind is moving east to west......................................................-->\
you set your sail facing the wind at a 45 degree angle (like this: --wind-->\ sail
the wind pushes against you (always) at 30 mph, the 45 degree sail....-->\
turns the wind from a horizontal into a vertical movement.
so, you can get 120 mph on a 30 mph wind.
well, at least thats how i understand it.
I need a diagram to understand how this works.
If I were to take a guess, I'd say the wind is traveling from the front of the car to the back (not pushing it from behind), then he has some system in place that generates forward propulsion from that. As the car moves forward, the relative wind speed would increase too, which would cause the car to accelerate even more. The car continues to accelerate thanks to ever-increasing relative wind speeds (30 MPH wind + 90 MPH car = 120 MPH relative wind speed) until the car hits terminal velocity. From there it's just a matter of generating as much forward propulsion as possible and decreasing wind resistance to increase the terminal velocity value.
Granted, I really have no clue. But that sounds the most logical to me.
a. ouch, that was kinda off... :/
b. you should make that, sounds like a good idea.
"Yes, that sequence of words I just said made perfect sense."
A bunch of these wind-physics geniuses must have been standing around at the course and as they carefully explained how this sail car could get up to top speed, the wind velocity from their lungs must have propelled this vehicle to a record-breaking run. As it is, I'm starting to rise from all the hot air coming from these brainy comments.
Anyone kid could would know that the sail car just caught a brief 126 mile per hour gust of tail-wind as it went through the traps.
The important thing here to understand is that the speed of the wind is irrelevant (simplistically, in a world where a wind is simply a vector field with no turbulence).
The wind is the engine, it's just a force. You can collect as much energy out of it as you want, and that's determined by the size of the sail.
The sail is a variable speed transmission, the angle of the sail with respect to the wind determines how fast you move. If it helps to relate to cars. The wind is a very low rpm engine, but with TONS OF TORQUE. And just like in cars, there's no direct link between the rpm peak and the top speed.
Imagine a scenario where the wind is blowing directly from the side. You start from 0mph, which means your sail is parallel to the wind (no wind is actually hitting the sail), then you begin tightening the sail. @45deg the wind is deflected exactly 90 degrees, thus your speed is equal to the wind. Turn the sail toward perpendicular to the wind, and your transmission reaches infinity.
(in reality it works NOTHING like this, but the principal is still the same). The main principal of these speed demons is to make these vehicles more theoretically simple (without resistance, without drag, without turbulence, etc.).
Wind goes through a nozzle, then powers a turbine which powers the wheels? Or something like that?
Actually, now that I think about it, it would be a diffuser that they'd want, not a nozzle..
My thermodynamics is rusty.
Subsonic flows require a converging nozzle for the fluid to accelerate, while super-sonic flows require the fluid to expand in order to accelerate (diverging nozzle). So unless a 30 mph wind is super sonic (laughs out loud), you would use a converging nozzle to accelerate the fluid.
But thanks for playing!
It must be very, very, oxidized. lets say the wind blows due north at 30 mph, and we know this car is going 126 mph. In an ideal world, this means that the final vector must be 126 mph (obviously) at a heading of 76.2 degrees ENE. Where does the 76.2 come from? The cosine of the record setting angle must equal the ratio of the wind divided by his speed. Hence; cos-1(30/126)=76.2. Considering losses due to friction, his tack must have been greater than 76.2 degrees off of the winds direction. More than likely, his approach started directly aligned with the wind. As he approached the winds 30 mph, he would have slowly turned his vehicle while keeping the sail perpendicular to the wind. Assuming a steady wind and gradual steering, his speed would have peaked at 126 mph. He would then make slight adjustments until he was at his percieved maximum velocity. (this heading, as stated above, would be >76.2 degrees, and
my comment got cut off;
"less than 90 degrees for obvious reasons.) Get it now?"
And if this tech takes off, perhaps one day we could even have ships powered by the wind!
i would call it...."a sailboat"!!!
why dont you call it timmy
Done. In '85.
