Wind-Powered "Greenbird" Seeks Land-Speed Record 38
Mike writes with this tantalizing excerpt: "Dale Vince of Ecotricity and engineer Richard Jenkins are setting up on the salt flats at Lake LeFroy in Western Australia, hoping to catch the right breeze and break the wind-powered landspeed record of 116.7 mph in their sleek wind-powered vehicle, the Greenbird."
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You may not know, since your hobby seems to be bitching about the accomplishments of others, but when you try new things, you tend to learn new things.
Things that can be put into practice in other ways.
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From TFA:
The team plans to take the knowledge they gain from these experiences and apply it to the real world, incorporating aspects from the design into the next generation of vehicles and micro turbines.
So there may be something useful achieved. But even if not, it's still a pretty cool thing. Besides, not everything has to be useful.
I think you need to ge
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I think you need to get out more.
He can't afford to, if he's going to continue being constantly useful!
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A lot of knowledge is gained by these types of endeavors. Even if they seem pointless.
Why do motor companies continue to invest in various forms of automotive racing? It isn't like they can sell F1 cars to very many people? They do it because they can learn things under extreme conditions. They learn about tire wear, aerodynamics, engine performance, etc. (and of course, they also get brand exposure, but that is a side benefit).
Setting the wind powered land speed record will aid in aerodynamics, harnes
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What does this engineering-masturbation have to do with transportation? It's not like it's useful for anything other than some weird bragging rights.
Well, since engineers can't get girlfriends, what other outlet do they have?
Faster than the wind? (Score:1)
Re:Faster than the wind? (Score:4, Informative)
I hate to do this but...
http://justfuckinggoogleit.com/search.pl?query=sailing%20faster%20than%20wind%20speed [justfuckinggoogleit.com]
>;-)
apparent wind (Score:2, Insightful)
http://en.wikipedia.org/wiki/Apparent_wind [wikipedia.org]
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The vertical hard sail is actually a wing, just like an airplane wing, there is a high pressure side and low pressure side when air flows around it. I would imagine the most challenging part of the drive is jump form going slower than the wind, where the sail is presumably acting like a sail, to going faster than the wind, where the sail acts as a wing.
Bah, who am I kidding, they're just going to pull it behind a truck until they get it up to above wind speed. They're only looking for the big number at the
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the sail is presumably acting like a sail, to going faster than the wind, where the sail acts as a wing.
Soft sails act as wings too, unless you're on a run. So really it is acting as a sail all the time. And a wing.
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They're traveling across the wind, not just being pushed straight forward by it. Think of a racing sailboat keeling over to the side--clearly it's not being pushed from behind (or at least, not always).
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Being a sailor, I get that queston quite often. The explanation is simple and appears to be a bit contradictory; the sails generate lift from the wind created by the boat's own movement. If you are familiar with vector addition, it is trivial to see that the resulting "apparent wind" is the "true" wind (the wind speed and direction as seen by a stationary observer) added to the the speed of the boat, both which are vectors with different angles.
This is also the reason why iceboats (and probably also the "bo
Re:3-5 times actual wind speed? (Score:4, Funny)
Re:3-5 times actual wind speed? (Score:5, Funny)
They use a rocket engine. The fuel was derived from oil, which used to be dinosaurs. The dinosaurs used the wind (or "air") to breath, and the plants (and other dinosaurs) they used for fuel also used the wind in a similar fashion. Thus, the vehicle is technically powered by wind.
See? This green stuff is easy if you just put a little thought into it.
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I'll give you a line of thought to follow, to get you started.
What happens when the wind hits the sail? Force is exerted on the sail, which is transferred into forward momentum of the vehicle. What happens when the wind hits the sail from directly behind the vehicle (in relation to its path)? What is the force exerted by the wind on the sail when the speed of the vehicle is equal to the speed of th
Re:3-5 times actual wind speed? (Score:4, Informative)
For more information, people can go to the Greenbird web page [greenbird.co.uk] or to the relevant wikipedia page [wikipedia.org].
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I took a course on sailing once. The instructor was fond of pointing out that a sailboat is actually sucked forward rather than blown forward. Repeatedly. I think this guy may have had issues beyond a fuzzy understanding of the physics involved but he wasn't totally off the mark either.
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you use a more than 1 sail to catch the deflected wind. I just googled it and came across this page.
http://www.physclips.unsw.edu.au/jw/sailing.html [unsw.edu.au]
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Thanks! (Score:2)
I realize now that I mis-interpreted my original reading of that page. Thanks for having me go back and check it over!
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The wind pushing you forward creates another wind because you are moving through the air. Imagine coasting down a hill on a bicycle or skateboard. If the wind directly behind you is pushing you at the same speed, they will cancel each other out. So you hit the wind at an angle so the wind created by you moving through the air isn't clashing and canceling each other out. Now, they trim the sails into a wing of sorts that instead of being pushed, it is actually being pulled by lift. As long as you are moving
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I've seen drivers doing it but alcohol was usually involved.
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This thread delivers the lol.
How does it go? (Score:1, Funny)
Someone tell me how stupid I am.
Re:How does it go? (Score:4, Informative)
Really stupid ;-)
Just kidding, of course. The thing does have a sail, but it might not be obvious to the uninitiated. It's that thing that looks like a vertical airplane wing. As you may be aware, the sail on a modern sailboat functions much like the wing of an airplane. The rigid sail on this landsailer is actually much more efficient than a cloth sail.
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The rigid sail on this landsailer is actually much more efficient than a cloth sail.
This has been tried on boats too. From Wikipedia: [wikipedia.org]
Yes, "Scaled" refe
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I wonder why that design hasn't become more popular. I suspect it was made illegal for racing.
Rigid sails are extremely inflexible compared to their soft counterparts. Every wind needs its own sail shape; different wind speeds, directions, wave heights, etc. all require different shapes. There is no rule against rigid sails, it's just too hard to bring dozens of huge metal foils on a boat.
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"There is no rule against rigid sails, it's just too hard to bring dozens of huge metal foils on a boat."
besides which converting a modern ship from diesel to sail powered is very hard, that's why they're using kites, which can easily be added to a conventional freighter, to reduce the fuel consumption. http://www.treehugger.com/files/2008/03/beluga-skysails-cargo-ship-kites.php [treehugger.com]