To Max and Archive,
You've explained to all of us why this is happening but not HOW it happens. So it is one thing for you to tell everyone it is like a sailboat and it has to do with the vector of the forces by the wind, but you still have not even begun to explain HOW this enables travel faster than wind speed.
since there is sooo little drag on the vehicle it can be super fast.
sailing down wind it will never be faster than the wind speed ever.
but it can move across the wind... even angle up wind and
since the wheels have little drag on the flats, and the craft is soo slippery
in the wind, it can keep accelerating beyond the wind speed recorded
if you were standing still.
Actually it is possible for a wind-powered vehicle to travel down-wind faster than the wind, see http://www.youtube.com/watch?v=xHsXcHoJu-A
@cibyr, that's an interesting clip, but it's not sailing.
interesting.... but the craft does not sail.
I can see why people especially sailers
would refute this as sailing, not sure you agree.
It looks like a large green electric toothbrush...still no idea how this works.
It works on exactly the same principle.
take THAT "physics"!
car moves in forward direction at 120 mph...
wind at 30mph
when car moves at this speed it is still only moving at a speed of say 10mph with respect to the wind at an angle
so from the perspective of the car when it is moving at 120mph there is still a 20mph wind blowing on it
thats the general gist of it
@jarofchris the crappy comment system i have not explination for
i'm gonna drive through a tornado and beat him
Tornado vectors are not uniform and/or linear etc. Won't work.
Found a simple page with a decent explanation at http://www.boatsafe.com/kids/bramp1099.htm
The following is oversimplified but easier to understand. If you're going the same direction of the wind, you can only go as fast as the wind (minus friction of course). If you're at an angle you're constantly adding the velocity you gain from deflecting wind from the side to the rear (equal and opposite reaction) to the velocity you already have, allowing you to (in time) go infinitely fast in theory if you disregard friction, friction is what limited him to 126mph
This will take a bit of explaining since I don't have a diagram so please, bear with me.
It might be easier to visualise components if you imagine a pixel grid on a screen. To make a vertical line, you move up five pixels. To make a horizontal line you move across five pixels. But to make a diagonal line you must move across five pixels then up fixe pixels and join up the result. This isn't directly analogous but it gives you an idea.
First we assume North/South is up/down and East/West is across. We will be using the equation:
(Vertical component) = (car's velocity) * sin(angle between the car's direction and the horizontal)
Imagine the wind is travelling 30MPH North. If the car travels North too then it can expect to reach about 30MPH (excluding frictional forces). At this point the vertical component of its velocity is 30MPH and the horizontal component is 0MPH. However when the car is at 15MPH, the vert. is 15MPH and the horiz. 0MPH, but the wind speed (north) is still 30MPH vertically so the car will accelerate until the vertical component of its velocity matches that of the wind.
Now we move the car so that it is, for example pointing North-East (angle 45 deg.). When it is moving 30MPH North-East, its vertical component is 30*sin(45) = 21.2MPH, so it will accelerate until its vertical component matches that of the wind. In this case that's 30MPH so we can work out by rearrangement of that formula the car will be travelling 30/sin(45) = 42.4MPH.
So, for the car to be travelling 126MPH, with a vertical component of 30MPH, its angle from the horizontal will be roughly:
sin^(-1)(30/126) = 13.8 degrees.
To summarise: if the wind direction is North, the the car will have been travelling 14ish degrees above East to achieve this kind of speed.
I hope this helps you to understand even a little! Reply if you need any more info.
--nimro
Ah it took so long to write that that loads of people got there before me!
I should have said that this results in a direction of 76.2 degrees. Thanks to Tim above for seeing this ( I am glad our numbers agree!).
It's also worth noting, as others have done, that I am assuming no friction in these calculations. In reality, it is very difficult to achieve this kind of speed from wind because of friction.
parallel parking that thing would be impossible
Looks like something my wife would use to keep herself 'busy' when I am not around!
Funny car
Hopefully the technology will progress so that one day cars like this won't look quite so phallic.
Wait a second. Where's the source for the 30mph wind claim? I don't see it on any of the supplied links.
I'm not claiming it's not real, I'm an engineer, I get the math. Just wondering if the 30mph is correct or not, as I don't see that claim anywhere but on engadget.
It's more of a wing on the top of the car, rather than a sail.
Have air flowing over an airfoil, and you have a force perpendicular to the wind.
For someone who made such an insightful comment, I'm surprised you didn't know that most "sails" act as wings most of the time. Lift is the primary movement force in sailing boats. Modern sails are just flexible "wings" (or airfoils).
I think the best way to think of this is a wakeboarder being pulled through he water. When he goes straight he goes the same speed as the boat but when he cuts in at an angle he will be going faster.
I guess if this takes off the weather gage will become an important factor to consider in your travels.
"Wind on demand?" Isn't that called... oh, I don't know... a fan?
So, it sounds to me like the basis for my favorite mathematical formulaa which is based on the "Angle of The Dangle"
or is it also related to that other formula that allows crap to flow up hill?
Man I do like math.
So, it sounds to me like the basis for my favorite mathematical formula which is based on the "Angle of The Dangle"
or is it also related to that other formula that allows crap to flow down hill?
Man I do like math.
Go easy on me for the Double Post mistake.
I can only offer an excuse of Old Age, it is way late at nite and last, I apologize.
Engadget, shouldn't that be "Brit" not "Briton"? considering "Briton" is strictly the name for an ancient people from the UK... as a Brit myself I am offended.
a vid of the beast!
http://www.youtube.com/watch?v=GPOqlkzW8KU
their youtube channel has the world record video
http://www.youtube.com/user/greenbirdproject
Its like squeezing a watermelon seed.
Your fingers are moving slowly, yet the seed is propelled much faster, in a direction different than the seeds propelled direction. Your fingers are the wind. The seed is the land-sail-boat.
Those of you trying to solve this quickly are looking a bit too simply at the model. Keep in mind that at a certain point sailboats are able to "create their own wind" thanks to the wonders of fluids (apparent wind).
Took a course in college called "physics of sailing"- it was pretty incredible and on par if not harder than a lot of my aerospace classes.
could just hit up the read link http://www.greenbird.co.uk/about-the-greenbird/how-it-works
from what i understand, its the combination of the wind from the side that pushes on the sail to get the car going forward. This creates "wind" as the vehicle moves through the air. The sail is similar in shape to an airplane wing, that is upright. The wind that is "created" as the craft moves forward, and the natural wind combine to create the apparent wind at a point inbetween the two. The sail is matched to this wind. Thanks to the bernoulli principle, an area of low pressure is created on the front side of the sail, and an area with higher pressure on the back which helps push the vehicle forward.
thats just how i understand it, hope its right.
Ok so it seems no one knows how the wind functions. I been windsurfing for over 15 years and always get going faster than the wind. Also it's not the wind thats blowing you along. You are infact being sucked along because of the lower pressure area behind the sail. If you can lower the resistance between you and the surface then speeds like this are easy possible with the correct sail size and shape. There is a method to work out BHP from the size of the sail and you would be very surprised at how much power these new sail/wing designs and make.
"Now, if only we could figure out a cheap and easy way to generate wind on demand, we'd really be onto something."
Mmmm how about nuclear winter?
Why did you call him "Sir Richard Jenkins"?
The BBC source does not use that title...
LMFAO those guys are REALLY excited.... lol and proud to be british... damn son.
I'm guessing that record wasn't set by taking an average on a round track then eh.
i see a green penis
This is the funniest string of comments I've seen in a long time. Bravo!
Now if they could just get it to look like something other than a transvaginal ultrasound transducer.
Meanwile here in the US we are still driving cars that look like boxes.
if you want wind on demand...buy a fan...plug it in...and aim it at your car...
Perhaps it is best explained by saying it is not the direct pressure of the wind on the wing that results in the forward movement, but instead the pressure differential on either side of the aerofoil created by the wind moving over its surfaces. The "higher" you sail into the wind, the speed of the wind apparent to the aerofoil is also increased, increasing the pressure differential and therefore forward force on the car. This aerofoil effect can be much greater than just the direct pressure of the wind. (Think of how the many tonnes of a commercial airliner can be lifted by its wings but not by the engine thrust alone)
To related it to sailing, think of the difference between a mainsail and a spinnaker. When using a mainsail and sailing across or towards the wind the mainsail tends to act like a wing and the principles of an aerofoil apply (I.e. propulsion comes from 'lift'). When sailing downwind the spinnaker tends to act more like a large kite (propulsion mainly from direct pressure).